Optimizing an indoor lifestyle for cats
■ Margie Scherk, DVM, Dipl. ABVP (Feline Practice) catsINK, Vancouver, BC, Canada Dr Scherk graduated from the Ontario Veterinary College in 1982 and opened the “Cats Only Veterinary Clinic” in Vancouver in 1986, practicing there until 2008. She has written numerous book chapters and has published several clinical trials on feline topics; she is also an active international speaker and enjoys teaching on-line. Dr Scherk has served extensively within the American Association of Feline Practitioners, as well as other veterinary organizations, and is co-editor of the Journal of Feline Medicine and Surgery. Her interests include all things feline, but in particular analgesia, the digestive system, renal disease, nutrition and enabling more positive interactions with cats.
■ Introduction (2), whereas in the United Kingdom the majority of cats People benefit from living with pets. As companions, were allowed outside (3) whilst a study from Melbourne, they provide stress relief, stability of routine, and im- Australia reported that 23% of cats were “mainly in- PROVED HEALTH 9ET HOW TO BEST CARE FOR OUR CATS RE- doors” (4). Why are there such “cultural” differences? mains controversial, and there are cultural and regional The decision to keep a cat indoors may be practical: liv- differences in what people believe is the best way to ing on the 21st floor of an apartment building in a busy house cats. As long ago as 1997, between 50-60% of city prevents ready access to the outside. In other situa- cats were housed strictly indoors in the United States tions, it is true that keeping a cat indoors reduces the risks from wandering, poisoning, automobile accidents, contagious disease or fights with other animals (5,6), and owners may also believe that it removes the risk of internal and external parasites (e.g., heartworm, fleas). +%9 0/).43 /THER REASONS TO KEEP CATS INDOORS INCLUDE AVOIDANCE OF s #ATS RESTRICTED TO INDOOR LIVING HAVE A unwanted pregnancy (assuming the pet is not spayed) REDUCED RISK FOR VEHICULAR TRAUMA PREDATION and to protect wildlife. AGGRESSIVE INTERACTIONS WITH CATS AND OTHER ANIMALS AND EXPOSURE TO INFECTIOUS ■ What are the effects of indoor living DISEASES on cats? s )NDOOR LIVING IS NOT WITHOUT RISKS Are there any downsides to keeping cats strictly indoors? s .OT ALL CATS CAN ADAPT READILY TO AN INDOOR There is a reality-perception mismatch if owners think LIFESTYLE AND MAY BE AT INCREASED RISK FOR that their indoor cat’s life is free from perils, as the indoor CERTAIN BEHAVIORAL AND MEDICAL PROBLEMS cat experiences different hazards. These include falls s !LL ENVIRONMENTAL AND SOCIAL NEEDS MUST from balconies and windows, kitchen scalds or burns, BE MET FOR SUCCESSFUL INDOOR LIVING AND THE and access to toxic cleaning products, unsuitable food WELLBEING OF EACH CAT NEEDS TO BE EVALUATED (e.g., onion, garlic) and plants (3) (Table 1). Studies REPEATEDLY OVER TIME comparing mortality of cats housed indoors with those s 0REDICTABILITY FAMILIARITY ROUTINE AND allowed outside are not available in the North American HAVING A SENSE OF CONTROL ARE KEY FACTORS IN veterinary literature (7). However, cats have not been REDUCING STRESS selectively bred to be indoors 24 hours a day, and many s /FFERING OUTDOOR ACCESS DOES NOT do not adjust to living in close contact with people (4). COMPENSATE IF THE CAT HAS POOR CONDITIONS For this adaptation to be successful, a cat must have INDOORS had complete and successful socialization to people prior to eight weeks of age (4). Additionally, because fearful traits can be inherited, some cats will be unsuited
2 / Veterinary Focus / Vol 26 n°2 / 2016 to close human contact (4). Similar concerns exist when Table 1. Comparing lifestyle risks (adapted from (3)). trying to integrate cats from different sources: this REQUIRES EARLY SOCIALIZATION AND CATS HAVE DIFFERENT PER- Increased risks Increased risks sonalities (e.g., sociable, timid and unfriendly, active and associated with living associated with aggressive) that may be incompatible (8). strictly indoors outdoor access s ,OWER URINARY TRACT s )NFECTIOUS DISEASES A monotonous and overly predictable environment is DISEASES IDIOPATHIC &E,6 &)6 RABIES stressful (9). Cats may not be able to perform behaviors AND CALCIUM OXALATE PARASITES that express their natural telos – their cat-like nature. The UROLITHIASIS s 6EHICULAR ACCIDENTS resulting psychological and physiological stress may s (YPERTHYROIDISM s 4RAUMA FALLS develop into either problem behaviors (natural behaviors s /BESITY that are unwelcome, e.g., spraying or scratching), s !LTERCATIVE TRAUMA s $IABETES OTHER CATS OTHER behavior problems (e.g., obsessive grooming), or physi- ANIMALS cal illness. Signs of stress and anxiety may be overt s /DONTOCLASTIC RESORPTIVE LESIONS s 'ETTING LOST (e.g., changes in appetite, grooming, increased vocal- ization, hiding, vigilance, aggression, spraying or com- s "OREDOM s 4HEFT pulsive behaviors (Figure 1)), or subtle (e.g., decreased s (OUSEHOLD HAZARDS s 0OISONING ACTIVITY PLAY EXPLORATORY BEHAVIORINQUISITIVENESS FACIAL BURNS POISONS FALLS marking, affiliative interactions with people and other s )NACTIVITY DECREASED animals) (10). lTNESS s 0ROBLEM BEHAVIORS Certain physical illnesses are more prevalent in indoor SPRAYING SCRATCHING cats (Table 1) although it can be argued that indoor s "EHAVIOR PROBLEMS cats may be more closely observed, so that behavior OBSESSIVE BEHAVIORS changes are more readily noticed, or they receive more s $ERMATOLOGIC PROBLEMS FREQUENT VETERINARY CARE SO THAT DISEASES ARE IDENTIlED ATOPYACRAL LICK more readily than in free-roaming cats, but this is only DERMATITIS CONJECTURE /NE SOURCE STATES THAT hTHE DISPARITY BETWEEN physical and psychological stressors is an illusion. Host defence mechanisms respond in adaptive and meaning- Figure 1. 0SYCHOLOGICAL AND PHYSIOLOGICAL STRESS MAY ful ways to both” (11). RESULT IN UNWELCOME PROBLEM BEHAVIORS SUCH AS SPRAYING ■ What cats need to be cats 2EDUCING STRESS FOR CATS REQUIRES AN UNDERSTANDING OF who and what a cat is and what they need. Cats are ter- ritorial, with their territories based around essential RESOURCES MOST PROMINENTLY FOOD "OTH MALES AND females mark their territories with olfactory clues: spray- ing urine, rubbing against objects and scratching vertical surfaces (which provides both olfactory and visual sig- nals). Resource areas may be time-shared, so cats cir- cumvent confrontation by avoiding contact. Fighting is a last resort and occurs when escape is impossible. Cats REQUIRE PRIVACY FOR HIDING SAFETY OBSERVATION UNDIS- turbed rest, and sleep, whilst vantage positions allow cats to avoid or evade intruders, predators and other threats. Socially, cats may live on their own or in groups. Colonies consist of related females and their offspring, with males visiting for reproductive purposes, although they may help to provide care for related young until they
are mature, either sexually or socially (12). Terry Curtis/Margie© Scherk
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The ”Five Freedoms”, first described in 1965 to define CATS EAT AND MAY INTERPRET INQUISITIVE VERBAL OR RUBBING farm animal welfare*, have more recently been adapted CUES FROM A CAT AS A REQUEST TO BE FED REWARDING SUCH for cats, as follows (3): actions with food reinforces the cat’s behavior, and the 1. Provision of food and water: a balanced diet that owner feels needed and cared for. We inadvertently train meets the animal’s nutritional needs at every life stage, cats to ask for food and they train us to respond to their and fresh water. boredom or other unmet needs by feeding them. 0ROVISION OF A SUITABLE ENVIRONMENT ADEQUATE SPACE and shelter, with sufficient light, low noise levels and Neutering (males and females) reduces energy re- no extremes of temperature. The area can be indoor- QUIREMENTS BY BETWEEN MOST STUDIES INDICATE only or with outdoors access. 20-25%). Additionally, feeding induces release of neu- 3. Provision of healthcare: vaccination, neutering (steril- rochemicals that make the cat feel good, and eating ization), parasite control, individual identification (micro- becomes a solace for negative experiences (distress, chip, collar), and prompt access to veterinary care. fear) or boredom. In a multi-cat household, if the cats 4. Provision of opportunities to express most normal are stressed due to incomplete socialization, they can behaviors, including those directed towards conspe- express this by overeating, especially if they cannot cifics and humans. achieve and maintain a comfortable spacing. 5. Provision of protection from conditions likely to lead to fear and distress. /BESITY IS A HUGE PROBLEM IN CATS /NE STUDY DETER- mined that the risk factors associated with overweight or While the vast majority of cats kept indoors will have OBESITY WERE FREQUENCY OF FEEDING AND NEUTERED STATUS ADEQUATE FOOD AND WATER AND ILLNESSES ADDRESSED WHEN regardless of whether cats were indoors or outdoors. noticed, many do not have the ability to express normal Cats fed 2-3 times daily were more likely to be overfed cat behaviors. This may result in distress, fear, undesir- than those offered ad libitum feeding. While contradict- able behaviors and potentially illness. Typical cat behav- ing the findings of other studies, this reinforces the iors include play, investigation, observation, hunting, importance of owner education regarding the amount feeding, drinking, grooming, scratching, traveling, scent and type of food to feed. Many diets developed for marking, eliminating, resting and sleeping (13-15). Addi- indoor cats have a higher proportion of calories derived tionally, cats are crepuscular i.e., their peak activity times from protein to help offset decreased exercise, and are are around dusk and dawn. fiber enhanced to improve stool character, reduce fecal odor and to help promote intestinal motility to reduce Indoor confinement predisposes to obesity. There are hairballs. numerous reasons for this, including the most obvious one i.e., ingesting more calories than they are utilizing. ■ Optimizing the indoor environment However, it is more complicated than this. In nature, There are two aspects that need to be considered: the cats do not have ad libitum food intake. To avoid starva- first is to decrease stressful stimuli and the second is to tion, the drive to eye, stalk, pounce and kill is perma- improve and enrich the environment. They may overlap nently active, and a cat makes numerous hunting in some instances, e.g., boredom is not a direct threat in attempts for every successful kill (16). Mostly prey are the way that confrontation with another pet might be, small mammals or birds, and a cat may hunt 100 times but it is still a source of stress. EACH DAY TO MEET ITS CALORIC REQUIREMENTS SMALL prey), an intellectually stimulating and physically active Stress results from unpleasant, noxious stimuli that endeavor. cannot be predicted or controlled (18). These may be physical or social in nature. Early life experiences, as /UR CATS RECEIVE FOOD WITH MINIMAL EFFORT BECOMING OVER- well as genetics, play a role in an individual’s ability to weight because they eat too much and their food is often adapt to situations. A barren environment or a chaotic CALORIE DENSE /NE MOUSE KCAL MEAL IS APPROXI- one with excessive novelty are both undesirable; e.g., a mately 10 pieces of an average maintenance dry food; new member in the household, changes in routine or in even eating 10 extra pieces per day can result in a 10% the physical environment. Poor relationships with other LB WEIGHT GAIN OVER A YEAR /WNERS LIKE TO SEE THEIR animals and humans are stressful. Competition for resources may be real (with another animal or a teasing 4HE "RAMBELL 2EPORT $ECEMBER (-3/ ,ONDON )3". human) or perceived (inability to reach resources, fear of
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ambush). Most anxiety disorders (e.g., urine spraying) are a result of social or environmental stress (12). The source of stress should be identified and removed whenever possible. Reducing disruption and creating a more predictable, harmonious schedule and environ- ment is helpful. When the stimulus lives with the cat, (e.g., another cat, a person), a gradual and prolonged reintroduction protocol, paired with positive, pleasant reinforcement, will be needed in order to reshape the cat’s experience.
