SPRING MEETING, APRIL 2010 BIRMINGHAM BRITISH VETERINARY DERMATOLOGY STUDY GROUP SPRING MEETING

7th APRIL 2010 INTERNATIONAL CONFERENCE CENTRE BIRMINGHAM

SPONSORS

Diamond sponsor: DECHRA

Platinum sponsor: VIRBAC

Gold sponsors: ANIMAL CARE AXIOM NATIONWIDE NOVARTIS PFIZER PROTEXIN

Silver sponsors: IDEXX MERIAL

Bronze sponsors: JANSSEN

The B.V.D.S.G. committee and members would like to thank our sponsors for their generosity and support of this meeting Proceedings published for the British Veterinary Dermatology Study Group by Adventis Health Limited, Adventis House, Post Office Lane, Beaconsfield HP9 1FN Proceedings editor: Sarah Warren BVetMed MSc MRCVS, Mildmay Veterinary Centre, Easton Lane, Winchester, Hampshire, SO23 7RU, UK.

1 PROGRAMME

POCKET PET DERMATOLOGY

WEDNESDAY 7 TH APRIL 2010

9.00 - 9.30am REGISTRATION AND COFFEE

Morning session

9.30 - 10.15 Husbandry and handling of small mammals Anna Meredith

10.15 - 11.00 Rabbit dermatology Frances Harcourt-Brown

11.00 - 11.30 COFFEE AND COMMERCIAL EXHIBITION

11.30 - 12.15 Dermatology of Guinea pigs Anna Meredith

12.15 - 1.00pm Skin diseases in ferrets – not just adrenal disease Nico Schoemaker

1.00 - 2.00 LUNCH

2.00 - 2.30 COFFEE AND COMMERCIAL EXHIBITION

Afternoon session

2.30 - 3.15 Rodent dermatology: Mice and rats Ian Sayers

3.15 - 4.00 Rodent dermatology: Hamsters and gerbils Ian Sayers

Abstracts

4.00 - 4.15 Differing patterns of antimicrobial sensitivity among meticillin-resistant coagulase positive staphylococci isolated from canines Stephen Steen, Peter Webb

4.15 - 4.30 Differing patterns of sensitivity to topical shampoos among meticillin-resistant coagulase positive staphylococcus pseudintermedius isolated from canine cases of superficial pyoderma Stephen Steen, Sue Paterson

2 CONTENTS

Page no. Husbandry and handling of small mammals ...... 5 Anna Meredith

Rabbit dermatology ...... 13 Frances Harcourt-Brown

Dermatology of Guinea pigs ...... 19 Anna Meredith

Skin diseases in ferrets – not just adrenal disease ...... 23 Nico Schomaker

Rodent dermatology ...... 27 Ian Sayers

Differing patterns of antimicrobial sensitivity among meticillin-resistant coagulase positive staphylococci isolated from canines ...... 33 Stephen Steen, Peter Webb

Differing patterns of sensitivity to topical shampoos among meticillin-resistant coagulase positive staphylococcus pseudintermedius isolated from canine cases of superficial pyoderma ...... 35 Stephen Steen, Sue Paterson

3 NOTES

4 HUSBANDRY AND HANDLING OF SMALL MAMMALS Anna Meredith MA VetMB CertLAS DZooMed MRCVS

RCVS Recognised Specialist in Zoo and Wildlife Medicine, Head of Exotic Animal and Wildlife Unit, Royal (Dick) School of Veterinary Studies, University of Edinburgh

RODENTS The order Rodentia has 29 families, 468 genera and 2052 species, making it the largest mammalian order. Weights range from 20g up to the largest of all rodents, the capybara, at up to 50kg. Fortunately only a select few are commonly kept as pets, but all the pet species have been selectively bred to create numerous types and varieties. While rats and mice have been domesticated for hundreds of years, and the “fancy” is well developed, some are more recent introductions. It is believed that all the Syrian hamsters kept as pets are derived from one female and her litter captured in the Syrian desert in the 1930s and gerbils were only introduced in the 1960s. Guinea pigs are still kept as meat animals in South America (the word “pig” is believed to reflect the fact that the meat tastes like pork). Chinchillas were hunted almost to extinction for their fur, and are also used for acoustic research due to their very large tympanic bullae and acute sense of hearing. Classification of rodents has recently changed, and is still controversial, but for simplicity we can refer to the old system of dividing them into three suborders, based on mandibular structure:

Suborder Family Genus & species Common name Myomorpha Muridae Rattus norvegicus Rat Mus musculus Mouse Cricetidae Meriones unguiculatus Gerbil Mesocricetus auratus Golden Hamster Phodopus campbelli Russian Dwarf Campbell Phodopus sungorus Russian Dwarf Winter White Phodopus roborovski Roborovski Hamster Cricetulus griseus Chinese Hamster Hystricomorpha Caviidae Cavia porcellus Guinea Pig Chinchillidae Chinchila laniger Chinchilla Octodontidae Octodon degu Degu

Scuirimorpha Scuiridae Eutamias sibiricus Chipmunk

General points: • From the Latin “rodere” = to gnaw • Dental formula 1/1 0/0 0/0 3/3 myomorpha, 1/1 0/0/1/1 3/3 hystricomorpha, 1/1 0/0 2/1, 3/3 scuirimorpha • Sharp, chisel-shaped, orange/yellow – white, open-rooted, constantly growing incisors • Premolars and molars open-rooted and constantly growing in Guinea pigs chinchillas and degus • Large diastema • Mandible wider than maxilla • To gnaw: Lower jaw moved forward so incisors oppose but molars do not, and cheeks drawn in across diastema. Thus can gnaw for long periods without wearing molars or swallowing debris • To chew: Lower incisors behind upper, and molars opposed • Simple stomach, large sacculated caecum, long colon. • Exhibit coprophagy which enhances absorption of vitamins B and K • Females have a separate vaginal and urethral opening; vaginal opening usually non-patent until oestrus • After mating a vaginal plug is formed • All species (except chipmunks) show a post-partum oestrus within about 24 hours of parturition, and females should be separated from the males unless a constant state of pregnancy or lactation is desired.

5 Biological Data

Species Av Life Maturity Oestrus Gestation Size of Age at Adult Body temp expectancy period litter weaning weight ºC (yrs) Mouse 1-2.5 3-4 weeks Every 4-5 19-21 5-12 21 days 20-40g 37.5 days days

Rat 3 6 weeks Every 4-5 20-22 6-12 21 days 400-800g 38 days days Gerbil 1.5-2.5 10-12 Every 4-6 24-26 3-6 21-28 70-130g 38 weeks days days days

Syrian 1.5-2 6-10 weeks Every 4 15-18 3-7 21-28 100-200g 38 hamster days days days Hibernates

Chinese/ 1.5-2 6-10 weeks Every 4 19-22 3-5 21-28 20-40g 38 Russian days days days hamster

Guinea 4-7 Male 8-10 Every 60-72 2-6 21 days 750-1000g 38-39 pig weeks 15-16 (av 65) Female days days 4-5 weeks Chinchilla 10-15 8 months Every 111 1-4 6-8 wks 400-500g 38-39 30-35 days days Nov-May

Degu 5-7 3-4 months Every 87-93 1-10 28 days 200-300g 38 21 days days (av 5-7) (induced ovulator) Chipmunk 3-5 1 year Every 28-32 2-6 6-7 weeks 80-150g 38 14 days days Hibernates Mar-Sept Handling • Mouse – base of tail; scruff • Hamster – cup in hands; scruff • Gerbil – around shoulders; scruff. NEVER HANDLE BY TAIL. (Degloving tail injuries are common in this species). • Rat – around shoulders, support rear if large/pregnant; base of tail and support weight; scruff. • Chinchilla – around shoulders, support rear. Beware fur slip if handled roughly. • Chipmunk – around shoulders, with thumb under chin to prevent biting; scruff • Guinea pig – around shoulders, support weight if large/pregnant.

Sexing • Rats, mice, hamsters, gerbils Ano-genital distance greater in the male. Nipples visible in female. In hamsters, testicular bulges in mature male visible when viewed from above. • Guinea pigs Preputial orifice is round and penis can be extruded by gentle pressure cranial to prepuce. Vulva is V-shaped. Both sexes have 2 inguinal nipples. • Chinchillas Ano-genital distance greater in the male. Females have large urethral process below the slit-like vulva – can be confused with penis. Males have no scrotum and testes are in or near the inguinal canal.

6 Husbandry • Mouse, rat Main varieties Mice • Self: Solid body colour – includes black, blue, chocolate, fawn, dove, etc. • Tan: One colour on upper body and tan underside • Marked • Any Other Variety(AOV) eg long-haired, chinchilla Rats • Self: solid body colour • Hooded Housing • Indoors in commercial metal or glass cages. avoid wood or plastic – will gnaw • Mesh must be small enough to prevent escape of young if breeding animals (one wire/cm for mice; one wire/1.5cm for rats) • Provide enough space for cage “furniture” – branches, tubes, ladders, exercise wheels (solid rather than open to prevent tail injuries) • Mice and rats are highly social animals so keep as single sex groups (females best, males may fight), breeding pairs or harems • Bedding – wood shavings best, plus paper nesting material. Clean out 2 – 3 times a week to avoid odours Feeding • Omnivorous opportunists • Feed a commercial rodent mix (carbohydrate type seeds – wheat, maize, oats, barley, higher fat type seeds – sunflower, peanuts, biscuit, dried rolled peas) supplemented with fruit and vegetables, household scraps, dog biscuits • Scatter food amongst wood shavings so they have to forage for it • Rats have a sweet tooth and love chocolate and cake, but beware obesity. • Ad lib water in drinking bottles Breeding • Females polyoestrus with oestrus every 4-5 days. • Mice – vaginal plug can persist up to 2 days, gestation 19-21 days • Rats – vaginal plug falls out in 12-24 hours, gestation 20-22 days • Young are altricial • Separate male from female before parturition if you want to avoid mating at the post-partum oestrus. Avoid disturbing the mother for the first 2-3 days or she may eat the young

• Hamster From the German “hamstern” – to hoard. All species have well-developed cheek pouches for storing food. Golden/Syrian hamster. The most commonly kept. • Solitary, and will fight if kept together. • Hibernate at low temperatures (<5ºC). Varieties • Golden – golden brown with white underside and dark cheek flashes • Self – includes cinnamon, cream, honey, grey, white, chocolate (name often includes eye or ear colour, eg red-eyed cream) • Marked – banded most common – white band across back Also piebald, mosaic, tortoiseshell etc. • Satin coat • Long-haired Chinese hamster • Mouse-like body shape with prominent tail • Social • Do not hibernate

7 Russian hamsters (Dwarf Campbell, Dwarf winter white, Roborovski) • Rounded body shape • Social • Do not hibernate. Housing • Commercial cages - simple box shape (wire with plastic base), clear plastic or glass tank, or a system of plastic tunnels and living/nesting “rooms” • Hamsters require a lot of exercise (in the wild are said to travel five miles a night) so space and cage furniture important - solid exercise wheels, climbing bars, wood to gnaw. • Burrowing animals by nature so require deep layer of shavings or peat/shavings mixture, plus a secluded nest box • Use paper or hay for nesting, not cotton wool as this can become impacted in cheek pouches. Feeding • Commercial rodent mix plus fruit, vegetables and nuts • Do take occasional insects and animal protein in the wild • Prefer to eat from the cage floor rather than a bowl • Hoard food in nest box, so must remove perishable items regularly • Ad lib water from a drinking bottle Breeding • Supervision is usually necessary for golden hamsters to ensure they don't fight - the females can be very aggressive towards the males • Use neutral territory or take the female to the male • Female shows oestrus every 4 days and has a vaginal discharge • Vaginal plug is deep and not obvious after mating • Gestation 15-18 days (Syrian), 19-22 (Chinese/Russian) • Privacy is essential for the nursing mother • Young are altricial.

