British Shorthair Breed Advisory Committee
Guidelines
For
Healthy
And
Responsible
Breeding
Breeding Policy For The British Shorthair
Jun-18 Draft British Shorthair Breeding Policy – Genetics Committee – after BAC Seminar
Summary
When an individual or group makes a decision to ‘breed’ an animal for any purpose that decision carries a degree of responsibility. This British Shorthair ‘breed specific’ policy seeks to safeguard the genetic health, distinctive type and integrity of our wonderful breed, by providing our breeders with sufficient information to inform their breeding programs or systems, such that they understand those responsibilities relative to the genetics of the breed and seek to protect and improve all aspects of the most popular pedigree cat in the UK today.
This policy is intended to support and accompany the British Shorthair Registration Policy.
Acknowledgments
• The GCCF Breeding Policy
• Steve Crow and the Asian Breeding Policy
• Dr Diane D. Addie and her Invaluable Website.
• Contributing British Shorthair Breeders1
• Robinson’s Genetics for Cat Breeders and Veterinarians
• Photographers: Alan Robinson and Robert Fox
1 These can be found at Appendix 4 Contributing Breeders
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Contents
Summary ...... 2
Acknowledgments ...... 2
Contents ...... 3
1. Introduction ...... 6
1.1. Purpose of this Document...... 7
1.2. Exclusions ...... 7
2. Background to the British Shorthair Cat ...... 8
2.1. Origin ...... 8
2.2. Breed Description ...... 8
2.3. The Show Cat ...... 9
2.4. Registration ...... 9
2.5. Characteristics and Temperament ...... 9
2.6. Longevity ...... 10
2.7. Recognition ...... 10
3. Breeding System Information ...... 11
3.1. Genetic Make Up ...... 11
3.2. Size and variety of gene pool ...... 14
3.3. Inbreeding ...... 15
3.3.1. Best Practice Advice and Recommendations ...... 20
4. Type ...... 21
4.1. Overall ...... 21
4.2. The Head ...... 21
4.3. Nose ...... 21
4.4. Chin ...... 22
4.5. Ears ...... 22
4.6. Coat ...... 22
4.7. Eyes ...... 23
4.8. Body ...... 23 3
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4.9. Legs & Paws ...... 23
4.10. Tail ...... 24
4.11. Size and Weight ...... 24
5. Health ...... 25
5.1. Genetic Defects ...... 25
5.1.1. PKD ...... 25
5.1.2. HCM ...... 25
5.2. Blood Groups and Neonatal Isoerythrolysis ...... 26
5.2.1. Recommendations ...... 28
5.3. Brachycephaly ...... 29
5.4. Weight ...... 29
5.5. Infectious Disease ...... 30
6. The Self Coloured British Shorthair ...... 31
6.1. The White Self ...... 33
6.2. Black and Blue Self ...... 37
6.3. Chocolate or Lilac Self ...... 40
6.4. Cinnamon or Fawn Self ...... 42
6.5. Red or Cream Self ...... 45
6.6. Tortoiseshell (all colours) ...... 49
7. Non-Self/Non Tabby ...... 52
7.1. Bi-colour ...... 52
7.2. Van Pattern (Preliminary) ...... 56
7.3. Tortie and White and Van Pattern Tortie and White . 59
8. Smoke ...... 61
9. Tabbies and Spotties ...... 64
9.1. Ticked Tabby ...... 67
9.1.1. Ticked Tabby (All colours) Non Silver (Preliminary)67
9.1.2. Silver Ticked Tabby (Preliminary) ...... 71
9.2. Mackerel and Classic Tabbies (non Silver) ...... 72
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9.2.1. Mackerel Tabby ...... 73
9.2.2. Classic Tabby...... 75
9.2.3. Spotted Tabby (non-silver) ...... 78
9.2.4. Silver Tabby, (All colours) ...... 79
9.2.5. British Silver Spotted Shorthair...... 81
10. Tipped – Silver Series ...... 83
10.1. Black Tipped ...... 83
10.2. Golden Tipped including all Non-silver Series Tipped.87
11. Colourpointed ...... 92
11.1. Colourpointed, Non-silver, without white spotting ..... 92
11.2. Colourpointed -Silver Series ...... 101
11.3. Colourpointed & White (Any colour) Preliminary ..... 104
11.4. Silver Colourpointed & White (Any colour) Preliminary106
12. British Shorthair Variant ...... 107
13. Eye Colour ...... 109
14. Record Keeping ...... 112
15. Recommendations ...... 114
Appendix 1 References ...... 115
Appendix 2 Glossary ...... 116
Appendix 3 Key Genes ...... 117
Appendix 4 Contributing Breeders ...... 117
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1. Introduction
It is very easy to breed a cat, in fact if you share your life with a female cat and do nothing to prevent it you will soon have a litter of kittens and a very good mother taking care of everything. However, if one makes a decision to become a breeder of pedigree cats all sorts of responsibilities accompany that decision.
Fortunately in the UK we have a well respected registration body, the GCCF 2 which has an established framework that determines the Registration Policy for each breed of cat and an official Standard of Points3. To accompany these, the British Shorthair Group Committee (Breed Advisory Committee) 4 has compiled this ‘breed specific’ Breeding Policy, the aims of which are to provide the dedicated and ethical breeder with advice and guidance such that the cats that they breed, whether for companion, show or breed purposes, are healthy, and conform to the Breed Standard.
GCCF
BAC Breeders
Registration Breeding SOP Policy Policy
Breeding decisions become easier if breeders develop and manage a breeding program within which they consider the key points of cat breeding, which are:
• Maintenance and perpetuation of the Breed • Improvements in quality of the phenotype (appearance) as measured against the Breed Standard
There is a trade off in any successful breeding program, in order to increase homogeneity (similarity) we must reduce random variation. Therefore, breeders must use a robust process of selective breeding.
2 Governing Council of the Cat Fancy 3 SOP 4 BAC
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In doing so we run the risk that:
• Undesirable, and even harmful, genetic anomalies will begin to express themselves • extremes of physical type may begin to appear • Inbreeding becomes attractive
In order to achieve the desirable goals, whilst managing the risks the breeders system should give consideration to:
• The maintenance of a robust, healthy and viable breeding population of cats. • Properly documented monitoring of the outcomes of any mating that produce anomalies. • The wide range of genetic cat tests that are available.
1.1. Purpose of this Document
The purpose of this document is to provide breeders with some guidance as to ‘best practice’ in breeding the British Shorthair Cat and to ensure that the Breed Standard, as set out within the Standard of Points, is at the forefront of any breeding program, together with due regard for the health and integrity of the breed.
1.2. Exclusions
This document is not intended to guide breeders as to the day to day welfare and care of the breeding animal.
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2. Background to the British Shorthair Cat
2.1. Origin
The Romans introduced large numbers of cats to the United Kingdom as working cats to help reduce the rodent population. These cats interbred with the native wild cats of Great Britain to produce the native domestic shorthaired cat. The accepted date of origin of the British Shorthair as we know it today is 1870.5
Despite being popular at the Crystal Palace cat show of 1871, by the end of World War II along with many other British cat breeds, the British Shorthair numbers were devastated. A number of careful breeders worked to recreate and restore numbers using a combination of British Shorthairs, Persians, Russian Blues, Burmese and other pedigree and non pedigree shorthair varieties.
Whilst the diversity helped with the health of the breed, breeders found that the ‘foreign type’ was persistent in the background and breeders found that they had to keep falling back on the Persian occasionally to keep type. Always, the objective was to reach a point where the British would breed true without any need for outcrosses. (The longhair gene remains recessive amongst some British Shorthairs today)6
2.2. Breed Description
The breed standard states that;
The British cat is compact, well balanced and powerful, showing good depth of body, a full broad chest, short strong legs, rounded paws, tail thick at base with rounded tip. The head is round with a good width between small ears, round cheeks, firm chin, large round and well opened eyes and a broad short nose. The coat is short and dense. A muscular cat with an alert appearance and in perfect physical condition
Extract from the British Shorthair Cat Club;
The British Shorthair is one of the largest breeds of cat. It is chunky and substantial; the male is much larger than the female. The face is round with full cheeks and the nose is short and broad. The chin is deep and strong. The ears are small and rounded and set so as to blend with the round contour of the head. The eyes are large and round. The head is set on a short thick neck. The body is cobby with a short level back. The chest is deep and the shoulders are strong. The legs are short and strong with round paws. The tail is thick and of medium length.
5 Robinson 6 Genetic tests for the LH gene are now available)
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Within these descriptions we can read that this is a cat whose beauty is all about balance, size and roundness, balanced by strength and physical health.
2.3. The Show Cat
The British Shorthair is a hugely popular show cat and with the wide range of colours and patterns available it is one of the biggest breed sections at GCCF cat shows.
2.4. Registration
The British Shorthair is the most popular pedigree cat, with more kittens registered with the GCCF each year than any other breed.
Registered breed numbers have risen by 48% over the past 10 years to almost 6,800 in 2008.7
2.5. Characteristics and Temperament
British Shorthairs are an easygoing breed of cat. They have a stable character and take well to being kept as indoor-only cats, making them ideal for apartment
7 Latest GCCF data published
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They like attention and enjoy being petted. They are not a very vocal breed but will meow to communicate with their owners. British Shorthairs like to follow people from room to room, as they often wish to be with their owner and see what is going on. Some do not mind being cuddled, but most prefer to keep four paws on the ground and be patted rather than picked up.8
2.6. Longevity
British Shorthairs are very healthy and long lived. You can expect a British to live from 14 to 20 years.
2.7. Recognition
The British Shorthair is recognized by all the exhibiting bodies across the continents.
8 Extract from Wikipedia
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3. Breeding System Information
As we can see from the background information the British Shorthair is a popular and robust cat, deserving dedicated and ethical breeders with the time to establish good breeding systems and practices. And whilst breeding cats is ‘just a hobby’ it is not possible to breed responsibly without a basic understanding of genetics.
We will cover some aspects of the genetics of our breed, but much more information can be found in works such as Robinson’s Genetics for Cat Breeders and Veterinarians and of course the Internet is a valuable source of materials for those seeking further information.
For some experienced breeders much of this information is already well known and understood, but as a BAC we have responsibility to help the novice breeder establish a basic understanding.
One of the very first terms to get to grips with is - Phenotype and genotype
The phenotype is basically, that which you can see, phenotypes result from an individual’s genes as well as the impact of environmental factors and the possible effect that the latter may have upon the former. The genotype is the genetic make-up of a cell, or an individual.
That fabulous rusty coloured (phenotype) cat that you may admire as chocolate, may well in fact be a very happy black (genotype) cat enjoying the sun (environmental)
3.1. Genetic Make Up
Unlike many breeds where origins can be traced back to individual named cats, the origins of the British lie very firmly with Felis Silvestris or Felis Lybica, a mackerel tabby ancestor, with just a bit of help along the way.
By the beginning of the 20th century standards had been written for many of the colours and type was generally as seen today, round compact cats with large round heads and eyes, coats described as short and deep, fine texture with dense undercoat.
(By 2009, the BAC determined that type had been successfully fixed and outcrosses no longer permitted.)
In common with the Asian breed the BSH has one of the largest numbers of gene variations of any breed of pedigree cat recognised by GCCF.
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Whilst we understand much about how these genes work, there are so many that even the scientists struggle to understand and complex polygenes9 make the effects of major genes even harder to get to grips with. Sometimes we have to accept that the evidence for how these genes and polygenes work together lies in the ability to breed with consistent results.
It will help if we explain that there are genes for colour and genes for pattern. The genetic penny drops for many novice breeders when they are able to separate the genes that govern colour from those that govern pattern
3.1.1.Coat Colours
Essentially there are four basic colours for coat or pigment in the cat, these are Black, Chocolate, Cinnamon and Red.
Red is confusing because it isn’t really a colour in its own right, it is actually a modifier of the other three colours, but because the result is a distinct colour then it is easier if we consider it as a colour
White is not a colour, it is a ‘masking’ gene that masks anything.
And just when it seems simple, we have to consider the effect of the dilute gene on the basic gene colours. And it always helps breeders to understand the rules of colour dominance.
Figure 1 shows the dominance hierarchy and the effect of the dilute gene.
Dominant Dilute
Black Blue Dominant over Chocolate and Cinnamon Dominant over Lilac and Fawn
Chocolate Lilac Dominant over Cinnamon Dominant over Fawn
Cinnamon Fawn
Figure 1
9 Genes with small but cumulative effects on the expression of a characteristic
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Red is the sex-linked orange gene, ‘O’ and ‘O’ determines if there will be any red or cream (dilute) hair. ‘O’ completely replaces the black pigment gene.
Because Red is replacing Black, Red is also a dominant colour. It is easiest if we think of Red and Black as being of equal dominance.
3.1.2.Coat Patterns
It seems as we have more coat colours than we have because of the genes for ‘pattern’ which modify the colours. The main genes for pattern in the British are:
• The Tabby genes • The Siamese gene • Silver undercoat genes • Bi-colour and white spotting genes
To help us get to grips with the genes for colour and pattern we need to know some basic terms.
These terms will crop up throughout the document and so are well worth understanding.11
Table 1- Basic Terms in Genetics Genes Are individual units of inheritance. Each gene (or combination of genes) determines a characteristic that govern the eventual shape, size, sex, colour, pattern and hair length of the individual animal. Genes work in pairs – but the pairs do not have to be identical Chromosomes Genes are located on the chromosomes. All cats have 38 chromosomes in each body cell, 19 from each parent. Chromosomes appear in pairs. With the exception of the sex chromosomes each pair is the same size and shape. Locus Is the exact position on the chromosome where the gene is located Allele Refers to the different forms of a gene Homozygous Refers to having the same 2 alleles at a given locus on a chromosome Heterozygous Refers to having two different alleles at a given locus on a chromosome Dominant Is one which is capable of expressing its trait even when carried Gene by only one member of a chromosome pair. Recessive can only express itself when both members of the chromosome Gene pair contain the gene10 Wildtype The phenotype of the most typical or normal form.
10 This list is repeated in the Glossary 11 A list of the key genes at work to produce the many patterns of British Shorthair can be found at appendix 1.
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3.2. Size and variety of gene pool
Any ‘best practice’ breeding system must include the planning of the actual breeding program, this is where a breeder decides his or her objectives, seeking to maintain good breed type, and make improvements. The breeder will make a decision to mate a certain queen to a given stud, often with great hopes for the outcome.
As a part of this policy document we will ask our breeders to consider health, selection of parents and inbreeding.
In common with other pedigree breeds, we do not have an unlimited choice of parent cats. Figure 2 shows an estimate13 of the number of British Shorthair queens and studs contributing to the total number of kittens registered in 200915
Breed Kittens Estimated Estimated Registered in 2009 Queens Stud Cats
Self excluding 2248 375 81
Red and Cream
Silver Tabby Inc 762 127 25 Smoke
Colourpointed 438 72 15
Tortoiseshell16 405 68
Bi-Colour & Tortie 322 54 11 and White
Non Silver Tabby & 302 50 17 Red & Cream Self
Tipped (Silver & non 204 34 7 Silver)
Cinnamon & Fawn 29 5 1
White 23 4 1
Other 682 114 23
TOTALS 5,414 903 181
Figure 2 – Estimated Breeding Population
13 Assumptions: The average litter size is 4; the average queen will have 3 litters in 2 years. There is on average one stud cat for every 5 queens. 15 There is a table of British Registrations available on the BAC website 16 The calculated fathers of these tortie kittens have been shared between self and red/cream.
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3.3. Inbreeding
Robinson’s Genetics’ section on inbreeding opens with
“Inbreeding is an emotional topic for some people”
Well it certainly is, the media are full of tales of ‘mutant cats and dogs’ and if one ‘Google’s’ ‘Inbreeding cats and dogs, the first four resources offered all refer to ‘problems’ However, as well as being ‘emotional’ it is also an extremely complex topic. Therefore, in this section we will seek to provide basic information for novice breeders and share some best practice advice from more experienced breeders.
Further reading and information can be found both in Robinsons Genetics For Cat Breeders and Veterinarians and also, the GCCF breeding policy17 provides a section on inbreeding.
In line with our ethos of keeping this simple, it is virtually impossible for breeders of the British Shorthair to avoid inbreeding. Data provided by Robinson18 tells us that if we wished to prepare a 20 generation pedigree for two cats with no duplicated ancestors we would need in excess of two million cats. To get this into perspective we only have to see that the above table is suggesting that we have somewhere in the region of 1000 queens and 200 studs currently at work in the UK. We must also accept that of the possible 200 stud cats available, many of these will be at closed stud, limited stud, or simply the wrong colour.
Within these constraints, breeders dedicated to producing healthy kittens will always have to consider to what extent their chosen cats are related.
The following table provides an explanation of some of the terms used in breeding.
Term Simple Explanation % Inbreeding coefficient calculated19 Inbreeding This is the mating of closely related cats. Such as Father 25% to Daughter, Mother to Son and Brother to Sister Line- This term is not used by geneticists20, and is described as breeding a ‘less intense’ form of inbreeding. 12.5% But it is still breeding within a family line and may include Half Brother to sister, Aunt to Nephew, Grandparent to Grandchild. 6.25% Single First Cousins 3.13% Single First Cousin to Second Cousin and Single Half First 1.56%
17 Available free of charge on the GCCF website. 18 Robinson’s Genetics for Cat Breeders & Veterinarians. 19 Sourced from RGCB&V 20 To a geneticist it is all inbreeding.
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Cousin
Single Second Cousin
Some breeders would consider that mating cats that are related by at least one common ancestor within the first three generations of their parents as line-breeding.
Outcrossing This is when the two parents are unrelated.
Realistically, in pedigree animals, this condition almost impossible to meet. Especially within a ‘closed’ gene pool such as the British.
Breeders, often refer to an outcross when common ancestor does not occur behind either queen or stud within a four /five generation pedigree. (i.e. when any inter-relatedness cannot easily be seen)
Breed True Two parents with a desired phenotype produce offspring of that same phenotype exclusively
Grading Up A rapid improvement of the quality of breeding stock by mating inferior with superior strain. Back Cross The mating a son or daughter to one of the parents. Either to continue a ‘Grading Up’ process or to capture a recessive gene Inbreeding The loss of Hybrid Vigour. Depression Figure 3
So, we are saying that inbreeding is unavoidable, and to a certain extent we must accept that despite the ‘bad press’ inbreeding is, if correctly managed, important. After all without it we would not have the cat that we all know and love today.
The important point is ‘correct management’ and if we can ascertain some form of best practice we can hope to influence the decisions of both experienced and reputable breeders, who will hopefully mentor novice breeders and thus help to keep a healthy balance of inbreeding within the breed as a whole.
In order to understand why breeders would wish to ‘inbreed’ we must go back to our basic understanding of inheritance, the gene is the basic physical and functional unit of heredity. Genes, which are made up of DNA, act as instructions to make molecules called proteins. Every cat has two copies of each gene, one inherited from each parent. Alleles are forms of the same gene with small differences in their sequence of DNA bases. These small differences contribute to each cat’s unique physical features.
When we mate two cats together their offspring will each be given one gene from each parent, when these genes are different, the offspring will be said to be ‘heterozygous’ for the inherited characteristics.
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These genes will combine to determine (to a greater or lesser extent) the following characteristics:
Health
Coat Colour & Temperament Type
Reproductive Ability
Therefore, it would seem to make sense that breeders will select superb specimens of their breed to mate together and thus produce even more wonderful cats. However, to produce cats which closely meet the desired standard, breeders often mate together animals which are related and which share desirable physical characteristics. Some breeders create a line which will ‘Breed True’ and breeders can predict not just how the offspring will look, but that the offspring will, largely be uniform within a litter.
All of this sounds fine so far until we remember that it is not only the ‘phenotype’ of the cat that is ‘breeding true’, behind the scenes the ‘genotype’ may also becoming uniform.
This is caused by a switch in the genetic makeup from a heterozygous state, to one which is ‘homozygous’
Once again, if the breeder is responsibly managing all four aspects of the above inherited characteristics, and can be reasonably certain that all the kittens from these ‘inbred’ matings will be sound, healthy, long-lived and able to produce, without difficulty, sound and healthy kittens. Then all will be well.
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Where it starts to go potentially wrong is when any one or any group of breeders start to breed for certain characteristics such as ‘coat’, – breeding a daughter back to her father in the hope that:
Short Short Short Crisp Crisp Crisp Coat Coat Coat
Is fine unless both cats also carry the gene for disease, then sadly the outcome for the offspring could be very bleak.21
PKD/HCM PKD/HCM PKD/HCM
It is not just the risk of genetic disease that comes with inbreeding. The more that we use inbreeding to ‘fix’ desirable traits the more likely it is that kittens will also inherit the same set of genes for the immune system from both parents, and be born with potentially compromised immune systems. Persistent inbreeding will build up over successive generations as the offspring become genetically more uniform, an increase in sickness may result.