If a change in routine is unavoidable, proactive positive conditioning will be helpful – so, for example, to prepare for a veterinary visit, encourage the pet to regard the cat carrier in a positive manner e.g., by putting food in the carrier and emphasizing its desirability and safety.
Environmental enrichment refers to both the physical and Curtis/Margie Scherk Terry © social environment and should include temporal com- Figure 2. )F THEY HAVE BEEN WELL SOCIALIZED AS KITTENS plexity (i.e., variability) (15). The goal is to offer more be- AND THERE IS SUFlCIENT SPACE WITH APPROPRIATE NUMBER OF SEPARATED RESOURCES CATS MAY LIVE TOGETHER HAPPILY havioral diversity, increase the use of space, enhance the human-cat relationship and – ultimately – improve an individual’s ability to cope with adversity, thus decreasing 1. A safe space: namely, somewhere that a cat can rest, the expression of abnormal and undesirable behaviors (3). relax and sleep without fear. Cats also need to be able to observe from this, or other, vantage points; hence the $EPENDING ON RESOURCE AVAILABILITY FREE RANGING CATS space is often raised. A dip in a perch or shelf allows the occupy huge ranges, from 1.2-2450 acres (0.48-990 cat to remain concealed and have a sense of control. hectares). Clearly indoor apartments are too small for Hiding is an essential coping behavior for cats: not hav- the average cat, and this situation is made worse by ing the ability to hide can contribute to stress and illness adding unrelated and/or unfamiliar cats (12). An indoor (12) (Figure 3). In a household with more than one cat or environment should consist of at least two rooms, but with a dog or a person that might invade the cat’s safe cats also need complex, stimulating, three-dimensional space, it is essential that the cat cannot feel trapped, so space; allowing a cat to climb provides distance from a safe space must have more than one entry. There should other cats as well as the ability to survey their environ- be at least one safe space per cat in the household, ment and to predict (and evade) suspicious or threaten- Figure 3. (IDING IS AN ESSENTIAL COPING BEHAVIOR FOR CATS BUT ing stimuli (3). Most cats do not get along well in a mul- IN A MULTI CAT HOUSEHOLD IT IS ESSENTIAL THAT THE CAT DOES NOT tiple cat environment if they have not been socialized FEEL TRAPPED together. Adult cats accustomed to outdoor access may have difficulty adjusting to indoor-only housing. However, if they have been well socialized as kittens, introduced properly (over several months) to the new cats, and there is sufficient space with appropriate number of separated resources, cats may live well together (Figure 2). Cats may also live comfortably with a dog or other companion animal assuming that they have been habituated to each other.
■ What can we do to optimize a cat’s living area? Recent guidelines (19) define “five pillars of a healthy
feline environment”, as follows: Terry Curtis/Margie© Scherk
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separated from each other, and placement may depend away from sources of unexpected loud noises (e.g., on an individual’s physical restrictions, e.g., a cat with washing machine, boiler). Trays must be scooped at least limited mobility needs a ramp access or a space that is daily (preferably more often) and should be emptied com- low and easy to get into. pletely and washed weekly.
2. Multiple and separated key environmental Scratching surfaces must be stable. Heavy immobile resources: Given that territory is based on resource avail- posts covered in carpet or sisal, rush or rattan matting, or ability, cats must have access to all key resources with- corrugated cardboard surfaces (on the floor or affixed to OUT RUNNING A REAL OR IMAGINED RISK OF HARM "ASIC RE THE WALL ARE SUITABLE OPTIONS $RINKING STATIONS MAY CON- sources are food, water, toileting areas (litter trays), sist of a variety of bowls, vases, and fountains or a drip- areas for scratching and playing, and places where they ping tap. Water should be fresh. In a safe, home situation, can observe, rest and sleep. While socially gregarious, whiskers can touch the edge of the food or water bowl, cats hunt and eat alone (20). Although cats are preda- but in a clinic or unsafe environment, bowls should be tors, they are also at risk of being prey if they are caught wide and flat (Figure 5). This is because cats’ whiskers unawares, so covered litter trays in a multiple cat house- sense air movement; if a cat feels a need to be vigilant hold may contribute to stress from a real or perceived (e.g., in clinic), then using a bowl that restricts the ability to fear of attack. Separation of resources reduces competi- sense something may cause a cat to avoid the bowl. In tion and the chance of ambush, with each resource lo- situations where cats have bonded as affiliates and cated in a separate area from the others rather than in belong to the same social group, they may share the cat’s “own room” (20). Additionally, cats should have resources, but physical separation between different a choice for each resource: two or more feeding areas, resources is still needed, (e.g., water should not be beside water bowls, elimination stations, etc. Litter trays must be food), and every cat needs at least one feeding station. large – at least 1.5 times the length of the cat (Figure 4), numerous (one or more per cat) and clean. Individual cats 3. Occupational needs: cats need to play and hunt, have different preferences for type and depth of litter; in and as noted above, predation makes up a significant general, since soil and sand are the natural substrates part of their day. Cats should be able to engage in all for toileting, sand-like or fine clay litters are readily ac- ASPECTS OF THE PREDATORY SEQUENCE LOCATING STALKING cepted by most cats. Litter boxes must be distributed chasing, pouncing, killing, preparing and eating their throughout the home, just as other resources are, and prey. In a household situation, this translates into pseudo-predatory play and feeding behaviors. If these needs aren’t met, cats can become bored or frustrated Figure 4. ,ITTER BOXES MUST BE DISTRIBUTED THROUGHOUT THE HOME AND SHOULD BE LARGE AND CLEAN )NDIVIDUAL CATS HAVE and obese. Cats may play on their own or with their DIFFERENT PREFERENCES FOR TYPE AND DEPTH OF LITTER BUT SAND LIKE owner, but rarely in a group unless raised together. En- OR lNE CLAY SUBSTRATES ARE READILY ACCEPTED BY MOST CATS sure that there is sufficient personal space between cats when they play (> 3 meters (10 feet)), or provide different play times. Exploration of novel objects, such as boxes or baskets, also provides stimulation, and dif- ferent cats may prefer certain toys (21). Allowing them to hunt for their food bowl or using a feeding toy are mentally stimulating activities.
Scratching is an essential need, not just for sharpening claws and to shed the nail sheaths, but also for stretch- ing and for depositing scent on vertical objects. In addi- tion to providing scratching surfaces, owners can under- take nail trimming with positive, treat-based reinforcement. If an owner is concerned about a cat damaging furniture, nail caps may be beneficial (although the owner should still trim the cat’s nails regularly) and sticky tape may act as a deterrent if a particular surface or object is valued.
© Terry Curtis/Margie Scherk Terry © Motion detectors may be used to deliver an aversive
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a B © Royal Canin/Youri Xerri © Royal Canin/Youri Figure 5. )N A SAFE HOME SITUATION WHISKERS CAN TOUCH THE EDGE OF THE FOOD OR WATER BOWL (a), BUT IN A CLINIC OR UNSAFE ENVIRONMENT BOWLS SHOULD BE WIDE AND mAT (b).
SOUND AND BLAST OF AIR AS A DETERRENT IF REQUIRED BUT THEY Figure 6. 6ISUAL STIMULATION IS IMPORTANT FOR CATS AT LEAST must be used carefully and the desired behavior must be ONE RESTING AREA e.g., A CLIMBING PLATFORM SHOULD ALLOW SAFE VISUAL ACCESS OF THE OUTDOORS REWARDED 6ISUAL STIMULATION IS IMPORTANT FOR CATS AT LEAST one safe resting area (window ledge, climbing platform) should have visual access of the outdoors (Figure 6). 6IDEOS OF BIRDS MICE AND SQUIRRELS PROVIDE VISUAL AS WELL as auditory stimulation and may be useful, especially when there is no opportunity to see or hear the outdoors. Placing a ping-pong ball in a bathtub for 30 minutes each day provides exercise as well as visual and auditory stim- ulation. Cat grass provides a textured gustatory stimulus that many cats enjoy, whilst rolling on a soft, textured mat (sprinkled with catnip) provides tactile stimulation.
4. Respect a cat’s olfactory sense: Cats use their sense of smell to perceive the world to a far greater degree than humans do. They also detect and communi- cate through pheromones. The aromatic environment – both deliberate and unrecognized – created by humans can greatly impact cats. Air fresheners, cleaning prod- ucts, perfumes, and scented cat litter may be pleasant for us but overwhelming or confusing for a cat. Smells brought in from the outside on shoes or with a visitor may be threatening for a cat. Restrict the use of fragrant products and leave footwear and shopping bags near the entrance to help reduce perceived threats. Catnip (Nep- eta cataria), honeysuckle wood (Lonicera tatarica), vale- rian root (Valeriana officinalis) and silvervine (Actinidia polygama) are pleasurable olfactory stimulants (Figure 7).
Use of familiarly scented clothing and bedding at home Terry Curtis/Margie© Scherk
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or in the clinic may be reassuring; avoid washing all of the responds to the cat’s attentions, the stronger the bond cat’s bedding at once to provide olfactory continuity. New will be. After initially sniffing at the person, most cats pre- items (e.g., furniture) brought into the home should be fer to be stroked around their head and neck rather than exposed to the cat after rubbing the furniture with a cloth over their whole body. When a cat chooses to move that has been in contact with the cat’s scent glands. AWAY ONE SHOULD NOT PURSUE CONTACT /F COURSE CATS ARE These glands, which produce a variety of pheromones, individuals and some prefer assertive, more forceful play; are located on the cheeks, in the temporal region, around HOWEVER WHEN BECOMING ACQUAINTED WITH ANY CAT FELINE the muzzle, on the tail and dorsal tailbase, and interdigit- manners prescribe head and cheek petting only. Fixed ally. When a cat marks a surface or a corner with their eye contact (staring) is both rude and threatening to cats. cheek or by scratching, they are depositing their scent Some cats prefer being stroked or groomed, while others and making it familiar; such marks should not be washed prefer their interactions to be oriented around play. off. Providing sturdy scratching options (vertical or hori- zontal) throughout the home (but especially at the entrance) Cats spend over 3.5 hours of the day grooming (14) and helps to provide “safety” without the need to spray urine this is clearly an important behavior. When a cat does as a means of marking/defining territory. Synthetic phe- not live with another cat to groom or be groomed by, the romones that replicates parts of the cheek pheromone owner may need to step in, but as with stroking, unless are available in many countries and may be beneficial a cat specifically solicits it, combing and brushing should for a sense of security. be restricted to the head and neck areas (15,20).
5. The social world: Consistency and predictability are ■ The best of both worlds key to positive human-cat interactions. As already men- Wherever possible, safe alternatives to a strictly indoor tioned, socialization between 2-8 weeks of age is critical lifestyle should be sought. This can be achieved through FOR CATS TO LIVE SUCCESSFULLY WITH HUMANS $URING THIS secure yet stimulating, complex enclosures that prevent period, cats should be exposed to at least four handlers cats from escaping and other animals entering; various and gently introduced to many, brief, positively reinforced cat-friendly fencing options and outdoor enclosures experiences. Human attention is very important, but cats designed for cats are available (Figure 8). Finally, learn- OFTEN PREFER MORE FREQUENT LESS INTENSE INTERACTIONS THAN ing to walk on a harness and leash suits some cats, but we might think. In addition, cats like to choose the time (not unexpectedly) they should be allowed to explore and place for the social contact. The more the owner rather than be led.
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■ Conclusion: in search of behavioral wellness When the environmental and social needs of cats are met /UR CURRENT STATE OF KNOWLEDGE DOES NOT ANSWER THE AND ADEQUATE SPACE AND RESOURCES ARE PROVIDED MANY QUESTION AS TO WHETHER STRICT INDOOR LIVING IS PREFERABLE TO cats will adapt to indoor housing, especially if they have outdoor access, and there are risks and benefits associ- been exposed to this lifestyle from an early age. However, ated with both options. Each case should be assessed cats accustomed to having outdoor access may find it individually and the wellbeing of the cat, the owner and difficult to make the adjustment as adults (3,4). the environment should be reassessed as necessary.