• Gerbil A desert rodent originally from Mongolia. Reached UK in the 1960’s. Varieties • Agouti - natural colour - sandy coat with black guard hairs and black tip to tail. Pale underside. • Self - Albino, cinnamon, black, grey, dove, chinchilla etc • Marked Housing • Social animals so keep in single sex groups (introduced before puberty) or a breeding pair • Best housing is a “gerbilarium” – a glass or plastic tank with a close fitting wire mesh lid or plastic cover half-filled with a mixture of peat and sawdust or shavings • Sand, although “natural”, is not a good substrate as it causes abrasions to the nose. A sand bath can be offered for grooming purposes • Provide nest material and wood to gnaw. • Cardboard rolls and boxes are enthusiastically destroyed • Keep the tank out of direct sunlight as it can overheat. • Gerbils will spend all their time creating a system of burrows that they will constantly rearrange. This system only needs to be cleaned out 2-3 times a year as very little urine is produced. The only disadvantage is they can be difficult to catch. Feeding • Commercial rodent mix supplemented with fresh fruit and vegetables • Gerbils have a great preference for sunflower seeds but don’t overfeed these as they are high in fat and low in calcium • Do take insects in the wild. • Ad lib water should be provided from a drinking bottle. Breeding • Gerbils are unusual in that they form monogamous pairs and the male assists in rearing the young • Female is polyoestrus, every 4-6 days, and shows a congested vulva

8 • Vaginal plug is deep and not easily seen • Gestation 24-26 days • Young are altricial.

• Guinea pig Guinea pigs are referred to as Cavies by serious breeders/fanciers. The name is thought to derive from “Guiana” in South America, and from the fact that their meat tastes like pork. They are still bred for meat in Peru. Breeds and varieties Three main breeds: • English Commonest. Short smooth coat. • Abyssinian Rosetted rough coat. • Peruvian Long-haired – mainly kept as show animals All come in a variety of colours: • Self • Agouti – gold, silver, lemon, salmon, cinnamon • Tortoiseshell/and white • Himalayan – white/cream body and coloured points • Dutch Housing • Guinea pigs are highly social grassland dwellers • Keep in single sex groups, pairs, or harems • They are not hardy animals and you need to consider summer and winter accommodation. They cannot tolerate wet weather well. • A wide range of wooden hutch designs are available. Most have two compartments – one mesh-fronted and one solid-fronted for a nesting area. Wood shavings and hay or straw is suitable bedding • Hutches should be raised off the ground if outside to avoid damp. • Regular daily opportunities to exercise and graze should be provided – a moveable run or ark, or permanent outdoor pen. This should be covered to prevent predation and should have a shelter – the hutch, box or an old piece of drain pipe – to give a bolt hole if the animal is startled. • In winter the hutch should be moved indoors or in to a garage. and an indoor run with wood shavings can be provided • Do not house with rabbits as rabbits tend to bully Guinea pigs and can transmit disease, e.g Bordetella bronchiseptica. They also have differing dietary requirements (vitamin C) Feeding • Guinea pigs have an absolute dietary requirement for vitamin C. They need 10mg/kg per day, rising to three times this in pregnancy • Commercial Guinea pig diets are often supplemented with vitamin C, but the shelf life is short, and cool dark storage conditions must be provided • Feed a limited amount of commercial mix plus ad lib good quality hay and a variety of greenfoods – groundsel, fresh grass, dandelion, cow parsley, broccoli etc. Must provide enough roughage/fibre in the form of hay or grass to maintain dental and gastrointestinal health • Ad lib water from drinking bottle. Breeding • The female is polyoestrus, with oestrus every 15-17 days. • A female in oestrus will arch her back if stroked (lordosis). • An obvious vaginal plug is present after mating. • The young are born after a long gestation period (63 days) and are precocious • Females will synchronise litters if kept together. • It is essential to breed female Guinea pigs young, ideally at about twelve weeks old. After one year old the pubic symphysis fuses and if they are bred for the first time after this dystocia will occur • Approaching parturition can be detected by feeling separation of the pubic symphysis – 24-36 hours before birth the gap widens to approximately 2 cm.

9 • Chinchilla • Chinchillas live at high altitudes in the Andes of South America, and were originally bred in captivity for their beautiful fur • The coat is extremely dense and is too dense for ectoparasites. It is easily damaged or shed if handled roughly (“fur slip”) • Chinchillas are largely nocturnal. Colour forms • Natural colour is a bluish-grey, but mutations of white, brown velvet, black velvet, charcoal, and pastels now exist. Housing • Housing must be indoors • Chinchillas gnaw everything so all-wire cages are best. These should be as large as possible and at least 2m x 2m x 1m • A nest box must provided and plenty of branches to gnaw • A dust bath must be provided to keep the fur in good condition • Females are aggressive to each other so keep singly, or in a breeding pair Feeding • Chinchillas are essentially grassland dwellers and should be fed chinchilla pellets (grass based) and good quality hay, supplemented with vegetables • Avoid sugar-rich treats which can lead to dental caries Breeding • Oestrus occurs every 30-50 days, and is shown by an open vulva and mucoid vaginal discharge • Chinchillas will form monogamous pairs, or you can use a harem system with a male having access to several separate females • A large vaginal plug is present after mating • Gestation 111 days • The young are precocious

• Degu Originate from Chile, introduced to the UK in the 1950s for use in diabetes and jet lag research. • Diurnal, does not hibernate • Vocalises with soft chortles and whistles • Highly social • Live in colonies and dig burrows • Females communally rear young • Used experimentally for circadian rhythm, sleep and jet-lag studies

Housing • Caging as for chinchilla • Provide tunnelling, nest box, sufficient bedding to dig, exercise wheel • Will stockpile food Feeding • Herbivorous, hind gut fermenter • Natural diet is grass, leaves, bark, herbs, seeds, fruits fresh cattle/horse droppings • Feed chinchilla pellets and hay • Supplement with small amounts fresh greens Breeding • Breed all year – multiple litters (6-8/litter) • No regular oestrus cycle; require presence of male to ovulate • Sexually mature 6m • Gestation 90 days • Eyes open 2-3 days • Wean 4 weeks

10 Rodents as pets – advantages and disadvantages

Species Advantages Disadvantages Mouse Small, cheap, cling to handler Smell, tend to be more active at night

Rat Intelligent, responsive, No obvious disadvantages. Many people find sociable, cling to handler hairless tail unattractive Gerbil Odourless, active during day Can be difficult to handle, easily dropped

Hamster Odourless Nocturnal, can bite, easily dropped

Chipmunk Active during day Easily stressed, difficult to handle, best kept outdoors Guinea pig Rarely bite, active during day Can be nervous

Chinchilla Very attractive, soft fur. Little Destructive, often dislike being handled, odour largely nocturnal

FERRETS Ferrets are carnivores and belong to the family Mustelidae. They are related to weasels, otters, badgers and skunks and have been domesticated for many centuries. They are biologically very similar to cats and dogs. On average males (hobs) weigh 1-2kg and females (jills) 0.5-1kg. Their average life span is 5-8 years.

Handling Most pet ferrets are docile and easy to handle with gentle restraint around the neck and shoulders and allowing the hindquarters to dangle. Very heavy or pregnant animals should have the hindquarters supported. In fractious animals it may be necessary to scruff the animal, however the author finds it easiest to encircle the neck with one hand (acting as a neck brace). The body weight and hind limbs should be supported with the other hand, or may be tucked under the elbow to free up the other hand for clinical examination. Take care not to bring a fractious animal close to your face since ferrets have poor eyesight and reflex reactions may result in a bite to the face or nose. Ferret bites may be deep and once attached, the animal may be difficult to dislodge. If this occurs place the ferret on a table and attempt to pry open the mouth. Cold water applied to the head may encourage the animal to let go. Very fractious individuals may need sedation prior to clinical examination. These animals may appear frightened and hiss or scream, indicating that they are likely to be difficult to handle. Biological Data

Average Lifespan 5-8 years Maturity 6-9 months Oestrus Reflex ovulation; seasonally monoestrus – Feb-Sept Gestation period 42 days Size of litter 2-10 Age at weaning 8 weeks Adult weight Hob (male) – 1-2 kg & Jill (female) – 500 – 900g Body temp 37.8 – 400C Heart rate 200 – 400 beats per minute Respiratory rate 33 – 36 breaths per minute

Husbandry

• Housing Ferrets do well in a large hutch-type accommodation outdoors during the summer months and moved into an outbuilding over the winter. A run or court area and opportunites to exercise and play are very important. Direct sun should be avoided as they are susceptible to heat stress. Ferrets will use a latrine area/litter tray. These are usually cornered trays with two

11 high sides. Ferrets can be taken for walks on a harness and enjoy this immensely. They are social and can be kept in single sex or mixed sex pairs or in larger harems. They also do well as solitary animals. House ferrets should have a secure cage to avoid any ‘accidents’ while the owner is out. Bedding can consist of hay or straw or torn newspaper for outdoor ferrets, or vetbed etc for house ferrets. Fibre based products may be ingested and must be carefully inspected for their suitability. The latrine should be cleaned daily and the rest of the cage as required (typically 1 – 2 times a week). Environmental enrichment is important and a variety of tubes, boxes and climbing platforms will suffice.