The GCCF recommend that breeders calculate the inbreeding coefficient – If we look at Figure 3, we will see that we can add a ‘percentage’ value to the offspring of any mating we do. The calculation works on a ‘path’
21 Please note that this diagram is illustrative. The genes for PKD and HCM are both dominant mutations. Therefore, cats only need to carry one copy in order to develop disease. However, it is thought that kittens born with two copies of the HCM mutation are more likely to develop serious disease and PKD is almost certainly a deadly double domiant.
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The following ‘traffic light’ might be useful for breeders able to calculate the coefficient.22
% Coefficient
• ACCEPTABLE 1-25% • Over 8 Generations (where only 5 generations 1-17%
• BE CAREFUL 26-39% • Over 8 Generations (where only 5 generations 17-27%)
• STOP 40-50% • Over 8 generations (Where only 5 generations 28-33)
Figure 4
The truth is that there are no hard and fast rules that can help us determine a ‘safe level’ of inbreeding. What we can do, both as individuals and as a group is to ‘listen’ to our cats. There is no perfect coefficient ‘number’ that can declare one mating safe and another risky – one sure fire way of knowing that we are going too far is too look out for signs of Inbreeding Depression, some of which are23:
• Males showing signs of reduced ‘sex drive’ or fertility • Females failing to come into heat or failing to conceive • Falls in average litter size • Low birth weight • An increase in stillbirths • High kitten mortality • An increase in abnormal kittens • Kittens failing to thrive or grow into healthy good sized adults • Signs of poor immune systems leading to an increase in infectious diseases.
Of course, any of the above signs may occur randomly, or indeed may be traceable to a single animal, which could then be removed from a breeding program. True inbreeding depression, describes an ongoing state of affairs that will continue unless responsible breeders step in and make a genetic correction.
22 Taken from GCCF Breeding Policy 23 Taken from various sources including Robinson
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There is a risk that all of this sounds very depressing, but in truth many experienced breeders naturally manage their breeding programs holistically, taking all the characteristics into consideration. These, our best breeders, will not hesitate to remove an otherwise superb physical specimen from their breeding programs if a genetic defect is suspected or found.
The following advice might help inform a ‘good breeding program’
3.3.1.Best Practice Advice and Recommendations
• Breeders should avoid inbreeding as much as possible. • Stud cat owners should ask for copies of the pedigree of any queen wishing to be mated. • Novice breeders should always take advice from a mentor. • Breeders should only use inbreeding as a part of their breeding system when they are certain that they have the ability and experience to recognize early signs of inbreeding depression. (and the courage to make any necessary corrections) • Kittens from closely related parents should not be sold to novice breeders. • Remember breeders computer programs can only feedback on data input – if only 4-5 generations are available for a breeding coefficient calculation – the program cannot calculate the inbreeding of any missing generations. • Ensure that you understand the pedigree of any cat you might wish to buy for breeding or use at stud, avoid kittens with pedigrees where any one ancestor is over represented. • Avoid over use of ‘fashionable’ stud cats • Breeders may work in groups and agree to avoid any inbreeding within say three or four generations of a pedigree. • Importing new bloodlines will refresh the gene pool. However, check the pedigree to ensure that the overseas breeder is not breeding from recently purchased UK stock. • Breeders to accept collective responsibility for the breed health and integrity.
The good news is that the BSH does not show signs of dangerous inbreeding at a breed level.
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4. Type
This section is intended to add additional information to inform breeders as to the phenotype24 we should all be aiming for.
4.1. Overall
The British Shorthair cat is compact, well balanced and powerful, showing good depth of body, a full broad chest, with generous, strong shoulders standing four square on short thick legs, with strong hips. He has rounded paws, with a tail thick at the base with a rounded tip. A muscular cat with an alert appearance and in perfect physical condition.
We are looking for a cat that has an overall body shape that is a series of curved or rounded shapes from his head and paws to the tip of his tail.
4.2. The Head
The Breed Standard looks for, a round face with full cheeks and good breadth of skull with round underlying bone structure. The head should be set on a short thick neck. A good way to describe a ‘good head’ is a broad apple shape with chubby cheeks.
Importantly, the head should always be in balance with the body, an oversized head is just as undesirable as a head that is too narrow.
The eyes are large, round and should be an important facial feature. Top breeders aim for a sweetness of expression as well as eye colour.
4.3. Nose
The Breed Standard calls for a nose that is short, broad and straight. In profile, a rounded forehead should lead to a short straight nose with a nose break that is neither too pronounced nor too shallow.
Almost all experienced breeders of the British Shorthair will know that ‘short, broad and straight’ seems so simple and yet the reality is that getting the British Shorthair nose and forehead right is frustratingly difficult.
24 The ‘visible’ cat
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Keeping the nose short, with a balanced break is just one of the juggling acts most breeders have to perform.
Irrespective of fashion the extreme Brachycephalic look is not a feature of the British Shorthair25.
4.4. Chin
The Breed Standard is very clear, a strong, firm and deep chin is essential.
Any deviation from this to be considered a fault.
The bite MUST be level, the tip of the chin to line up with the tip of the nose in the same vertical plane.
Breeders seeking to emphasize the roundness to the head seek to create a slightly rounded chin and powerful jaw.
4.5. Ears
Breed Standard asks for, small, rounded at the tips. Set far apart, fitting into (without distorting) the rounded contour of the head.
External ear to be well covered with fur, internal furnishings not to be excessive.
Getting those ears right presents a real challenge to our breeders, why oh why do ears want to be large and sitting high on the head?
Experienced breeders remove the ear tufts for showing to accentuate the roundness and neatness.
4.6. Coat
The SOP26 calls for a coat that is short, dense and crisp. A soft and / or overlong and fluffy coat is incorrect.
The above statement makes it all sound so simple, yet the British Shorthair coat is unique, no other cat breed has this wonderful coat. Read through Judge’s reports and find words such as cracking, crisp, scrunchy, dense and firm. Judges
25 Shortened muzzle and face 26 Standard of Points
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4.7. Eyes
Breed Standard says, large, round and well- opened.
Set wide apart with no tendency to Oriental shape. No squint.
For some breeders it is all in the eyes – not just colour - but shape and set.
4.8. Body
The SOP says - Cobby type with short level back.
Low on legs with broad deep chest.
Equally massive across the shoulders and the rump.
Medium to large, but not rangy.
We are looking for cat with hips and shoulders of the same width.
A well balanced cat will also have a firm body, without sagging. Breeders are looking for good bone and a sound muscular body.
4.9. Legs & Paws
The Standard asks for; Short strong legs.
Paws round and firm. Toes carried close, five on each forefoot (including dew-claw) and four on each back foot.
That gentle roundness carries right through even to the feet.
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4.10. Tail
According to the SOP the tail should be thick and of medium length, thicker at the base with rounded tip.
4.11. Size and Weight
The male British is noticeably larger, broader and rounder than the female, with weights ranging between 6-7 kilos. But the female is also a big cat with weight, when in condition, around 5-6 kilo’s.
The British is a slow growing cat and should be given time to mature. The adult will not reach full maturity until three to four years of age.
The British Shorthair may be a big cat but it should not be a fat cat.
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5. Health
5.1. Genetic Defects
Just as genes determine all the good characteristics they also contribute to many ‘bad’ characteristics. We only have to look over our shoulder at some of the unfortunate attributes that have slipped into some of the pedigree dog breeds. But closer to home, the Munchkin Cat has been produced as a result of deliberate breeding of a genetic mutation. Genes also contribute to disease and as breeders seek to fix type they may inadvertently fix disease.
Fortunately, there are tests available for some devastating genetic diseases and breeders can make informed choices. Reputable breeders should be aware of the genes that can adversely affect the British. Where testing is possible, these should be performed routinely and affected animals removed from breeding programs.
Section 6 of the GCCF Breeding Policy gives details of the well known genetic anomalies; we will just mention two of these:
5.1.1.PKD
Polycystic Kidney Disease – PKD, a gene mutation which causes enlarged kidneys composed of dilated cystic channels, resulting in early kidney failure and death. This mutation has been found in the British Shorthair. Fortunately simple, effective DNA tests are available. These can be undertaken by your veterinary practice or simple swab tests can be carried out at various laboratories27
5.1.2.HCM
Hypertrophic cardiomyopathy (HCM). Sadly, according to the Feline Advisory Bureau a familial incidence of HCM has been reported in the British Shorthair breed. Whilst this may be due to an inherited gene defect, as yet the defective gene has not been identified in this breed. (See screening scheme info on www.fabcats.org/hcm)
The GCCF section on genetic anomalies states that the majority of HCM is genetic. Unfortunately, at the moment testing in the British is limited to scanning with ultrasound, which can be unpleasant for the animal and expensive. Amongst British Breeders in Europe, annual HCM tests have become routine, but it has not yet become custom and practice for British Breeders here in the UK. Our current recommendation is that any breeder with reason to suspect an inherited HCM condition in any of their cats, should seek a scan and if the animal is affected remove him or her from the breeding population. Any progeny should also be scanned and monitored.
27 A list of laboratories can be found on the BAC website – some of these offer discounts to breeders as members of the breed clubs
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5.2. Blood Groups and Neonatal Isoerythrolysis
Blood Group Mismatch is an issue for the British section. As a BAC we have decided to include a section on Neonatal Isoerythrolysis as it is the kittens of our breed that are most likely to be affected by blood group mismatch.
It is estimated that 92 % of the UK domestic shorthair feline population are blood group A. However, only 47% of the British Shorthair population are group A, the remainder being blood group B or the very rare AB. In recent years blood group ‘mismatch’ has been identified as being responsible for some cases of fading kitten syndrome.28
There are experienced breeders in the UK today who have bred cats for many years who do not know the blood group of their cats, who add new stock to their lines and yet have never lost a kitten due to blood group mismatch. There are others who have sad stories of entire litters have lost to a fading kitten syndrome that has been diagnosed as Neonatal Isoerythrolysis.
Fortunately today it is possible for breeders to test their breeding cats for blood type in their own homes using non-invasive inexpensive swab tests.29
The following detail is extracted from data provided by UC Davis.
The A and B blood groups are genetically determined.
UC Davis has proposed the following ‘naming’ system:
Nomenclature Blood Genetic Make Up Note Group A A A/A, A/a or A/b Dominant to B a AB Probably less than 1% of all cats. b B b/b
A genetic mutation associated with the B blood group in most cats has been identified and a DNA test has been developed. Animals can be tested at an early age from a buccal swab.
The DNA blood group test identifies cats that have the B serotype (two copies of b allele) and also that are B carriers (one copy of the b allele, A or AB serotypes). Because the DNA test cannot distinguish between a Type A versus a Type "AB" cat, the non-b allele is reported as "N". The cat could have a Type A or Type AB serotype.
28 Data courtesy of Dr Diane Addie and FabCats 29 DNA Laboratories can be found online via search engines. Many cat clubs operate a discount scheme with accredited laboratories.
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Results reported as:
Test Blood group status Result
N/N Cat is Type A or Type "AB"
Cat is a carrier of B factor; serotype could be Type A or Type N/b "AB"
b/b Cat is Type B
Once a breeder knows the blood type of all their breeding cats they need to understand that Neonatal Isoerythrolysis represents the most serious problem to any A offspring of a B mother. This risk increases with every mating that may result in A group kittens. The effect of the antibodies is accumulative.
On her website Dr Diane Addie makes the following statement regarding Ab Queens mated to Ab studs and thus potentially carrying B group kittens -
“Queens with blood group A have less anti-type B, antibody than blood group B queens have anti-group A, antibody, so the type B kittens of this mating might survive. However, if the mating is repeated, the queen will build up anti-B antibody and eventually one fourth of her kittens could die of Neonatal Isoerythrolysis.”
Despite much research amongst UK BSH breeders we have no evidence that kittens from Ab to Ab matings are fading from NI. However, record keeping is vital and if breeders experience any fading kitten in Ab to Ab matings blood tests may help to inform future matings.
Figure 5 shows how to calculate any risk (note we have ignored AB as it is so rare and is covered by Dr Diane Addie in full)
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B Ab A, or Ab Stud B , or B Ab or A Stud B Stud Queen Queen
Quee
Offspring will be Offspring will be either Offspring will either blood blood group Ab or B be either group A, Ab or B Any non B kittens may blood group B be at risk or Ab Risk Increases For B group Not at Risk kittens
It is the antibodies from B group dams that represent the greatest risk to A kittens
Figure 5 Figure 5 shows that a B group stud can be mated to any queen and an A queen can be mated to any stud. Breeders need to manage the matings and or kittening of their B group queens. Records of any fading kittens in Ab to Ab matings should be kept.
5.2.1. Recommendations
1. Breeders should use available technology to inform their breeding programs. (ie, Blood Group Tests) 2. Inexperienced Breeders with B group queens should seek to mate those queens to B group studs. 3. Kits to test blood group using placental blood are available.30
30 These are available to Veterinary practices from the Oxford Cat Clinic.
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5.3. Brachycephaly
Brachycephalic is a word that is hard to say, meaning short headed or broad headed, wherein the length of the cranium is shorter than the width. This gives the top and sides of the cranium a round shape, often referred to as 'apple- head'.31 Whilst we are very happy to have that lovely apple-head description, if one were to Google ‘Brachycephalic’ all sorts of distressing articles and images appear, especially in relation to poor breeding practice in the dog world.
As the British BAC, our remit is limited to the welfare of the British Shorthair, and whilst we are attracted to a short, broad nose we are also very proud of the reputation that the British Shorthair has for health and for being as natural as possible for a pedigree cat.
5.4. Weight
The British can be a lazy cat, and may be prone to weight gain. Overweight stud cats can find the mating act difficult. Overweight queens may have difficulty in getting pregnant and giving birth.
Keeping your breeding ‘team’ at the right weight takes patience and skill, but the health benefits to your cat are worthwhile
31 Wikipedia
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5.5. Infectious Disease
There is much information available for breeders regarding infectious diseases both viral and bacterial. The feline, unlike the canine, is not a pack animal, and there is no doubt that the feline physiology cannot cope with the stress that can accompany some cattery environments.
We recommend that breeders acquaint themselves with the following diseases, such that they understand symptoms, treatments, impact and remedy.
Table 2 Viral Bacterial Parasites Feline Calicivirus (FCV) Feline Chlamydia Fleas Feline Panleukopenia Campylobacter Ear Mites (Distemper) Feline Leukemia Virus Bordetella Bronchiseptica Hookworms, (FeLV) Ringworms and Tapeworms Feline Rhinotracheitis Toxoplasma Coccidia (Feline Herpesvirus) Feline Immunodeficiency Streptococcus Tri Trichomonas Virus Corona (FCoV) and Staphylococcus Giardia Feline Infectious Peritonitis Ringworm Key: Diseases in Green have vaccines available. Blue, have treatments available. Red, these diseases have no vaccines or treatments in common use.
Our best recommendation is that all our breeders find a good Vet, one that is prepared to be a partner on our journey to produce happy healthy British Shorthairs. Breeding is teamwork and the support and care of a good Vet is invaluable.
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6. The Self Coloured British Shorthair
In order to understand the genes for coat pattern at play in the British self we must first understand the Agouti (A) gene - the natural “wild” gene that is the basis of the tabby cat. The base agouti pattern is bands of black on a yellow or orange background. This dominant, wild-type (A) causes the agouti shift phenomenon which causes the hairs to be black pigmented at the tips and orange pigmented at the roots this is overlaid with one of the tabby patterns.
There are three tabby patterning genes, which give rise to the patterns that we know: Mackerel (Mc) with the basic stripes, Classic (mc) a mutation of (Mc) which blotches the pattern, Ticked (T), a form that removes most of the stripe pattern, Spotted (Sp) a gene that breaks the pattern into spots.
Working with the tabby patterning genes we have the Wide-banding (Wb) gene. This little understood, and much argued over, gene has the effect of pushing the darker, pattern colour in the cat up away from the hair base towards the tip, turning the normal tabby patterns into a Shaded or Tipped cat.
Now that we understand the basis for the ‘original’ pattern of the BSH ancestor, we must now accept that genes can mutate32 overtime.
When the dominant Agouti gene (A) mutated into the weaker Non-Agouti gene (a)33 what actually happened was that the gene became faulty and no longer works properly, so that the little genetic trick known as the ‘agouti shift’34 simply doesn’t happen, or at least not properly in (aa) cats.
In the absence of the ‘agouti shift’ the basic tabby cat turns into a self black because the whole hair shaft is allowed to fill with eumelanin35 meaning that the whole animal appears black, although often in certain light the underlying tabby pattern may still just be discernible, especially in kittens. Other genes work to change this black pigment to other colours.
Something important for breeders of the self coloured British to bear in mind is that whilst not all cats are Agouti, they are all Tabbies, the loss of the Dominant A gene does not affect the base tabby pattern. Thus those underlying patterns we see in kittens can be stripes, spots or indeed ticked.
Another point to note at this early stage is that the (A) to (a) mutation has little effect on the (O) allele36 This explains why it is almost always possible to see the tabby markings on red and cream non agouti cats.
Our beautiful British Self coats are created in the embryo. Very early on, all the particles responsible for the colour of the coat flow into the hair shafts. This is a very complex process, not just technically, but also impacted by genes and polygenes that are not yet fully understood. What seems to be important to the ‘self’ is the speed of this process, the faster the colour pigments pour into the shaft the more even the hair colour becomes.
32 Mutations are changes in the DNA sequence of a cell's genome 33 Also known as the Hypermelanistic gene 34 Far too complicated for this section 35 Black pigment 36 The gene responsible for Red and Cream
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In the British Self we are looking for a coat with hairs that do not fade out as they get closer to the skin. This can be helped by selective breeding of individuals that have the most solid coats. What we are probably playing with are those polygenes that control the depositing of the melanin in the hair shaft and the length of time that the process takes.
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6.1. The White Self
Introduction
A beautiful cat with a sparkling non-silver white coat and dramatic eye colour, the white self is not often seen on the show bench today, although when one does appear it generates a lot of interest. In the early days of the British Shorthair they were very popular working cats often found in Flour Mills!
It is estimated that the White Self represents less than half a percent of total kitten registrations.
With a legacy of hearing problems and a need to understand the dominance of the genes for white coats the white self cat is a breed for the experienced and ethical breeder.
It will help at the outset if we understand that White is not a colour in the sense that Black is a colour – we need to think of a white cat as one that has not got a colour and thus appears white.
Genes for Coat The gene (W) that causes a cat to have a white coat is a dominant masking gene37. A white cat can be a homozygous white (Ww. 2 white genes) or heterozygous (Ww. one white gene/one nonwhite gene).
Keeping this very simple, what happens is, that as the embryo forms, the W gene interrupts some of the normal cellular activity, and those cells, for pigment or colour, that multiply and spread over the embryo, effectively get stopped in their tracks, so the skin of the newborn kitten has no pigment and the kitten is white.
A completely white cat could carry the genes for red/black, agouti/non-agouti, dilute/non-dilute, etc, but despite any hidden genetic codes for coat colour and pattern the cat may have, the cat will always be visually white.
Pure white cats often have a small patch of colour on the head at birth. This spot is evidence that the process of distributing cells for melanin actually started, but was then halted by the W gene. This is why this spot may reveal what colour the kitten carries. These patches usually disappear as the cat matures.
37 Epistatic
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It is, in rare cases possible to have a cat with a naturally white coat without this gene, as an extreme form of white spotting38, some small non-white patch usually remains, if only during kitten-hood.
This sweet baby aged 11 days carries the mark she was born with. The pigment mark shows how the pigment started to ‘migrate’ before the W gene caused the process to stop.
Eyes
Breeders are seeking to achieve the following eye colours:
• Deep Sapphire Blue • Orange, preferably copper, deep orange or deep gold • Odd eyed, one each of the above two striking colours
As the white coat may be masking many coat colours or patterns including the Himalayan gene40 the source of the eye colour in the white cat may not always be known. A blue eye colour, for example, may be as a result of have de- pigmentation of the iris of one or both eyes, or may be as a result of the Himalayan gene.
Nose and Paw Leather
Bright Clean Pink for the British White
The Show Cat Breeders are looking for a white ‘self’ which should have a dense pure white coat un-tinged with yellow. Kittens may have slight blue/black markings on their heads which should disappear when they reach maturity.