References
1. MacCallum Research Pty. Ltd. in association with H. Mackay. A Study of Our 11. Fleshner M, Laudenslager ML. Psychoneuroimmonology: then and now. Attitudes to Cat and Dog Ownership: Motivations and Benefits of Ownership: Behav Cogn Neurosci Rev 2004;3:114-130. the Personal, Familial and Social Context. Petcare Information and Advisory 12. Overall KL, Dyer D. Enrichment strategies for laboratory animals from the Service, Melbourne 1992. viewpoint of clinical veterinary behavioral medicine: Emphasis on cats and 2. Patronek GJ, Beck AM, Glickman LT. Dynamics of dog and cat populations in dogs. ILAR Journal. 2005;46(2):202-216. the community. J Am Vet Med Assoc 1997;210:637-642. 13. Landsberg G. Feline Behavior and welfare. J Am Vet Med Assoc 3. Rochlitz I. A review of the housing requirements of domestic cats (Felis 1996;208(4):502-505. silvestris catus) kept in the home. App An Animal Behav Sci 2005;93: Issues 14. Panaman R. Behavior and ecology of free-ranging female farm cats (Felis 1-2,97-109. catus L.). Zeitschrift fur Tierpsychology 1981;56:59-73. 4. Jongman EC. Adaptation of domestic cats to confinement. J Vet Behav Clin 15. Curtis TM. Making the Indoor Cat “Happy”. In: Proceedings, NAVC Institute App Research 2007;(2)Issue 6:193-196. Feline Medicine Course June 2015. 5. Rochlitz I. The effects of road traffic accidents on domestic cats and their 16. Rochlitz I. Basic requirements for good behavioral health and welfare of owners. Anim Welf, 2004;13:(1)51-55. cats. In: Horwitz DF and Mills D (eds). BSAVA manual of canine and feline 6. Loyd KAT, Hernandez SM, Abernathy KJ, et al. Risk behaviors exhibited by behavioral medicine. Gloucester, BSAVA 2009;35-48. free-roaming cats in a suburban US town. Vet Rec 2013;173(12):295. 17. Courcier EA, O’Higgins R, Mellor D, et al. Prevalence and risk factors for doi:10.1136/vr.101222. feline obesity in a first opinion practice in Glasgow, Scotland. J Fel Med 7. Buffington CAT. External and internal influences on disease risk in cats. J Am Surg 2010;12;746-753 Vet Med Assoc 2002;220(7):994. 18. Weiss JM. Influence of psychological variables on stress-induced pathology. 8. Karsh E, Turner D. The human-cat relationship. The domestic cat: the biology In: Porter R and Knight J (eds). Physiology, emotion and psychosomatic of its behavior. New York: Cambridge Press, 1988;159-177. illness. Amsterdam and New York: Associated Scientific Publishers, 9. Buffington CAT, Westropp JL, Chew DJ, et al. Clinical evaluation of multimodal 1972;253-280. environmental modification (MEMO) in the management of cats with 19. Ellis SL, Rodan I, Carney HC, et al. AAFP and ISFM Feline Environmental idiopathic cystitis. J Fel Med Surg 2006(8): 261-268. Needs Guidelines. J Fel Med Surg 2013;15:219-230. 10. Amat M, Camps T, Manteca X. Stress in owned cats: behavioral changes 20. Crowell-Davis SL, Curtis TM, Knowles RJ. Social organization in the cat: a and welfare implications. J Fel Med Surg 1-10. doi: modern understanding. J Fel Med Surg 2004;6:19-28. 10.1177/1098612X15590867. 21. http://indoorpet.osu.edu/cats/basicneeds/preypref. Accessed 8th Feb 2016.
9 / Veterinary Focus / Vol 26 n°2 / 2016 CONTROVERSIES ABOUT PROTEIN IN FELINE RENAL DISEASES Margie Scherk, DVM, Dip ABVP (feline practice) Vancouver, Canada
INTRODUCTION: NUTRITIONAL THERAPY AND CHRONIC KIDNEY DISEASES Since the 1950’s, dietary therapy has been the cornerstone for the treatment of chronic kidney diseases (CKD) in dogs and cats. It continues to be the most common recommendation made for affected small animal patients and has the highest strength and quality of evidence. [Roudebush] Along with protein restriction, modifications may include reduced phosphorus and sodium, increased caloric density, B- vitamins, omega-3 polyunsaturated fatty acids (PUFA), fiber and with adaptations to promote neutral acid- base balance. While accepted as a core part of therapeutic management, each patient’s response to the disease and to nutritional intervention varies dramatically, and individualized therapy is required, especially as different pathologic processes result in CKD. [Brown 1998, Burkholder 2000, Polzin 2000, Elliott DA 2006]
In any species, excessive protein restriction may lead to protein malnutrition, impairing immunological response, decreasing hemoglobin production, (causing anemia), decreasing plasma protein levels and promoting muscle wasting. Inadequate dietary protein decreases urinary excretion of magnesium, predisposing to Ca PO4 precipitation in the kidneys. A decline in body condition is a negative prognostic indicator for longevity. [Baez, Cupp 2010, Finn, Freeman, Krick, Lawler] Monitoring for evidence of protein: calorie malnutrition should include serial evaluation of body weight, and serum albumin. Weight loss, hypoalbuminemia, poor hair coat quality and muscle wasting are indications of inadequate dietary protein.
As obligate carnivores, cats require more of their dietary calories from protein than omnivores do. Unlike omnivores and herbivores, adult cats are often unwilling to eat a very low protein diet. Using protein sources of high biological value is important to ensure bioavailability. Should a patient have concurrent intestinal disease (e.g., inflammation associated with uremic gastritis) or be elderly, nutrient absorption may be compromised. This presentation will incorporate the American Association of Veterinary Nutritionists’ (AAVN) “Circle of Nutrition” concept to ensure that all aspects: the patient, the diet and the client/feeding management, are addressed.
1. Cats with Chronic Kidney Diseases Questions: What do healthy adult cats need nutritionally? What do cats diagnosed with CKD need nutritionally? Evidence? 2. Diets Designs for Renal Disease Questions: is there a "single best" diet on the market for cats with CKD? Why or why not? Which diets could work? Which ones to avoid? Evidence? 3. Feeding Management Questions: How should cats with CKD be fed? Where? When? Does it matter if there are other animals in the home? Can they all eat the same food? Evidence?
UNIQUELY FELINE Cats have obligatory dietary requirements for nutrients that are not essential for many other species including specific amino acids (carnitine, arginine, taurine) and some vitamins (niacin, A and D). They also have a higher maintenance requirement for protein than omnivores do. Dietary protein is required to provide essential, non-disposable amino acids as well as “disposable” nitrogen to build those amino acids and other nitrogen-containing compounds that it is able to synthesize [Morris].
Urea cycle enzymes in the liver of cats are always “turned on“. Cats are able to adapt their protein oxidation to a wide range of dietary protein concentrations, provided their minimum protein requirement is met [Green]. If dietary intake is below this minimum, they are unable to decrease protein oxidation adequately to maintain a neutral nitrogen balance. In other words, they are flexible in their ability to up- regulate the urea cycle in face of high protein meals (the native diet), in order to protect themselves from ammonia toxicity. This has been termed “hypercarnivorism” [Eisert].
While other species are able to rest their metabolic pathways from the efforts of glucose (energy) synthesis when they have been fed, cats must continue gluconeogenesis in both the fed and fasted states. When anorectic, they catabolize body proteins. Protein supplementation during fasting will actually slow hepatic lipid accumulation [Biourge]. A recent hypotheseis states that “cats do not have a high-protein requirement per se, but rather a secondarily high elevated protein requirement in response to a high endogenous glucose demand” because of a relatively larger brain for a mammal of its size resulting in a ready need for glucose [Eisert]. As such, they have developed metabolic strategies that avoid ketonemia and amino acid carbon skeletons are used for gluconeogenesis to meet the endogenous glucose demand independent of dietary carbohydrate intake. This evolutionary strategy reflects survival on a high-protein, low carbohydrate, prey-based diet for a small mammal with a large brain.
Macronutrient Profiles What is known about the composition of their meals in nature? What proportion of the energy sources protein, fat and carbohydrates (macronutrients) is ideal for a cat? In their native state, cats rely on a diet solely based on animal tissues to meet their nutritional requirements. In an attempt to evaluate the dietary nutrient profile of free-living cats, Plantinga assessed 27 studies that looked at the diets of wild or feral cats. Results showed that feral cats receive their daily energy from crude protein (52 %), from crude fat (46 %) and from nitrogen-free extract only 2 %. This reflects the nutrient intake to which the cat’s metabolic system has adapted [Plantinga 2011].
Two further studies have been done regarding macronutrient (protein, fat and carbohydrates) profiling. In the first, in an experimental setting, when cats were allowed to choose one of several diets (each having a different macronutrient proportion), they consistently chose to eat a diet made up of 50% protein, 40% fat and 10% carbohydrate. When this preferred diet was made less palatable by adding aversive flavouring and the less desirable lower protein diet was flavoured with a favourite flavour, the cats learned quickly to select the nutritionally beneficial, rather than the tasty, hedonistically preferable diet [Hewson-Hughes, 2011]. This group also showed that cats were able to regulate food selection and intake to balance macronutrient intake despite differences in moisture content and textural properties of the foods provided [Hewson-Hughes, 2013].
How Much Protein Do Cats Need? Daily energy requirements are based on resting energy requirements (RER) X a factor based on life stage and health where RER = [BW(kg)0.75 X 70] (see Table 1). In addition to meeting energy needs, protein requirements must be met. A recent study has shown that healthy adult cats need at least 5.2 g protein/kg to maintain their lean body mass. This is significantly more than needed to maintain a nitrogen neutral balance and is substantially higher than current AAFCO and NRC recommendations [Laflamme 2013].
While animals, (cats included), can adapt to low dietary protein and maintain nitrogen balance while depleting lean body mass, loss of lean body mass and an associated reduction in protein turnover can result in compromised immune function and increased morbidity [Laflamme 2013]. A decrease in exogenous protein may force cats to utilize endogenous protein stores. Does muscle catabolism contribute to uremia and renal azotemia?
A survey of cats with CKD was conducted in 2002 to evaluate risk factors for the development of CKD using diet and lifestyle variables. It found that increased levels of dietary protein, sodium, magnesium and fiber were associated with lower odds of developing CKD, whereas ad libitum feeding and increased ash intake were associated with an increased risk of developing CKD. [Hughes]
What About the Effects of Ageing and Weight Loss After 12 years of age, about 15% of cats have a low body condition [Armstrong, Courcier] and over 14 years of age, cats have a 15 times greater risk for being under condition [Courcier]. In a study on feeding the healthy, older cat [Cupp 2008, 2010], the use of dietary antioxidants (Vitamin E, beta carotene) alone or in combination with a prebiotic (chicory root) and a blend of oils to supplement n-3 and n-6 fatty acids were evaluated as to any beneficial effect on the health and longevity of cats when compared to the identical complete and balanced die without these supplements. Ninety healthy cats over seven years of age (grouped into 7-9, 10-12 and 13 + years of age at time of start) were studied in a controlled environment for over five years (until death). An average weight loss of almost 50% of adult weight was found but there was less weight lost by cats in the fully supplemented diet. In fact, further analysis showed that each 100g loss of weight increased the risk of death by 6.4%, each 100g loss of lean body mass increased the risk of death by 20%, but that each 100g loss of body fat increased the risk of death by 40% [Cupp 2010]. Other beneficial effects noted were improved LBM scores, improved fecal microflora, fewer diseases (notably gastrointestinal) during the study, and longer life.
Sarcopenia, age-related loss of lean body mass, is not caused by disease and is a gradual process, progressing with aging. Initially it is inapparent because increases in body fat maintain, or even cause increases in body weight. Loss of muscle can occur without fat loss or a decrease in body condition score (BCS) and individuals can retain an obese or overweight BCS yet be under muscled (“overcoat syndrome”). Therefore, both subjective BCS and muscle condition scoring (MCS, Table 2) should be performed in all cats, in order to evaluate fat mass and lean mass independently of each other [Freeman 2011]. Similar to humans, a mean loss of 34% LBM has been reported in a group of geriatric cats over eight years of age [Cupp 2010]. Sarcopenia is associated with increased morbidity and mortality in cats [Cupp 2010].
In cats, while metabolic energy requirements (MER) decrease until about 10-12 years of age resulting in weight gain, MERs per unit body weight actually increase after this age [Armstrong, Freeman 2011, Cupp 2004, Perez-Camargo 2004, Laflamme 2002, Sparkes].