• Feeding Ferrets are carnivores and naturally feed on a wide variety of prey items. Protein is the primary metabolite, fat is the major energy source and carbohydrate is hardly utilised and the short gut cannot digest fibre easily. Although many owners still feed a more natural diet (prey items such as dead day chicks will be fed) these can lead to deficiencies if too much muscle is fed. Most people now feed complete dry ferret diets which are commercially available. The occasional prey item or a whole raw egg will be relished. Scatter feed to provide enrichment. Ferrets can stash food and this should be removed regularly. Fresh water should be available at all times either in a bowl or a drinker bottle.

• Breeding Sexing is by ano-genital distance. This is greater in the hob and there is an obvious prepuce on ventral abdomen.Testes descend only during the breeding season (Jan-Aug). Jills have a short ano-genital distance and are seasonally monoestrus (Feb – Sept). This occurs in the first spring after birth (typically sexual maturity is nine months of age). Jills are induced ‘reflex’ ovulators. Coitus lasts up to 3 hours, with violent neck biting by the male. The pregnant female should be separated from the male. Gestation lasts for 42 days. Dystocia is very rare. The kits are altricial with weaning at 8 weeks. Cat milk formulae with extra egg yolk can be used for hand rearing. If not mated jills will remain in season (with an obvious swollen vulva) and high levels of oestrogen results in ‘oestrogen toxicity’ leading to bone marrow suppression, immunosuppression, anaemia and collapse. Fur loss is also a common clinical sign. This is not a condition seen in the USA as ferrets are generally neutered at a young age prior to pet ownership which has resulted in a smaller gene pool. American ferrets are also usually smaller than European ferrets. Males can also be vasectomised and kept with females to keep them out of season by sterile matings. Current recommendations are NOT to neuter ferrets but to use hormone therapy such as the ‘jill jab’ for females (proligestone) which lasts for one season in 80% of females or GnRH implants (deslorelin) every 18 – 24 months in either sex. Neutering can lead to adrenal gland disease. Neutered males are known as ‘hobbles’. Implantation of neutered ferrets with deslorelin will prevent adrenal gland disease.

USEFUL REFERENCE TEXTS BSAVA Manual of Rodents and Ferrets. Eds Keeble and Meredith. BSAVA Publications (2009) BSAVA Manual of Exotic Pets 5th Edn. Eds Meredith and Johnson-Delaney. BSAVA (2010) Exotic Animal Formulary 3rd Edition. Carpenter JW. Elsevier Saunders (2005) Ferrets, Rabbits and Rodents. Clinical Medicine and Surgery. 2nd Edition. Quesenberry KE and Carpenter JW. W.B.Saunders (2004)

12 RABBIT DERMATOLOGY Frances Harcourt-Brown BVSc FRCVS, Dip ECZM (Small Mammal)

RCVS Recognised Specialist in Rabbit Medicine and Surgery 30 Crab Lane, Bilton, Harrogate, N.Yorks HG1 3BE Tel: 01423 508945 Fax: 01423 563899

INTRODUCTION It is not possible to cover the whole subject of rabbit dermatology in one lecture, so only the common and/or interesting conditions of pet rabbits will be described. A ready reckoner for the drugs that are most commonly used in rabbit medicine is included. Skin disease in rabbits is common and has the same range of underlying causes as in other species. Neoplasia occurs and general ill health, parasites, fluffy coats and deep skin folds underly many common skin conditions 1. The diagnostic tests are similar to other species, with histopathology as the cornerstone, but unlike dogs and cats, there is not a large amount of available data so it is not unusual to come across a condition that is unfamiliar to the histopathologist. Treatment of skin diseases also follows the same principles as other species except for bathing the rabbits, which is not recommended unless it is absolutely necessary. It can be stressful.

DERMAL FIBROSIS Like cats, thickened skin is a secondary sexual characteristic of entire male rabbits. It can be marked in some cases. Entire male rabbits are also prone to multiple small skin fibromas.

MOIST DERMATITIS AND FLYSTRIKE Moist dermatitis commonly occurs on the face, under the chin or between the hindlegs. It is a usually a consequence of constantly damp fur or deep skin folds. Chronic epiphora, dacrocystitis, dental disease, urinary tract disease, obesity and uneaten caecotrophs are common underlying causes. Flystrike is the consequence of the moist dermatitis, but is an indication of another problem. Healthy active rabbits that can groom effectively do not get flystrike, even if they are exposed to flies. Clipping and cleaning fur from areas of infected skin is essential for successful treatment of moist dermatitis. Infected areas of skin should only be bathed after all the overlying hair has been removed. If the hair is not clipped off, the infected skin is left covered in moist, soiled fur, which is counterproductive. A dedicated set of clippers, with good quality fine clipper blades, for use in rabbits and not dogs or cats makes life much easier. A sharp pair of pointed curved scissors are also useful. Many rabbits, especially female Dwarf Lops, develop deep skin folds especially in the perineal area, but sometimes under the dewlap or on other part of the body. These folds of skin do not go away, even if the rabbit loses weight. Elderly male rabbits often develop skin infections under the scrotum, which becomes increasingly pendulous with age. These skin folds harbour infection and surgical removal of the skin folds alleviates the problem. Surgery is usually straightforward. Elderly male rabbits require scrotal ablation. Vicryl Rapide (3/0 or 4/0)is a useful suture material for skin repair if there is no tension on the skin wound. It is soft and wipes off after 10 days Post-operative antibiotics are essential in these cases.

ECTOPARASITES The most common ectoparasites are Leporacarus gibbus and Cheyletiella parasitovorax. These mites can be found in asymptomatic rabbits. Clinical signs (scaling, pruritus) are usually associated with heavy Cheyletiella infestation and invariably linked with a grooming problem. Dental problems, especially incisor problems, obesity and spondylosis are often associated with cheyletiellosis because the rabbit cannot groom and remove the mites and scale from the fur. Psoroptes cuniculi is less commonly encountered and tends to be a disease of breeders’ rabbits rather than the individual pet. Fleas (Ctenocephalides spp.) can be transmitted to house rabbits from dogs and cats. They usually cause intense pruritus. Flea allergic dermatitis can occur. Rabbit fleas (Spillopsyllus cuniculi) are rarely seen in pet rabbits. Close contact with wild rabbits or their burrows is required. Lice are also unusual.

13 Selamectin (8-16mg/kg) is a very effective treatment for mites in rabbits. It seems to be more effective than ivermectin, presumably because a single application lasts long enough to kill all stages of the life cycle. It is also effective against fleas although imidacloprid (Advantage) is preferable and carries a product licence for use in rabbits. Fipronil (Frontline) should not be used in rabbits. There are reports of fatalities after its use.

INFECTIOUS DISEASES Treponema cuniculi is a spirochaete that causes crusty lesions on the genitalia and on the face, especially around the nose and mouth (rabbit syphilis). In pet rabbits, the disease is most commonly encountered in juvenile rabbits less than a year old although it is occasionally seen as a new condition in adults that have had no contact with other rabbits. Presumably these are asymptomatic carriers that have been stressed and developed overt disease. T. cuniculi is not sensitive to most antibiotics, including enrofloxacin. However, it is responsive to penicillin (and chloramphenicol). The treatment of choice used is 3 injections of long-acting procaine penicillin at weekly intervals. Unfortunately many of these preparations are now discontinued so daily injections of short-acting penicillin can be used instead. Myxomatosis causes characteristic skin swellings, usually on the eyelids, genitalia and nose. It is spread by insect vectors; mosquitoes or midges. The course of the disease is approximately 6-8 weeks during which time the rabbit can have serious respiratory problems and discomfort from the lesions around the eyes and genitalia. Death can occur at any time from secondary infection, respiratory obstruction, starvation or gut stasis. Occasionally a rabbit will survive, which makes it hard to insist on euthanasia at the outset. It is impossible to know which rabbit will be the one to survive. Vaccination offers some protection but it is still possible for vaccinated rabbits to die from myxomatosis if they are challenged. ‘Atypical’ myxomatosis is described when immune rabbits are challenged. This term usually refers to nodular skin lesions that eventually resolve. Ringworm is occasionally encountered, usually in batches of rabbits from the same breeder or petshop. Itraconazole is effective but expensive. Topical antifungal preparations work well. The disease is usually self-limiting in a household with one or two rabbits.

CONTACT DERMATITIS This appears to be common in pet rabbits. Many rabbits are bedded on wood shavings or newspaper, which are likely culprits to cause contact reactions. Also many owners use an array of detergents and disinfectants to clean hutches and cages. Although lesions may be evident on hocks and feet, they can also occur over the ears and eyes as the rabbit grooms and spreads any compound that may be present on the feet.

ABSCESSES Abscesses can occur anywhere in the body but are most commonly encountered around the head and face due to underlying dental problems. Periapical infection can cause extensive osteomyelitis. Radiography is essential, both to assess the extent of the problem and to confirm the presence of an abscess rather than a tumour 2. Sometimes long deformed crowns grow into the cheek and cause abscesses over the cheek. The base of the ear is another site where abscesses form, usually in association with purulent infection of the horizontal ear canal that has eroded through the cartilage. Penetrating wounds, usually fight wounds, can result in abscesses anywhere on the body although the perineum and base of the tail, the nose and eyelids are common sites. Treatment of abscesses is often successful although perseverance is sometimes required. All necrotic and infected tissue must be removed, including teeth and bone. Some well circumscribed abscesses can be removed like tumours, others cannot. For example, lateral wall resection is required for ear abscesses. Sometimes there is extensive skin loss associated with abscesses, especially after fight wounds and this can affect the prognosis. After surgery effective topical and parenteral antibiotic therapy is necessary. This can be provided by implantation of antibiotic impregnated polymethylmethacrylate beads into the abscess cavity. Alternatively, the cavity can be marsupialised by suturing the capsule to the skin, which permits daily cleansing of the abscess cavity and application of topical therapy. Generic gentamicin ear/ear drops followed by Manuka honey can be very rewarding. Honey is effective because concentrated sugar solutions have hygroscopic and bacteriocidal properties. The sugar molecules ‘tie up’ water molecules so that the bacteria have insufficient water to support

14 growth. Honey has all the benefits of strong sugar solutions plus other properties. It actively promotes wound healing. Bees' saliva contains enzymes that convert glucose to antibacterial gluconic acid. Glucose in honey is also enzymatically converted to bacteriocidal hydrogen peroxide 3. Honey from the New Zealand tea tree called ‘manuka’ is reputed to have the most antibacterial properties. Laboratory studies in rabbits have shown that the application of honey accelerates wound healing. 4,5 Honey acidifies the wound and promotes the formation of clean, healthy granulation tissue. Effective systemic antibiotic therapy is also necessary for the successful treatment of abscesses. Despite holding a product licence for use in rabbits, enrofloxacin is often not effective. Penicillin and penicillin-related compounds are preferable and are safe if they are administered parenterally and not orally. Metronidazole may be given at the same time.