Specific Health – Skin Care
Due to the lack of pigmentation in the skin, white cats are more sensitive to sunlight and are more likely to affected by sunburn and develop skin cancer.
Deafness
It would be irresponsible not to mention the deafness that is associated with the gene for White (W).
38 See White Spotting Gene and Section on Bi-Colour British 40 See Appendix 1 and Section on Colourpointed.
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There is much data available giving statistics, the following data paints a picture.
• Deafness in the general cat population is extremely rare • 5% of the general cat population is White • Estimates are that about 50% of these cats are deaf in one or both ears and when one or two eyes are blue the chances of deafness rises to nearer 80%
During our research for this section we came across several papers each arguing the case both for and against the existence of a gene for deafness in white cats.
In the absence of a definitive position we must settle for the generally accepted position which is;
• There may be a gene for deafness which may be found one day. • The deafness may be caused by the W gene halting the normal migration of pigment cells that causes both the eye to be blue and the degeneration of the canal of Corti, (the part of the cochlear duct that leads to deafness) • Studies have shown that it is the same stem cells that cause the lack of pigment in the blue eye and the absence of a cell layer in the inner ear that is found in deaf cats. • White cats irrespective of eye colour may be deaf, but it is more common in blue-eyed white cats than in yellow-eyed. • The deafness is caused by the W, gene working with polygenes. • Odd-eyed cats are often deaf on the ear which is situated on the same side as the blue eye.
What all this tells us is, that we breeders need to be very careful when dealing with the W gene, and studies have proved that there is a considerable fall in the incidence of deafness in pure bred cats, so it is clearly possible to breed a healthy hearing White cat.
Best Practice and Responsible Breeding
• GCCF registration of white male stud cats requires a BAER test. • The registration policy for the White self restricts full registration to matings between White and Self/tortie. • Responsible breeders, of white cats will breed only from cats that have undergone the BAER test which tests for bilateral hearing. • Caring and ethical breeders can promote awareness of the test on their websites to raise the profile of the test in cats and hopefully steer people away from breeders that may not have the interests of the unborn kitten at heart. • Breeders should offer copies of their BAER test certificates to people buying their kittens.
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Recommendations White Self
• All White British Shorthairs on the active register irrespective of gender should be BAER tested. • White x White breeding should be discouraged (research suggests that cats that carry two copies of the W gene (WW = homozygous) are more likely to produce deaf offspring. • As any cat can be covered by the white gene, Breeders should mate cats as close to the breed standard as possible to produce whites that are as good as they can be. • Breeders looking to achieve a higher incidence of odd eyed whites in their breeding programs might like to consider experimenting with Bi-colours with UNEAVEN facial markings41
41 One breeder interviewed suggested that using cats with perfect V shaped blazes seemed to produce a higher number of kittens with single eye colour.
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6.2. Black and Blue Self
Introduction
The British Blue almost needs no introduction being the most loved of all pedigree cats in the UK today.
Together with the Chocolate and Lilac series, the British Black and Blue account for almost 42% of all BSH registrations42
Genes for Coat
Colour Agouti Black Dilute Orange White
Black aa B- D- oY/oo ww Blue aa B- dd oY/oo ww B- = BB or Bb or Bbl
To arrive at the coat that defines the superb cat that is the British Black we must go back to the Non-agouti (a) gene the recessive gene mutation that turns the basic tabby cat into a self black. The pigment granules in each hair of the cat's coat contain Eumelanin43 which is black. Black melanin or eumelanin granules are thought to be oval in shape and absorb almost all light.
The B (black/brown) gene has a lightening effect on eumelanin. The D (dense/dilute) gene affects the density of pigment in the hair and affects the eumelanin, the effect is a washed out version of the original colour and the Jet Black of the British Black becomes the light to medium blue that is so desirable.
Black is a dominant gene for colour
The above genetic explanation of colour does not explain the superb texture of the British Black and Blue coat. The plush, dense coat sets the standard for all the other British Breeds’.
42 Data provided by the GCCF using 2009 registration data 43 Eumelanin is, in the absence of colour modifier genes, black
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The blue colour of a British Shorthair can range from a gentle pale grey to a dark charcoal. The colour should be solid and even throughout the body. Any ghost tabby rings on the tail are forgiven only in immature cats.
Eyes
Breeders seek to achieve dramatic effects with stunning eye colour of copper, orange or deep gold. Eyes should be large and round, giving rise to a sweet, open expression.
Nose and Paw Leather
Nose leather follows coat colour. Black for the Black British and Blue for the Blue.
The Show Cat
The sight of the British Black at the top of his or her game on the show bench always causes a stir and high awards are usually met with great approval, the black needs to be jet black, with no paling to the roots, the coat must be dense and plush. Eye colour needs to be as good as it can be. This fabulous coat will show any dust so good grooming is vital. Kittens may show some rustiness, but this will not be expected in the adult cat.
The British Blue carries the banner for the breed and competition is very tough. Breeders work very hard to achieve the balance of coat; texture and colour, eyes; shape and colour, ears; size and set; body; size and weight and because this is such a popular colour, judges all know just how good this cat can be. The SOP calls for a light to medium blue coat in the show cat and heavy silver tipping is a fault.
There should be no tabby markings in either cat on the adult show bench.
Best Practice, Responsible Breeding and Recommendations
• Breeders seeking to breed from black or cats with other genetically dominant traits should ensure that they understand how the genes for colour and dilution are inherited. Breeding from a black cat that does not carry the genes for dilute or chocolate/cinnamon will only produce black cats. • Just because the British Blue enjoys huge popularity both on and off the show bench – breeders should not compromise on type or quality. 38
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Silver Tipping
One of the topics of discussion during review of this breeding policy and the seminar held in April 2011 was the Silver Tipping seen on the coats of some British Blues.
Despite some detailed research we have as yet been unable to determine the genetic nature of the ‘tipping’ seen on some blue coats or to ascertain as to when the British Blue coat first started to show this tipping.
If we go back to our introduction we can read that after both wars many other breeds of cats known to have this Silver Tipping were used to re-establish the British.
There is much debate amongst established breeders as to whether what we see today is a relatively new phenomenon or something that has ‘always’ been there.
There are some renowned Blue breeders who are actively breeding to keep their lines free of this tipping, whereas others feel that it is a not unattractive price to pay for an otherwise good for type cat with a pale blue coat.
As genetic information becomes more available we will, hopefully, learn more about the genetic make-up of our most popular colour of British. In the meanwhile breeders are free to choose the polygenic phenotype of their breeding programs, whilst our Judges have to make their own interpretation of the definition ‘heavy silver tipping’
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6.3. Chocolate or Lilac Self
Introduction
The chocolate British Shorthair is a huge favourite and very desirable companion animal. The chocolate colour mutation was first seen in the Siamese breeds, where it was thought to be ‘just a poor or strange’ Seal44 Records for the Chocolate Siamese appear in the 1880’s and they were first registered by the GCCF in 1950.
It was not until the 1980’s that breeders started to bring the colourpointed pattern into the British Shorthair and with it the Chocolate and Lilac colours.
The Chocolate Self did not gain championship status at GCCF shows until 2009.
Genes for Coat
Colour Agouti Black Dilute Orange White Chocolate aa bb or bbl D- oY/oo ww Lilac aa bb or bbl dd oY/oo ww
The chocolate colour is a true mutation of the gene for Black and can be found by gene tests. In chocolate cats, the round or oval black pigment granules (eumelanin) which absorb almost all of the light, are a bit flattened. This means more light can be reflected and the coat looks paler. This gene for Chocolate is recessive.
When we add two copies of the dilute gene to the Chocolate cat the result is a delicious lilac shade.
Nose and Paw Leather
Nose leather and paw pads should be a Pinkish lilac.
44 Seal is the colour description for the Black Colourpointed
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The Show Cat
The breed standard for Chocolate calls for any shade of rich chocolate in a sound coat with chocolate or pink nose leather and paw pads.
The Lilac cat should be a Frosty grey with a distinctive pinkish tone, giving an overall lilac appearance.
The Chocolate and Lilac series are always popular on the show-bench. Judges are looking for chocolate coats that are the mid-warm tone of a chocolate Labrador, which are also sound to the roots, something that breeders find hard to achieve.
Best Practice, Responsible Breeding and Recommendations
• Experienced breeders of the chocolate colour find that using black self cats within their breeding programs helps to produce chocolate or lilac coats with more desirable tones to the colour. • Novice breeders should appreciate that this colour is relatively new to the breed and still needs work to get sound coats. • Rufous genes appear to be reducing barring and making colours warmer in other breeds. Selective breeding should help to see whether this can also be true in chocolates and lilacs. • Some breeders advise breeding chocolate cats not carrying the colourpointed gene • Some trial matings are showing that chocolate coats in cats carrying cinnamon are lighter in shade. • Experienced breeders are experimenting with the effect of using cats known to have an underlying non agouti ticked base pattern to see if there is an improvement in the quality of the coats.
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6.4. Cinnamon or Fawn Self
Cinnamon is the third true cat colour. Just as the Chocolate ‘b’ gene is flatter and longer than the oval shaped Black ‘B’ the Cinnamon (b¹) granules are even longer and thinner than those in the Chocolate, causing the hairs to be a lighter and warmer brown colour.
The dilute gene causes the Cinnamon colour to fade to Fawn. Fawn is similar in tone to lilac but is paler, perhaps more beige in colour.
Genes for Coat
Colour Agouti Black Dilute Orange White Cinnamon aa b¹ b¹ D- oY/oo ww Fawn aa b¹ b¹ dd oY/oo ww
Although we are attempting to keep the genetic explanations as simple as we can, the truth is feline genetics are complex, and the genes that we do understand and can test for work in complex ways with genes that we cannot test for and can only really ‘prove’ by experiment and testing our theories.
And whilst the above table shows that the Cinnamon gene for colour looks an awful lot like the black gene for colour on paper, the truth is that little b¹ gene has travelled a long way into the British and has potentially bought some interesting companions.
In order to explain, we need to go back into the history, firstly of the Cinnamon colour, and secondly how it has arrived onto the British show bench today.
History of the Cinnamon colour45
Essentially the Cinnamon colour was first identified in the Sorrel Abyssinian. This cat had been labeled as ‘red’ until the late 1960’s when tests proved that the genotype of the Red Abyssinian was in fact that of a Cinnamon Tabby. The genes responsible for the Abyssinian coat pattern are dominant to most other genes, hiding recessives such as non-agouti, other colours and other tabby patterns.
Cinnamon arrives in the British Section
It was a passion for the richness of the Cinnamon colour that tempted a group of breeders to seek to introduce the colour into the British early in the 1990’s. Much discussion over ‘where to go’ to outcross ensued, with the Abyssinian and the Oriental being the main contenders. Eventually it was decided to go out to the Oriental46.
45 Interesting reading includes - The Abyssinian Cat, by Vicky Hakin Smith 46 Malsome British Shorthairs have some background information.
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The main reason for choosing the Oriental over the Abyssinian was the fact that the Abyssinian ‘genotype’ included the dominant ticked agouti gene and the Oriental Cinnamon Self is a non agouti cat.
The Oriental section had originally out-crossed to the Abyssinian47 but selective breeding of the recessive ‘a’ gene produced a cat with all the magnificent colour of the Abyssinian in a non ticked form.48
Those of you still paying attention will note that, although the agouti gene may have bowed out leaving his recessive cousin in charge – the underlying non- agouti tabby pattern passed through the subsequent generations may well be ‘ticked’49
The first outcrosses started, and what a task these brave breeders set themselves – the Oriental50 is a beautiful cat, but the phenotype is almost as far from the British as it is possible to get.
It takes passion and a great deal of patience and many many years to convince all those polygenes to make the shift from the Oriental to the British and we should be proud of those dedicated breeders who break the first ground
Nose and Paw Leather
Nose leather and paw pads should be a pink or cinnamon brown.
A lovely example of the Fawn Coat.
Now, does that coat look as if it has an underlying non-agouti ticked base?
47 More information can be found via the ‘The Oriental Cinnamon and Fawn Breeders Group’ 48 Just out of interest see both cats at shows – note the effect the ticked agouti gene has on the colour. 49 The effect the underlying (non-agouti) pattern may have on the British Coat is a ‘hot topic’ in the British section. 50 Photo of Mewzishun Symphonia taken by Alan Richardson in 1996. This cat shows the Oriental Cinnamon type as used by the British/Cinnamon project.
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The Show Cat (Preliminary Status)
The breed standard for Cinnamon calls for a warm cinnamon brown and for Fawn a warm rosy mushroom.
This wonderful, short legged, cobby girl with neat ears shows just how much has been achieved by some of our ground breaking breeders.
Best Practice, Responsible Breeding and Recommendations
• Novice breeders should appreciate that this colour is relatively new to the breed and should seek to understand fully the pedigree of any breeding animal. • Getting ‘type’ right is imperative. This cat’s ancestor has, large tall ears and a long nose – selection will be key as this breed progresses. • Experienced breeders are removing the colourpointed gene from the phenotype of some lines – to ‘fix’ the Cinnamon and Fawn Self. • As this breed moves into Championship Status, it is likely to be adopted by a greater number of breeders. Remember, to protect the colour, that warm burnt sienna, cinnamon colour, was after all what the last 20 years was all about.
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6.5. Red or Cream Self
Those budding geneticists amongst us, will have remembered that the (A) to (a) (agouti to non-agouti) mutation has little effect on the (O) allele51 This explains why it is almost always possible to see the tabby markings on red and cream non agouti cats. So it is not surprising that breeders are still working hard to get the Red Self through the Preliminary Status52 stage. Whereas the dilute form, the British Cream is a very popular cat both on and off the show-bench.
Because the genetics of the red and cream series start to get a bit more complicated it is not surprising that when they popped up in Tortoiseshell litters in the 1800’s breeders were often uncertain how to actually breed the cream self. It was not until the 1920’s that breeding programs became established.
Having explained eumelanin53 we now need to get to grips with the only other feline pigment – phaeomelanin the pigment for red. Essentially what the ‘O’ gene does is get rid of any eumelanistic 54pigment from the hair shaft.
We must also remember that in the dominance stakes black and red are equal.
And whilst we practice pronouncing ‘phaeomelanin’ we must also take a step back to our biology lessons and recall the rules that determine whether we are male or female or more importantly whether our cats are male or female.
Each cat has two chromosomes for ‘SEX’ or gender –
Females, have a pair of chromosomes that appear identical and are X shaped. Therefore, we refer to females as: XX
Males also have a pair of chromosomes, but one of the males chromosomes is smaller and looks like a Y or an incomplete X with the right lower ‘leg’ missing.
XY
The reason this is important information is because the genes for colour55 are carried on the X chromosome and once the penny drops that girls have two XX places to carry or inherit colour/pigment and boys only have one X to carry or inherit colour/pigment we can begin to understand why we can have tortie’ girls but not boys. The ‘O’ gene sits on the X chromosome and we call it a ‘sex linked’ gene
51 The gene responsible for Red and Cream 52 Preliminary status breeds compete in Assessment classes 53 The pigment for black 54 Black, Chocolate, Cinnamon 55 Important to note this refers to the genes for colour – NOT the genes for pattern.
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The following table may help:
Example XY Genotype Phenotype XX Black on both X Black Female Chromosomes XX One black & one Red Dominant Tortie X Chromosome Female XY Black on X Black Male Chromosome XY Red X Chromosome Red Male XX Red on both X Red Female chromosomes Figure 6
• If any cat carries two copies of the dilute gene then cats will be blue, cream or dilute tortie. • We can substitute chocolate or cinnamon for black in Figure 6and the rules still apply.
For those of you still with us, we will just do a quick reminder of how gender is inherited and how that affects this ‘O’ gene.
In order to be a boy the male cat has to have one copy of the Y chromosome, which he can only get from his father. This is balanced by an X from his mother. Therefore, an orange/red male always gets his gene for colour from his mother.
A female cat gets an X from each of her parents.
Genes for Coat
Colour Agouti Black Full Dilute Orange White Coat Red aa C- D- OY/OO ww Cream aa C- dd OY/OO ww
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This picture shows a delicious cream female at the top of her game.
The delicate cream tones that make this girl blend into her blankets are exactly what breeders are trying to achieve. However, it is not easy to produce this pale, balanced, colouration.
The good news is that Breeders are making progress and this colour group - together with the non-silver series of tabby – is one of the few British Shorthair varieties that had an increase in registrations in 2009.
Nose and Paw Leather
Leather should be brick red for the red and pink for the cream.
The Show Cat
The cream colour should be an even-toned cream, with as few markings as possible and no white hairs. Paler shades are preferred. Kittens are forgiven any ghost tabby markings.
Best Practice, Responsible Breeding and Recommendations
• A popular mating to produce good examples of the cream is blue-cream females mated to blue or cream males. • It is thought that producing cream kittens from a red or dominant tortie parent carrying dilute may contribute to a ‘hot’ cream. However, some breeders have found the reverse to be true! • Because the Red-Self is still at the preliminary stages, breeders are still working ‘against’ the genes that make the agouti markings appear on non- agouti cats. Some of the breeding ‘trials’ underway include: • Working with ‘Rufousing polygenes’ 56which seem to blur the contrast between the pattern and the ground colour. • Breeding self cats with an underlying base pattern that is ticked tabby rather than classic, spotted or mackerel57
56 Appendix 3 57
Ticked Tabby (footnote continued) 47
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A beautiful youngster showing an underlying non agouti spotty pattern
A lovely rich red girl – so rarely seen
Ticked Tabby (All colours) Non Silver (Preliminary
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6.6. Tortoiseshell (all colours)
This is a very popular variety of the British Shorthair, especially amongst breeders who find the multi-colour useful in breeding programs and who also appreciate just how difficult it is to produce a ‘correctly’ patterned ‘tortie’ for the show-bench
Just when things were starting to get simple, we learn that the tortoiseshell pattern is not genetically a pattern – it is actually something that happens when a cat is born with two colours showing.
A female cat inherits an X chromosome from each of her parents.
If neither parent has the gene for ‘red’ then the colour of the female kitten will be determined according to the rules for colour inheritance58
If the father is red or cream,59 then his daughter can only receive that colour from him and so she will have one X chromosome with the red colour carried. If her mother is also red or cream she will have two X X and she will be a red or cream female. If the dam is Black, Blue, Chocolate, Lilac, Cinnamon or Fawn, then we will have a tortie female.
What happens next is complicated,60 but important to all tortie breeders.
Shortly after the mating, the original cells start dividing like mad. Quite quickly, the process determines that there is altogether too much ‘stuff’ coming from both those XX’s – and so the process shuts down or inactivates one of the X chromosomes in each cell. This shutdown is random and happens early in the embryo. But meanwhile some of the cells for colour from each of the two XX’s have ‘made it through’ we can see this visibly in skin cells as they produce either red or black61 pigment and as the skin cells multiply they form patches of varying sizes and shapes. It is thought that the red and black cells multiply equally and actually compete with each other. It is the resulting ‘mosaic’ of colour that determines the distribution of red and black.
What this means is, that to all intents and purposes, the arrival in a litter of a beautifully marked tortie is largely due to good fortune.
Genes for Coat
Tortie Agouti Black Full Dilute Orange White Colour Coat Dominant aa B-/bb-/bb¹ C- D- Oo ww Dilute aa B-/bb-/bb¹ C- dd Oo ww
58 Robinson’s genetics have a table showing the likelihood of colour inheritance (thankfully) 59 Note: These rules also apply to bi-colours, colourpointed or tabbies with red. 60 And not completely understood as yet 61 Or one of the black/blue mutations.
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A Black/Red (dominant tortie) kitten, showing beautifully mingled colour distribution.
Despite the ‘naughty tortie’ reputation, this delightful cat has the 4th highest registration numbers.
Nose and Paw Leather
Pink and/or the colour corresponding with the coat colour.
The Show Cat
The tortoiseshell is a mixture of the base colour with red or cream as appropriate, evenly intermingled, with both colours clearly defined over the whole animal but without any obvious patches of any colour. A small blaze on the face is permissible.
Judges will fault, uneven balance of colour, unbroken legs and paws, tabby markings and brindling.
The tortie is shown in the following combinations: Black, Chocolate and Cinnamon with Red and Blue, Lilac and Fawn with Cream.
Best Practice, Responsible Breeding and Recommendations
• The tortie is also what is called an obligate heterozygote. Therefore, she cannot breed true. And as we have learned that the distribution of colour is largely out of the breeders hands, we should seek to breed our torties’ using the best for health, temperament and type parents that we possibly can. In doing so even if we fail to achieve that oh so desirable mingled coat we will at least produce kittens that are otherwise correct for eye colour, coat etc, that will be happy, healthy kittens that are a credit to our breeding. • Breeding from an otherwise ‘poor’ tortie with good mingling will probably just end in disappointment.