Studies in geriatric cats have shown a reduced digestive ability and this may contribute to their increased MER [Cupp 2004, Perez-Camargo 2004, Sparkes]. In cats as young as 12 years, fat digestibility has been shown to decrease with age [Michel]. Perez- Camargo showed a reduced ability to digest protein in 20% of geriatric cats with about 33% having a significant reduction in their ability to digest dietary fat, as high as 30% [Perez-Camargo]. Another study revealed similar results reporting an 8% average reduction in energy digestion and 6% in protein digestion [Bermingham]. Micronutrient absorption is also decreased in healthy cats: potassium, phosphorus, sodium, choline, B vitamins and Vitamin E [Perez-Camargo 2005].
This is of clinical relevance when we try to design the optimal nutritional regime for already thin, muscle wasted older cats. Due to the possibility of a reduced digestive ability, a high energy, highly digestible diet with an increased protein content may be appropriate. Unpublished data suggested that 6.5 g protein/100 kcal of food is sufficient to maintain lean body mass over 30 weeks when fed to cats with CKD. [Yu 2011] Nguyen showed that proportion of dietary protein content not only affects feline body composition and the ability to maintain LBM, but also that extra protein is useful to the cat and not simply excreted. Data published in 2013 [Laflamme] suggests that diets should contain approximately 10-13 g protein/100 kcal metabolizable energy to provide enough protein to healthy cats. Older cats require 5-6 g of protein/kg body weight and insufficient dietary intake results in muscle catabolism [Laflamme 2013 Abst, Laflamme 2013, Wolfe]. If cats are eating only small amounts of food, a higher percentage of calories from protein may be needed to meet their needs. Kitten diets may be an appropriate choice as they are fortified with micronutrients and are highly digestible.
Additionally, factors resulting in stress, such as environmental or social changes may also contribute to decreased food intake. Difficulty getting to food comfortably is often due to arthritis but may also be from interference by other individuals; this can result in muscle and/or weight loss. A decline in the senses of taste, smell or vision may cause inappetence. Pain and nausea can certainly interfere with eating: pain is commonly associated with arthritis and oral disease (periodontal disease, root exposure, odontoclastic resorptive lesions, stomatitis and oral masses); nausea is believed to occur with CKD.
PROTEIN AND CKD The purpose of protein restriction along with other aspects of dietary modification is to minimize uremic, extrarenal manifestations of CKD. To date, there have been two studies evaluating spontaneous CKD in cats. [Elliott 2000, Ross SJ 2006] Unfortunately, neither compared a renal diet with the same diet plus protein to limit confounding parameters.
Dietary acceptance may be better when diets are first introduced in Stage 2 before a patient becomes inappetant. In mild to moderate CKD (IRIS Stage 1, early Stage 2) restriction of dietary protein, may limit the kidney's compensatory response. It is reasonable to consider protein restriction moderate azotemia persists in the stable, well-hydrated state (late Stage 2-Stage 3). In Stage 4, dietary recommendations are not controversial: restriction of both protein and phosphorous are required to ameliorate the clinical signs of uremia.
Nevertheless, individualization is still needed because excessive protein restriction for an inappetant individual may be harmful, when sustained calorie deficit causes catabolism of body proteins for calories and the resulting nitrogenous end products further aggravate uremia. Uremia is associated with variable dietary intake, intestinal malabsorption, metabolic acidosis and co-morbid conditions, which independently influence nitrogen balance. A balance needs to be found between reducing protein intake and the patient’s willingness to eat and their quality of life. If the cat is unwilling to eat adequate quantities of food, then he/she will have inadequate intake of all nutrients, ingesting even less protein than was intended. Increasing fat content provides additional non-protein calories and may benefit palatability, however, protein: calorie malnutrition may occur. A Table at the end of manuscript lists the differences in quantities of protein, phosphorus, sodium and fat in commercial restricted protein diets.
Despite numerous experimental studies [Adams 1993] [Adams 1994] [Finco 1998], a survey [Hughes] and clinical trials, [Elliott J, 2000] [Plantinga 2005] [Ross SJ 2006] questions about feeding protein to the cat with renal disease still remain. These include, but are not limited to, the following: 1. What is optimal amount of protein for a cat with CKD? How much restriction is necessary? 2. Do different types of kidney disease require different dietary therapies? 3. At what point in disease progression should protein restriction be implemented? 4. Does the type of protein fed make a difference? 5. Does every meal have to be restricted? 6. Is phosphorus restriction as, or more, beneficial than protein restriction in Stages 2 and 3? 7. Might some cats with advanced disease benefit from increased protein levels? 8. Should the diets of cats with proteinuria be protein restricted or enhanced?
Non-protein Nutrients and Uremia Several other studies have attempted to identify what role different dietary components play. We know that insufficient dietary potassium in an acidifying diet precipitates the development of nephropathy in normal cats and exacerbates pre-existing interstitial nephritis and fibrosis. [DiBartola 1993]
Early work, presented by Brown et al ACVIM Forum 1998, showed that dietary supplementation with n-3 polyunsaturated fatty acids in normal male cats modified lipid metabolism while increasing GFR. The omega-3 fatty acids eicosapentaeonic acid (EPA) and docosahexaenoic acid (DHA) from fish oil appear to have some beneficial effects in human cachexia [Murphy, Vaughan]. As these have anti-inflammatory effects in cats as well, it may be reasonable to incorporate them into therapy for muscle-wasted cats with or without CKD. A dose of 40mg/kg of EPA and 25mg/kg DHA (approximately 1g fish oil per 5kg ideal body weight/day) has been suggested for any animal with cachexia [Freeman 2012]. While antioxidants have not been studied specifically in this context in cats, oxidative stress plays a role in cachexia.
Oxidant stress may play a key role in the progression of CKD. [Brown 2008] Dietary supplementation of a dry food with the antioxidants vitamins E and C and β-carotene resulted in significantly reduced oxidative damage to DNA in cats with spontaneous CRI. [Yu 2006] As mentioned earlier, healthy cats receiving Vitamin E, beta carotene, a prebiotic and fatty acids in the diet and longevity study [Cupp 2008, 2010], lived approximately one year longer and preserved their BCS and lean mass.
Monitoring body weight, body condition score and muscle condition score will provide subjective evidence of therapeutic efficacy. Once daily energy requirements have been calculated (Table 1), this needs to be converted into measureable amount of food and communicated to the healthcare team and the client along with directions to notify the clinician when too little is being eaten. Following food intake helps to distinguish between weight loss associated with progressing disease vs. that associated with inadequate nutrient consumption. Some individuals with a good appetite will need more food than calculated; this will be detected by rechecking their weight, BCS, and MCS. When adequate calories are not being ingested to maintain or regain optimal condition despite using an appetite-stimulating drug and controlling gastrin, a feeding tube may be a valuable proactive tool to enhance quality of life, rather than be considered only a salvage measure. [Goldstein, Quimby]
Slowing the Progression of Chronic Kidney Disease The IRIS staging system focuses on factors which, when managed, slow the rate of progression (azotemia, metabolic acidosis, hyperphosphatemia) or improve longevity and well-being (hypertension, proteinuria, and anemia). Azotemia, metabolic acidosis and, to some degree, hyperphosphatemia are affected by hydration.
Phosphorus: In an experimental study (using a reduced renal mass model), comparing the effect of dietary phosphorus restriction to a normal phosphorus diet, no difference in renal function was found, however, histopathologic changes (mineralization, mononuclear inflammation and interstitial fibrosis) were much more severe in the cats on the normal phosphorus diet. [Ross LA 1982] Hyperphosphatemia results in progression of CKD. [Chakrabarti] It is important to restrict phosphorus in moderately azotemic patients and to detect the problem early through PTH changes rather than waiting for serum phosphorus levels to increase. [Barber, Elliott J 2006]
When a cat refuses to eat a restricted protein diet but requires phosphorus restriction, intestinal phosphate binders are an option. Aluminum hydroxide, aluminum carbonate, calcium carbonate and calcium acetate are options. They are dosed at 90 mg/kg per day divided to be given with meals. To be effective, most (not Ca acetate) must be given within two hours of a meal to bind dietary phosphorus within the lumen of the gastrointestinal tract, preventing absorption and facilitating fecal excretion. Many cats object to being given these agents. [Kidder] EpakitinTM (chitosan and calcium carbonate) is designed as an alternative to feeding renal diets as a method to reduce serum phosphorus. Two clinical studies of this agent showed a significant reduction in BUN and phosphorus levels during the treatment period with minimal increase in serum calcium. [Wagner] [Brown 2008.] Recently (2014), Pronefra TM, containing chitosan, “vasoactive peptides” and an extract of Astragalus membranaceus has been released.
Hydration Undoubtedly, adequate hydration is of critical and key importance perfusing tissues with oxygen, carrying nutrients and scavenging waste. [Grauer 1998] Rehydration aids in acid-base homeostasis and helps to improve renal blood flow, tissue perfusion and GFR. [Elliott J, 2003] With an impaired ability to concentrate urine, despite polydypsia, exogenous fluids (isotonic, polyionic fluids IV or SQ) are required if the cat is unable to maintain hydration. Plenty of fresh water should be available at all times. Increasing oral intake of water can be encouraged by provision of a circulating water fountain, flavoured water (broth) or ice cubes, offering milk, and tinned foods. Supplementation with water-soluble vitamins should be considered.
In IRIS Stage 2, home fluid therapy is generally not yet required, however in-clinic rehydration may occasionally be needed. It is not too early to discuss this treatment with the client as part of future home care when the disease advances. Many clients are willing to give daily or less frequent subcutaneous fluids once they see the improvement in demeanor that rehydration provides. They can assess their cat’s state of hydration by evaluating the character of the feces: feces should be moist and shaped like logs rather than pellets/pieces. Once rehydrated, the goal is to maintain this state, i.e., the skin should not become less elastic, the feces should not become more firm, etc.
Anemia Cats with CKD develop anemia by several mechanisms. [Chalhoub, Cowgill 1992, 2003] These include: • “Anemia of chronic disease” (believed to be associated with iron sequestration); • Anemia from protein malnutrition, (from inappetence or being fed a diet not meeting protein requirements); • Blood loss (associated with uremic gastritis induced gastrointestinal bleeding); • Decreased red cell life-span due to azotemia; • Erythropoietin deficiency
Despite potential risks, erythropoeitin therapy should still be considered in the individual anemic cat with CKD. Some products appear to be more antigenic than others and while there is a risk of antibodies developing, the majority of cats will enjoy the benefits of an improved hemogram. Cats should be monitored closely as some patients will experience adverse effects, however, the benefits arguably outweigh the potential for problems. [Cowgill 1992, 1998, 2003] Consider using epo when PCV is < 20% and the patient has evidence of lower energy, inappetence or pale mucous membranes.
Iron administration at the beginning of the regime is recommended at least until the patient’s appetite is good. The recommended dose is Iron dextran 50 mg IM q3-4 weeks or ferrous gluconate 50-100 mg (total dose) PO per day. Nothing is known regarding the biological availability of different iron compounds (e.g., ferrous gluconate vs. ferrous sulfate) in cats.
Feeding Management The natural feeding behavior of this species is to eat 8-10 small meals/day. From a client’s perspective, this can be achieved through using feeding toys/devices for dry food while offering as much wet diet as the cat will eat, two-three times a day. In a multicat home, feeding locations should be chosen with the goal of reducing social stress (i.e., away from other cats, dogs, noise, threats, etc.) while being very accessible. If other cats without CKD are present, unless they have a condition for which the renal diet is contraindicated, the base common diet should be the one suitable for the cat with CKD. Use of a microchip-activated cat flap in a door within the home, can help separate diets.
PROGNOSIS Chronic kidney disease due to tubulointerstitial nephritis often progresses to renal failure. The prognosis is variable because progression occurs at widely differing times in different individuals. Because amelioration of metabolic acidosis, azotemia, hyperphosphatemia, have all been shown to halt or slow this progression, the earlier these are identified, the better. [Boyd] Hypertension does not appear to cause progression of disease as it does in other species, however when proteinuria is present in hypertensive cats, survival is negatively affected. [Jepson] Anemia is predictive of progression [Chakrabarti] but it is unknown whether correction of this problem affects outcome. Proteinuria has been negatively associated with survival but not progression in one study [Syme 2006] but predictive on another. [Chakrabarti]
Cats with CKD have widely variable and often lengthy survival depending on what stage they are identified and how they are treated. Regardless of what therapeutic diet is recommended, it is very important to assess how a given individual is responding to that diet by reevaluating them: checking body weight and muscle condition cannot be done over the phone.