SEBACEOUS ADENITIS (EXFOLIATIVE DERMATITIS) This condition is usually secondary to thymic masses, which are one of the more common tumours of rabbits. Radiography of the chest of rabbits with signs of exfoliative dermatitis is mandatory as thymic tumours can be ‘silent’ until they are very large. An increased respiratory rate and exophthalmos are indicators that may be missed. The author has also seen two cases of exfoliative adenitis in association with chronic diarrhoea. Successful treatment of the underlying cause can result in apparent resolution of the exfoliative dermatitis. There is a report of successful treatment with cyclosporin and triglycerides in a case that was not due to a thymoma 6.

SELF-MUTILATION Self-mutilation can be a problem in some individual rabbits. It seems to be a stress response and is more common in entire males. It can be very difficult to manage. Secondary inflammation and infection are common. Elizabethan collars and/or bandages can add to the stress and result in anorexia. Premature baby vests are effective barriers in some rabbits. As well as minimising the opportunity for self trauma, treatment is also aimed at eliminating the stressor, if it can be identified. Neutering can help, so can the provision of large amounts of hay and leafy green plants. Oral antibiotics and NSAIDs are indicated. Some rabbits become so hypersensitive that injections seem to stimulate self-mutilation. Corticosteroids are only used as a last resort in rabbits. Antihistamines (chlorphenamine) can be effective. See overleaf for READY RECKONER FOR SOME COMMON MEDICATIONS

REFERENCES 1. Harcourt-Brown, F.M. (2001) Textbook of Rabbit Medicine, Butterworth Heinemann, Oxford. 2. Harcourt-Brown, F.M. (2009) Dental disease in pet rabbits 3. Jaw abscesses. In Practice, 31, 496- 505 3. Molan, P. (1999). The role of honey in the management of wounds. Journal of Wound Care, 8, 415-418. 4. Bergman, A., Yanai J., Weiss J. et al. (1983). Acceleration of wound healing by topical application of honey. An animal model. American Journal of Surgery, 145, 374-376. 5. Oryan A., Zakar S.R. (1998). Effects of topical application of honey on cutaneous wound healing in rabbits (Abstract). Zentralbl. Veterinarmed., 45, 181-188. 6. Jassies-van der Lee, A., van Zeeland, Y., Kik, M., Schoemaker, N. (2009). Successful treatment of sebaceous adenitis in a rabbit with ciclosporin and triglycerides. Veterinary Dermatology, 20, 67-71

15 READY RECKONER FOR SOME COMMON MEDICATIONS NB. Many of these products are not licensed for use in rabbits. The responsibility for the effects of these preparations lies with the prescribing vet. The dose rates are based on the current state of knowledge, which may be anecdotal.

WEIGHT OF RABBIT 500g 1.0kg 1.5kg 2.0kg 2.5kg 3.0kg 3.5kg Amoxycillin/clavulanic acid (SYNULOX) 7mg/1.75 mg/kg SC 0.05ml 0.1ml 0.15ml 0.2ml 0.25ml 0.3ml 0.35ml **NOT FOR ORAL USE: MAKE SURE THAT THE RABBIT CANNOT LICK THE PRODUCT FROM INJECTION SITE Atipamezole (ANTISEDAN) Start with half the dose of Domitor up to: 1mg/kg IM 0.05ml 0.1ml 0.15ml 0.2ml 0.25ml 0.3ml 0.35ml Buprenorphine (VETERGESIC) 0.03mg/kg SC, IV 0.05ml 0.1ml 0.15ml 0.2ml 0.25ml 0.3ml 0.35ml Carprofen (RIMADYL) 3mg/kg SC 0.03ml 0.06ml 0.09ml 0.12ml 0.15ml 0.18ml 0.21ml Cephalexin (CEPOREX) 20mg/kg SC 0.06ml 0.12ml 0.18ml 0.24ml 0.3ml 0.36ml 0.42ml Chlorphenamine (PIRITON Syrup) 400mcg/kg sid or bd 0.5ml 1ml 1.5ml 2ml 2.5ml 3ml 3.5ml Domperidone 0.5mg/kg bd oral 0.25ml 0.5ml 0.75ml 1.0ml 1.25ml 1.5ml 1.75ml Doxapram (DOPRAM-V) 5mg/kg IV.IM 0.12ml 0.25ml 0.37ml 0.5ml 0.62ml 0.75ml 0.87ml Enrofloxacin (Licensed for rabbits) (BAYTRIL) 10mg/kg SC sid (2.5% injection) 0.2ml 0.4ml 0.6ml 0.8ml 1.0ml 1.2ml 1.4ml 10mg/kg Oral bid (10% liquid) 0.05ml 0.1ml 0.15ml 0.2ml 0.25ml 0.3ml 0.35ml Fenbendazole (PANACUR) 20mg/kg oral sid Panacur 10% liquid 0.1ml 0.2ml 0.3ml 0.4ml 0.5ml 0.6ml 0.7ml Panacur paste (graduations) 0.2 grad 0.4 grad 0.6 grad 0.8 grad 1 grad 1.2 grad 1.4grad HYPNORM (fentanyl/fluanisone licensed for rabbits) As Pre-med 0.2ml/kg SC 0.1mls 0.2mls 0.3mls 0.4mls 0.5mls 0.6mls 0.7mls Marbofloxacin (MARBOCYL) Injection 0.5mg/kg SC 0.25ml 0.5ml 0.75ml 1.0ml 1.25ml 1.5ml 1.75ml (Marbocyl 2% ) Oral: 20mg tabs sid) 1/8 1/4 1/3 1/2 2/3 3/4 1 Meloxicam (METACAM) Metacam injection (0.3mg/kg) SC 0.03ml 0.06ml 0.09ml 0.12ml 0.15ml 0.18ml 0.21ml Oral (0.3mg/kg) 2 drops/kg 1drop 2drops 3drops 4drops 5drops 6drops 7drops CAN HAVE DROPS TWICE DAILY

16 WEIGHT OF RABBIT 500g 1.0kg 1.5kg 2.0kg 2.5kg 3.0kg 3.5kg Metoclopramide (MAXALON) 0.5mg/kg SC, PO bid 0.05ml 0.1ml 0.15ml 0.2ml 0.25ml 0.3ml 0.35ml (Maxalon syrup 5mg/5ml) 0.25ml 0.5ml 0.75ml 1.0ml 1.25ml 1.5ml 1.75ml DOMITOR/ketamine/ buprenorphine (low dose- for premedication) (Domitor ) 50µg/kg 0.025ml 0.05ml 0.075ml 0.1ml 0.125ml 0.15ml 0.175ml + Ketamine 5mg/kg 0.025ml 0.05ml 0.075ml 0.1ml 0.125ml 0.15ml 0.175ml + Butorphanol (Torbugesic) 0.5mg/kg 0.025ml 0.05ml 0.075ml 0.1ml 0.125ml 0.15ml 0.175ml + Tramadol 0.025ml 0.05ml 0.075ml 0.1ml 0.125ml 0.15ml 0.175ml Mix in same syringe and give SC or IM Metronidazole (FLAGYL) 40mg/kg oral BID 0.5ml 1ml 1.5ml 2.0ml 2.5ml 3.0ml 3.5ml (Flagyl 40ml/ml) Penicillin and streptomycin (STREPTOCARE) 40mg/kg 0.1ml 0.2ml 0.3ml 0.4ml 0.5ml 0.6ml 0.7ml **NOT FOR ORAL USE: MAKE SURE THAT THE RABBIT CANNOT LICK THE PRODUCT FROM INJECTION SITE Penicillin – long acting (ULTRAPEN LA) 40mg/kg 0.06ml 0.13ml 0.2ml 0.25ml 0.33ml 0.38ml 0.45ml **NOT FOR ORAL USE : MAKE SURE THAT THE RABBIT CANNOT LICK THE PRODUCT FROM INJECTION SITE Prochlorperazine (STEMETIL syrup) 500µg/kg oral tds 0.25ml 0.5ml 0.75ml 1.0ml 1.25ml 1.5ml 1.75ml Ranitidine (ZANTAC) Injection: 2mg/kg IV sid 0.08ml 0.16ml 0.24ml 0.32ml 0.4ml 0.48ml 0.56ml Syrup: 5mg/kg PO bid 0.15ml 0.33ml 0.5ml 0.66ml 0.75ml 1ml 1.15ml Tramadol 5mg/kg SC, IV, po 0.025ml 0.5ml 0.075ml 0.1ml 0.125ml 0.15ml 0.175ml Trimethoprim/sulpha 48mg/kg SC sid or 40mg oral bid (TRIBRISSEN 24%) 0.1ml 0.2ml 0.3ml 0.4ml 0.5ml 0.6ml 0.7ml 40mg/kg Oral Susp bid 0.4ml 0.8ml 1.2ml 1.6ml 2.0ml 2.4ml 2.8ml (SEPTRIN paediatric suspension)

17 NOTES

18 DERMATOLOGY OF GUINEA PIGS Anna Meredith MA VetMB CertLAS DZooMed MRCVS

RCVS Recognised Specialist in Zoo and Wildlife Medicine, Head of Exotic Animal and Wildlife Service, Royal (Dick) School of Veterinary Studies, University of Edinburgh

ECTOPARASITES Trixacarus caviae causing sarcoptic mange is the most significant ectoparasite of the Guinea pig. The mite causes intense pruritus leading to severe self-trauma, and in some cases, fitting. Abortion and foetal resorption may be seen in pregnant animals. Lesions are seen on the shoulders, dorsum and flanks. Secondary bacterial infection is common. Chronic infection leads to lichenification and hyperpigmentation, crusts, scales and alopecia. A stressor such as old age often triggers clinical disease, concurrent disease or hypovitaminosis C. The mite can cause dermatitis in humans. The life cycle takes 10-14 days. Diagnosis is by skin scrapes, and treatment is with ivermectin 200-400 µg/kg sc every 10 days for three doses. All in-contact animals should be treated and the housing thoroughly cleaned, as the mite can survive for some time off the host. Chirodiscoides caviae is the Guinea pig fur mite. Pruritus and alopecia are only noticed in heavy infestations. Gliricola porcelli and Gyropus ovalis are Guinea pig lice and are commonly found. Heavy infestations will cause pruritus and alopecia especially around the ears. Diagnosis is by visualisation of lice or nits. Treatment is with pyrethrins/pyrethroids or ivermectin. Cheyletiella parasitovorax occasionally produces pruritus and scaling along the dorsum. Treatment is with ivermectin. Demodex caviae rarely causes alopecia, erythema, papules and crusts. Diagnosis is by deep skin scrapings and treatment is with weekly amitraz dips (250ppm) until four weeks after negative skin scrapes are obtained. Underlying disease or stressors should be investigated.