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• Experienced Breeders might like to experiment with the Rufous polygenes,62 to see if they can see an improvement in the richness of the tortie reds.
Just for the record we will settle the argument as to whether this section is really ‘one for the girls’ or not. According to Robinson’s Genetics one in every 3,000 male cats born is a ‘tortie’. Those of you with enough time to invest in understanding the reasons for something so rare will find the answers in Robinson’s under the section ORANGE.
62 These have not yet been identified, but breeders are enjoying selecting for them nevertheless
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7. Non-Self/Non Tabby
7.1. Bi-colour
The Bi-Colour represents the 5th most popular of British Shorthairs registered, making up almost 6% of the total registered.
A well bred Bi-Colour is an extraordinarily pretty cat causing much admiration. They can be shown in any of the recognized ‘self’ colours with the addition of white.
Those of you who think that the sentence above suggests that all we have do is mate the self white with any of the self colours and hey presto! we will get Bi- colours just haven’t been paying attention. The gene for White is W, which always delivers a completely white cat.
The gene responsible for our beautiful Bi-Colour is known as the ‘S’ gene.
The S gene, known as the Spotting gene or the Piebald gene is a Semi-dominant Gene63 and produces variable results. A cat may have almost no visible white spots or may be completely white, with almost any variation in between.
In the British it is the S gene that is needed to produce both the Bi-Colour and Van Pattern64. The S/s gene is extremely variable, the following diagram65 may help.
Figure 7
63 Producing an intermediate phenotype in the heterozygous condition 64
Van Pattern (Preliminary) 65 Thanks to Wikipedia
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In Figure 7 we could guess that:
• Cats with high to medium grade spotting (numbered 7-9) would be homozygous for the S gene, (SS) • Cats with low to medium grade spotting (numbered 2 – 4) would be heterozygous for the S gene (Ss) • Cats with medium grade spotting (numbered 5-6) could be either SS or Ss.
The British Bi-colour cat falls very neatly into the mid-point and although we cannot yet test for this gene we can be fairly certain that our Bi-colours may fall into either genetic ‘camp’
This wonderful picture just may help with all the genetic information in this section.
Unlike the tortie, the British breeder is able to influence the Bi-colour through selective breeding. This is because by breeding only the cats with a lot of white on them you can increase your chances of getting cats with more white. This is possible because every gene that we know about has all those little polygenes hanging around, it is these polygenes that help to influence the amount of white inherited and it is widely accepted that selective breeding can make good use of polygenes.
At this stage it is worth a shortened and simplified explanation of the geneticist’s best guess as to how the white pattern is ‘formed’
After mating, and the egg is fertilized, cells change66 and multiply, and begin to form what will be the ‘finished’ kitten. During this embryonic stage some cells called melanoblasts start to move, or migrate from the top (neural crest) of what will be the kitten, down towards the bottom of the embryo.
66 Differentiation
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These cells, become the cells that produce melanic pigment (colour).
If these cells do not contain either the white gene (W)67 or the spotting gene (S) they will cover the whole embryo and the result will be a fully coloured kitten.
If the cells contain one or two copies of the spotting gene, (SS or Ss) a defect occurs and the migration of cells fails to complete and the parts of the kitten furthest from the neural crest does not get a fair share of ‘colour cells’ and the result is white patches – this is why so many breeders refer to the white pattern as ‘falling to the bottom’ when in fact it is actually the colour that fails to fall!!!
Genes for Coat
Bi- Colour Agouti Black Full Dilute Orang Spotting Coat e Dominant B aa C- D- Oo Ss B-/bb-/bb¹ Dilute B aa B-/bb-/bb¹ C- dd Oo Ss Dominant aa C- D- OY/OO Ss O Dilute O aa C- dd OY/OO Ss
Eyes
Colour in line with the breed standard for the Self British. Incorrect rim colour or flecks will be faulted.
Nose and Paw Leather
Pink and/or the colour corresponding with the patches.
The Show Cat
Judges are looking for patches of one self-colour and white. The patches must be clear and well defined, without tabby markings. At least one third and not more than half the coat to be white. No scattered white hairs. The coloured patches must be sound and any blue must not have silver tipping.
Symmetry of design is desirable, with colour on the top of the head, the ears, cheeks, back, tail and flanks. Tail to be fully coloured.
67 It seems that the W gene also interferes with melanic migration – almost as soon as it starts around the neural crest – it is thought that this melanic ‘defect’ is related to the deafness that is associated with the W gene.
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Exploding Some Popular Bi-Colour Myths (Just for Fun)
• The Bi-Colour gene does not have anything to do with the White Masking gene (W) • Mating your Bi-Colour to a white cat will not add any more white to your Bi-colour program68 • Using Bi-Coloured cats in a breeding program does not cause lockets
Best Practice, Responsible Breeding and Recommendations
• It is clear from the high expectations from the Breed Standard that the Bi- Colour is not a cat for the novice breeder. Getting the pattern and self colour right for the show bench calls for hard work and dedication. As we have read, the show quality coat can be selectively bred, and using a dam or sire with poor markings can set back a breeding program. • Working with Bi-Colours teaches breeders a huge amount about just how diverse cat genes can be – those at the top of their game, must have patience in abundance and a sense of humour.
68 Geneticists are confident that the W gene sits at a separate locus from the S gene. Experienced Breeders (anecdotally) report using White (W-) cats with Bi colour (S-) does result in high grade Bi- colour – see section on Van Pattern.
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7.2. Van Pattern (Preliminary)
The Van Patterned British Shorthair is a rarely seen attractive cat, that can be bred in all the British self colours with white. The phenotype is a white cat with colour confined to the head and tail, although up to three small patches of colour on the body are acceptable.
Essentially the Van Pattern British is an high grade Bi-Colour, and if we go back to Figure 7 we can see that the Van Pattern is a grade 8 or 9 suggesting that the genotype for the Van pattern is usually the dominant piebald or spotting gene SS.
It is generally accepted that selective breeding can exert influence over the tricky Spotting gene and his polygenic mates69, which is why Breeders of the Van Pattern British have sought to get this (probably) dominant variety recognised in its own right.
Because both the British White (W) is an established breed, as is the Bi-Colour (SS or Ss) it seems sensible to expand upon the genetics of the Van at this point as (at least, in phenotype) the Van seems to fall part way between the two genotypes.
Some breeders of both White and Bi-Colour have long assumed that the Spotting gene is just a different form70 of the White gene. This is understandable because in practice the two genes work in such a similar way.
Much work has been done to prove that there are in fact two separate genes in two separate places71 The following figure seeks demonstrate evidence for there being two separate genes in two places.
69 Birman Breeders have done wonders with Gloving! 70 An allele 71 Loci
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Time for a little lesson in the inheritance of genes!
1 2 3 Self White Van-Patterned Self White Sire Dam Male Kitten aa Ww ss B- aa ww SS B- aa Ww Ss B- D- dd Dd
Figure 8
3 4 5 Self White Blue Self Blue Self Male Kitten Female female Kitten aa Ww Ss B- aa ww ss B- aa ww ss B- Dd dd dd
Figure 9
In Figure 9 we mate a non agouti, heterozygous Self White male (1) masking black to a non-agouti, homozygous blue Van Patterned female (2) and we get a Self White Kitten (3)
If we look at kitten (3) we can see that he has inherited his W gene from his dad and his w gene from his mother. Because it sits at different locus from the W gene he gets an S gene from his mother and the s from his father. He gets the B, black gene from both his parents so he is genetically black. He gets the dilute gene from his mother. When he grows up and we mate him to cat (4) they have a blue self kitten, who gets her father’s w gene paired with her mother’s w gene, she gets an s, a B and a d from each of them and so we get a non-agouti, non white, non spotted, dilute black cat, in phenotype and genotype a Blue Self.
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Genes for Coat
Colour Agouti Black Full Dilute Orange Spotting Coat Dominant aa B-/bb-/bb¹ C- D- oY /oo Ss or SS Dilute aa B-/bb-/bb¹ C- dd oY/oo Ss or SS Dominant aa C- D- OY/OO Ss or SS O Dilute O aa C- dd OY/OO Ss or SS
Eyes
The breed standard calls for eye colour to be deep gold or copper or orange. (there is anecdotal evidence of deafness in blue eyed van patterned cats, this breed standard is a wise example of selective breeding)
Nose and Paw Leather
Pink or corresponding body colour
The Show Cat
The breed standard is looking for a cat with one self colour with white. He patches should be clear and well defined with no tabby markings. A predominantly white cat with small patches of colour on the head, but not below the level of the eye or beyond the base of the rear of the ears. The colour on the head should preferably be separated by a vertical white blaze. The tail should be fully coloured. For perfection, no colour on the body or legs but up to three small thumb prints of colour on the body would not fault an otherwise superb show cat.
Best Practice, Responsible Breeding and Recommendations
• Until the Van Pattern is established and can breed true, and we can be certain that that high white gene for Van (probably homozygous for spotting SS) does not start to bring a hearing problem into the Bi-Colour, it is recommended that only experienced breeders, with experience of both White Self and Bi-Colour breeding, undertake a Van breeding program. • If novice breeders wish to join a breeding program they should be mentored. • Breeders should keep detailed records of all matings and outcomes, both positive and negative. Keeping good records of ALL kittens born to a breeding program are valuable aid in informing decisions. • Breeders finding evidence of best practice that would suggest a review of the registration policy should gather evidence and approach their breed club.72
72 Anecdotal evidence suggests that mating a self white to tri-colour produces ‘good Van’s.
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7.3. Tortie and White and Van Pattern Tortie and White
The Tortie and White is another very popular cat on the show bench causing heads to turn. The tortie and white can be bred in any of the usual tortie colours.
Called the Tri-colour, by breeders, genetically, the tortie and white is ‘just what it says on the box’ but our old friend the white spotting gene SS or Ss has an interesting effect on the tortie pattern.
Remember the ‘migration’ that the cells for pigment make73, with the red and black competing for space – resulting in a mingled cat? And then add the ‘lazy’ factor that the white spotting gene SS or Ss brings74, causing the migrating cells for colour to stop, before they reach the bottom of the cat?
It seems that the spotting gene causes fewer pigment producing cells. Therefore, less competition between them as they migrate into position. Cells reach an area and then multiply where they are to create a patch of colour.
Genes for Coat
Tortie Agouti Black Full Dilute Orange Spotting Colour Coat Dominant aa B-/bb- C- D- Oo SS or Ss /bb¹ Dilute aa B-/bb- C- dd Oo SS or Ss /bb¹
73 See Tortie Section 74 See Bi-Colour Section
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The Show Cat
A good show girl will have patches of base self-colour, with either red or cream and white. The patches must be clear, well defined and balanced without mingling or tabby markings. For the non-Van patterned at least one third, and not more than half the coat to be white, with patches of colour on top of the head, ears, cheeks, back, tail, legs and flanks. Tail to be fully coloured. (Van patterns to have markings as per Van pattern.
Symmetry of design is desirable, with colour on the top of the head, the ears, cheeks, back, tail and flanks.
Nose and Paw Leather
Pink or corresponding body colour
Best Practice and Recommendations.
• Although we have seen in the ‘Tortie’ section that Breeders cannot influence that tortie mingling, it seems that the ‘S’ gene can be ‘biddable’ so have some fun and just see if the bigger the white areas, the bigger and better defined the separate patches of blue and cream become.
Oh! – And don’t forget that type matters!!
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8. Smoke
Rarely seen on the British Show-bench, the Smoke is a ‘self’ non-agouti (aa) cat with the addition of the Dominant Melanin Inhibitor (I) gene and whilst we may not often see a fine example of the British Smoke, the impact of the Inhibitor gene is all around us and it would be wise if we get to grips with it sooner rather than later.
Some Facts
• The I gene is called the Inhibitor gene because it ‘inhibits’ the feeding of melanin or colour into the growing hair75. • It seems to have more effect on the part of the hair shaft with the least pigment, which is the part of the hair nearest the body. • The gene seems to have a stronger effect on the production of the pigment phaeomelanin76 more than the pigment eumelanin77. • It has a ‘variable’ effect in aa cats (that do not have the agouti gene)
What this results in is a self coloured cat with a silver undercoat and breeders are looking for a cat with as much contrast as possible between a good strong self colour and a shimmering clear silver/white undercoat.
The problem is that the Silver78 (I) gene is extremely unpredictable in the absence of the agouti (A) gene and breeders rarely get what they would like.
The problems are many and varied, the inhibitor gene may actually not inhibit very much at all and then the little bit it does inhibit might not be a glorious silver white colour and instead may be a murky dark grey colour that blends into the ‘self’ coloured hair shaft. To add insult to injury, the (I) gene may also cause the ‘self’ colour to be washed out or rusty. These Cats with little contrast between under coat and top coat colours may look self coloured. And if that isn’t enough, the smoke cat would love to be a tabby and ghost markings abound. At this
75 Not like the S gene that affects melanin getting to skin cells
76 Orange 77 Black 78 Inhibitor
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point we can blame all the various, nameless, polygenes yet to be identified, but the fact remains, breeding a good smoke is tough going.
This is possibly a sensible place to ‘discuss’ the registration policy regarding cats with ‘Silver’ in the pedigree. To experienced breeders of cats incorporating the Silver gene, it can often be irritating to receive GCCF paperwork over-stamped with ‘Silver in Pedigree’. And yes, as a BAC we understand that the difference between a good Brown Spotty and a Black Silver Spotty is very evident even to novices. But it quite simply isn’t that simple. In the wrong hands, a poor smoke may well be bred as a self. The over stamping of Silver is intended to be informative. To those who know what they are doing, it should be of no consequence whether the beautiful British Blue they are breeding from has an ancestor who was a Silver, nor should it matter if the registration paperwork makes reference to that ancestry. Colourpointed Breeders are grateful for this information, as it can be extremely difficult for even the most experienced breeder to discern the Silver, especially in the Tabby colourpointed series.
Genes for Coat
Smoke Agouti Black Full Coat Dilute Inhibitor Orange
Dominant aa B-/bb-/bb¹ C- D- I B oY/oo
Dilute B aa B-/bb- C- dd I /bb¹ oY/oo Dominant aa C- D- I OY/OO O Dilute O aa C- dd I OY/OO Dom/Torti aa B-/bb- C- D- I Oo e /bb¹ Dilute/Tort aa B-/bb- C- dd I Oo ie /bb¹
The Smoke may be bred in any of the self or tortie colours.
Eyes
Large and round, should be copper, orange or deep gold in colour.
Nose Leather and Paw Pads
Corresponding with coat colour and mingled with pink for torties.
The Show Cat
The top coat should be one of the recognised self or tortie colours, over a silver undercoat. When the cat is still it will look solid-colored, but when the coat is parted the silver should flicker through creating an ephemeral effect.
Recommendations and Best Practice
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• The British Smoke can be a lovely sight on the show bench. Often produced as a ‘by-product’ of a silver program, this cat can be overlooked. Any show quality variety needs work. • There are some superb examples of the Smoke cat to be found on the Persian show benches, with breeders devoting entire breeding programs to this variety. Never forget, we all have much to learn from experienced cat breeders, irrespective of breed.
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9. Tabbies and Spotties
In the section on The British Self, we said that in order to understand the genes for the ‘Self’, we must first understand the Agouti (A)79 gene. We then went on to deliver a couple of paragraphs about ‘agouti’ and ‘tabby’, throwing in the odd ‘Mc’s’ for good measure. In doing so we made it all sound oh! so simple. For those of you wanting an easy life turn back now; because, despite our best efforts, it’s going to get a teensy bit complicated now.
Part of the problem is that we live in very exciting times for the discovery of genetics and our understanding is being constantly challenged and as breeders we are necessarily in the business of experimentation and boundary pushing. Far better then, that we are as informed as much as possible about the ‘genotype’ that makes up our beautiful cats.
Hopefully, by now, we know that a self cat is non agouti (aa) but rather confusingly a self cat is still a ‘tabby’, this is because all cats are tabbies. And this is one of those ‘light bulb’ moments for most cat breeders, when the understanding dawns, that there are TWO genes that make a cat a TRUE TABBY as we know it.
So all cats have the ‘T’ gene for pattern, but only tabbies have the A gene for Agouti. It is almost as if the A gene turns on a magic switch that lets us see the pattern. Before we go any further, it would be sensible to agree on the symbols we shall use for this section.
The Agouti gene (A) is nice and easy, but the (T) (tabby) gene is not quite so simple and often causes confusion. This is because of the relationship between the Ticked, Classic/Mackerel and Spotted Tabby genes. Recent studies80 have suggested that there are in fact three separate genes at different loci81
Therefore, we feel it will be easier if we discard the use of T except for the Ticked Tabby and use Mc and Sp82 instead83.
The following table may be useful for future reference.
Tabb Former Updated Notes y Gene Gene code Pattern code If this gene is present the cat will Ticke Ta Ta show as a ticked tabby regardless of any d other tabby genes they may have. Mack T Mc Can only be seen when Ta is not erel present. Dominant over mc Class tb mc Recessive to Mc ic This is a modifier gene, effective only Spott Ts Sp when Ta is absent. Sp breaks up the ed
79 The natural “wild” gene that is the basis of the tabby cat. 80 Genetics Society of America, 2009. 81 A locus is the exact position on the chromosome where the gene is located 82 See Robinsons Genetics section on Tabby and Non-Agouti. 83 This convention has also been adopted by the GCCF and the Asian BAC.
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patterns of Mc and mc. Figure 10
It is difficult when producing an introduction to the Agouti cat such as this, to know just how much detail we need to go into, too much would take up far too much space and time. Whilst, too little may mean that we do not provide enough of a basis to allow a proper understanding.
19 Pairs of Chromsomes
Locus for Locus for Locus for Locus for Locus for Locus for Spotted Inhibitor Agouti Genes Tabby Genes Colour Genes Masking Modifier Genes Genes Genes 2 alleles 2 alleles 2 alleles 2 alleles 2 alleles 2 alleles
Genome or Blueprint for the Finished Cat
Figure 1184
If we look at Figure 11, we should remember that all the genes along the chromosome start life at the moment of conception.
This will really help us understand that the genes for Tabby Pattern and the Genes for Agouti colouring are working at the same time and affecting each other.
As the hair grows in the hair follicle eumelanin85 is produced by cells and dropped into the hair shaft. When the Agouti gene is present it causes a protein to join the process and as this protein builds up in the cell it causes the production of eumelanin to falter and suddenly the cell switches to produce phaeomelanin86 , this process is known as the Agouti shift.
The result is hair shafts with alternating bands of
84 There are many other Genes of Course 85 Black Pigment 86 Red pigment
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Whilst the Agouti gene is busy creating these banded hairs, if the cat has also inherited the tabby genes Mc or mc, these genes set up in competition with the Agouti gene, stealing patches of skin and follicles and reducing the amount of Agouti protein produced in these patches. The shift from black to red on the hair shaft does not happen. Instead these patches of hair show as groups or patterns of black hair beautifully offset by the Agouti coloured, ‘ground colour’ hairs. These patterns are of course the well known Tabby patterns.
At this point it seems prudent to mention something discovered during our research regarding the Agouti shift87.
According to Robinson the Agouti shift, switches pigment between eumelanin and phaeomelanin. However, there is an argument that the pigmented hair shaft does not shift from eumelanin to phaeomelanin, but instead the Agouti protein cause the hair granules to thin and shred, it is this weakening in the granules that causes the banded hair colour to fade to the yellow/orange colour alternately.
The UCLA Davis website does refer to the Agouti shift but does not confirm the mechanism for the colour change.
Finally on this point, current opinion suggests that the colour of the Agouti band can be influenced by ‘Rufus’ type polygenes These Rufus factors have not been identified but breeders have been able to select for them to reproduce warmer, richer background colors in the Tabby. Selective breeding in the Brown Tabby is producing a rich redder background colour.
87 We have used many sources and resources for our research; wherever and whenever opinion differs we have fallen back on Robinson’s Genetics for Cat Breeders and Veterinarians as our base reference. However, it must be noted that the latest edition was produced in 1999. Where there has been compelling evidence that evidence has changed we have sought to validate opinion and have found the UCLA Davis website invaluable.
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9.1. Ticked Tabby
9.1.1.Ticked Tabby (All colours) Non Silver (Preliminary)
If you decided to play a game of ‘scissors, paper, stone’, against a Brown Ticked Tabby, you would lose. This beautiful cat is, genetically, at the top of the domesticated feline tree.