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Dietary crude protein of 28.5% maintains long- term lean body mass in cats with impaired kidney function, ACVIM Forum 2011 (Abstr NM-9) 1
MULTICAT FEEDING- A NUTRITIONAL CHALLENGE Margie Scherk, DVM, Dip ABVP (Feline Practice) Vancouver, BC, Canada
MULTIPLE CATS, MULTIPLE NEEDS The goal within a multi-cat household is to: 1) determine an appropriate base/common denominator diet available to everyone achieving a feeding strategy that puts no one at risk nutritionally, as well as, 2) to meet any additional individual nutritional needs of each member of the group as closely as possible twice or more times a day “behind closed doors”. This requires analyzing the clowder’s nutritional needs, personalities and physical abilities.
In order to determine what doesn’t put anyone at risk, we need to think about what disease condition is most responsive to or, the reverse, most damaged by feeding the wrong diet. In other words, which cat is most fragile, from a nutritional point of view? Cats are obligate carnivores. This concept is central to understanding the nutritional needs of cats and planning dietary therapies for health disorders, especially when dealing with multiple cats with differing health considerations. We need to review basic nutritional needs of this species before we can decide what modifications can be made safely.
FOOD, FEEDING AND NUTRITION IN A FELINE CONTEXT Cats diverged from dogs approximately 30 million years ago, evolving metabolically into obligate carnivores with unique strategies for the utilization of protein and amino acids, fats and vitamins. This concept must be at the centre of trying to understand the nutritional needs of cats and planning dietary therapies for health disorders. Domestic cats have not evolved from the wild cat model. They are anatomically and physiologically adapted to eating as many as 10-20 small meals, (a reflection of their hunting behaviour), throughout the day and night. This allows them to hunt and eat when their prey are active. Small rodents make up the majority of their diet, with rabbits, birds, insects, frogs and reptiles making up a smaller proportion. The average mouse provides ~8% of an average feral (i.e. active, unaltered) cat’s requirements. Repeated hunting throughout a 24-hour period is needed to meet this need, resulting in the normal grazing behaviour of domestic cats.
Being obligate carnivores has affected everything about cats: their hunting behaviour; that they eat many small meals a day alone; the small size of their stomach; their lack of salivary amylase; their social structure. Cats are hunters, yet the drive to hunt is independent from the need to eat. Hence, feeding more food doesn’t stop them from killing birds or mice, it merely makes them gain weight. Most cats needs 10-15 attempts to be successful at killing prey, thus the drive to “eye, stalk, pounce and kill” is permanently turned-on to avoid starvation. The average mouse provides 30-35 kcal of energy. Needing 50 kcal/kg ideal weight/day, the 5 kg cat needs 250 kcal or 8 mouse-sized portions/day. These meals are spread out throughout the day, not consumed all at once.
Feeding twice a day or having a bowl that is never empty are not “natural” ways for cats to eat. A 30 kcal meal is approximately 10 pieces of an average maintenance dry food; even eating 10 extra pieces/day results in a 10% (1 lb) weight gain/year. Our need for interaction with our cats also contributes to obesity. Cats generally interact with us frequently and at a low intensity/casually; people generally want fewer, more intense/focused periods of interaction with them. Eating is not a social activity for cats. We may feel like a bad provider or rejected if our cats don’t eat their food eagerly and seek second helpings. And, because their meals are so small, we misunderstand and want them to eat more. We try different diets until we have “evidence “ that they enjoy their food. We train them to ask for food and they train us to respond to their boredom or other unmet needs by feeding them.
Opportunities to express hunting behaviour are a basic need for a cat. If a cat doesn’t have the opportunity to hunt, toys meeting appropriate criteria are small (prey-sized), make high-pitched squeaks or cheeps and move in a rapid, unpredictable fashion. The Indoor Pet Initiative offers an informative piece on choosing the correct toy for an individual cat: http://indoorpet.osu.edu/cats/basicneeds/preypref/index.cfm. Allowing them to hunt for their food (bowl) or using a feeding toy are mentally stimulating activities. Examples of feeding toys include:
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Cat Activity Fun Board (www.traininglines.co.uk/cat-activity-fun-board-3397-0.html) FUNkitty Egg-Cersizer: (www.petsafe.net/search?q=egg-cersizer) Aikiou Stimulo (www.aikiou.com/stimulo-cat-bowls-and-feeders/) Catit Design Senses Food Maze (http://usa.hagen.com/Cat/Feeding/Accessories/50745) NoBowl (www.nobowlcat.com)
Cats are very sensitive to the feel of a food (physical form), its odour and taste. They eat their prey head- first. This is a tactile response to the sensation from the direction of the hair/feathers. Most cats prefer foods that are solid and moist, like flesh, not powdery, sticky or greasy. They prefer their food at fresh- killed body temperature rather than room temperature, out of the refrigerator or hot.
Under stressful situations, cats will refuse a novel food; under other circumstances, the same cat may be very adventuresome and chose a new diet over their familiar food. A new diet is more likely to be accepted if it is offered at home rather than in the clinic setting.
Numerous studies have been performed all showing that spaying and neutering/castration decrease energy expenditure by 7-36%. It is, therefore, very important to counsel clients to change from a growth to an adult formulation and to restrict the caloric intake after surgical altering. In general, unaltered cats need 60-80 kcal/kg/day; after altering, they need about 40-50 kcal/kg ideal body weight/day.
While other species are able to rest their metabolic pathways from the efforts of glucose (energy) synthesis when they have been fed, cats must continue gluconeogenesis in both the fed and fasted states. When anorectic, they catabolize body proteins. Protein supplementation during fasting will slow hepatic lipid accumulation. Urea cycle enzymes in the liver of cats are always „turned on“. Adult cats have a much higher requirement for protein than dogs or humans. Expressed as a percentage of diet, adult cats need 29% vs. the adult canine requirement of 12% or the human need for 8%. Over the long-term, cats can adapt to lower protein diets and use carbohydrates as an alternate energy source. In a paper that is in press (J Fel Med Surg) at time of writing these notes (Feb 2013), Laflamme has shown that healthy cats need a minimum of 5.2 g protein/kg/day in order to maintain a neutral nitrogen balance.
An elegant study (Hewson-Hughes) has shown that, when cats are able to choose the constituents of their diet, they will aim for a macronutrient profile of 52% protein, 36% fat and 12% carbohydrate. This fits with the many studies of the diets of free-roaming feral cats. In a review of 27 studies, Plantinga showed that the native diet consists of 52% protein, 46% fat and only 2% carbohydrate.
QUANTITY TO FEED 50 kcal/kg/day provides a rough guide and refers to ideal body weight. If a cat is overweight, calculate their caloric requirement for maintenance at their ideal weight. This “rule-of-thumb” is adequate for calculations to determine how much a patient should be getting on a daily basis in clinic and as a starting point for the patient when they are discharged. The client should be advised of the actual amount of food to feed when sent home with canned or dry food. Make sure that you are communicating with common vocabulary as what one person thinks of as a “cup“ may not be an 8 oz/250ml measuring cup. The most accurate method for measuring food quantities is by using a kitchen scale.
Once feeding any therapeutic diet, it is very important to check and see how the individual patient is responding to the diet by reevaluating them, just as we would recheck a patient on any other medical therapy. Checking body weight and condition cannot be done over the phone. For cats outside of the 2- 7kg (5-16lb) range in ideal condition, the 50 kcal/kg/day formula isn’t accurate enough. The following formula is more appropriate: 70 (BW in kg)0.75 (raised to the 0.75 power). Alternately and more easily, a nutritional calculator is available at: http://petnutritionalliance.org.
FEEDING FOR LIFE-STAGE OR USING THERAPEUTIC DIETS AS PART OF DISEASE MANAGEMENT Let’s apply this overview of very basic nutrition and feline feeding facts to a multi-cat home with multiple nutritional needs to a household consisting of the following twelve individuals:
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1. an elderly cat with International Renal Interest Society (IRIS) Stage 3 renal insufficiency 2. a thin, arthritic cat 3. a 4 month old healthy kitten 4. a 2 year old healthy cat 5. a 7 year old obese cat (BCS 8/9, high morphometric measurement) 6. an adult cat with “IBD” who vomits and gets diarrhea readily 7. a 10 year old cat with diabetes. 8. a 7 year old chronically constipated cat 9. a 9 year old cat with CaOx history 10. a 2 year old cat with struvite crystalluria 11. a cat with hepatic lipidosis 12. a 14 year old hyperthyroid cat
What dietary strategy can accommodate what appears to be completely disparate nutritional needs?
FEEDING CATS WITH RENAL DISEASE We would like to feed first cat, an elderly individual with Stage 3 renal disease, a protein-restricted diet suitable for renal insufficiency. Do all cats with renal disease have the same etiologic cause for their decline in renal function? Are they all at the same stage? Do they have identical nutritional requirements? Could this cat, perhaps, benefit from being fed a protein enhanced diet, a recuperative diet, a growth diet, a senior diet or a maintenance diet?
Protein: calorie malnutrition occurs when a cat is getting enough calories but not enough of them come from protein. As a result, there may or may not be weight loss, but there will be muscle wasting as well as a deterioration in the hair coat quality. Because protein is component in antibodies, immune function may be compromised; anemia may be exacerbated due to the lack of building components for hemoglobin; albumin levels may decrease and tissue healing may be affected. Protein is a preferred flavour, so if a cat is already inappetant, restricting protein may result in inadequate intake of all nutrients, and the protein intake may fall below that required for normal function.
As an obligate carnivore, if a cat doesn’t get enough dietary protein to meet metabolic requirements, he must draw on endogenous, stored protein sources to meet those needs. Over months, cats can down- regulate their protein needs and switch to use other pathways, but in the short and intermediate term, muscle will be catabolized. The resulting muscle wasting and decreased mass reduces the serum level of creatinine (Cr) measured. This makes it difficult to know how much of a Cr decrease seen in a cat fed a restricted protein diet is from improvement in renal function and how much is because there is less functional muscle producing Cr.
Despite numerous experimental studies and clinical trials, questions about feeding protein to the cat with renal disease still remain, including: 1. What is optimal amount of protein for a cat with CKD? How much restriction is necessary? 2. Do different types of kidney disease require different dietary therapies? 3. At what point in disease progression should protein restriction be implemented? 4. Does the type of protein fed make a difference? 5. Does every meal have to be restricted? 6. Is phosphorus restriction as, or more, beneficial than protein restriction in Stages 2 and 3? 7. Might some cats with advanced disease benefit from increased protein levels? 8. Should the diets of cats with proteinuria be protein restricted or enhanced?
Protein levels in “restricted” and “high” protein diets fall within the nutritional guidelines, merely at the low or at the high end of the range. Protein-restricted therapeutic diets are not all the same; there are some marked differences in their composition, not just in protein sources and quantities, but also in the calorie source, in phosphorus, potassium, and sodium content. (Table 1)
Dietary protein is not, in and unto itself, toxic to kidneys. Because of inherent progression of chronic renal
4 insufficiency, IRIS staging focuses on factors which, when managed, are known to slow progression. These are: azotemia, metabolic acidosis, hyperphosphatemia, proteinuria and hypertension.
Azotemia, metabolic acidosis and, to some degree, hyperphosphatemia are affected by hydration, thus optimizing hydration through the use of canned diets, adding water to food, encouraging drinking by use of flavoured liquids or a fountain along with the use of daily subcutaneous fluids are beneficial to the well- being of the patient. The patient should enjoy the diet offered, regardless of what illness he/she has. It is always more important that they eat, rather than what they eat. And the amount consumed must be monitored. This requires calculating the caloric requirements for each individual. 50 kcal/kg/day is a reasonable goal. By being made aware of how much food this is equivalent to, they can notify the veterinarian should the cat be eating less than that amount. This helps prevent confusion regarding weight loss associated with progressing disease vs. that associated with inadequate nutrient intake.