BACTERIAL DISEASE Staphylococcus aureus has been reported as causing erythema and exfoliation of the epidermis in Guinea pigs, caused by epidermal cleavage through the stratum granulosum. 1 Staphylococcal cheilitis, thought to be secondary to the feeding of abrasive or acidic foodstuffs, e.g. hay, apples, is also seen 2 (See under miscellaneous conditions). Pododermatitis is relatively common in Guinea pigs. Staphylococcus aureus is generally isolated, although Corynebacterium pyogenes may also be found. Obesity, poor hygiene, hypovitaminosis C, and wire flooring are all predisposing factors. Treatment involves topical antiseptic and systemic antibiotic therapy and bandaging, plus addressing the underlying cause. However, treatment is often unsuccessful, and systemic amyloidosis often occurs due to the chronic infection.

FUNGAL DISEASE Dermatophytosis is common in Guinea pigs and is invariably due to Trichophyton mentagrophytes. Non-pruritic scaling and alopecia occur around the face and head, with the dorsum also affected in severe cases. Occasionally, more inflammatory pruritic pustules, papules and crusts occur. Diagnosis and treatment are as for other species. Experimentally, skin lesions can be produced in Guinea pigs by the cutaneous application of Candida albicans and Malasssezia ovale, but the significance of these in causing spontaneous lesions is unclear.

VIRAL DISEASE A pox virus has been detected in association with cheilitis in two Guinea pigs with crusting ulcerated lesions around the lips and philtrum. 3 A pox virus was also detected in large fibrovascular proliferations in the thigh muscles of a group of 8-month old Guinea pigs. 4

19 ENDOCRINE DISEASE Cystic ovarian disease is extremely common in aged female Guinea pigs (a 76% incidence in animals between 1.5-5 years old has been reported). The aetiology is unknown, although oestrogenic substances in hay have been implicated. Initially cysts may be asymptomatic, however as they increase in size, non-pruritic alopecia develops over the back and symmetrically over the flanks. Abdominal enlargement and infertility may also be evident. Diagnosis is based on history, abdominal palpation, radiography and ultrasonography. The cysts are usually bilateral and may be up to 10cm in size and painful on palpation. They are often associated with concurrent cystic endometrial hyperplasia, mucometra, endometritis and fibroleiomyomas. Ovariohysterectomy is indicated, however the use of human chorionic gonadotrophin has been reported to temporarily resolve this condition. Percutaneous drainage of the cysts may also be possible under anaesthesia. It is common to see sows with non-pruritic bilateral flank alopecia during late pregnancy. Hair loss due to telogen defluxion, associated with intensive breeding, is thought to be due to reduced anabolism of maternal skin, associated with foetal growth and reverses following parturition. Diagnosis is based on reproductive history and ruling out other causes of alopecia such as dermatophytosis, barbering, vitamin deficiencies, ovarian cysts and ectoparasites. Hyperadrenocorticism has been reported in the Guinea pig 5, due to adrenocortical neoplasia. Classical signs of Cushing’s disease are present – PU/PD, obesity, lethargy and bilateral symmetrical alopecia. The enlarged adrenal gland may be detected ultrasonographically. In the only published report, diagnosis was made by measuring salivary cortisol levels via cotton buds and performing an ACTH stimulation test (20.I.U im). Treatment with trilostane at 2mg/kg bid resulted in a significant improvement in clinical signs. One other case of surgical removal of the adrenal gland is reported but this animal died post-operatively.

NUTRITIONAL DISEASE Hypovitaminosis C is common in Guinea pigs. They have an absolute dietary requirement of 10mg/kg/day, rising to 30mg/kg/day in pregnancy. Important early cutaneous signs are roughened hair coat, and scaling of the pinnae. Inadequate dietary levels of vitamin C or anorexia will rapidly lead to clinical signs.

NEOPLASIA Trichofolliculoma is the most common cutaneous neoplasm. They are benign and usually solitary, and generally occur on the dorsum. A central pore through which keratinous or haemorrhagic material is discharged, is often seen. Complete surgical excision is curative. Sebaceous adenoma, fibroma, fibrosarcoma, lipoma, liposarcoma, schwannoma and lymphoma have all been reported in the Guinea pig.

ENVIRONMENTAL AND BEHAVIOURAL CONDITIONS Fur chewing and barbering are associated with a lack of fibre in the diet, and with stress or overcrowding. Occasionally ear chewing will be seen.

MISCELLANEOUS CONDITIONS Guinea pigs possess sebaceous scent glands on the rump and perineal area. In male animals the oily secretions make the fur matted. Owners can mistakenly assume this is abnormal. However, occasionally the secretions can become impacted and cause irritation. Washing the area with a mild antiseptic shampoo will relieve the condition and help to prevent recurrence. Cheilitis is thought to be associated with the feeding of acidic and abrasive foodstuffs. Secondary bacterial infection (Staph.) is common, and a poxvirus has been associated with this condition in two animals (see above). The author has had good success in treating cases of cheilitis by packing the ulcers with a carmellose soduim, pectin and gelatin ointment (Orabase™; Squibb). Stressed or ill Guinea pigs frequently shed large amounts of hair.

20 Hyperkeratosis and cutaneous horns can develop on the footpads, especially in heavy Guinea pigs and those on wire-bottomed cages. These can be clipped or filed away. Hereditary alopecia is reported in the Guinea pig.

REFERENCES: 1. Ishihara C. An exfoliative skin disease in Guinea pigs due to Staphylococcus aureus. Laboratory Animal Science 1980;30,3:552-557. 2. Smith M. Staphylococcal cheilitis in the Guinea pig. Journal of Small Animal Practice 1977;18:47-50. 3. Culley D. Poxvirus as a cause of cheilitis in the Guinea pig. British Veterinary Dermatology Study Group Newsletter Spring 1995. 4. Hampton EG, Bruce M, Jackson FL. Virus-like particles in a fibrovascular growth in Guinea pigs. Journal of General Virology 1968;2: 205. 5. Zeugswetter F, Fenske M, Hassan J, Kunzel F (2007). Cushing’s syndrome in a Guinea pig. Veterinary Record 160, 878-880.

Further reading: Patterson, S. (Ed.) Skin Diseases of Exotic Pets, Blackwell Publishing, 2006. Huerkamp, MJ, Murray KA Orosz SE.Guinea pigs. In: Handbook of Rodents and Rabbit Medicine, ed. K Laber-Laird, M Swindle, P Flecknell. Pergamon, Oxford;1996:118-124. Collins BR. Dermatologic disorders of common small nondomestic animals in: Dermatology. Contemporary Issues in Small Animal Practice Volume 8. Ed Nesbitt GH. Churchill Livingstone;1987 Scott DW, Miller WH and Griffin CE. Dermatoses of pet rodents, rabbits and ferrets. In: Muller and Kirk’s Small Animal Dermatology 2001; Chapter 21.

21 NOTES

22 SKIN DISEASES IN FERRETS; NOT JUST ADRENAL DISEASE Nico J. Schoemaker, DVM, PhD, Dip ECZM (Small Mammal & Avian), Dipl. ABVP (Avian)

Division of Zoological Medicine, Department of Clinical Sciences of Companion Animals Faculty of Veterinary Medicine, Utrecht University, the Netherlands, Yalelaan 108, 3584 CM, Utrecht, the Netherlands, [email protected]

INTRODUCTION The causes for skin diseases in ferrets can be divided into infectious and non-infectious. Of the infectious agents, parasites − especially ear mites − and dermatophytes are the most common. Bacterial infections are usually secondary. The non-infectious diseases can be divided into endocrine-related, tumour-related and allergies. Adrenal disease is by far the most common dermatological disease in ferrets.

INFECTIOUS DERMATOLOGICAL DISEASES Ectoparasites − Different ectoparasites have been diagnosed in ferrets (i.e. Sarcoptes scabei, Demodex spp, Lynxacarus mustelae, Otodectes cynotis, Ctenocephalides spp). Diagnosis and treatment of mites does not, in essence, differ from that in other mammals. Sarcoptes, Demodex and Lynxacarus are seldom found in ferrets, while the ear mite Otodectes cynotis is very frequently found and often recurs after apparent successful treatment. Some ferrets do not show any signs of an infection, while others show signs of discomfort (scratching at the ear and shaking with the head). An overproduction of earwax may be seen. The mite can easily be visualized with an otoscope or endoscope. Examining a scraping of the black/brown earwax under the microscope, however, is more exact. My preferred treatment is the application of selamectin at the base of the head. Ferrets are just as susceptible to flea infestations as dogs and cats. Clinical signs are also similar, although hypersensitivity is not commonly seen in ferrets. Treatment is similar to that of other companion animals. Dermatophytosis − Microsporum canis as well as Trichophyton mentagrophytes infections have been diagnosed in ferrets. Microsporum infections are reportedly more common. Annular lesions and alopecia are the most frequent finding. Just as in the other domestic carnivores, pruritus is not as common as it is in rabbits and rodents. Cats are usually the source of infection. Some reports recommend shaving the affected areas and only treat topically. My personal preference is to treat these animals systemically as well, as in my mind this will limit the risk of developing a carrier state. Griseofulvin or itraconazole can be used for this. Use of an antifungal shampoo (containing enilconazole) is also recommended for the animal as well as the environment. Owners should be informed of the zoonotic potential of this disease.