Whilst it is generally accepted that Felis Silvestris or Felis Lybica, both striped cats are the original UK wildcat species, it is less well known that the first domesticated or companion cats were probably ticked tabbies, imported as pets. These early imports were crossed with the British Shorthair to create the cat known today as the Abyssinian.
The ticked coat can be seen in the Somali and Singapura breeds as well as the Abyssinian. At first glance the entire cat will appear to be one colour until one gets closer and notices that in fact each individual hair has alternating bands of colour giving rise to a flecked appearance. The British Ticked Tabby can be bred in all self colours including tortie.
Genes for Coat
Ticked Agouti Colour Coat Dilute Tabby Orange Dominant B A- B-/bb- C- D- Ta- oY/oo /bb¹ Dilute B A- B-/bb- C- dd Ta- oY/oo /bb¹ Dom/Tortie A- B-/bb- C- D- Ta- Oo /bb¹ Dilute/Tortie A- B-/bb- C- dd Ta- Oo /bb¹ A- can be: AA or Aa D- can be: DD or Dd
C- can be: CC or Cs Ta- can be: TaTa or Tata
Any Tabby Pattern may also be carried see Figure 10
Ticking results when the agouti gene (A) causes the individual hairs to have bands of light and dark pigmentation. As the hair starts to grow, the agouti gene allows full pigmentation into the hair shaft, it then causes a sudden stop and the hair shaft goes lighter, the process then turns back to full pigment for a bit longer. As the hair reaches its full length this process known as the Agouti shift stops. The result is a hair shaft that has dense colour at the tip, then a band of yellow to orange, then a band of dense pigment, fading to yellow or orange at the base.
What is special about the Ticked feline is that they carry a dominant gene for Ticking (Ta) and when Ta is present it prevents other feline tabby patterns from developing. However, like all tabbies, it may have tabby markings on the face and agouti hairs on the body.
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This cat shows a ticked pattern showing the stripes and markings on the head, legs and tail.
This cat is likely to be Heterozygous for the Ticked Gene Tata
Figure 12
This cat has no tabby markings on either his body or tail – he is likely to be Homozygous for the Ticking Gene TaTa.
Figure 13
Eyes Figure 14
Copper, orange or deep gold
The Show Cat
The coat should be evenly ticked with two or three bands of colour extending well down the hair shaft ending with the base colour at the roots. This ticking may be heavier along the spine line and extend down the length of tail. The face, legs and abdomen clearly show the base colour and on the head the ticking may be more dense, or even solid in kittens, which may clear to an ‘M’ on the forehead. Other facial markings are as per standard British Classic Tabby standard.
Necklaces may be broken or unbroken but a lack of these is not a fault.
Apart from the underside of the abdomen, which should be spotted, the body should be free of spots stripes or blotches.
The tail may be ringed with complete or broken rings or have a continuation of the darker colour of the spine line, the tip of the tail being the same colour as the markings. In adults the legs may or may not be barred.
Markings –the ticking should be of the appropriate colour affording a good contrast with the base colour. The Base Colour should be even in all areas other than the lips and chin, which may pale significantly, but should not be white and should not extend down the chest. Tarnishing or discolouring of the silver base colour is undesirable.
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This variety of British Shorthair arrived unexpectedly in 2007, in a litter born to an experienced breeder88 of Tabby British Shorthair.
The following section is a little lesson in genetics to help explain how this sweet baby arrived:
A lilac British Shorthair Stud cat imported from Sweden with a genotype of:
Colour Agouti Tabby Black Full Coat Dilute Orange White Lilac aa Ta89 bb C- dd oY ww Sire
Was mated to
Colour Agouti Spotty Black Full Coat Dilute Orange White Choc’- Spotty A- Sp bb C- Dd oo ww Dam
The resulting kitten Inherited:
Genes From Dad From Mom Note Agouti aa A Mum’s dominant agouti gene prevailed Tabby Ta - Although non-agouti, the sire’s ticked tabby gene is dominant for underlying base pattern. Spotted - Sp The mother’s spotted gene will override any other Mc or mc genes. Black bb bb Chocolate Full Coat C C Full Coat Dilute d D 1 copy of dilute so kitten is Chocolate Orange o o No red gene to have White w w No white gene to have
88 Mrs Celia Leighton (Porteous) 89 Ticked tabby
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The only really surprising thing about this entirely natural production of a delightful chocolate ticked tabby is that it hasn’t happened more often.
Best Practice and Recommendations
• Whilst breeds are in the preliminary stages it is best leaving the development to experienced breeders and those breeders working in breeding groups. • When working with the gene for ticking, try to understand the pedigree of the cat, remember that any cat that is Homozygous for ticking can only throw Ticked kittens. (When the cat is Tata, heterozygous, the cat is most likely to have bars and markings on the legs, tail, face, etc) • You may be able to tell what colour a tabby is by looking at the color of its stripes and its tail tip. • The agouti shift, describes a process where the switch between dark and light pigment happens suddenly. But there are also variations in just how often the ‘switch’ turns on and off, Ticked tabby breeders are looking for as many bands of colour on each hair shaft as possible, this can vary between 4 and 6, but up to 8 have been reported90. • The Wide Banding91 gene can play havoc with the ticked bands, causing the dark hair to the tips – avoid mating shaded or tipped cats in a Ticked breeding program. • Breeders should experiment for the Rufusing gene, it is evident from the great variety of colours in the Agouti ground colour that polygenes are able to produce coats that range from rich creamy oranges through to pale washed out greys. Mating cats with good ground colour to cats with good ground colour is advisable. • Remember that although this variety is new to the British, other breeders have extensive experience of working with the genes for Ticking, personal knowledge transfer is invaluable. • Breeders may find that despite their best efforts, the ticked gene will cause the agouti colour on the muzzle and throat to pale almost to white.
90 Chaos and Confusion genes may be at work see Tipped section. 91 Theoretical at present
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9.1.2. Silver Ticked Tabby (Preliminary)
The Silver Ticked tabby cat is essentially the agouti cat the Ticked tabby with the addition of the Inhibitor gene for Silver (I)
This colour can be seen in other breeds such as the Abyssinian and the Somali. In fact all the silver Abyssinians bred in Britain today are descended from an outcross to a British Silver Spotty in the 1960’s.
Despite the British input to other breeds, the Silver Ticked is not yet a common sight in the British Section.
However, they are being bred and indeed shown – A rather lovely tortie-silver has appeared at several GCCF shows.
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Eye Colour Green or Hazel.
Genes for Coat
As the non-silver Ticked plus the dominant (I). The gene for Silver (I) changes the rich Agouti ground colour to a cooler sparkling silver.
The Show Cat
In silvers the colour of the ticking may lack warmth and this should not be penalised.
Figure 15 An American Best Practice and Recommendations Silver Ticked Tabby
Remember that it is possible to breed silvers with every colour of ticking, and some of the paler varieties in other breeds can be very pretty.
If we peep over our shoulders into the Asian Breeding Policy, it suggests that mating non silver to non silver and silver to silver ticked produces the best results93
92 Photo by Milt Webb 93 Of course our gene pool is tiny as yet
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9.2. Mackerel and Classic Tabbies (non Silver)
The basic ticked coat is quite common and can be seen in mice and rabbits. The feline has developed a secondary system of pigmentation which creates dark stripes flashed throughout the ticked coat94.
These stripes or patches are caused by genes that ‘fight’ with the Agouti gene (A), and effectively ‘stop’ the agouti protein from performing the agouti shift, in some patches of the skin, thus preventing the eumelanin to phaeomelanin shift95. Hair shafts in these patches only have the darker colour. This leads to an impression of one dark-coloured pattern superimposed upon another pattern.
The genes responsible for these dark patterns are either Mackerel (MC) which is dominant over (mc).
The face of the British Tabby can be beautiful, and the markings should be clearly defined and dense. On the forehead there should be a letter 'M' giving the impression of a frown. There should be an unbroken stripe running back from the outer corner of the eye and narrow lines on the cheeks.
Brown Classic tabby at 6 weeks
On the neck and upper chest there should be unbroken necklaces, the more the better. The edges of the ears to be the same colour as the markings with a central patch of ground colour resembling a thumb-print.
Muzzle and Throat It is worth mentioning the colour of the chin and lips of the tabby. Sometimes there can be a reduction in the pigment in this area, such that the ground colour can appear almost white. Whilst we can expect that the ground colour will pale from the chin to the throat, breeders should try not to use cats that show ‘white’ in this area in their breeding programs.
94 Probably for camouflage 95 If indeed it is phaeomelanin!
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9.2.1.Mackerel Tabby
The non-silver series Mackerel Tabby is not often seen on the British Show bench. However, the Mackerel pattern is probably the ancestral striping pattern, which is seen in the African wild cat (Felis libyca) and the European wild cat (Felis silvestris).
The stripes are always vertical, and gently curving, on the body, ringing the tail, and lining the legs. The Mackerel pattern can be found in any of the self colours, but the pattern of the stripes will always remain the same.
Genes for Coat
Mackerel Agouti Colour Pattern Dilute Tabby Orange Tabby Pattern Dominant B A- B-/bb- C- D- Mc- oY/oo spsp /bb¹ tata Dilute B A- B-/bb- C- dd Mc- oY/oo spsp /bb¹ tata Dominant O A- C- D- Mc- OY/OO spsp tata Dilute O A- C- dd Mc- OY/OO spsp tata Dom/Tortie A- B-/bb- C- D- Mc- Oo spsp /bb¹ tata Dilute/Tortie A- B-/bb- C- dd Mc- Oo spsp /bb¹ tata A- = AA or Aa Mc- = McMc or Mcmc C- = CC or Ccs
Eyes
In copper, orange or deep gold, with no trace of green
The Show Cat
The SOP calls for a narrow unbroken central spine line, on either side of which is a broken spine line from which the narrow lines which form the Mackerel Pattern run vertically down the body; these lines should be as narrow and numerous as possible. The tail rings, which should be as narrow and numerous as possible, 73
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Markings of the appropriate colour to be clearly defined and dense in colour, without brindling, affording a good contrast with the ground colour. The colour should reach as near the roots as possible.
Ground Colour, should be even, in all areas other than the lips and chin, which may pale significantly but should not be white.
Best Practice and Responsible Breeding and Recommendations
• Some Breeders believe that the Mackerel Tabby makes the best ‘base cat’ for Spotted Breeding Programs – believing that Spots are more numerous when they break the Mackerel Pattern rather than the Classic Pattern • Conversely – some breeders believe that the Mackerel pattern in the British doesn’t actually exist – being instead poorly marked Spotties!
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9.2.2.Classic Tabby.
Also known as the blotched tabby, this tabby pattern is recessive to the Mackerel pattern. The ticked hairs alternate with the solid hairs making the pattern that is so much loved by breeders. The recessive, mutant, mcmc causes the dark pigmented hairs to form thicker stripes, which travel horizontally across the cat's body, often swirling and creating spirals.
The Classic tabby pattern without silver, is not seen very often on the show bench which is a great shame, because, the combination of pattern and agouti colour presents a super playground for breeders as we can see in other non- British breeds on the show-bench96
Genes for Coat
As for Mackerel tabby, just substitute Mc- for mcmc.
As we have learned throughout the sections, genes are never as simple as they might seem, they really do work with groups of mates, either as yet unproven genes or polygenes. Experienced breeders see something in a cat that they really like and selectively ‘breed’ for that trait, in doing so they not only select the ‘obvious’ genes for Classic Tabby, they are also selecting97 some ‘best friend genes’ that enhance or subtly alter the phenotype.
This is probably the right time to present some of these hypothetical modifier genes.
‘Best Friend Genes’ (Hypothetical)
1. Rufous genes – Everybody wants to be in with this gang (except perhaps silver breeders)98 – this lovely group are thought to make the agouti pale colours warmer and richer and dark colours darker – what more could any tabby breeder want from her mates? It seems that Rufous modifiers can get more intensive over successive generations. Fabulous news for breeders’ intent on selection over many generations. 2. The Tabby Pattern Size modifier - Breeders may recognize this group of ‘friends’ who seem to alter the Classic Tabby Pattern by creating pale areas within the blotched markings.
96 Have a wander around the show-benches and have a guess at the genes underneath the coats. 97 Often without really knowing it 98 See section on Silver Tabbies.
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The reason the Classic tabby appears so infrequently probably lies in it’s recessive qualities, in the scissors, paper, stone game – the classic tabby loses out to the hugely popular Silver series, the not so sought after Mackerel pattern, the Spotty99 and of course the Ticked tabby.
The Classic, comes in all the colours of the self, Black, but just to confuse we call it the Brown tabby, Blue, Chocolate, Lilac, Cinnamon, Fawn and of course Red and Cream.
The Brown tabby in the wild has a sort of murky appearance, the agouti banding is evident, but the pale bands are cool and greyish.
Generations of breeding the pedigree tabby has produced a cat with rich dark browns for the eumelanin pigment and warm orangey tones for the phaeomelanin.
See how the colours on these sweet litter brothers differ from each other.
The Show Cat
Breeders are after four things:
1. Pattern – On the forehead there should be a letter 'M' giving the impression of a frown. There should be an unbroken stripe running back from the outer corner of the eye and narrow lines on the cheeks. On the neck and upper chest there should be unbroken necklaces, the more the better. The edges of the ears to be the same colour as the markings with a central patch of ground colour resembling a thumb-print.
A series of lines runs from above the 'M' marking, over the top of the head and extends to the shoulder markings. The shoulder markings form the outline of a butterfly, when viewed from above. Both upper and lower 'wings' should be clearly defined with the central areas broken by small areas of ground colour. On the back there should be an unbroken line running down the spine from the butterfly to the tail, and there should be a stripe on either side of this, running parallel to it. These stripes should be separated from each other by stripes of ground colour. On each flank there should be an 'oyster-shaped' patch which should be surrounded by one or more unbroken rings.
The tail should have complete rings, as numerous as possible, with the tip of the tail being the same colour as the markings. The legs should be barred evenly with bracelets from the body markings to the toes which are spotted. Markings on the hind legs extend (when adult) from the soles of the feet, up
99 See section on Spotted Tabby.
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the back of the leg, to the hock. The abdominal region should also be spotted. Ground colour and markings should be evenly balanced and both sides of the cat should have identical markings.
2. Markings – These are the dark pigmented areas, creating the ‘pattern’ these markings must be solid in colour and sound to the roots they may be black or various shades of brown. The depth of pigment should be the same from the facial drawings through to the tip of the tail. And if that isn’t enough, breeders must not allow any stray agouti hairs to drift into the markings, so no ticked or banded hairs.
3. Ground Colour – This is the agouti ticked ground colour against which the pattern is presented. The warmer and richer breeders can get this ground colour the better.
4. Type – Of Course!
Best Practice and Recommendations
• There can be no doubt that breeding classic tabbies is a job for those with patience, but as we can learn the benefits of exploiting all these polygenes can be just so rewarding. • As we learn more about cat genetics we can begin to see that sometimes we cause a conflict for ourselves. Silver tabby breeders have over the years worked really hard on getting that wonderful classic tabby pattern to stand out clearly against a crisp silver undercoat. In doing so they have bred out polygenes for Rufousing, because these polygenes probably cause the silver to tarnish, in doing so any non-silver Mackerel or Classic tabbies in the litter will be short of those lovely colour enhancing Rufousing chaps and the results may be poorly coloured well patterned kittens. • Breeding programs for show quality non silver tabbies and silver tabbies may benefit from some separation100.
100 Experienced breeders will already have separate breeding programs.
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9.2.3.Spotted Tabby (non-silver)
The Spotted tabby is exactly what it sounds like and comes in the same colours as the Classic tabby. This popular variety of British Shorthair offers breeders the same challenges as the Classic tabby, with spots on!
Genes for Coat.
Spotted Agouti Colour Pattern Dilute Tabby Orange Tabby Pattern Dominant A- B-/bb- C- D- Mc- oY/oo B /bb¹ mcmc Sp- tata Dilute B A- B-/bb- C- dd Mc- oY/oo /bb¹ mcmc Sp-tata A- = AA or Aa Mc- = McMc or Mcmc C- = CC or Ccs Sp- = SpSp or Spsp
Note: The genes for coat are as for Mackerel tabby, but spsp becomes Sp-
Naturally occurring Spsp is the spotting or modifier gene. Sp is dominant over Mc – and mcmc and causes the basic tabby patterns to break into spotted patterns. Mackerel tabby patterns will have more, smaller spots which run in vertical lines. The Classic tabby will have larger spots that are scattered more randomly.
A beautifully marked brown spotty baby
(Now do we think these spots are Mackerel or Classic based?)
The Show Cat101
The pattern on the body and legs should consist of numerous, well
101 The pattern is often less obvious in the dilute cats
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defined, oval, round or rosette-shaped spots which follow the tabby pattern in distribution.
9.2.4.Silver Tabby, (All colours)
The Silver Tabby and Spotted British Shorthair is the second most popular variety, with more than 14% of registrations being this wonderful cat.
Silver Tabby Breeders aim to produce the Classic and Spotted Patterns in all the usual Self British Colours.
The Silver tabby is essentially the same cat as the Classic tabby with the addition of the dominant Inhibitor gene, (I) introduced in the Smoke section. But this time the Inhibitor gene gets to come out to play with the Agouti gene (A) and with quite spectacular results.
In the Silver Tabby, agouti hairs have colour or pigment at the tip, but the remaining hair shaft is stripped of agouti colour by the I gene, leaving a sparkling silver grey. The solid hairs have normal colouration. Breeders are seeking the greatest contrast between the now almost-white agouti hairs and the markings made by the fully pigmented patches of hair.
Genes for Coat
Silver Agouti Colour Pattern Silver Dilute Tabby Orange Tabby Pattern
Dominant B A- B-/bb- C- I- D- Mc- spsp oY/oo /bb¹ tata Dilute B A- B-/bb- C- I- dd Mc- spsp oY/oo /bb¹ tata Dominant O A- C- I- D- Mc- spsp OY/OO tata Dilute O A- C- I- dd Mc- spsp OY/OO tata Dom/Tortie A- B-/bb- C- I- D- Mc- spsp Oo /bb¹ tata Dilute/Tortie A- B-/bb- C- I- dd Mc- spsp Oo /bb¹ tata A- = AA or Aa Mc- = McMc or Mcmc C- = CC or Ccs Sp- = spsp I=II or Ii
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Eyes We have all heard about the influence of polygenes on coat colour and pattern. But polygenes also come together to help us with eye colour. The Black Silver Tabby should have green or hazel eyes, whilst all other colour of silver tabby should have copper orange or deep gold.
The Show Cat Just to keep us on our toes the British Breed Standard for the Classic Tabby pattern is more exacting than that in the American Shorthair. The pattern requirements for the Silver Tabby are as for the non-silver tabby. The key to the show cat is clear, sharp markings, against an untarnished silver backdrop.
Best Practice, Responsible Breeding and Recommendations
The Silver series British Shorthair benefits from a breeder group that has developed an extremely high standard. But popularity within a breed can sometimes lead to inexperienced breeders producing kittens that ‘let the side down’. In safe hands the Inhibitor gene can sparkle, but it also has a tendency to tarnish, and there are three schools of thought as to why.
1. The Inhibitor gene does not work alone and has a bunch of polygene friends, sometimes some of these friends do not pull their weight and the result is a poor silver colour. 2. Breeding cats can be Homozygous for Silver (II) or Heterozygous (Ii) and effectively carrying the genes for Brown. Some breeders believe that it is the genes for non- silver that ‘show through’ and spoil the show. 3. When a non- silver parent is used in a silver breeding program, if that non-silver parent carries a large dose of those lovely (if you want them) Rufousing genes, then those Rufousing genes can cause the silver to tarnish.
The good news is that all of the above can be dealt with by careful breeding selection. But, as with all breeding programs, it is not a quick fix, breeding a high quality line takes years of patience.
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9.2.5.British Silver Spotted Shorthair.
This stunning cat is hugely popular. Genetically, breeders take the Silver Tabby, either Mackerel or Classic, add the Spotty gene and the result is quite simply stunning.
Genes for Coat
See the table in the Silver tabby section and substitute sp for Sp.
Because the Spotty gene Sp- sits at a separate location from Mc- or mcmc, unless your breeding cats are Homozygous for Spots, litters can be full of both tabby and self kittens.
Whilst we cannot be certain if the breeder was hoping for more spotted kittens, the Queen will love them all equally.
The Show Cat
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Judges are looking for SPOTS, lots of them, and please make them as dramatic as possible.