Returning to the cat in question, we do not know from the description (Stage 3 chronic kidney disease) whether the cat is proteinuric or not, nor what the phosphorus or potassium levels are. A protein- restricted diet (which one?) may be appropriate, but one of the other aforementioned diet types (protein enhanced, recuperative, growth, senior or maintenance) might be the correct diet for this individual. Just because someone has a specific illness does not automatically mean that the diet designed for that condition is the best diet for that individual.
Every time we send home a therapeutic diet, we are performing a feeding trial with one subject in it (n=1). We have to get the cat back into the clinic and see how he/she is doing on that food. How is his weight? Increased? Decreased? How is his coat? Does he eat with enjoyment or vigour? What are his stools like (moist logs or dry pellets, cow patties or coloured water)? How energetic is he since he has been on this diet? Has there been a change in his PCV and proteins? In this case, have the BUN and Cr, the phosphorus and calcium or usg changed? Is he proteinuric and potentially protein deficient? What about his blood pressure? Have these parameters increased or decreased?
Feeding for arthritis What are the nutritional requirements for cat #2 who is thin and arthritic? Options include a mobility/joint die or, for weight gain, a kitten diet, a recuperative diet, or possibly a senior diet. Assuming that the physical examination and diagnostics do not reveal a cause for her weight loss, it is reasonable to try a variety of diets including all of above in case she has become bored with her food. The addition of omega-3 fatty acids appears to be beneficial as does supplementation with green-lipped mussel extract and glucosamine/chondroitin sulfate.
Feeding growing cats and elderly cats Young cats have growth requirements, which include an increased proportion of animal based protein and more calcium and phosphorus. The 4-month old kitten (#3) and the 2-year old healthy adult (#4) would ideally be fed a kitten diet and a maintenance diet respectively. Elderly cats over 12 years of age have been shown to have an increased need for protein, relative to adult cats. They also need more calories from fat than during their adult stage. In part this is because of a decreased ability to digest and absorb fat and protein.
Feeding obese cats For the fifth cat, the 7-year old obese kitty with body condition score (BCS) 8/9 (or 4.5/5) the therapeutic strategies may include a high fiber diet, a high protein, low carbohydrate balanced diet, or a low fat diet. Exceeding a cat’s protein needs beyond maintenance requirements helps induce satiety. In a study by Laflamme et al, when cats were fed a diet with 45% of calories from protein, cats lost more fat and less lean mass compared with cats fed a diet with 35% of calories from protein, despite similar total weight loss and rate of weight loss.
Traditional belief holds that it is the calories ingested versus expended that is required for weight loss and that it doesn’t matter which approach we choose, (making this cat very flexible) as long as the caloric intake is reduced, the diet is balanced, the cat isn’t feeling deprived and pestering the client and the diet is balanced. Given the benefits of achieving lean body mass by feeding a high protein diet, a goal of at
5 least 40% protein, dry basis, in a low-fat diet (6% to 10% fat) is a healthy approach to take. Feeding closer a native, paleolithic high protein, lower carbohydrate diet may have hormonal benefits that favour lean, however this idea has not been proven. The KEY is in determining how much the cat should weigh. The nutrition calculator at: http://petnutritionalliance.org is very helpful and is a simple way to calculate current intake and desired intake based on body condition score.
The thermic effect of food (TEF) refers to the energy cost of digesting and absorbing food. TEF is higher when meals are small and frequent, so feeding multiple small meals is preferable to feeding one or two large meals. One way to incorporate this into the diet—and give the cat a little challenge (and exercise)— is to divide the day’s food into six or seven small portions, using feeding balls or placing it on saucers throughout the home as if the cat were on a “treasure hunt”. This feeding strategy makes the cat less likely to gorge and entices him or her to look for more, all of which has a higher TEF cost.
Include the calories in the treats and supplements, people food and pill pockets that the kitty is being given when you figure out the quantity of food to recommend. As with the protein-restricted diets, the composition of therapeutic diets designed for weight loss are very different from each other.
Feeding cats with intestinal sensitivity Our dietary choices for cat #6, the adult with the sensitive gastrointestinal tract and a diagnosis of “IBD” are either a limited antigen, a “hypoallergenic” or a hydrolyzed protein diet. Some cats may tolerate a highly digestible, low residue intestinal diet.
Feeding cats with diabetes Cat #7 is the 10-year old diabetic. Feeding strategies include a high protein, low carbohydrate diet or a high fiber diet. However, a diabetic cat can be controlled with insulin as long as the diet and treats fed remain consistent from day to day.
Neither carbohydrates nor dry extruded diets are cause of diabetes or obesity. However, exchanging dietary carbohydrate for protein appears to be useful for weight loss treatment and management of non- insulin dependent diabetes in cats.
In a prospective, randomized, double blinded 10-week study (Hall et al), 12 cats (7/12 obese) of whom six were newly diagnosed and six were poorly controlled diabetics evaluated standard maintenance diet vs. lower carbohydrate, higher protein (LCHP) diets. The cats ate dry or canned based on their preference. All were treated with glargine and assessed at weeks 1, 2, 4, 6, and 10 with fructosamine, BG curve and clinical signs. One cat from each diet group achieved remission by week 10. All cats improved clinically, increased weight and achieved good glycemic control. Those fed the LCHP had a significantly greater decrease in fructosamine. The conclusion, based on this small study was that using insulin, “frequent monitoring is key to achieving glycemic control in diabetic cats; potential benefits of dietary modification require further evaluation”. The author summarizes all of the preceding studies and approaches: high fiber & low fat, high insoluble fiber vs. low fiber, LCHP canned, low carbohydrate diet vs. low carbohydrate diet plus acarbose, low carbohydrate & low fiber diet vs. moderate carbohydrate & high fiber diet. None of these approaches appears to make a meaningful difference in the small numbers of cats in each study.
Feeding the constipated cat Constipation is, first and foremost, treated through rehydration. As long as cellular dehydration is present, the need will exist to resorb water from renal and gastrointestinal systems. Addition of fiber to the diet should be avoided until the patient is adequately hydrated. Use of enemas, promotility agents and laxatives prior to addressing this underlying problem is ineffective at best and has the potential for exacerbating the problem. Once that has been accomplished (or simultaneously to rehydration), once can focus on assisting the passage of the feces by mechanical or pharmacologic means.
Soluble fibers are helpful in diarrhea; insoluble fibers are beneficial for constipation. Dietary fiber is a combination of soluble and insoluble fibers. Recently a dry diet enhanced with psyllium has been
6 marketed for the treatment of constipation. Along with rehydration, feeding this diet alleviated obstipation in cats with megacolon allowed them to cease medication, avoid surgery or euthanasia. Another approach is to reduce fiber feeding a low residue diet.
Feeding cats with lower urinary tract disease Ensuring that urine is in a neutral pH and stays dilute enough so that mineral components don’t come out of solution (i.e., urine remains undersaturated) will help reduce the chance of either CaOx or struvite crystals from forming.
Feeding for hepatic lipidosis The most important thing is that the cat gets adequate calories without restricting protein. Lipidosis is a disorder of lipoprotein metabolism. Additionally, L-carnitine, S-adenosylmethionine, B vitamins and taurine may be supplemented. If the cat has an esophagostomy tube in place, ensuring nutrition is easy if kitty isn’t eating enough on his/her own.
Feeding for hyperthyroidism Use of the extremely low iodine-containing diet in a multi-cat household such as this is inappropriate.
NOTE: For all cats in the household: Make sure that water, the most important nutrient, is readily accessible. Have lots of water stations around the home. They should be in places other than the “kitchen” as well, so that cats don’t have to compete and because cats like to eat and drink in different places.
Baseline diet The first of the two goals for feeding a multi-cat household is to achieve a feeding strategy that puts no one at risk nutritionally having the base/common ground diet available to everyone. Of these twelve cats, the one at greatest risk if fed the wrong diet is the cat with “IBD”. If the cat with renal disease were in IRIS stage 4, he may well be the most delicate, but just getting adequate calories into a uremic cat becomes the main concern at that point and placing a feeding tube would allow us to deliver an appropriate diet. We would also have to think about a different strategy for restricting access to other diets if he were feeling well enough to be roaming the house. If he is hyperphosphatemic as well as being in stage 3, using intestinal phosphate binders is a viable and necessary alternative to using a restricted protein diet as the baseline, everyone eats, diet. (He can still get the restricted protein diet twice a day.)
Supplementing requirements The second goal is to meet the individual nutritional needs of each member of the household as closely as possible twice a day “behind closed doors”. Certainly the “IBD”-safe diet can be left out during the day for all cats to eat. Twice daily all cats other than the cat with gastrointestinal disease, can be placed in separate rooms to be supplemented with their different or additional needs. This requires analysis of the clowder’s needs as well as their personalities and physical abilities. The elderly cat who is less able to jump can be prevented from eating the food of an agile youngster if the growth diet is placed high up. An overweight cat can be prevented from getting to any food other than that designed for weight loss (the base diet) by putting a latch on a door, building a creep feeder or using a “keyed” cat flap (such as one that responds to the cats’ pre-existing microchips: www.sureflap.ca) so only the thinner cats can get through the narrower space. Treasure hunts using small quantities of food as well as feeding balls (which some cats won’t want to us) will also help. Figuring out creative strategies to use based on the strengths and weaknesses of the individuals is an intriguing challenge and needs to take the cats’ physical, personality and nutritional profiles into consideration.
Reducing stress in the multi-cat household must always be a focus. Cats are social but with strict social rules and restrictions to keep distance in order to avoid confrontation. Recognizing the environmental needs is extremely important. Ellis writes eloquently about this. http://www.catvets.com/guidelines/practice-guidelines/environmental-needs-guidelines.
Key points
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1) Don’t assume that a diet designed for a particular clinical condition is necessarily the best diet for every cat with that condition. 2) The quantities to be fed listed in product guidelines are a starting point. Each cat is different. 3) Monitor the clinical response of the individual patient to the dietary prescription.
SUGGESTED READING: • Ellis E. Environmental enrichment: Practical strategies for improving feline welfare. J Feline Med Surg 2009. 11: 901–912 • Ellis SL, Rodan I, Carney HC, et al. AAFP and ISFM Feline Environmental Needs Guidelines. J Feline Med Surg 2013. 15: 219-230. • Hall TD. Effects of diet on glucose control in cats with diabetes mellitus treated with twice daily insulin glargine. J Feline Med Surg.11(2):2009. • Hewson-Hughes AK, et al. Geometric analysis of macronutrient selection in the adult domestic cat, Felis catus. J Expl Biology 2011, 214, 1039-1051. • Laflamme DP, Hannah SS. Increased Dietary Protein Promotes Fat Loss and Reduces Loss of Lean Body Mass During Weight Loss in Cats. Intern J Appl Res Vet Med; 2005: 3 (2): 62-86. • Plantinga EA, Bosch G, Hendriks WH. Estimation of the dietary nutrient profile of free-roaming feral cats: possible implications for nutrition of domestic cats. Br J Nutr 2011;106, S35–S48 • Ross SJ, Osborne CA, Kirk CA, et al. Clinical evaluation of dietary modification for treatment of spontaneous chronic kidney disease in cats JAVMA 2006;229(6):949-957. • Scherk MA, Laflamme DP. Controversies in Veterinary Nephrology: Renal Diets Are Indicated for Cats with International Renal Interest Society Chronic Kidney Disease Stages 2 to 4: The Con View. Vet Clin N Am Sm Anim. 2016; 46(6):1067-94.
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THE GERIATRIC CAT: COMPLEX MANAGEMENT IF MULTIPLE DISORDERS Margie Scherk, DVM, Dip ABVP (Feline Practice) Vancouver, Canada
Elderly cats often present with multiple concurrent conditions. "Age-associated” or “age-appropriate” illnesses that we expect to see in older cats include problems related to the urinary tract (chronic kidney disease (CKD), pyelonephritis, calcium oxalate ureteronephroliths, bacterial cystitis), endocrine system (hyperthyroidism, diabetes mellitus, hyperaldosteronemia), degenerative joint disease (DJD) and other musculoskeletal conditions, dental diseases and neoplasia. Constipation may become an ongoing concern. Certain infectious diseases become more likely in the older individual (e.g., FIP). A decline in functioning of the special senses occurs frequently and behaviour changes suggestive of cognitive dysfunction may be seen in some individuals.