NON-INFECTIOUS DERMATOLOGICAL DISEASES Skin tumours − Different skin tumours have been diagnosed in ferrets. Sebaceous epitheliomas (40% of all skin tumours) and mast cell tumours (30% of all skin tumours) are the most common seen, but others such as cutaneous lymphoma (Mycosis fungoides) can also be seen. Although sebaceous epitheliomas have a malignant appearance, they are actually benign tumours of basal cell origin. Multiple tumours are frequently present and they have an irregular appearance. Since the tumour does not spread into the subcutis, this tumour can easily be removed. Mast cell tumours are, in contrast to dogs and cats, benign tumours. These tumours also do not spread into the dermis and are therefore also easy to resect. Mast cell tumours may, in time, reappear at a different site, but these tumours should not be considered metastases. A typical tumour for ferrets is the chordoma. This is a tumour of neural origin which can be located at all locations within the spine. The vertebrae are severely affected. The most common presentation is a swelling at the tip of the tail. These tumours can easily be resected. Tumours at other locations cannot be treated. Food allergy/intolerance − Alopecia is association with pruritus has been seen in some ferrets as a result of a food intolerance. No elimination diets have been proposed for ferrets, and it is

23 not recommended to use the same, high carbohydrate, diets as used in other species as ferret diets should contain a minimum amount of carbohydrates. It is usually sufficient to switch the diet a different brand or to a diet consisting of prey animals. Hyperadrenocorticism − In neutered pet ferrets hyperandrogenism is the most common form of hyperadrenocorticism. In recent years, evidence has been gathered that increased concentrations of gonadotrophins, which occur after neutering (due to the loss of negative feedback), stimulate the adrenal cortex, eventually leading to an adrenocortical neoplasm. This may also explain why hyperadrenocorticism has, up to recently, been considered a rare condition in ferrets in the United Kingdom. Clinical signs of hyperadrenocorticism in ferrets include symmetrical alopecia, vulvar swelling in neutered female ferrets, recurrence of sexual behaviour after neutering, urinary blockage in males (due to peri-prostatic or peri-urethral cysts), occasional mammary gland enlargement in female ferrets, and pruritus. The skin is usually not affected, although some excoriations may be seen. Alopecia usually begins in spring, which coincides with the start of the breeding season, and may disappear without treatment. The next year the alopecia usually returns after which it usually does not resolve spontaneously at the end of the breeding season. Polyuria and polydipsia are reported in ferrets with hyperadrenocorticism. It is not clear, however, whether adrenal hormone production is responsible for these signs, or if these (elderly) ferrets have concurrent kidney disease. The most important differential diagnoses for a ferret with signs of hyperadrenocorticism are a non-ovariectomized female or a ferret with active remnant ovaries. As described above, food allergy/intolerance is seen in ferrets and may result in severe alopecia and pruritus. Although many advanced techniques can be used in diagnosing hyperadrenocorticism in ferrets, the clinical signs remain the most important. Further confirmation can sometimes be obtained by palpating a (tiny) firm mass craniomedial to the cranial pole of the kidneys. The right adrenal gland is more difficult to palpate due to the overlying right caudate process of the caudate liver lobe. Hormones that are commonly elevated are androstenedione, oestradiol, and 17-hydroxyprogesterone. Elevation of one or more of these hormones has been considered to be diagnostic for hyperadrenocorticism. Plasma concentrations of the latter hormones are identical in intact female ferrets compared to those in hyperadrenocorticoid ferrets. It is therefore likely that this hormone panel does not aid in differentiating between a ferret with hyperadrenocorticism and one with an active ovarian remnant. The author therefore does not routinely measure these hormones in the diagnosis of this disease. However, they can be used for evaluating effect of treatment. Plasma cortisol concentrations have – just as in dogs – been found to be of no use for the diagnosis of hyperadrenocorticism in ferrets. Although an increased urinary corticoid-creatinine ratio (UCCR) has been found in ferrets with hyperadrenocorticism, this is not considered to be of diagnostic value because this ratio is also increased in intact ferrets during the breeding season, and in ferrets with an active ovarian remnant. The UCCR can be of use to screen populations for the occurrence of the disease. The most useful tool in diagnosing hyperadrenocorticism in ferrets is abdominal ultrasonography. Ultrasound is especially of great value prior to surgery, if you want to determine which adrenal gland is affected, or if an ovarian remnant is present. In this way the owner can be informed about the potential surgical risks that may be encountered. Another advantage of this technique is that other abdominal organs can be evaluated during the same procedure. By using specific landmarks the adrenal glands can fairly easily be detected in nearly 100% of the cases. When attempting to treat a ferret with hyperadrenocorticism, the most ideal treatment would probably be a combination of surgery and placement of an implant containing deslorelin (a depot GnRH analogue). Surgical removal of the left adrenal gland is fairly easy. The location of the right adrenal gland (attached to the dorsal surface of the caudal Vena cava ) makes it much more difficult to remove. The most effective drugs at this moment are the depot GnRH-agonists of which leuprolide acetate (Lupron Depot, TAP Pharmaceutical Products Inc.) is the most well known. Deslorelin (Suprelorin ®6, Virbac, Europe) is another pharmaceutical GnRH-analogue. Advantages of these implants over leuprolide acetate are that the drug does not need to be reconstituted, lasts much longer than the depot injections, is registered for use in animals, and is much cheaper. These implants have already been used in ferrets with hyperadrenocorticism and are considered very effective. In Europe there is no need to use leuprolide acetate anymore. It must be realized that deslorelin is a GnRH-agonist and will therefore result in an

24 initial stimulation of the adrenals. After approximately 2 weeks this stimulation will subside and the signs of the disease will disappear. The tumour will not decrease in size. In a minority of ferrets (<5%) the tumour may increase in size after a treatment period of at least 2 years. Melatonin has also been proposed as therapeutic option for hyperadrenocorticoid ferrets. Melatonin supposedly suppresses the release of GnRH. Clinical improvement is seen in hyperadrenocorticoid ferrets either receiving 0.5 mg melatonin daily PO or an implant containing 5.4 mg melatonin. In the study in which melatonin was given orally, however, hormone concentrations, in general, rose and the tumours continued to grow. This treatment may therefore pose a risk to the ferrets as their condition deteriorates, which remains unnoticed by the owner.

25 NOTES

26 RODENT DERMATOLOGY Ian Sayers BVSc CertZooMed MRCVS

South Devon Referrals, Abbotskerswell Veterinary Centre, The Old Cider Works, Old Cider Works Lane, Abbotskerswell, Newton Abbot, TQ12 5GH

INTRODUCTION There is a lot of information available about disease problems within laboratory rodents, but not all of these are seen commonly in pet varieties. However this does not mean that they are immune to such problems. Similarly, because a disease problem has not yet been reported in a species does not mean that it cannot succumb. The basic structure and function of the skin of rodents is similar to that in cats and dogs, thus it is important to approach cases in a similar manner whilst being aware of differences. Cell types found in the epidermis are similar to other mammals, i.e. keratinocytes, melanocytes, Langerhans cells and Merkels’ cells. Albino animals possess melanocytes, but melanin is absent. The subcutis, consisting of loose connective tissue and fat, is ample in smaller rodents thus aiding the ease with which animals may be ‘scruffed’ for restraint. However, whilst there is definitely a place for this method of restraint, it should be emphasised that it is not necessarily the ideal approach to immediately adopt upon presentation of a rodent. More gentle approaches are recommended for initial examination and are often less resented by the patient. Hair covers most of the body of small rodents apart from the plantar aspect of the feet and ears. Gerbils are an exception as the dorsal surface of the pinnae is haired. As with other mammals there are three main types or hair: Primary/Guard hairs; Secondary hairs; and Tactile hairs/vibrissae. The primary/guard hairs generally cover the body and lie close to the skin giving the coat a smooth appearance. The secondary hairs are thin and wavy and usually shorter than the guard hairs. It is these attributes that give the characteristic appearance to Rex varieties as they lack guard hairs. Hairless varieties are also bred for specifically. Unlike other mammals rodents do not possess apocrine (epitricheal) sweat glands and thus are prone to heat stress (however their large surface area to volume ratio means they are also susceptible to hypothermia under anaesthesia). At first glance it would appear that tail of rats and mice is hairless but this is not the case. Although the tail is ‘scaly’ in appearance, and is indeed covered with square scales, small hairs grow from under the scales, numbering between two to six, covering caudal scales. The tail of a gerbil is long and haired but the skin is very thin, thus gerbil should not be handled via the tail as it is easy to tear the skin (See ‘tailslip’ below) Hair growth is cyclical. The cycle consists of the anagen/growing phase and telogen/resting phase with a catagen/transitional phase occurring between the two. The cycle is usually synchronised such that adjacent hairs are in the same phase. Hair growth occurs in waves but moulting patterns are not usually seen in small rodents (unlike rabbits). Rodents have often been referred to as “children’s pets” but this term is no longer appropriate. There are many adults who care for rodents in the same way as dogs and cats, and, in the UK with the Animal Welfare Act 2006 there should always be a responsible adult supervising children caring for pet rodents. Full clinical examination should be performed and appropriate diagnostic testing discussed with the owner to reach an appropriate action plan. Invariably the costs of investigation and treatment will exceed the purchase price but it is important not to assume an owners financial limits, and this should not prevent a good service being offered. Where necessary referral should be discussed and considered. Similar to a number of exotic species, signs of pain are not overt and may be overlooked by owner or clinician, but analgesia should not be ignored. Where cost is a problem patient welfare should be paramount. The clinical approach to a dermatological problems should be similar to that for more familiar species. In order to get some samples it may be necessary to anaesthetise the small rodent patient. Although there is a risk associated with any anaesthetic if appropriate steps are taken these risks can be minimised and samples can be obtained in a minimally stressful manner (for both patient and clinician!).

ECTOPARASITES A wide range of ectoparasites can be seen in pet rodents and are summarised in the table overleaf. Clinical signs are largely associated with alopecia, scaling, ulceration and secondary bacterial infection associated with self-trauma. Skin scrapings, coat brushing, hair plucks (trichograms)

27 or sellotape strips should be used to demonstrate the presence of adults mites and lice, insects, nymphs or eggs. Examination of the coat with a hand lens may also demonstrate large parasites.

Species Parasite Comments Myobidae: Fur mites: Low numbers rarely cause signs. Alopecia Myobia musculi and ulceration in large infestations or Radfordia affinis immunosuppression Mycoptidae: Mange mites: Similar to fur mites but less severe Mycoptes musculinis, Trichoecius rombousti (rare) Mice Polypax serrata Sucking louse rarely seen on mice but zoonotic importance as vector of tularaemia Psorergates muricola Burrowing mite that causes small white nodules on ear pinnae and body Liponussoides sanguineous House mouse fur mite: Asymptomatic unless very large numbers. Environmental control required. Myobidae: Fur mites: Pruritus around head and shoulders leading Myobia musculi to self-inflicted ulcerative and scabbing lesions. Radfordia affinis Radfordia ensifera Notoedres muris Watery papular lesions associated with yellow crust on Rats the nose and ear flaps. Can also be erythematous and vesicular or papular lesions on tail, limbs and genitalia. Polypax spinculosa Sucking louse of lab rats. Can cause pruritus, restlessness and anaemia and act as a vector for disease. Demodex spp Incidental – unknown if associated with disease Demodex criceti (in keratin and Alopecia, dry scaly skin, erythema and small pits of epidermis) haemorrhages. Not often pruritic unless infected and Demodex aureti (in hair follicles) associated with immunosuppression or ageing (although small numbers can be found in healthy Hamsters hamsters). Notoedres notoedres (ear mite) Thick, yellow crust with associated alopecia and Notoedres cati (cat mange mite) erythema on the pinna, tail, genitalia, paws and muzzle. Trixacarus caviae Sarcoptes scabei Demodex meroni Associated with immunosuppression and underlying disease such as old age, poor diet and husbandry- related problems. Causes alopecia, scaling and focal ulcerative dermatitis with secondary infection. Acarus farris (fur mite) Alopecia, scaling and thickening of the skin over the tail, hindquarters and head. Gerbils Liponyssoides sanguineous House mouse fur mite: Asymptomatic unless very large numbers. Environmental control required.