3 A beautiful Queen snoozing on show afternoon.
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10. Tipped – Silver Series
10.1. Black Tipped
In the 1970’s a Chinchilla (longhair) was mated to a British Silver Tabby102. A breeding program ensued, which included the British Blue and other cats from the silver series, culminating in the development of the Black Tipped as we know it today. This was recognised as a distinct British type in 1978.
The ‘Tippy’ can be bred in any of the British colours. However, it is the gorgeous Black Tipped that is seen out most often.
At this point it would be lovely if we could just say that genetically the Black Tipped is just a slightly complicated version of the Silver Tabby, throw in a pretty picture and move right on.
But, that would be taking the easy way out.
If we start with the Simple Genes for Coat:
Black Agouti Black Full Dilute Silver Tabby Orange Tipped Coat Pattern A- B- C- D- I- Ticked Ta- oY/oo Mackerel Mc- tata Classic mcmc tata Spotted Sp- tata A- = AA or Aa B- = BB or Bb or Bbl C- = CC or Ccs
D- = DD or Dd I – II or Ii Wb- can be: WbWb or Wbwb
We can see that this looks an awful lot like the Silver Tabby series and yet the Tippy looks so different. This ‘difference’ that breeds true has led breeders and
102 The pioneer of this program was Norman Winder of the Peerless prefix
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It seems that this hypothetical Wideband gene can only work with agouti cats as it is the agouti shift that causes the colour change on the hair shaft – that the Wideband gene then forces into a wider band.
It would also appear that when teamed up with either the Inhibitor gene I- (Silver) or the Rf- genes for rufousing the Wb- gene is Incompletely Dominant.
At this point it may help if we understand Incomplete Dominance –
Firstly, the cat must be a hetrozygote (two different copies) for the allele in question – and is a condition that expresses itself by showing a phenotype (appearance) that lies somewhere in between the phenotype of the two parental phenotypes.
So, for example, a Black Tipped cat with a good expression of the Wideband gene (probably Homozygous for Wb) is mated to is mated to a Brown Tabby –
The offspring will be heterozygous for Wideband, Rufousing and Inhibitor. The resulting litter may well include Silver Shaded cats with pretty orange noses!!!
With the following genotype A- B- Tata or tata Mc- Sp- or spsp Wbwb Ii Rfrf
Sometimes we can distinguish those cats that are homozygous from those that are heterozygous by studying these little phenotypical clues.
We know that there are many genes that we cannot yet test for, but that we can ‘see’ such as the Inhibitor gene (I) – and it is widely accepted that these genes are present and one day we will have tests for them.
However, The more ‘theoretical’ genes e.g. Rufousing require a greater act of faith, and it is important that we as breeders understand the counter argument.
The argument for the presence of genes such as Wideband and Rufousing is the exploitation of polygenic traits by careful selection.
The first breeders of the Black Tipped bred cats which had significantly heavier tipping than we see today. By selecting parent cats with less tipping and clear undercoats, subsequent generations of Black Tipped cats have evolved with wider intermediary (yellow) agouti bands.
Therefore, we should keep our minds open to the question – how are breeders achieving the wide range of tipped bands that we see?
• Are we dealing with complex polygenes that are happy to let us clear undercoats and minimize the expression of black pigment to produce our Tippies • Is there an Incompletely Dominant Wideband gene? • Or has the agouti gene mutated to allow better and better suppression of pigment production? 84
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Because it makes discussion easier – we will embrace the theoretical Wideband gene throughout this breeding policy! But we will also accept that even the Wideband genes will have help from those polygenes!
Eyes
Black Tipped - Green. In all other colours Copper, Orange or Deep Gold. The skin outlining the eyes to be appropriate to the colour of the tipping.
The Show Cat
This silver cat, most often in the form of the Black Tipped, can be shown in any of the standard British colours including tortie.
The colour is restricted to the ends of the hairs in the form of tipping and the undercoat is so pale as to appear white. The coat on the back, flanks, head, ears and tail should be tipped with colour.
The tipping should be evenly distributed and it is the even distribution rather than the degree of tipping which is of paramount importance. Heavily tipped cats must not be penalised as long as the tipping is even and free from tabby markings: in fact, they are preferable to cats with so little tipping that they are almost white.
The legs should show tipping which will decrease towards the paws, but which should be as even as possible. The chin, stomach, chest and undertail should be as pale as possible.
Nose Leather and Paw Pads
Nose Leather - Brick red preferred, outlined in colour appropriate to the colour of the coat tipping.
Paw Pads - Appropriate to the colour of the coat tipping.
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Some Extra Genetic Information
Under the GCCF we breeders in the UK do not have to worry about the distinction between Silver Shaded or Silver Shell (more lightly Tipped) instead Tippy breeders can happily breed for personal preference, with the emphasis on evenness of colour.
To what extent Tippy breeders can influence their preferences by using genes for pattern, is still the subject of much debate - Let us remind ourselves what the agouti shift does to affected hairs – remember that the hairs that make up the darker ‘pattern’ remain a solid colour – but in Agouti cats there are areas of coat wherein the hairs have bands of colour or tipping – and the Wideband gene can only work on hair shafts that have these bands of colour –
If we look back at the table for genes for coat on page 83 we can see that the Black Tipped cat like all other agouti (and non agouti) cats has a base pattern, of either Ticked, Mackerel/Classic tabby or Spotted. It is important that we picture this – because it is this base pattern that is affected by the Wideband gene.
We know that the Chinchilla is predominantly based on a Classic pattern
Some breeders believe that the Tippy sparkle that can be observed in some lines is due to as yet unidentified ‘sparkle’ genes such as the Glitter in the Bengal. The Tippy sparkle can best be seen in October when the new undercoat comes through!
Best Practice and Recommendations
• Breeding show quality Silver Series Tipped – is quite simply not easy. In the British Section there are a few dedicated breeders producing kittens of excellent type – but the gene pool is very small and it is difficult for breeders to make improvements without making a sacrifice of some sort. • As litters are born breeders should look to see if they can detect the base pattern of their kittens and keep records as to which base pattern results in the best Tippy pattern. • The Ticked gene as a base pattern is causing some excitement amongst breeders and there is a sense that the ticked base pattern may offer the best opportunity for evenness of ticking. (Breeders working with the ticked gene should note that when the cat has two copies of the ticked gene it will override all other agouti patterns) • Black Tipped Breeders may wish to consider keeping a Black only line - undoubtedly – cats that are Homozygous for silver (II) produce the best Black Tipped coats – free of tarnishing. • Breeding Tipped to other colours of BSH may help type – but first generation will not make show cats – they will probably be too dark. But hopefully second generation will pull back. • Just for fun Tippy breeders could experiment with the other Tipped colours! • Some Tippy breeders would welcome more definitions of ‘Tipped’ such as Shaded, Cameo, Shell etc.
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10.2. Golden Tipped including all Non-silver Series Tipped.
As each BAC prepares a breeding policy for the breeds within their remit, it provides a fresh opportunity to study the registration policy and the standard of points in conjunction with the breeding policy.
Overtime, as new generations of kittens are born, breeders gain an increasing awareness of the genetics at play in their cats and new genetic information becomes available or is updated.
For us in the British BAC it is the Non-silver series of Tipped British that is presenting us with some of the most interesting genetic puzzles – but first we will explain the genetic make-up of the Golden Tipped as seen on our show benches. To that end we will start with the show cat!
The Show Cat
This is the non-silver version of the British Tipped in which the hair is a rich golden apricot colour, sound to the roots with black/dark brown tipping. The coat on the back, flanks, head, ears and tail should be tipped with colour. The tipping should be evenly distributed and it is the even distribution rather than the degree of tipping which is of paramount importance. The legs should show tipping which will decrease towards the paws, but which should be as even as possible. The chin, stomach, chest and undertail are a pale apricot colour.
Eyes - Green. The skin outlining the eyes to be black/dark brown.
Nose Leather - Brick Red, may be outlined in black/dark brown.
Background and Genes
Genes for coat Golden Agouti Black Full Coat Dilute Silver Tabby Orange Pattern
Tipped A- B- C- D- ii Ticked oY/oo Ta- Mackerel Mc- tata Classic mcmc tata Spotted Sp- tata A- = AA or Aa B- = BB or Bb or Bbl C- = CC or Ccs D- = DD or Dd I – II or Ii Wb- can be: WbWb or Wbwb
If we look carefully at the above table we can see that the only difference between the Golden Tipped and the Silver Tipped is the fact that the Dominant
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Inhibitor gene (I-) is in its ‘switched off’ state. This absence of a gene in the dominant state is sometimes referred to as being ‘recessive’.
What this tells us is that we have a cat that has a genotype that is indistinguishable from the Brown Tabby and yet looks nothing like his genetic twin.
If we just confirm that which we know about this beautiful cat – he is:104
• Genetically Black, (with Chocolate and Cinnamon Possible) • He could carry dilute, so blue, lilac and fawn offspring possible. • He is Agouti for sure, but he may be Homozygous AA or Aa. • Somewhere he will have a tabby base pattern (we know this because all cats do) – and that will probably have been quite obvious to his breeder when he was a kitten – but without carrying out some test-matings we just don’t know what he carries
But how we get from the Brown Tabby to the Golden is a subject of much conjecture.
Five Theory’s
• There is a gene for Golden • The Inhibitor gene forces a tabby pattern to the coat tips, but when the silver gene is not passed on to offspring, the result is a ‘Golden’ tipped instead of ‘Silver’ tipped cat. • A Wide-band gene, exploited by Chinchilla breeders, causes a wider agouti band that allows us to see more of the ‘yellow’ pigment. • Years and Years of breeders working on producing the silver and golden Persians have perfected a polygenic mix of both agouti and inhibitor genes. • Rufousing Polygenes working in conjunction with any of the above!
A Gene for Golden?
Some breeders working with the Golden gene do believe that there is a separate gene for the Golden colour -
Can this Golden gene be separated from the Agouti gene? –
Perhaps this is something that breeders could work on?
104 This is also true for the Black Tipped – but add the Inhibitor Gene
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Golden and Inhibitor Gene
Many breeders believe that it is in fact the Inhibitor Gene (ii) that forces the tabby pattern to the tips of the coat – but that in its ‘recessive’ state it does not restrict the melanin or colour from the hair shaft – a theory that suggests the Silver gene is in a sort of sleeping rather than switched off state – (There are anecdotal accounts of Golden cats producing Silver offspring)
The coats of Golden cats look very similar to the Silver series Tipped, with dark tipping or shading. However, the ground colour or undercoat is a warm cream which combined with black tipping produces a wonderful 'golden' appearance. This warm creamy-red undercoat proves that the Silver gene is not present (and we know that it cannot be carried)
Wide-banding, Rufousing and Polygenes
The Golden Tipped, seems to strengthen the argument in favour of a separate gene or set of polygenes, for ‘widebanding’ independent of the Silver Inhibitor Gene. Although, it must be pointed out that the Silver (I-) gene does seem to have the effect of widening the wideband to create the ‘Shell’ effect of the Chinchilla, whereas the Golden’s ‘tips’ bleed more deeply into the hair shaft to produce an effect that is more of a black smudge than a tip.
But Golden breeders must always remain grateful to those past Chinchilla breeders and the newer BSH Black Tipped breeder’s, because it is the selective breeding over many many generations for clear, wide Silver bands that has set the stage for the appearance of the Golden trump card, Rufousing!
Rufous genes are the second theoretical genes that are thought to be a critical part of what makes the Golden so special. Rufism is a term describing the genetic or polygenetic factors that breeders have been able to select for that allows them to produce ever warmer ground colours in non-silver agouti cats.
Essentially, the amount of rufousing determines whether a brown tabby cat will have a warm brown pigment or a colder grey colour.
The impact that these Rufous genes can have is very important when breeding for colour. And it certainly seems as if the effect is accumulative the more one breeds for Rufism the warmer the tones on Brown and Red cats.
So, we have either a Black Tipped with the Silver gene switched off and a good dose of Rufousing or we have a Brown Tabby, with a big dose of widebanding that allows us to exploit that Rufousing!
All this now sounds quite simple! – but actually breeding the Golden is more complicated than it might first seem – which is why we do not see many examples on the Show bench and there are two main reasons for this:
1. Many Golden Tipped breeders breed Golden’s as a ‘by-product’ of a Black Tipped program – and whilst the exploitation of Wideband is very good for both silver and non-silver series, the Golden badly needs that dose of Rufousing, which is really counter-productive to Silver breeding. 2. The Wideband and Rufousing genes are incompletely dominant and as such just don’t breed true in the early generations of a breeding program. There are many breeders who have been present at the birth of a much anticipated 89
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‘golden’ litter only to find that they are looking at a litter of very sweet, but poorly marked Brown Classic tabbies or Spotties.
Best Practice and Recommendations
• Golden breeding is not for the short term breeder. Persian breeders have taken many years to achieve the beautiful Golden Persians we see today. • Homozygous seems to be the answer, Homozygous for Agouti, Wideband and Rufous – will all help to breed true! • It seems that the greater the Rufousing dose, the less contrast we get between ground and marking colour. • Understand your base pattern - On neonate tipped kittens we can usually see signs of tabby/mackerel/spotted/ticked patterns. • Keep meticulous records – these kittens have a habit of changing – many is the ‘Brown Spotty’ kitten born to Golden parents – that slowly turn into lovely Golden adults. • Try to run some kittens on to understand your lines. • Keep Golden series separate from Brown or Silver unless you need to ‘go out’ for genetic diversity – in which case be prepared to spend time ‘undoing’ any effects of Incomplete dominance! • Remember that Golden kittens can be born to non Homozygous for Silver Black Tipped parents – • Avoid the red- gene – novice breeders already confuse well rufoused Spotties from Tipped to Spotty matings with Tortie/Tabbies.
The Genetic Puzzle
Earlier in this section we alluded to puzzles, conjecture and theoretical genes, none of which are for the faint hearted –
Unlike the long term Persian breeding programs that have produced the Silver and Golden longhairs – the Tipped British is still in its infancy. Whereas the Chinchilla Persian is very likely to be Homozygous for Agouti, Black, Silver and Wideband – generations of ethereal cats breeding true, we cannot be certain without testing what the British Golden gene pool looks like – and of course whilst we can test for the Agouti gene we cannot yet test for the Tabby base pattern.
There is a great deal of argument about the relationship between Wideband and Silver – The ‘Golden’ suggests that the two are separate. There is also an argument that says we cannot have Wideband without the Agouti shift, because there is no ‘band’ to widen - but the Smoke is a non-agouti cat, with the Silver gene and there is a ‘band’ before the colour kicks in – not very wide – but it is there all the same.
Tipped breeders, along with Colourpointed breeders are increasingly becoming interested in the properties of the Ticked tabby or the Ticked base coats.
Golden Tipped breeders are intrigued by the dilute Golden, the really rather beautiful Blue Golden The creation of the gentle shades of warm, but pale cream tipped with the softest tones of pale blue combine to produce one of the most gorgeous cats imaginable. And this colour-way works much better within the Golden program than the Black tipped.
What all this adds up to – is that we have de-stabilized the genetics that the Persian and Abyssinian breeders have spent many generations to ‘fix’ – and we now have to put our time in to get these beautiful Tipped cats to a point where we can predict what we will get in our litters.
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This little Blue Ticked Tabby appeared in a litter. The Golden Tipped sire’s genes were AA, Tata B Dd ii WbWb – so homozygous, for Agouti, and Wideband, Black, carrying dilute. Non Silver and hetrozygous for Ticked.
The Dam was a simple lilac colourpointed105.
We could have expected this kitten to show some widebanding and certainly much more tabby markings – but apart from her facial markings and one necklace – this little girl had no tabby markings at all –
More recently breeders are adding the colourpointed gene into the Golden Mix with some intriguing results. Kittens with very definite, golden ears, noses and testicles!!! – can this all be down to the agouti shift?
Another issue for breeders of the non-silver Tipped series, is Type and Coat. This combination of genes just loves to have either long fluffy coats or very short almost oriental coats – and getting round faces, eyes and cheeks is hard won!
The Golden tipped and the newer, as yet, unrecognized Blue Golden represents a great deal of genetic interest to the dedicated breeder. They are a lovely sight on the show bench and breeders producing good examples deserve a hearty congratulation.
Now, anybody still hungry for genetic challenges can do some research on the late colour change phenomenon!!!106
Précis from Robinsons Genetics on Wide Band107
The following extract gives Robinson’s opinion on the Wide Band debate
The presumed effect of the gene is to widen the agouti band on the hairs. In addition, the gene is said to make the tabby pattern less distinct or blurred. The overall effect is a tabby of a rich golden hue. Examination of hairs from golden tabbies reveals that the hair shafts are nearly completely yellow with a black tip, with a suggestion of pale. blue at the base. This is just as would be expected for a wide band pheno•type. The breeding data to substantiate the existence of the wide band gene are slim; but the gene has been theorized as a dominant (either complete or incomplete) and has been provisionally symbolized by Wb However, the apparent difference between silver tabbies and chinchilla silvers, and thus brown tabbies and goldens, could be easily explained by polygenetic effects on the quantitative expression of the agouti and inhibitory proteins. As the level of these inhibitory proteins increases pigment production is reduced. A chinchilla golden is simply brown tabby with such high amounts of agouti protein production that the agouti-shift occurs very early during hair growth. This inhibitory effect is so strong that it causes the shade of yellow pigment seen in the agouti band to change to a lighter colour characteristic of golden cats.
105 Was she a Ticked based Colourpointed? 106 More incomplete dominance perhaps! 107 Where there is a genetic ‘argument’ we the BAC will ‘present’ Robinson’s view
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11. Colourpointed
11.1. Colourpointed, Non-silver, without white spotting
The Colourpointed British Shorthair is a huge success story. During the 1980’s a group of breeders decided to cross the Colourpointed Persian with the British Blue and the result today is a beautiful cat that has the third highest108 number of registrations, with only the self and the Silver Tabby series ranking higher.
So successful is this breed that it boasts its own club, which holds a championship show annually.
The colourpointed in the UK is registered in all the colours of the British Shorthair except the Tipped Series.109
The genetic codes behind this beautiful cat are the same as those in all the other sections except for a variation of the gene on the C110 Locus – so we will concentrate on this gene.
However, before we start to examine gene codes we need to sort out some misunderstandings regarding the common names for this gene.
The colourpointed Persian carries what we commonly call the Siamese gene. The longhaired colourpointed cats were originally bred using Siamese breed stock. What this means is that the genes that we use in the British Shorthair are the same as those in BOTH the Persian and the Siamese.
Also known as the Himalayan gene we shall refer to the gene in our beautiful cat as the Siamese gene.
The ‘C’ gene governs the expression of ‘full coat’ and is a dominant gene. The Siamese pattern is believed to be a natural random temperature sensitive mutation that occurred hundreds of years ago in Siam.111 It is thought that all colourpointed cats have descended from this original mutation.
Basically the C gene is required for the production of any pigment.
108 8% of British Shorthair Kitten Registrations 2009 109 April 2011 110 Also called the Albino Locus – we shall call it the Full Coat Locus 111 Now Thailand
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There are five alleles (forms) of this gene: Full Colour C, Burmese cb, Siamese cs, blue-eyed albino ca and albino c.112
The mutations of C are all a form of Albinism and pointed cats are what we call partial albinos.
The Pointed mutations are temperature sensitive mutations, which mean that the C gene, is only active at low temperatures.
The gene code for our colourpointed cats is cs (Siamese)
The other genetic mutations of the C gene as shown in the following table.
Table 4 C – Full Coat Genotype Description Phenotype C/C Homozygous - Solid Coloured Solid colour C/- Heterozygous - Solid Coloured Solid colour carrying a single copy of a recessive. c/c Albino with pink eyes White with pink eyes ca/ca Albino with blue eyes White with pale blue eyes cs/cs Siamese Colourpointed Colourpointed, Siamese pattern cb/cb Burmese/Sepia Burmese pattern cb/cs Tonkinese – Co-dominant Tonkinese pattern Himalayan/Burmese
So in summary:
• The full colour form (allele) C, is Wildtype, dominant, and produces a full expression of the coat colour • The Siamese form cs, is recessive to C, co-dominant with the Burmese form, cb and dominant to the blue-eyed albino ca and albino c. The albinism produced by this form is more temperature sensitive than cb, causing the classic Siamese pattern with blue eyes. • The Burmese form cb, is recessive to C, co-dominant with the Siamese form Cs, and dominant to the blue-eyed albino ca and albino c. This form of the gene produces a slight albinism. Black becomes dark brown. It is best known in the Burmese breed, which has green or green/gold eyes. • The blue-eyed albino form ca, is recessive to C, cb and cs but dominant over the albino allele. Cats will show an almost complete albinism, with washed out blue eyes and pigment free, translucent white coat. • The albino form c, is recessive to all the other forms producing a pink eyed complete albinism.