Making management recommendations may be challenging as treatments, at first glance, may appear to be in conflict. Thankfully, the body is complex and all systems relate to one another. The four most important therapeutic considerations that must be incorporated in caring for every patient, especially those who are older, are optimizing comfort through analgesia, hydration, nutrition and ensuring that the environmental needs are met so they can perform normal behaviours.
MANAGING A CAT WITH STAGE 2-3 CHRONIC KIDNEY DISEASE, HYPERTHYROIDISM, HYPERTENSION AND DEGENERATIVE JOINT DISEASE Renal disease is fairly common in untreated hyperthyroid cats. It may be masked due to increased cardiac output, renal blood flow and glomerular filtration rate (GFR). The effects of muscle wasting exacerbate the lower Cr concentrations. Monitoring renal parameters and muscle condition during therapy is advised. Similarly, hypertension may become evident only during the course of therapy or even after the patient is euthyroid. It is well recognized that amelioration of the hyperthyroid state by any method (i.e., medical therapy, 131I treatment or surgery) can result in decreased GFR, elevations in serum urea nitrogen and creatinine (Cr), and, in some cases, overt azotemia. The decline in GFR stabilizes by approximately four weeks (Adams, Becker, Boag, DiBartola, Graves).
Numerous studies have attempted to identify parameters that predict declining renal function before correcting hyperthyroidism. Glomerular filtration rate can be measured using plasma clearance of exogenous creatinine exo-iohexol or endo-iohexol; N-acetyl-beta-D-glucosaminidase index and retinol- binding protein have been assessed as possible biomarkers (Lapointe, Riensche, Slater). Symmetric dimethylarginine (SDMA) is a promising biomarker for estimating GFR (Hall JA). It has been shown to be an accurate and precise biomarker for calculating estimated GFR in humans. It is a more sensitive biomarker than serum Cr for assessing early renal dysfunction. By reducing the lower limit of the Cr reference interval and monitoring this parameter longitudinally to look for upward trends, earlier detection in GFR decline can be achieved. False positive elevations occur with SDMA just as they do with Cr with prerenal azotemia, therefore pre-renal causes of decreased GFR and causes of acute kidney injury have to be eliminated before interpreting the result. What role it, or any other early predictive biomarker, will play in the management of CKD in cats is uncertain.
Using common clinical measures, cats with hypertension and/or an increase urine protein: creatinine ratio (UPC) are more likely to develop problems while cats with elevated plasma globulins, a high urine specific gravity (usg) and hematocrit are less likely to.
A practical approach to a patient with concurrent hyperthyroidism and CKD is to treat medically until the serum T4 is adequately controlled at which time the effect of permanent therapy may be predicted. If renal decline becomes apparent once euthyroidism has been achieved, exogenous thyroid hormone can be supplemented to support the kidneys. A balance must then be struck between creating iatrogenic hyperthyroidism and maintaining renal function as iatrogenic hypothyroidism appears to contribute to azotemia and decreased survival. (Peterson 2013, 2013, 2014, Williams, Aldridge) It is recommended to monitor serum TSH levels post radioiodine or during medical therapy to avoid iatrogenic hypothyroidism (Peterson ACVIM 2014, Peterson Enrollment in Clinical Study, 2016). These cats should either receive a lower dose of medication or be supplemented with thyroxine before the develop overt disease or CKD.
The foundation of any treatment plan includes attending to hydration, nutrition, analgesia, and addressing environmental comfort. In this scenario, maintaining euvolemia will be reflected in coat and stool character as well as subjective measures of well-being including grooming, interaction and posture. Daily subcutaneous fluids (warmed to body temperature) may be appropriate. A client handout is included at the end of these notes. Appetite may be negatively affected by renal disease from uremic toxins or, less likely, uremic gastritis. Unlike humans and dogs, cats with CKD are more likely to have gastric fibrosis rather than uremic gastropathy (McLeland)). Nausea associated with uremic acidosis may be alleviated with famotidine 5 mg PO q24h or another H2 antagonist. However, the proton pump inhibitor omeprazole has been shown to provide better acid suppression than famotidine in cats (Parkinson). Additionally, twice-daily omeprazole is more efficacious at suppressing acid production than once daily dosing or ranitidine therapy (Šutalo).
Appetite stimulation with mirtazapine (1.88 mg PO q48h) has been shown to benefit cats with CKD (Quimby 2013). Interestingly, maropitant, while effective in palliating vomiting, did not significantly improve appetite or support weight gain in cats with Stage II and III CKD (Quimby 2015). Cats with untreated hyperthyroidism may have an increased appetite yet, due to increased metabolism, lose weight and muscle. Once euthyroid, their appetites generally normalize.
It is generally recommended to feed cats with Stage 3 kidney disease, a protein-restricted, renal diet. We must consider several questions when treating each individual. Do cats at every stage of CKD have identical nutritional needs? Do all cats at the same stage have the same etiologic cause for their decline in renal function? Could this cat, perhaps, benefit from being fed a protein enhanced diet, a recuperative diet, a growth diet, a senior diet or a maintenance diet?
Protein: calorie malnutrition results from ingesting adequate (or excessive) total calories, but insufficient protein calories. Weight loss may or may not be occur, however there will be muscle wasting as well as a deterioration in the hair coat quality. Additionally, because antibodies are protein, immune function may be compromised; anemia may be exacerbated due to the lack of building components for hemoglobin; albumin levels may decrease and tissue healing may be affected. If a cat is inappetant, restricting protein may result in inadequate intake of all nutrients, because amino acids are key in palatability, resulting in the protein intake falling below that required for normal function.
It appears that some loss of weight and lean body mass (LBM) is part of normal aging (Armstrong, Dora- Rose, Bellows), and is not caused by illness but we may be able to address it nutritionally, potentially improving longevity as well as quality of life. In part this is associated with decreased digestion of fat and protein, (Perez-Camargo) in part due to increased requirements for protein and calories that may not be met. (Perez-Camargo, Harper, Laflamme X2, Villaverde) Maintenance of weight and condition prolongs life. (Cupp) Given that cats with CKD often live for a long time, (King 2007, Boyd) the nutritional needs of older cats should be taken into consideration in treatment of those with CKD.
Weight loss with poor muscle condition is common among cats with CKD. Weight loss begins before 1 to 3 years before a diagnosis of CKD has been made (Freeman) and is associated with decreased survival. (Boyd, Freeman) A decrease in muscle mass is associated with increased morbidity and mortality in human CKD patients (Wang). Protein synthesis is reduced in these individuals compared to healthy human patients. While inadequate calorie intake contributes to weight, fat and LBM loss, reduction in dietary protein exacerbates the CKD-related muscle loss (Wang) in attempts to meet the needs for protein turnover and ongoing metabolic needs. Increasing dietary protein helps to regulate acid-base balance through excretion of hydrogen ions associated with ammonium. (Remer) This is of clinical relevance when we try to design the optimal nutritional regime for our older feline patients: protein and fat restriction may well be contraindicated. Especially if underweight, older cats will benefit from a more energy-dense, highly digestible diet to help offset these age-related digestive and metabolic changes.
As obligate carnivores, cats have evolved to manage a high dietary protein load (Hewson-Hughes X2, Plantinga), but adapt to various intake as long as their minimum needs are met. (Green) Dietary protein is not toxic to kidneys. Creatinine and urea result from metabolizing ingested protein as well as from turnover of endogenous stores in health or in protein deficiency. In excess of 60 purported uremic toxins are reported. (Vanholder 2003) Interactions between many endogenous metabolites (Lisowaska-Myjak) resulting from inflammation, malnutrition, increased concentrations of protein-bound solutes and hypoalbuminemia as well as non-nutritional toxins contribute to the clinical spectrum of uremia. (Vanholder X2, Stenvinkel) Thus, while uremic toxins can result in malnutrition, malnutrition itself results in inflammation, morbidity and mortality in human patients with CKD. (Vanholder 2002)
Despite numerous experimental studies and clinical trials, questions about feeding and managing the cat with CKD remain. Some of these are: 1. Do we over-rely on diet? Are there other approaches we could utilize to reduce uremic toxin production or absorption? The renal effects of endogenous protein breakdown have not been studied but may potentially be no different than those of dietary protein. 2. Do different types of kidney disease require different dietary therapies? Fibrosis associated with interstitial changes is the end-point for most cats, however what etiology initiates the process is generally unknown in an individual cat. 3. At what point in disease progression should dietary therapy be implemented, if at all? In theory, would it be better to address acid-base balance initially, and then phosphorus binding, or vice versa? 4. What is the optimal amount of protein for cats with CKD? How much restriction, if any, is necessary? Similar to cats, protein malnutrition, sarcopenia, and iron deficiency are clinical problems in human CKD patients following low protein regimes. 5. Does the type of protein, or the amino acid composition of the protein, make a difference in cats? There is evidence in humans and rats that types of protein can differentially influence the effect of protein on GFR, acid-base and other effects. (Williams, Kontessis, Pecis) 6. Will a cat in IRIS stage 3 or 4 benefit adequately if phosphorus is restricted by means other than diet? No controlled clinical trials address this question. 7. Might some cats with advanced disease benefit from increased dietary protein levels? As discussed earlier, regular reassessment of the patient enables evaluation of muscle and body condition, which is helpful in changing dietary treatment recommendations if warranted. As loss of lean mass is detrimental as well as predictive of progression, increasing dietary protein and using alternate methods to restrict phosphorus or uremic toxins should be considered. When patients fail to eat adequate calories (protein, fat or carbohydrate), then feeding support is required. 8. What are the actual uremic toxins that cause adverse effects in cats and what can we do about them? 9. Should we be investigating phosphatonins (e.g., fibroblast growth factor-23 [FGF-23]) and their role in phosphate homeostasis in cats and potentially seeking ways to block or correct FGF-23 as GFR declines? Finch et al (2013) reported an inverse relationship between FGF-23 concentrations and GFR and demonstrated that FGF-23 is increased in cats that go on to become azotaemic before phosphate concentrations increase. PTH also changes before serum phosphorus. Would these make better markers of progression of renal dysfunction? 10. Progression of renal fibrosis is thought to be related to the ongoing production of pro-inflammatory and pro-fibrotic cytokines. Proteinuria, hypoxia, hyperphosphatemia, ageing and chronic inflammation have been investigated and are believed to maintain this state (Lawson). Should the focus of early identification (e.g., SDMA) and treatment be modification of the inflammatory mediators? 11. Is it appropriate to restrict protein in cats with proteinuria? While protein in urine may initiate an inflammatory response that ultimately progresses to interstitial fibrosis (Lawson), muscle wasting and a perceived decreased quality of life may result in an earlier death, either due to general decline in health or earlier requested euthanasia. Would this be better addressed pharmacologically rather than risking malnutrition? Malnutrition also results in inflammation and mortality, therefore preventing malnutrition, (as well as sarcopenia), is critically important when managing the feline CKD patient.
Protein-restricted therapeutic diets are not identical; there are some marked differences in their composition, not just in protein sources and quantities, but also in the calorie source, in their phosphorus, potassium, and sodium content. They are variably supplemented with potassium and fatty acids, restricted in phosphorus. Every patient’s response to a given diet may differ and each cat should be rechecked to assess the effects and suitability of the recommended diet. Table 1 compares reduced protein and phosphorus foods as of December 2012: composition of these diets will have changed since this time.
With muscle wasting, Cr levels decrease making it difficult to know how much of a Cr decrease seen in a cat fed a renal diet is from improvement in renal function and how much is because there is less functional muscle producing Cr. Given the smaller number and size of the studies in veterinary medicine, we are unable to perform meta-analysis. It seems prudent to make the following recommendation: when prescribing restricted protein renal diets practitioners must carefully monitor their patients' protein and energy intake and nutritional status, as evidenced by body and muscle condition as well as enjoyment of meals/quality of life. If deterioration in any of these is noted with no other apparent reason, alternate diets or means to reduce phosphorus should be considered. The WSAVA nutrition tools are a useful resource for the BCS and MCS. http://www.wsava.org/sites/default/files/Body%20condition%20score%20chart%20cats.pdf http://www.wsava.org/sites/default/files/Muscle%20condition%20score%20chart-Cats.pdf The MCS may be found at the end of the notes.