Tyrophagus castellani Copra itch mite: Asymptomatic

Liponyssus bacoti Tropical rat mite – lives in the environment and only comes on the host to feed Any rodent Fleas Seen where there are dogs and cats. Also seen on wild species.

Treatment options are broadly similar for most of the parasites and for specific details the reader should consult the further reading. Reportedly effective treatments include: Ivermectin – 0.2-0.4mg/kg given by mouth, SC, or topically dissolved 1:10 in propylene glycol to improve absorption. Treatment should be repeated every 7-14 days for a total of 3 treatments. This will work well for most parasites although the authors have seen a number of treatment failures with topical administration – with both homemade and commercial preparations (e.g. Xeno 450; Genitrix). In these cases we recommend giving the ivermectin by SC injection. Large

28 colonies can be treated but calculating a “total dose” based on group bodyweight and then mixing with propylene glycol and spraying the group evenly. Selamectin (Stronghold; Pfizer) – Has been useful when used at 12-18mg/kg and repeated after 30 days to treat most ectoparasite infestations. Amitraz (Aludex; Intervet / Schering-Plough Animal Health) – Use diluted to 100ppm (0.01%) and bathe weekly until 4 weeks after negative scrapes. Alternatively it can be applied with a cotton bud. This can be toxic to small mammals so should be used with caution and informed owner consent, and is normally reserved for treatment of demodicosis. Licking should be prevented for 30 minutes post-application. Benzoyl peroxide shampoo (Paxcutol; Virbac) – This will stimulate follicular flushing and reduce the mite load. This is useful preceding amitraz treatment. Lime sulphur dip (Limeplus; DermaPet UK) – This is new in the UK and is keratolytic and useful in the treatment of Demodex sp., Trixacarus sp. and possibly other ectoparasites. Environmental Control – Regular bedding changes and good environmental hygiene and decontamination will help treatment of many infestations. Some sources recommend fragrant wood chips such as cedar or pine to control ectoparasites, but they can also be associated with skin hypersensitivity, so plain paper or recycled litter is preferable. In a single pet mouse that has signs of mites, but negative scrapes and no history of contact with others, consider biopsy for dermal hypersensitivity. Fipronil (Frontline; Merial) – The spray is occasionally used for rodents at 3ml/kg, by weighing the animal accurately; placing the appropriate volume on a swab or cloth, and then wiping carefully over the patient. Care must be taken to avoid excessive grooming and to keep the patient warm and well ventilated until dry.

BACTERIAL SKIN DISEASE In rodents bacterial skin disease is usually due to opportunistic pathogens. Staphylococcus aureus, Pasteurella pneumotropica and Streptococcus pyogenes are common isolates. Abscesses often occur after bites or other trauma. Diagnosis can be based on demonstration of bacteria on impression cytology. Culture and sensitivity can be performed but unless there is a resistant pathogen will not aid treatment. Abscesses are best excised surgically leaving abscess capsule intact but where this is not possible lancing and lavage under anaesthesia may be attempted. Treatment requires appropriate topical and/or systemic antibiosis and analgesia. Recurrence is common if the underlying cause is not addressed or the abscess capsule is not removed. Bacterial infection of the ventral scent gland in gerbils, or the flank gland in hamsters, may complicate diagnoses of scent gland neoplasia on initial presentation.

FACIAL DERMATITIS (NASAL DERMATITIS, FACIAL ECZEMA, “SORE NOSE”) This is a common condition in gerbils, especially in sexually mature, group-housed animals and incidence may be as high as 15%. The Hardarian gland is located inside the orbit and secretes both mucoprotein and lipids which are usually groomed away. Stress factors trigger hypersecretion, and accumulation in debilitated animals due to decreased grooming. Porphyrins are irritant which can result in rubbing of the face, self-trauma and secondary infection. Initial signs include erythema around the nares that can spread, to include the face, paws and abdomen. Areas of alopecia develop and progress to extensive moist dermatitis. Diagnosis is based on clinical signs, bacterial culture and cytology of impression smears. Treatment for secondary infection is indicated, but improving husbandry, environmental temperature and reducing humidity (to less than 50%) are important. Provision of a sand bath will improve fur quality and promote grooming.

FUNGAL SKIN DISEASE Dermatophytosis Dermatophytosis is not uncommon in rodents but can often be asymptomatic. Where signs are present they are often dismissed as mites. Most common aetiological agents are Trichophyton mentagrophytes, Microsporum canis and M.gypseum. Secondary bacterial infection will often complicate the disease. Affected animals may be asymptomatic or show typical dry circular lesions, alopecia, erythema and scaling.

29 Toothbrush brushing of the entire animal is recommended for dermatophyte culture, or microscopy of hair samples should be used for diagnosis. Trichophyton spp. and 50% of Microsporum spp. do not fluoresce, thus examination with a Wood’s lamp can be unrewarding. Treatment should be attempted with topical therapy to remove spores from the hair shafts and systemic therapy to act at the hair follicles. Small lesions can be clipped, but with multiple lesions a whole body clip may be beneficial. Systemic treatment with ketoconazole, itraconazole and terbinafine have all been reported. Under the veterinary drug cascade in the UK, itraconazole should be the first choice since it is licensed in cats. Topically, enilconazole can be applied daily or every other day with a toothbrush or cotton bud (although can be toxic when ingested), or a miconazole/chlorhexadine shampoo (Malaseb; Dechra) used every other day may be helpful. Treat until two negative cultures 2-4 weeks apart. Removal of spores from the environment is essential to prevent re-infection. Therapy in rodents is more challenging than cats and dogs. Therapy usually lasts longer than other patients due to the difficulty in preventing self-licking or scratching. Also owner compliance can be variable when challenged with having to bath and medicate a rodent daily for an extended period. Care should be exercised because of the potential for zoonosis.

VIRAL SKIN DISEASE Hamster Polyomavirus (Papovavirus) Hamsters polyomavirus (HaPV) causes cutaneous epitheliomas in Syrian hamsters with up to 50% affected in laboratory colonies. The host specific virus is also thought to be the cause of transmissible lymphoma (abdominal, thoracic or epitheliotropic) and other skin tumours (see Dermatology). Wart like lesions are seen in young (3-12 months) hamsters around the eyes, mouth and perianal area. The virus is transmitted via urine, is highly contagious, has a long incubation period (4-8 months) and is very resistant in the environment. There is no spontaneous resolution. Poxvirus Poxvirus is reported in lab rats but is extremely rare. It causes erythematous papules on the tail paws and muzzle, which can be crusted and necrotic. Diagnosis is based on histopathology and therapy is simply supportive with treatment of any secondary infection.

ENDOCRINE DISEASE Cystic Ovarian Disease Cystic ovaries have been reported in all small rodents but are most often seen in hamsters (2%) and gerbils (up to 50% of animals > 400 days of age). Clinical signs include poor coat quality, symmetrical alopecia, abdominal distension and dyspnoea. Adequate nutritional intake may also be affected due to the abdominal crowding. Diagnosis is made with radiography and ultrasound. Ovariohysterectomy is the treatment of choice although medical options with human chorionic gonadotrophin and GnRH implants have not been evaluated. Hyperadrenocorticism This can be primary (neoplasia of the adrenal cortex), secondary (excess ACTH secretion due to a pituitary tumour) or iatrogenic from glucocorticoid therapy. Hamsters demonstrating signs similar to hyperadrenocorticism in dogs do occur in practice, but only one case report exists, with one animal possessing elevated serum cortisol levels. Clinical signs can include bilateral symmetrical flank alopecia, hyperpigmentation, comedones and thinning of the skin, polydipsia, polyuria and polyphagia. Differential diagnoses of dermatophytosis, lymphoma and demodicosis need to be ruled out but the latter can often occur secondary to hyperadrenocorticism. Diagnosis is normally based on clinical signs; there are no reports of the use of the ACTH stimulation or dexamethasone suppression tests, but this may reflect the limited blood volume and practicalities of repeat sampling. Urine cortisol:creatinine ratio may be easier to rule out hyperadrenocorticism but reference ranges need to be established. Elevated serum cortisol (normal range 13.8-27.6 nmol/l) or alkaline phosphatase (normal range 6-18 IU/L) may be present but can also be elevated due to stress. The use of metyrapone was effective in one animal but other medications have not been fully evaluated. Hyperadrenocorticism has been occasionally reported in aged gerbils and rats, but is rare.

30 BEHAVIOURAL OR HUSBANDRY-RELATED SKIN DISEASE Barbering Barbering is typically reported in groups, or pairs, of rats and mice where a hierarchy is established. The dominant animal nibbles the whiskers and hair of subordinates; most commonly the face is affected. The underlying skin appears normal and there are no signs of pruritus. Often only the dominant animal is unaffected. Removal of this individual can resolve the problem, but it may only be temporary as subsequent dominant individuals may show the same behaviour. Barbering can also occur in other species. If it occurs in large groups of gerbils alopecia is generally seen on the dorsal head and tail base, whereas flank alopecia is evident in Guinea pigs. Decreasing stocking density is recommended. Sand baths Gerbils require sand baths to keep the coat in good condition, similar to chinchilla. Otherwise the coat becomes oily. Humidity Gerbils should be kept in a dry environment. Relative humidity should be kept below 50% otherwise an unkempt oily coat will result. “Tail Slip” The skin on the tail of gerbils is very thin. If animals are held by the tail there is a high likelihood that the skin will tear off exposing underlying connective tissue and bone which will become necrotic. Analgesia and surgical amputation, to the level of healthy skin, is indicated. Ringtail In rats aged 7-15 days, low environmental humidity (<20-40%) is associated with the development of annular constrictions of the tail, often near the base. The tail becomes oedematous, inflamed and then necrotic. Aetiology is unclear but may involve fatty acid deficiency, low or high temperature, genetics, dehydration and trauma. Treatment requires increasing humidity and attempts can be made to surgically release the constriction with small longitudinal incisions of the constricting band of tissue. Cheek pouch problems Hamster cheek pouches often become impacted with various materials including food and bedding. Animals present with distension of the face unilaterally or bilaterally which can extend as far back as the scapulae. If present for a long time, rupture of the pouch in the sub- cutaneous space can occur leading to infection. Treatment involves everting, emptying and flushing the pouches under general anaesthesia. Abrasions and infection should be treated with appropriate antibiosis (topical or systemic) and any rupture in the pouch can be sutured to prevent recurrence. Potential underlying causes such as dental malocclusion should be evaluated.