Whilst complete albinism is very rare in the domestic cat, partial albinism is common. These partial albino patterns are temperature sensitive mutations.
112 Some scientists dispute that both c and ca exist – and that there is only one recessive for pure albino.
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Temperature Sensitive Mutations
In order to understand the mutation we need to go back to the Wildtype form of the gene. The C gene is the Wildtype, the term Wildtype is sometimes used to refer to the most common phenotype (or genotype) found in the natural population.
The C allele or form of this gene is a gene with a job to do, and is usually kept busy producing an enzyme called Tyrosinase, and all the other forms of C have become lazy and have become ‘loss of function’ alleles. When a gene form loses function an enzyme or other protein may no longer be produced, or may be produced in a different form or at lower levels or indeed may become nonfunctional.
What has happened with our Cs gene is that Tyrosinase is still produced, but the enzyme they produce does not work at core body temperature. Instead pigment is only produced at below-average body temperatures.
Because of the uniform warmth in the mothers womb, Colourpointed kittens are born with almost pure white coats on a pink skin.
Where blood circulation is at its most efficient keeping the kitten warm the coat will remain white. Parts of the body with lesser blood circulation will begin to activate pigment.
By the time the kitten is 3-5 days of age, colour will begin to form on the ears, feet and tail. The darker the base colour the more quickly the colour will form. With the red/cream series being the last to show their true colours.
Over the next few weeks and months, pigment continues to form on the coolest parts of the body. Eventually colour creeps, from the feet up through the legs, and the mask bleeds out from a smudgy nose to form that famous colourpointed mask.
Specific Health - Eyes
Colourpointed cats are undoubtedly popular. And on the whole these temperature-sensitive partial albino genes are thought to be a beautiful and largely benign mutation. However we would be derelict in our duty if we did not touch on some of the issues behind those lovely blue eyes.
This is a complex topic, not yet fully understood, but we will do our best.
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For those people who share their lives with colourpointed cats, they can see them playing and hunting in the same way as other cats. For Breeders and exhibitors the spectre of Nystagmus or a squint is never far away.
Many breeders understand that these eye problems are linked to the colourpointed gene, which is correct; it seems that the mutated Tyrosinase found in temperature-sensitive albino cats does not act to pigment the eyes. This is why all cats with true colourpointed genes will have blue eyes.
The absence of pigment or melanin means that the eye does not develop properly in the womb. As the foetus develops, some parts of the eye, including the crucial optic nerves become disorganized and the result leaves the cat with problems with focusing and depth perception.
We humans, with our eyes facing forwards have what is known as binocular vision – our eyes are wired to our brains via our optic nerves – and this set up allows us to integrate the things seen by each eye into a single image.
Most birds and reptiles have their eyes on either side of their heads and have panoramic vision – the effect of this is that, each side of the brain only ''knows'' about the visual input from one eye,
Most cats have their eyes wired to their brains in the same way that we do but this is not true of the colourpointed cats – their optic nerve fibres do not cross properly in the brain113 and many end up connected to the wrong side of the brain, in a way that is much more similar to the birds and reptiles.
What we cannot know is the exact extent to how the visual fields of our cats are affected, and how they compensate for the mix-up in their wiring – but we can be certain that they cannot have full binocular vision and this may impact on their perception of distance.
In addition to this criss-cross wiring problem, partial albinism can also cause other vision problems including: Congenital Strabismus and Nystagmus.
Congenital Strabismus In simple terms this means a squint, and we will deal only with the squint as it occurs in the colourpointed cat.
When a cat with a Siamese gene has an eye (or two) that points down and over towards the nose this is called a convergent squint. When the eye or eyes point outward, away from the nose it is called a divergent squint.
(At one time these squints were commonly seen in the Siamese breed.)
This is a permanent condition, which cannot be cured and usually appears in the kitten at about 6-8 weeks of age.
We know that the primary cause, is an excessively high proportion of optic nerve fibres which cross over at the optic chiasm. This causes a reduced medial visual field. It is thought that when the kitten develops a congenital114 permanent squint, it is a muscle imbalance caused by the kitten’s eyes attempting to correct the distortion of the visual field.
113 Dr. R. W. Guillery, Neurophysiologist - University of Chicago 114 Condition present at birth or soon after.
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Affected kittens can be expected to have a near normal quality of life.
We also know that this permanent condition is relatively uncommon. We know that the Siamese breeders have to all intents and purposes bred it out. This means that it is likely to be a polygenic trait and affected kittens should not be used within a breeding program.
Occasionally, it is possible to notice the colourpointed eye drifting in either a convergent or divergent squint, which will correct as the cat refocuses – this can happen on the show bench. This is not to be confused with the permanent congenital squint
Nystagmus
It is probably true to say that virtually everyone with albinism has Nystagmus, so it is small wonder that it crops up in our colourpointed cats with their major genes for partial albinism.
Nystagmus is an uncontrolled movement of the eyes, usually from side to side, but sometimes the eyes swing up and down or even in a circular movement.
There are two types of Nystagmus recognised:
1. Congenital Nystagmus, that first appears in the early months of life. 2. Acquired Nystagmus, when the condition develops later in life.
However, colourpointed breeders report a sort of mid-way partial Nystagmus that comes and goes, usually when the cat is in a stressful state.
It is probably safe to say that whatever the ‘form’ of Nystagmus we see in our colourpointed cats it is usually due to the cross wiring of the optical nerves115
There is much that we do not know about Nystagmus in cats116 but it is likely to be at least in part Polygenic, and kittens that show sign of a severe and or permanent congenital Nystagmus should not be used in Breeding programs.
Most kittens and cats with severe or permanent early onset Nystagmus, will not have eye, brain or other health problems and are unlikely to be affected by constantly moving images, as the young brain can adapt to the condition. Additionally neither the condition nor the animal’s vision is likely to worsen as the animal grows up. The condition is not painful and kittens will benefit from the normal play stimulation that most kittens enjoy.
However, they are quite likely to experience some of the following symptoms. Breeders letting affected animals go to companion homes may wish to apprise new families of the condition.
• Nystagmus may be made worse by emotional and physical factors, such as tiredness, unfamiliar surroundings, nervousness and stress.
115 If an otherwise normal eyed cat, colourpointed or not develops a sudden late onset Nystagmus Veterinary opinion must be sought. 116 The GCCF genetics committee are working with the BAC’s to launch an investigation into Nystagmus with the University of Bristol, Langford.
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• Depth perception may be reduced. Affected kittens may seem a little clumsier than normal and may need watching if climbing higher objects.
Whilst it is important for breeders to understand the major genes that they are working with, such that they can ensure that they always act in the best interest of their breed, there are no contra indications to responsible breeding of the partial albino cat. Scientists, who have studied these visual issues, have been surprised that despite the very unusual wiring of those optical nerves, the average colourpointed cat appears to be able to operate pretty much as cats with normal eye/brain wiring.
Some Extra Information on the Colourpointed Cat
• The Siamese gene is recessive – both parents must either be colourpointed or carry the colourpointed gene in order to get colourpointed kittens. • The Blue eye is more sensitive to bright sunlight. • The gene that gives rise to the Siamese pattern is the same as pointed rabbits and goats found in the Himalayas.
The Show Cat
Points Colour - Mask, ears, legs and tail should be a clearly defined colour, matching on all points.
Body Colour - There should be a good contrast between points and body colour. Light shading, if present, should tone with the points. Shading in a mature cat should not penalise an otherwise good exhibit.
Eye Colour - A definite clear blue; deeper shades preferred.
Nose Leather and Paw Pads - Appropriate to coat colour.
Showing Colourpointed Cats - Shading and Eye Colour.
We can see from the earlier sections that no matter what colour British Shorthair one chooses to breed there are always pitfalls and the Holy Grail of colourpointed breeding is the clear coat.
Although the standard of points says that an otherwise good exhibit should not be penalised for shading, it also refers to ‘light shading’
The problem for colourpointed breeders is that the genes that cause pigment to form in areas of the body that are cooler due to reduced circulation keep working throughout the lifetime of the cat, and so as the cat ages and the circulatory system slows down as it does with all mammals the colourpointed cat begins to shade beyond the ‘points’ – at first it will be the shoulders and flanks and then 97
Draft British Shorthair Breeding Policy – Genetics Committee – after BAC Seminar gradually the whole upper body will eventually shade. Because this shading is related to pigment, the Seal and Blue series will be most affected, followed by chocolate.
Neutering can add to the natural slowing of the body metabolism and exacerbate the shading on the body.
The result is that when we do see older colourpointed cats on the show bench they will most likely be lilac!
It is frustrating for breeders who will try to campaign their young cats early knowing that they will inevitably shade and will almost certainly be faulted for something that is largely not polygenic.
Of course there are some lines that have managed to breed clearer coats, this may be due to a higher metabolic rate in some lines of cats – but we only have to look at the ratio of colourpointed kittens shown in the various colours and compare that to the number of adult cats shown, especially in the darker colours to know that this is an issue shared by most colourpointed breeders.
The other major headache for the British Colourpointed breeder is eye envy. Compared to the Siamese benches with their rich array of shades of blue, deepening to almost navy, the British colourpointed eye is often a disappointing wish washy blue.
This is a polygenic factor and almost entirely due to the success many British breeders have had with the orange eye.
The deeper colours of the orange eye are produced by polygenes for an increased volume of pigment producing cells (melanocytes) and a deeper pigment.
Whereas the green eye has less pigment producing cells but also produces a lot of pigment.
Now, this is all quite complicated but the colourpointed eye is set up in the same way as the orange and green eye and so also has melanocytes. But the melanin production is impeded by the fact that the eye is always warm and the temperature never gets cold enough to produce an orange or green eye.
So what we see in the colourpointed eye is actually blue light that gets refracted from the lens of the eye. And the less clutter in the eye, ie melanocytes, the more blue light gets refracted and hey presto we get a deeper blue eye.
Fortunately, all this seems to be polygenic so plenty of work to do on the colourpointed eye!
The Mask
Colourpointed breeders are seeking to produce a cat that is fully masked and where the margins between the mask and body colour remain distinct.
Tabby colourpointed although not fully masked should still have an obvious demarcation between the face and rest of the body.
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The ideal mask extends from above the eyes down through the chin and stretches beyond the eyes evenly on both sides.
Sometimes we see a cat that is hooded, where the mask extends over the head and sometimes, often on chocolate points we see incomplete masks, often around the mouth and whisker pads.
Best Practice, Responsible Breeding and Recommendations
• Colourpointed breeders should try as much as possible to understand the major Siamese genes as discussed in this policy. • The colourpointed British has inherited a potential for long soft coats from the Persian ancestors and a desire to have large ears and a long nose from the Siamese ancestory – balancing these factors to maintain good British type is a challenge! • Breeders may wish to work with the Colourpointed cat club to see if the standard of points that covers all colours of the Colourpointed is weighted against the darker colours on the show bench. • Experienced Breeders of the colourpointed and tabby colourpointed British might benefit from talking to some of the Siamese Breeders about their experiences of the dilute modifier genes – too complicated to go into here but very interesting, and deserving of further research. • The colourpointed Queen may require some careful management, like her Siamese cousins, she can be a precocious caller, often calling from early January through to December, and coming back on call within weeks of having her kittens. She may also have very large litters. Breeders will need to manage these situations carefully. • Also in common with the Siamese the colourpointed cat is deeply affectionate, which some people who like the British tempererment may find needy. This affection which may translate into a deep pair bond with her human owner, over whom she may feel possesive, may mean that some cats may not wish to share their lives with other cats. This trait may run in some lines.
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One last thing for the Experienced Colourpointed Breeder
If we go back to the table on page 89 Table 4 we can see that the alleles for the pink eyed albino c and the blue eyed albino ca are recessive to the genes for the Siamese pattern cs
There is a hypothesis that suggests that if we were to have a cat that was genetically cs/ca we would have blue eyed colourpointed cats with a higher contrast of colour between coat and points with a wishy washy blue eye. If any of our lines in the UK carried this combination of genes we might see clearer coats, but not necessarily good eye colour, breeders may occasionally see a blue eyed albino appear in a litter if they cross back into their own lines. Although the c and ca genes cannot be tested for and indeed some doubt whether they both exist, any breeder suspecting that their lines may hold such a combination may wish to keep detailed records and share these with the Colourpointed Club.
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11.2. Colourpointed -Silver Series
In previous sections we have covered the genetics behind the genes for Smoke and Silver and also for Colourpointed. Here we are looking at cats bred with an amalgamation of these two genes.
It is worth remembering that the Silver Inhibitor gene (I) is dominant whilst the Colourpointed (Cs) gene is recessive.
In the UK the Smoke or Silver Tabby Pointed British Shorthair is rarely registered with the GCCF.
However, in Europe breeders are working increasingly both with Silver and Wide- banding in their Colourpointed Breeding programs.
Essentially, this Series reflects the simultaneous presence of both the Inhibitor gene and the Siamese Partial Albino gene, either with or without The Agouti gene.
The Smoke or Silver Tabby Pointed Cat can come in the full range of solid and tortie point colours.
History
It seems that the first recorded Silver pointed cats in the UK were bred in Scotland in the 1940’s. These cats, known as Silverpoint Siamese were introduced to the cat fancy in the 1960s. It is not clear whether some of these cats were in fact Silver-pointed, but they were tabby pointed and in 1966, the Tabby Point Siamese was granted recognition by the Governing Council of the Cat Fancy (GCCF).
Smoke Pointed
The undercoat of the pigmented point colour of the Smoke Colourpointed should pale to silver at the roots. As with the British Smoke there is a great deal of variation in the effect of the Inhibitor gene in these cats, and breeders should select for those with the greatest degree of contrast.
With the dominant colours, Seal and Chocolate the points may appear darker than the non-silver series and the dilute blue and lilac colours may appear colder with a steel effect. And other pointed breeds with the Inhibitor gene, report that body shading is often more intense than in non- smoke individuals.
Silver Tabby (Lynx) Pointed
These cats display the main Tabby patterns on their ‘Points’ The stripes in the dominant colours of seal and chocolate, may appear darker than the non-silvered tabby point. Between the tabby markings the coat will appear to be silvery white.
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Again, body shading may be darker than the non-silvered cat . The dilute colours; blue, lilac, cream and fawn may appear to have very pale points.
Silver eye ‘goggles’ may show around the eyes of the smoke and silver tabby cats and full pigmentation may not develop until the cat reaches her second birthday.
The Problem
At the time of writing there is no test for the Inhibitor gene. If we remind ourselves of the fact that when the Inhibitor gene (I) is present the full development of pigmentation in the hair does not occur, and the non-agouti or 'Self' Cat turns into a Smoke, and an agouti cat becomes either a Silver Tabby or Silver Tipped. We know that the (I) gene has a hugely variable impact, some cats show a strong sparkling white base, whilst others show hardly any contrast and the breeder may not see the expression of silver at all.
It is this problem with the Silver gene that has caused the GCCF to over-stamp litter registrations with ‘Silver in Pedigree’
If we accept that Silver can be tricky to detect in the self cat, it doesn’t take a quantum leap to understand that with the colourpointed it can get really difficult and with the Red series colourpointed it can become nigh-on impossible.
16– A lovely Chocolate Smoke Pointed Female
In the Red-series Silver ground colour becomes Ivory and this is compounded by the effects of the Siamese (Cs) gene
During the research for this section, we interviewed several well known European breeders – during these interviews one breeder commented that she felt that as soon as a test for the (I) gene is found we will have to re-register at least 25% of all colour pointed British as Silver series.
Recommendations and Best Practice
Those colourpointed breeders interested in further research behind their pedigrees might like to make a visit to Pawpeds – and search for a cat born in 1982 named Beeblebrox Plum Crazy – this cat was originally registered in the UK as a Red Pointed and as such fathered a good number of offspring – he was later re-registered as a Red Silver Smoke and Pawpeds have him as BRI ds 33.117
117 EMS Breed Numbering System
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There are a great number of colourpointed breeders today both here and in Europe breeding from cats directly descended from Beeblebrox Plum Crazy118 – and if his Silver gene slipped through the net – how many others?
We have spoken with a number of UK breeders who have experimented with Silver in their colourpointed lines and who have decided that in the absence of a test for the Inhibitor (I) there are no benefits to be had.
There are a number of colourpointed lines with incomplete masks around the muzzles, with dark shaded coats and brindling of the points – and right now the only way to determine whether your colourpointed cat is secretly Silver is to test mate out to a self cat and evaluate the results -
118 Many Pedigrees still show this cat as red-pointed today.
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11.3. Colourpointed & White (Any colour) Preliminary
In previous sections we have covered the major genes for the Bi-Colour (White Spotting (S) and the Colourpointed (Cs) British.
Whilst new to the British Section in the UK, the Colourpointed and White genes are not strangers to each other and can be seen in both the Ragdoll and Snow Shoe breeds. The Birman (a pointed cat) also shows an expression of White Spotting (S) in the form of mittens on all four feet.
The British Colourpointed & White may be bred and shown in a mitted variety, Bi Colour and high white/Van pattern and although all patterns are acceptable, the pattern preferred by breeders is the Bi Colour.119
In all three patterns, breeders are looking for the White Spotting (S) gene to fall and mask the points colour on the feet and legs, leaving four white feet. The tail and mask will show pigment as the Colourpointed gene allows pigment to seep into the colder points and breeders hope that that lovely white Bi-Colour blaze will make it’s V pattern neatly in the centre of the face.
The tonal shading that often appears in the coat of a Colourpointed, takes the form of Bi Colour markings, this area is shaded only and not solid colour.
The Show Cat
Points Colour - The face should have an inverted V of white, starting on the forehead, but not exceeding the inner aperture of the eye, and extending down covering the nose and whisker pads.
Symmetry of design is desirable.
Remainder of mask, ears and tail should be clearly defined and matching in colour.
Body Colour - There should be a good contrast between coloured Points and body colour. Shading if present should tone with the coloured Points. Heavy shading in a mature cat should not be penalised in an otherwise good exhibit. Bib, chest and under body to be white. Legs should be white or have tonal shading, small patches of colour on the legs are permissible. All four feet must be white.
Eye Colour - A definite clear blue: deeper shades preferred.
Nose leather/paw pads-appropriate to coat colour or pink.
119 The SOP does not specify the amount of white on the body.
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Some Early Findings From Breeders
The following are the observations from breeders of Colourpointed and White.
• Breeders working on this pattern are finding that after several generations they can regularly produce kittens with that perfect face blaze. • The eyes are always blue as in the traditional Colourpointed. But some breeders are reporting a deeper shade of blue amongst some of those individuals with White. • When breeding for pattern the base colour of the Colourpoints does not affect the outcome. • It doesn't matter whether you mate two Colourpointed and White cats or a Colourpointed to a C/P and White – it seems that the litter will usually get a mixture of both patterns120 • Two C/P and Whites together are more likely to throw a Van Patterned C/P and White,
The Polygenic Properties of White Spotting (S)
Within the section on the Bi-Colour we touch upon the Polygenic121 properties of the White Spotting (S) gene – Although it is often said that the Bi-Colour pattern is completely random – we can see that the classic Bi-Colour pattern can be worked at over generations. These Polygenic traits of (S) are proving interesting to the Colourpointed and White breeders. The following paragraph is an extract from the records of one such breeder.
“Certain matings of mine breed true every time, perfect markings, others are more random. However, after previously breeding Bi-Colours, and having worked on the Colourpointed and White, I believe that you will produce very similar markings in the kittens as you have in the parents with White Spotting. To within a certain percentage, say the same markings to within 10 %, meaning more or less white either way and the markings in the same place as the parents give or take 10%.either way - Sometimes mitted kittens are produced, but the colour always stops where it should on the ankle, I have not known of any C/P and White kitten developing even one pigmented paw!”
120 One experienced breeder reports when any mating contains a C/P and White she will always have a kitten with White in the litter 121 Genes working alongside major genes that can be exploited in breeding programs
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11.4. Silver Colourpointed & White (Any colour) Preliminary
Please refer to the earlier Colourpointed sections.
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12. British Shorthair Variant
The British Shorthair we know today has a long and interesting history, we have learned how after the major world wars breeders worked hard to restore the breed by going out to the Persian breeds, we have read that the British Tipped and the Colourpointed breeds have been derived from the Persian and Chinchilla breeds.
And whilst breeders have worked for generations to get the Phenotype122 as close to the breed standard as possible the hidden Genotype or unseen genetic makeup of our beautiful breed has been carried from generation to generation.
One genetic legacy is the gene for long hair.