NEOPLASIA Skin neoplasia, e.g. trichoepithelioma, is seen in rats and mice, but the majority of skin masses are abscesses. In hamsters the most commonly reported cutaneous neoplasia are melanomas and melanocytomas followed by epitheliotropic lymphoma. Skin abscessation is more likely to be seen in group animals but, due to haematogenous spread from other sites, lesions may be seen without associated signs of trauma. Subcutaneous masses in rats and mice are most commonly related to neoplasia of the extensive mammary tissue. Mammary gland neoplasia This is the most common spontaneous neoplasm of mice and rats but is rare in hamsters and gerbils. Most mammary tumours in rats and hamsters are benign, whereas in mice and gerbils they are malignant. In rats 90% of mammary tumours are benign fibroadenomas and are uncommon in rats under 1year old. The tumours are usually single, firm, unattached to deeper structures and do not metastatise but their size can become a problem if not treated early. In mice 90% of mammary tumours are malignant adenocarcinomas and fibrosarcomas. Mammary gland tissue is extensive in rats and mice, extending from the neck to the groin and as high as the flanks and shoulders. In hamsters and gerbils mammary tissue is confined to the ventral thorax and abdomen. Surgical excision is indicated in the early stages. If surgery is not elected continued growth of the mass can result in ulceration of the mass, ambulatory problems, self- trauma or other welfare issues.

31 Epitheliotropic Lymphoma (EL) Old hamsters often present with clinical signs consistent with skin neoplasia, however, failure to reach a diagnosis and report findings means the true aetiology of these signs can be unclear. EL is thought to be the second most common tumour in hamsters and can be confused with demodicosis, and hyperadrenocorticism. Clinical signs can be varied depending on the extent and progression of the disease but includes: alopecia; pruritus; dry flaky skin; secondary infection; cutaneous plaques or nodules; cutaneous ulceration and crusts. Diagnosis is based on biopsy and impression smears. Previously treatment has not been recommended and euthanasia is carried out when the disease has progressed sufficiently to cause suffering. There is limited information about chemotherapy and survival times in hamsters with lymphoma and much is anecdotal or incomplete. Protocols have been based on drugs that can be given subcutaneously and orally at dosages used in other animals. With venous access ports, perhaps intravenous protocols may also be of use. Prednisolone therapy has been used with good effect as a palliative measure. Scent Gland Neoplasia Neoplasia of the scent glands occurs in both hamsters (flanks) and gerbils (ventrum), with or without secondary infection. Sometimes at initial presentation it can be difficult to differentiate between simple infection and secondary infection of a neoplastic gland. Glands can appear matted and moist during normal glandular secretion. Cytological examination of impression smears and response to antibiosis can be useful. Tumour growth is usually androgen dependant and simultaneous castration has been recommended, but the author does not routinely do so – with no observed detrimental effects. Benign adenoma, and malignant adenocarcinoma and squamous cell carcinoma are seen. Total gland excision is recommended, ideally in the early stages. Removal is usually achieved by a simple cutaneous incision and attention to haemostasis, and decreases the chances of local spread.

FURTHER READING Baker HJ, Lindsey JR, Weisbroth SH: The laboratory Rat. Volume 1: Biology and Diseases. New York, Academic Press, 1979 Burgmann P (1997) Dermatology of rabbits, rodents and ferrets. In: Practical Exotic Animal Medicine: The Compendium Collection, ed. K Rosenthal, pp. 175-179, 184-185. Veterinary Learning Systems, New Jersey Ellis, C., Mori, M. (2007) Skin diseases of rodents and small exotic mammals. Vet Clin North Am Exot Anim Pract. May; 2(4): 493-542. Carpenter J.W (2005) Exotic Animal Formulary 3rd Ed, Elsevier Saunders Ferrets, Rabbits and Rodents Clinical Medicine and Surgery 2nd Ed, 2004; Eds: Quesenberry, K.E. & Carpenter, J.W.; Saunders Keeble E: Endocrine diseases in small mammals.In Pract., Nov 2001; 23: 570-585 Krogstad AP, Franklin CL, Besch-Williford CL: An epidemiological and diagnostic approach to murine skin lesion [abstract]. Proceedings of the 52nd American Association for Laboratory Animal Science National Meeting, Baltimore, 2001, p.94 Kuntze A: Diseases of Guinea pigs and golden hamsters important in practice. [German] Monatshefte fur Veterinarmedizin 1992; 47: 143-147 Paterson, S (Ed) (2006) Skin Diseases of Exotic Pets Sayers IR, Smith S (2009) Rats, mice, gerbils and hamsters. In BSAVA Manual of Exotic Pets 5th Ed Eds:Meredith A, Johnson-Delaney C Renshaw HW, Van Hoosier GL Jr, Amend NK: A survey of naturally occurring diseases of the Syrian hamster. Lab Anim 1975; 9: 179-191 Schmidt RE, Eason RL, Hubbard GB: Pathology of Aging Syrian Hamsters. Boca Raton, CRC Press 1983 Vincent AL, Rodrick GE, Sodeman WA Jr: The pathology of the Mongolian gerbil (Meriones unguiculatus): a review. Lab Anim Sci 1979; 29: 645-651

32 DIFFERING PATTERNS OF ANTIMICROBIAL SENSITIVITY AMONG METICILLIN-RESISTANT COAGULASE POSITIVE STAPHYLOCOCCI ISOLATED FROM CANINES Stephen Steen, Peter Webb, Axiom Veterinary Laboratory, Newton Abbot, Devon

INTRODUCTION The incidence of infections due to meticillin-resistant staphylococci in domestic animals, particularly those caused by meticillin-resistant strains of Staphylococcus aureus (MRSA), is of concern for veterinary practitioners. Whilst much veterinary and medical attention has been focused on MRSA, there have been fewer reports concerning other meticillin-resistant species of staphylococci, particularly meticillin-resistant strains of Staphylococcus pseudintermedius (MRSP).

MATERIAL AND METHODS From 1st August 2007 to 31st July 2008 125 isolates of meticillin-resistant staphylococci were identified. Isolates were identified as staphylococci based on their colonial morphology, and, where appropriate, Gram stain and catalase reactions. All were tested for coagulase production using the tube method, and for susceptibility to a variety of antimicrobials using a standard British Society for Antimicrobial Chemotherapy (BSAC) methodology. Screening for meticillin resistance was performed using Oxacillin Resistance Screening Agar (ORSA), and Brilliance TM MRSA Agar (Oxoid Ltd., Basingstoke, UK), together with a conventional BSAC disk diffusion method, employing Iso Sensitest agar (with 4% horse blood) and disks containing oxacillin at a concentration of 1 µg disk (Oxoid, Basingstoke, UK). 43% of isolates were identified as coagulase positive MRSA, 14% as coagulase positive MRSP.

RESULTS All the meticillin-resistant staphylococci that were isolated showed in-vitro resistance (zone sizes <10mm) to ampicillin, cephalexin, cefovecin, enrofloxacin and marbofloxacin. The pattern of resistance to trimethoprim/suplhamethoxazole, gentamicin, doxycycline and clindamycin was more variable among these organisms. Whereas 64% of MRSA isolates were susceptible to all four of the antimicrobials, none of the MRSP were sensitive to all four of these drugs (p<0.05). Conversely, while no MRSA isolates were resistant to all four agents, 50% of MRSP showed resistance to all four, and, indeed, 94% of all MRSP isolated showed resistance to three or more of these agents. Notably, in those cases where multiple-resistance was seen, sensitivity to gentamicin was the most frequent finding.

33 NOTES

34 DIFFERING PATTERNS OF SENSITIVITY TO TOPICAL SHAMPOOS AMONG METICILLIN-RESISTANT COAGULASE POSITIVE STAPHYLOCOCCUS PSEUDINTERMEDIUS ISOLATED FROM CANINE CASES OF SUPERFICIAL PYODERMA

Stephen Steen, 1 Sue Paterson, 2 Axiom Veterinary Laboratory, Newton Abbot, Devon 1 Rutland House Referral Hospital, St Helens 2

INTRODUCTION Meticillin-resistant coagulase positive Staphylococcus pseudintermedius (MRSP) has now been recognised as a significant bacterial pathogen in canine pyoderma. The first multiply resistant isolates were described in 2007 by Loeffler. Meticillin-resistant Staphylococcus aureus (MRSA) shows resistance to most of the commonly used first line veterinary antibacterials but is generally sensitive to doxycycline, potentiated sulphonamides, clindamycin and gentamicin. MRSP shows the same resistance to first line drugs and in addition is commonly resistant to at least 3 and often all four of these antibiotics. Many cases of MRSP occur in dogs which have had multiple other antimicrobial therapies. This study was to assess the potential activity of topical therapy against MRSP to see if this could potentially be used as a means of supplementing systemic therapy and possibly preventing colonisation of the skin with MRSP in dogs on antimicrobial therapy.

MATERIAL AND METHODS Ten different topical preparations/shampoos were used these contained 2% acetic acid/2% boric acid, 1% povidone iodine, lime sulphur solution, EDTA tris aqueous solution, 2% colloidal oatmeal shampoo, EDTA tris + 0.15% chlorhexidine, 2% miconazole/2% chlorhexidine, 2% benzoyl peroxide, 10% ethyl lactate, EDTA tris +4% chlorhexidine. MRSP was identified from 29 cases of canine pyoderma 2 and isolated as previously described. Suspensions of the organism under test were prepared in exactly the same way as for susceptibility testing (i.e. according to BSAC standards and such that a semi-confluent lawn of growth was obtained). Plates were divided into 4 quarters, such that 4 ‘shampoos’ could be tested per plate. 12mm diameter holes were cut in each quarter of the plate using a sterile cork borer. 200 µl of ‘shampoo’ was then pipetted into the appropriate well of the plate, and plates incubated at 37C for 18 hours. The area of inhibition of the organism under test, around each well, was then measured (in mm) taking 4 measurements diagonally across the well and averaging the zone diameter.

RESULTS Results indicated that 2% acetic acid/2% boric acid, 2% miconazole/2% chlorhexidine, EDTA tris +4% chlorhexidine and 10% ethyl lactate shampoos were effective against all of the isolates of MRSP. The other topical preparations were inconsistent in their activity against MRSP only working in a few cases.

Mrs Paterson is the veterinary advisor to DermapetUK

35 NOTES

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