The length of fur in the feline is governed by the Long hair gene which is known as L. In the Wild Form123 the dominant form of L codes for short hair, whilst the recessive l codes for long hair.
To understand how hair length in the cat is determined we need to understand the cycle of hair growth.
Anagen is the active growth phase of hair follicles. During this phase, the cells in the root of the hair are dividing rapidly, adding to the hair shaft. Hair stays in this active phase of growth for a genetically predetermined period of time. At the end of the Anagen phase a signal causes the follicle to go into the Catagen phase.
In simple terms the Anagen Catagen Catagen phase is a short phase phase stage that effectively stops the hair growing.
The final stage is the Telogen phase, during which the hair or fur is in its Telogen resting state, neither phase growing or shedding
The L gene works as the switch between the Anagen (growth) phase and the Catagen (stop) phase - In the shorthaired cat, L steps in and creates the shorter coat we know in the British, in the mutated recessive l form the switch from Anagen to Catagen is delayed, the hair keeps growing and the longer haired cat results.
122 Appearance 123 Typical Phenotype
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The British Shorthair will be either Homozygous for Short Hair and have two copies of L so LL or will be Heterozygous so Ll – any breeder mating two Heterozygous cats together stands a good chance of those recessive l’s meeting and the result will be the really rather beautiful Long haired British Variant
17 - Exquisite British Longhair from Europe
The British Long Hair
Although currently registered with the GCCF as a Variant of the British Shorthair and as such cannot be shown, there is a good deal of interest in this very pretty cat.
Variously known throughout the world as The British Long Hair, The British Semi- Long Hair, The Britanica, The Lowlander and a bit confusingly the Highlander this cat is described by most registries to have the same standard of points as the British Shorthair, but with a Semi-Long coat standing away from the body.
Long Hair Mutations (extract from UC Davis)
One gene – fibroblast growth factor5 (FGF5) – determines hair length. Short hair is a dominant trait determined by the wild-type form of FGF5. Long hair is a recessive trait. Four mutations in FGF5 have been identified that are associated with long hair in cats. Long-haired cats can carry two copies of the same mutation (homozygote recessive) or have two different mutations, one on each chromosome (compound heterozygote). Three of the mutations are fairly breed specific, while the fourth is present in all long-haired cat breeds and crossbreds, as follows:
Mutation 1 (M1): present in Ragdolls
Mutation 2 (M2): present in Norwegian Forest Cats
Mutation 3 (M3): present in Maine Coons and Ragdolls
Mutation 4 (M4): present in all breeds of long hair cats, including Ragdolls, Maine Coons, and Norwegian Forest Cats.
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13. Eye Colour
The most common colour for wild, non colourpointed, cats is hazel somewhere on the scale between orange and green.
The British Shorthair comes with four distinct eye colours:
They can be sorted into two categories:
• The Polygenic eye colours: • The Major Gene eye colours:
The Polygenic eye colours:
These eye colours are not linked to major genes and breeders are able to manipulate polygenes to produce the desired colour and intensity.
• Orange/Gold/Copper • Green
Breeders breeding for eye colour will know that within each of those colours there is great deal of variation in the range of colours, both in depth of colour and hue. And the shades of orange can merge into green and vice-versa leaving cats with the hazel eyes of their wild counterparts.
The good news is that selective breeding can influence these polygenes so, within reason, eye colour can be stabilized. So when we see outstanding eye colour time and time again in a line – we know that this is thanks to hard work and planning.
The Major Gene eye colours:
When eye colour is linked to a major gene it means that breeders have to work with that colour.124
• Colourpointed Blue • Blue
Kittens are always born with blue eyes. The final eye colour begins to develop between 6 and 7 weeks of age. It will be at least 3 or four months before breeders will be able to see the much longed for colour.
124 For example it is not possible to breed a colourpointed cat with an Orange eye.
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HOW EYES GET THEIR COLOUR
There are two key factors that influence eye colour in the cat:
• Pigmentation • Blue Light Refraction
The iris has two layers of cells or melanocytes, Epithelium which produce pigment.
1. The Stroma - an outer layer made up of a bunch of loosely constructed cells. 2. The Epithelium – situated under the Stroma consisting of tightly packed cells.
Stroma
Just like the coat colour, the pigmentation of the iris is caused by melanin and the intensity of the colour depends on the numbers of melanocytes in the eye.
When melanocytes levels are low the eye colour will be in the green spectrum, as the number of melanocytes increase, possibly due to selective breeding, the eye colour will intensify to orange
When there is an absence of melanocytes, as in the un-pigmented white cat the eye will appear blue125 - all that blue light reflecting and refracting just bounces back -
Melanocytes don’t all produce pigment at the same rate – sometimes they can be quite lazy – so when a cat has fewer, but lazy melanocytes the eye will be a weak green. A black tipped, with stunning black-rimmed deep-green eyes will not have many melanocytes but those she has will be working hard at producing pigment. Using this logic we can understand that a cat with an iris packed full of melanocytes all working as hard as possible will result in a cat with fabulous copper eye colour.
The blue of the colourpointed cat is different again – the colourpointed eye could have eyes packed full of melanocytes or not – they could be the lazy sort or not – it won’t matter – because those melanocytes simply won’t work in the iris of a cat that cannot produce pigment unless core body temperature falls below normal -
Additionally the light that is taken in through the cats eyes is refracted and reflected and it is the number of fibres milling about in the Stroma level that determines the levels of blue light that interacts with the pigmented cells – this combination of blue coloured light playing over the pigmented cells determines the eventual eye colour of the cat.
Fewer fibres in the colourpointed eye will result in a deeper clearer blue – the breeder’s best chance of producing good blue eye colour is to consistently mate cats with good blue eyes to cats with good blue eyes!
125 Or in rare cases pink
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Finally, behind the retina we have the Tapetum Lucidum. This is reflective layer of tissue that sends light back through the eye. and helps cats see in low light - it also causes eye shine in flash photos. This layer is missing from the eyes of most blue eyed white cats.
ODD EYES
These occur when the cat has different genes affecting each eye – if pigment cells do not reach the eyes because they are halted by the White gene (W) the cat will have blue eyes. However, if pigment cells reach one eye the cat will have one orange eye and one blue eye -
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14. Record Keeping
Keeping good records is one of the cornerstone principles of a sound breeding management system.
This section will cover the importance of keeping accurate breeding and cattery records.
We will use the term Cattery, to help remind us that even if our cats are our much loved pets that live in our homes, as soon as we implement a breeding program of selected animals, a well managed system of housing and husbandry must be planned.
Running a cattery requires a full time commitment to health and welfare. It will require time, space, patience and financial support and critically it will require the breeder to keep accurate and long term records.
As a minimum the following records should be kept:
Purchase Cat Records Contact Breeding Records Records
Record details Pedigree Name Name of Sire of all cats purchased Pedigree Colour Address/Phone Name of Dam records number/email address Breeder Gender Relationship Inbreeding co- records efficient Cost to Date of Fellow Breeder Cost purchase Birth/Purchase/Sale including travel Vaccination Breeder Stud Cat Dates matings records owner observed Health Care/Veterinary Used your Describe the stud mating – how was the stud/how was the dam. Temperament Cat Club Calculate pinking up date Performance as stud Judge Calculate due date Performance as Dam Show Management Show Records Bought kittens from You Registration Number Sold kittens to you Genotype DNA Tests Nutrition
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Birthing Records Kitten Records Litter Records Book Keeping Records
Date and time Date and time of birth Success of Money In – by labour starts litter against type predetermined criteria (did you get what you hoped for!!) Describe queens Birth weight Overall health Money Out – by behaviour/any and vigour type discharge Time of Any birth notes, ie Number of live contractions Breech etc kittens born Time of first and Identification details Number of subsequent kittens lost in kittens nesting Time of last Daily weight records kitten Make a note of Nutrition all the placentas Birth weights Health records Assistance Worming required by dam/medications Fleas Vaccination Show potential Sale records/contracts
Fortunately there are a number of packaged software programs to help with much of this information and simple spreadsheets can be used to keep and calculate much of the required information.
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15. Recommendations
To be successful a breeding program must be undertaken in a planned, considered and structured way, within a system or framework of accepted best practice. However, a breeding program or system can only be as good as the breeder who operates the system.
Good breeders will set themselves goals and objectives. They will seek to understand the needs of the feline and ensure that they do not overcrowd or fail to meet the needs of the animals in their care.
Breeders will need patience, creating a line needs time, and an ability to see one’s offspring objectively. It takes courage to neuter animals with undesirable characteristics.
Breeders can often recognize cats bred by other breeders, they can recognize a ‘line’ by its look, this not happenstance, it is the product, often of many years, of careful planning, selection, heartache and luck.
The breeder that we all admire, will be selecting kittens that they like the look of, that have good health and temperament. They will seek to mate their queens to excellent stud cats in the hope that those selected queens will produce easily, strong sound kittens that have no genetic abnormalities but do have the kind of beauty that the breeder can be proud of. It is this balancing of genes for good and bad that is the true test for any breeder. If we get it right, we should be able to predict the outcomes, we should be able to produce kitten after kitten that have such distinctive attractive qualities that unmistakably stamp them as ‘ours’
Using this breeding policy in conjunction with the standard of points and the registration policy, breeders should be able to work with their clubs and each other to protect and improve this wonderful breed that is so very much loved.
The GCCF draft business plan for 2011-12 includes a scoping exercise for a “GCCF Breeder Scheme” – which will be promoting responsible breeding.
We recommend that our British Breeders support this initiative - In the final analysis it is we, the breeder that is the custodian of the British Shorthair Cat.
© British Shorthair BAC - 2010
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Appendix 1 References
We have referred to a greater or lesser extent to the following publications. We have also made much use of other widely available materials and are, as ever, grateful to those who have gone before us.
GCCF Breeding Policy Asian Breeding Policy The Official Standard of Points (GCCF) British Registration Policy (GCCF) Robinsons Genetics for Cat Breeders and Veterinarians Judges Reports (GCCF Website) Wikipedia Feline Advisory Bureau DEFRA Cat Welfare Policy PAWPEDS (www.pawpeds.com)
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Appendix 2 Glossary
Allelle refers to the different forms of a gene
Baer Test - The BAER test is based on the electrical response of the brain to auditory stimuli. When a sound enters the ear, tiny electrical impulses are generated by components of the auditory pathway. The signals can be picked up by recording electrodes positioned on the head and are, in turn, passed into a computer. The test offers quick, non invasive and accurate assessment of an individual’s hearing status.
Blood Groups - Blood consists of red blood cells, white blood cells and plasma. The red cells carry oxygen and their well-being is essential for life. Red blood cells, like most other components of the body, are made of protein, and proteins can be recognised and destroyed by the body’s immune system. The cat has essentially two blood groups: A and B (although there is a third, very rare, group, AB, which is a combination of the two). The red blood cell proteins are A in one group, B in the other (see figure 1). In fact, the proteins on the surface of type A and B red blood cells are only slightly different, but of course the immune system can detect the difference.
Chromosomes - Genes are located on the chromosomes. All cats have 38 chromosomes in each body cell, 19 from each parent. Chromosomes appear in pairs. With the exception of the sex chromosomes each pair is the same size and shape.
Dominant Gene is one which is capable of expressing its trait even when carried by only one member of a chromosome pair.
Genes - are the individual units of inheritance. Each gene (or combination of genes) determines a characteristic that govern the eventual shape, size, sex, colour, pattern and hair length of the individual animal. Genes work in pairs – but the pairs do not have to be identical
Heterozygous refers to having two different alleles at a given locus on a chromosome
Homozygous refers to having the same 2 allelles at a given locus on a chromosome
Locus - is the exact position on the chromosome where the gene is located
Recessive Gene can only express itself when both members of the chromosome pair contain the gene
SOP – The Standard of Points is established by Breeders and Breeder Groups, who present them via their Breed Clubs to the Breed Advisory Committee. The SOP is agreed by the GCCF Executive & finally by the full GCCF Council made up of representatives from affiliated clubs. Any changes to a published SOP follows the same procedure. The SOP is used by judges as the base criteria against which to award placings and awards. It is the SOP that ultimately protects the Breed integrity.
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Appendix 3 Key Genes
Agouti (A) – the natural “wild” gene that is the basis of the tabby cat. The base agouti pattern is bands of black on a yellow background; in the cat this is overlaid with one of the tabby patterns.
Non- agouti or “hypermelanistic” (a) - a recessive gene mutation that turns the original “wild” tabby cat into a self black by overlaying the agouti base colour with melanic pigment, making the whole animal appear black, although often in certain light the underlying tabby pattern may still just be discernible. Other genes work to change this black pigment to other colours.
Inhibitor (I) – a dominant gene that suppresses the development of pigment in the hair of the coat, typically producing hairs that are fully coloured only at the tip and have a silvery white base. It has greater effect on the lighter pigment in an agouti cat, removing the yellow colour and turning the base colour white or “silver”. In the case of a non-agouti cat the inhibitor removes colour from the base of the hair-shaft to produce a silvery white hair with a coloured tip, i.e a Smoke. This allele appears to interact with other genes to produce various degrees of tipping, ranging from deeply tipped silver tabby to lightly tipped silver shaded tabby.
Tabby patterning genes –
Mackerel (Mc) – the basic striped tabby pattern that overlays the agouti base (ie “wild” form)
Classic (mc) – a mutation of the mackerel allele recessive to all other tabby patterns which gives a blotched pattern with the characteristic “butterfly” motif across the shoulders and “oysters” on flanks.
Ticked (T) – an incompletely dominant gene which removes most of the stripe pattern leaving the ticked agouti base pattern on the body with minimal overlaying stripes on legs, chest (necklace) and face.
Spotted (Sp) – current thinking is that it is likely that a specific single gene causes the spotted tabby pattern, breaking up the mackerel or classic pattern into elongated or rounder spots respectively.
Wide-banding (Wb) – this has been hypothesized either as a gene (Robinson) or more probably a group of genes (Joan Wasselhuber, who coined the term “wide-banding genes”): increasing evidence for their existence has led to wide acceptance. Undercoat width genes determine the width of the undercoat whether or not the cat has a silver inhibitor gene. The term “undercoat” used here refers to part of the hair shaft closest to the body, and includes both guard hairs and the shorter hairs often referred to as “undercoat” hairs. The variability seen in the undercoat widths in cats points to the polygenetic nature of wide- banding genes. If a single gene it is likely an incompletely dominant gene mutation, the effect serving to push the darker, pattern colour in the cat up away from the hair base towards the tip, turning the normal tabby patterns into a Shaded or Tipped cat. Precisely how the agouti, inhibitor and wide-banding genes interact on a molecular level is not clear - one possibility is that the wide-banding genes influence the agouti protein production to remain high so that eumelanin
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Long-hair (l) – a recessive gene mutation which produces a semi-long haired cat. (still found today in the British owing to breeding legacy)
Chocolate (b) and Cinnamon (b1) – two mutations of the basic black non- agouti gene which modifies black into dark brown or medium brown respectively
The white masking gene, (W). The "W" gene prevents the normal replication and migration of pigment producing cells during embryologic development. As a result, WW and Ww cats have a greatly reduced number of melanocytes and appear white, no matter what other colour genes it may carry. Only a cat that is homozygous recessive (ww) will express normal pigmentation. Also called Dominant white (more properly "epistatic white" since it occurs on a different gene to the black-based or red-based colours)
White spotting or piebald spotting gene, S/s, - has variable expression, so that an SS cat often has more extensive white patching than an Ss cat. It is this gene that creates the familiar white blaze across the face, a white bib, tuxedo pattern, or dappled paws. A hypothetical Sb allele ("gloving gene") may cause the mittens in Birman and Snowshoe breeds. Some researchers believe that there are separate white spotting genes for distinct forms of white pattern, such as the white locket that some cats have on their neck or bellies.
Siamese (Himalayan) gene (cs) - The Siamese colored kittens are born completely white. The color of the mask doesn't appear until after a week. This is due to that the cells of Siamese colored cat cannot develop any pigment if the temperature is too high. When the kittens are in the womb of their mother's they are warm and comfortable, and no pigment at all is developed. When they are born it becomes cool enough for the pigment to develop on the cooler extremities, like for instance ears, legs and tail. This temperature dependant pigment production is called acromelanism. Acromelanism is present in other animals, for instance in rabbits.
Orange (O) – this is a mutation on the X chromosome and is thus sex-linked. The gene eliminates all melanin pigment (black and brown) from the hair fibres, replacing it with phaeomelanin, a lighter compound appearing yellow or orange depending on the density of pigment granules. The O allele is also epistatic over the non agouti genotype; that is, the agouti to non-agouti mutation does not have a discernible effect on red or cream coloured cats, resulting in these self- coloured cats displaying tabby striping independent of their genotype at this locus. This explains why you can usually see some tabby pattern on red, cream and apricot coloured non-agouti cats, even if only on the head/face. Rufus polygenes, as yet unidentified, affect the richness of the orange gene’s expression.
Dilute (d) – a recessive gene which reduces and spreads out the pigment granules along the hair-shaft and turns a black to blue, chocolate to lilac, cinnamon to fawn and red to cream.
Dilute modifier (Dm) – a dominant gene which serves to modify the action of the dilute gene (it has no effect on undiluted colours), it lightens and
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Draft British Shorthair Breeding Policy – Genetics Committee – after BAC Seminar
“caramelises” the colour turning blue into brownish-grey, lilac and fawn into pale taupe (in all three cases known as Caramel) and cream into a warmer pinkish- cream tone (Apricot)
Polygenes – these are collections of genes which modify the effect of the main dominant and recessive genes above. A build up of polygenes creates a bigger effect, for example a collection of certain polygenes increases the length and density of the long-hair gene to create the Persian, and a build-up of polygenes serves to enhance the effect of the main colour genes, turning the effect of the orange gene from the sandy colour of the ginger domestic tom to the rich vibrant red of the Red Persian, British or Asian Self. It is likely that a group of polygenes is the reason for variation in the degree of tipping in the Shaded Tabby/Burmilla, the polygenes working to create the band-width in interaction with the inhibitor gene (when present) resulting in the range of pattern from tipped to heavily shaded.
Rufus – (polygenes) as yet unidentified, can affect the richness of the orange gene's expression.
Genes not at ‘work’ in the British Section but Useful to Know!
Burmese Colour Restriction (cb) – a mutation on the albino allele one step up from the Siamese (Himalayan) gene. This reduces the amount of pigment produced in the coat but, because it is thermo-sensitive, the pigment is darker at the points and (slightly) lighter on the body; the action of the Burmese gene causing a genetically black cat to turn sepia brown, a red cat to turn pale tangerine.
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Appendix 4 Contributing Breeders
Just as the British Shorthair would not be the cat it is today without the love, tireless energy and sheer hard work that is invested by the breeders, a Policy such as this could not be produced without help.
Our heartfelt thanks to the following contributors and all of our breeders who are doing such a magnificent job on what is the best cat in the world.
Adrian Miller Cassandra Moss Jackie Steele Teknocat Regents Steeleaway
Andrea Zerrilli Celia Leighton Willowood Porteous Judith MacArthur Old Possum’s Mr and Mrs A Brown Christine Clayton Kolinga Malmo Julie Caffel Bluerain Ann Stubbs Elena Nikitenko Positively Bastet-a-tet Karen Holloway Windymeadow Ann Greatorex Jane Best Mewzishun Leonitara Lesley Tricker
Brenda Hollandt Jean Townsend Lizz Benson Pridycats Skellum Limatz
Bron Keeling Jean Wolfe Ludmila Pankova Gooderick Bumpkin Photographer
Caroline Prout Jenny Hemming Marion Wade Fergan Hinderslyne Rodwaye
Corinne Ash Joanne Hewitson Marilyn Storey Jococa Countrystyle Skidoosh
Dee Wiley Julia Oughtibridge Michelle Simpson Purrissimo Alejandro Althalus
Denise Conway June Payne Monica Acton Pampurred Poshpets Idlebeck
Doreen Goadby Hayley Wild Patrick Booth Apatchicats Kolinga Cougar Dorothy Parry Pinemartin Helen Maclay Sandie Holloway Kruzinkal Rayanshel Brenda Wolstenholme
Jun-18 Draft British Shorthair Breeding Policy – Genetics Committee – after BAC Seminar
Sandra Schürmans Suzanne Griss Aus-der-Mondberg Grisselian Viv Clerkin Terri Callahan Silvercloud Sue Lorton Hobbs Calla Cats Loraston Tamila Aspen British Empire Cats Ruta Towse Miletree Tammy Kingwell Purrade Shirley Bullock
Suzanne Dalton Veldes Carnell Donyosabuk Misskin
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