Because of inherent progression of CKD, IRIS staging focuses on factors which, when managed, are known to slow progression: azotemia, metabolic acidosis, hyperphosphatemia, proteinuria and hypertension.
Control of hypertension is important for its negative effects on cardiac function as well as progression of CKD. Amlodipine is the first choice (0.625 mg PO q24h, titrate as needed). In cats with proteinuria, telmisartan may be the best therapeutic choice (Jenkins) especially in cats that are also hypertensive (1 mg/kg PO q24h). (Sent)
Addressing the degenerative joint disease in a patient with CKD requires thought but is not insurmountable. The most common concern regarding drug therapy are side effects of using NSAIDs in a dehydrated patient and their effects on gastric mucosal health or on renal function.
Opioids are safe for pain relief in any age group and are excellent when used at the same time as other agents, especially NSAIDs. They are not, however, a first drug of choice for cats with arthritic pain as they are not very effective for DJD. This is not to suggest that they shouldn’t be used for “break-through” pain or for comfort during diagnostic testing. If they produce adverse side-effects (e.g., euphoria, constipation and inappetence) in an individual patient they may be reserved for palliative hospice care.
Pharmacokinetic data is lacking for safe, long-term use of many NSAIDs in cats. Carprofen half-life varies from nine to over 40 hours in cats (Taylor, Parton). As most NSAIDs have long half-lives in cats when compared to other species, one precaution to avoid toxicity is to reduce the frequency of administration. Interestingly, despite having a short half-life of under 2 hours in blood, robenacoxib (Onsior®) its effect persists for 24 h in clinical studies.
Metacam® 0.5 mg/ml oral suspension has been granted a licence in the EU for the alleviation of inflammation and pain in chronic musculoskeletal disorders in cats. The registered dose is 0.1 mg/kg on the first day followed by 0.05 mg/kg orally once daily. This is the first NSAID licensed for long-term use in cats.
Numerous efficacy studies have been performed regarding both of these NSAIDs. Two studies have evaluated long-term safety of this agent in older cats; one concluded that this agent is safe, efficacious and palatable for musculoskeletal pain at 0.01-0.03 mg/kg PO q24h for a mean treatment duration of 5.8 months; no deleterious effect on renal function was detected in cats studied. Gastrointestinal upset in 4% of cats was the only adverse effect noted (Gunew). The second, reviewed the medical records of cats over seven years of age treated for a minimum of 6 months with a daily maintenance dose of 0.02 mg/kg meloxicam and concluded that this dose does not hasten progression of renal disease in aged cats or aged cats with pre-existent stable IRIS stage 1-3 renal disease (Gowan).
A paper published in 2015 reported on the safety of robenacoxib (1–2.4mg⁄kg) for daily, month long treatment of DJD in cats including 40 with chronic kidney disease IRIS stages 2-4. There was no evidence of increased risk in the frequency of reported adverse events, or in deterioration in renal variables in the subgroup of cats with concurrent CKD (King 2015). Despite being similar to meloxicam (class and mechanism of action), at this time (September 2016) it is licensed only for short-term use.
A comprehensive review of the long-term use of NSAIDs in cats was published in 2010. This document may be accessed free-of-charge at: http://www.catvets.com/guidelines/practice-guidelines/nsaids-in-cats A suitable protocol for a cat with pain from DJD might be baseline NSAID (such as meloxicam or robenacoxib) with intermittent use of an opioid (such as burprenorphine) when break-through pain is evidenced by a decrease in appetite or mobility or social withdrawal. A recent study by King et al has shown that robenacoxib (1.0–2.4 mg/kg PO q24h) is safe in cats with, or without, CKD when administered for DJD for 30 days.
Disease-Modifying Osteoarthritis Agents: Over the past two decades, research has been aimed at attempts to slow the progression of cartilage degradation as well as to promote rebuilding of healthy matrix. Products have been developed that, in research on humans and dogs, have been shown to be beneficial in enhancing hyaluronic acid production, inhibiting catabolic enzymes in osteoarthritic joints, and encouraging normalization of the synovial fluid and joint cartilage matrix. There is no evidence for efficacy in cats.
Studies using radio-labeled compounds have shown that 87% of orally administered glucosamine is absorbed and is incorporated into the cartilage matrix. Glucosamine provides raw materials for synthesis of glycosaminoglycans. Since chondrocytes obtain preformed glucosamine from the circulation (or synthesize it from glucose and amino acids), adequate glucosamine levels in the body are essential for synthesis of glycosaminoglycans in cartilage. Glucosamine is required for the production of hyaluronic acid by synoviocytes. In vitro studies indicate that administration of glucosamine may normalize cartilage metabolism and stimulates the synthesis of proteoglycans. In one study, glucosamine stimulated synthesis of glycosaminolgycans, prostaglandin and collagen by chondrocytes and fibroblasts, suggesting it may actually up-regulate their synthesis.
Chondroitin Sulfate (CS) is a long chain polymer of repeating disaccharide units. It is the predominant glycosaminolycan found in articular cartilage and can be purified from bovine, whale, and shark cartilage sources. Bioavailibilty studies in rats, dogs and humans have shown that 70% of orally administered CS is absorbed, some of it intact. Studies in rats and humans using radiolabeled CS have shown that CS reaches synovial fluid and articular cartilage. Hyaluronate concentrations and viscosity were increased, and collagenolytic activity was decreased, in the synovial fluid of human osteoarthritis patients treated with CS for 10 days.
Both oral preparations (Cosequin) and parenterally injected preparations (Adequan) have been shown to have therapeutic benefit in in vivo studies. One caution is that a polysulfated glycosaminoglycan, such as Adequan, is a heparin analog, resulting in a transient prolonged partial thromboplastin time. Avoid using it in cats with bleeding disorders or pre-operatively and do not use it concurrently with either omega 3 fatty acids or NSAIDs.
Diet: Weight loss should be encouraged in the obese, arthritic cat to reduce the pressure on joints. The addition of omega 3 fatty acids may be beneficial by blocking the production of prostaglandins from arachadonic acid in the inflammatory cascade. Dietary modulation should be considered in the therapy of cats with DJD-associated pain (Lascelles). A therapeutic prescription diet for joint health: Hill’s j/d with omega 3 fatty acids is available in both a canned and a dry formulation (504 kcal/cup; 152 kcal/156g can); to date the author is not aware of peer-reviewed papers on this diet. Royal Canin has developed Mobility Support (391 kcal/cup) for cats. Both of these diets may not have sufficient protein for some older patients. A recently published study comparing the Royal Canin diet to the identical diet without the added high levels of eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) and supplemented with green-lipped mussel (GLM) extract and glucosamine/chondroitin sulfate. Forty cats with no detectable systemic disease but with radiographic evidence of at least one affected joint and who showed an aversive response to manipulation of that joint were fed one of the two diets (control or test diet) for nine weeks. Cats on the test diet showed significantly greater improvements including an increased ability to jump, increased time spent eating, less time sleeping, increased playing and interacting with other pets. In an earlier study that looked at efficacy and tolerance of an extract of GLM in dogs with DJD, a similar subjective improvement was noted by clients whether the dogs were receiving placebo extract or GLM extract.
Therapeutic exercise - Moderate exercise has benefits in maintaining range of motion in the face of joint capsule fibrosis, to maintain/build muscle mass and maintain/build healthy articular cartilage. In acute flare-ups, restricting activity may be warranted.
Additional therapeutic considerations – It is important to make environmental changes in the home as well as having empathic awareness in order to make appropriate changes in handling in a clinic setting. Decreased mobility can result in constipation due to retention, positional stiffness resulting in elimination outside of the litter box, falling when jumping onto or off the bed, inability to climb stairs, inability to crouch to eat resulting in weight loss. Raising bowls for cats with lumbosacral and hip DJD makes it easier to eat. Trimming nails regularly helps to maintain proper joint relationships. Ramps and steps onto favourite sleeping spots gives the cat access to safe places for sleeping and observation. Warm, soft, padded beds for stiff, painful, possibly bony joints should be considered. Adding a litter box so that kitty doesn’t have to walk as far may reduce inappropriate elimination as well as encourage regular voiding and defecation. Making sure that the rim of the litter box is not too high, and that the opening into the box is not too small is helpful. Scooping the litter several times a day and making sure that the litter isn’t too deep or too sparse will encourage regular use. Regular nail trimming helps by maintaining proper joint relationships. Ramps and steps to favourite sleeping spots may be helpful. Warm, soft, padded sleeping places for stiff, painful, possibly bony joints should be considered. Adding a litter box to reduce the distance between boxes may reduce accidents as well as encourage regular voiding and defecation. The rim of the box mustn’t be too high, nor the opening into the box too small. It should be scooped several times a day to encourage use.
Acupuncture may be considered and can safely be combined with pharmacologic approaches. While efficacy has been shown for acupuncture in a few conditions in humans, there is no solid scientific evidence at the time of writing that clearly supports its efficacy in cats. Peer-reviewed publications for efficacy of laser therapy and stem cell therapy are also lacking.
MANAGING A CAT WITH STAGE 2 CHRONIC KIDNEY DISEASE STAGE, DIABETES MELLITUS, PERIODONTAL DISEASE AND INFLAMMATORY BOWEL DISEASE One of the challenges with these comorbidities is nutritional (protein quantity and source, meeting all nutritional requirements). Another is achieving immunomodulation for IBD in the face of glycemic instability. Treatment with corticosteroids takes priority over glycemic effects because inflammation is recognized as a predisposing factor for susceptible individuals to develop diabetes. Franchini has shown at a molecular level that the inflammation induced by bacterial or viral infection can, via molecules recognized by toll gate receptors, damage endocrine pancreatic tissue. In some individuals, IBD can be managed using chlorambucil and metronidazole without corticosteroids.
The oral disease adds to difficulties controlling the diabetes. Inflammation and/or infection at any site (dental, urinary tract, etc.) interferes with the ability of all cell receptors to interact with insulin. Anaesthesia for dental care should be performed before the diabetes or IBD are controlled. Before the procedure, ½ of the current dose of insulin is given on the morning of the procedure. The cat should only be fasted for 4 hours with water freely available. Blood glucose measurements should be made during and after the anaesthetic until the cat is able to eat on his own.
Concern regarding safety of performing anaesthesia in elderly cats should not be over-emphasized. Two studies have verified that in cats, as in people, age is not a risk factor and should not be a limiting factor in determining whether or not to undertake a medically beneficial procedure. (Hosgood, Brodbelt)
The American Society of Anesthesiologists (ASA) characterizes risk using the following physical status classification system that is based on the physical status of the patient. Five categories are defined as follows: • Class 1: Normal, healthy patient • Class 2: A patient with a mild systemic disease • Class 3: A patient with severe systemic disease • Class 4: A patient with a severe systemic disease that is a constant threat to life • Class 5: A moribund patient not expected to survive without the operation
Feeding strategies for diabetes include a high protein, low carbohydrate diet or a high fiber diet. However, a diabetic cat can be controlled with insulin as long as any diet and treats fed remain consistent from day to day. Neither carbohydrates nor dry extruded diets are cause of diabetes or obesity. However, exchanging dietary carbohydrate for protein appears to be useful for weight loss treatment and management of non-insulin dependent diabetes in cats.
In a prospective, randomized, double blinded 10-week study (Hall TD), 12 cats (7/12 obese) of whom six were newly diagnosed and six were poorly controlled diabetics evaluated standard maintenance diet vs. lower carbohydrate, higher protein (LCHP) diets. The cats ate dry or canned based on their preference. All were treated with glargine and assessed at weeks 1, 2, 4, 6, and 10 with fructosamine, BG curve and clinical signs. One cat from each diet group achieved remission by week 10. All cats improved clinically, increased weight and achieved good glycemic control. Those fed the LCHP had a significantly greater decrease in fructosamine. The conclusion, based on this small study was that using insulin, “frequent monitoring is key to achieving glycemic control in diabetic cats; potential benefits of dietary modification require further evaluation”. The author summarizes all of the preceding studies and approaches: high fiber & low fat, high insoluble fiber vs. low fiber, LCHP canned, low carbohydrate diet vs. low carbohydrate diet plus acarbose, low carbohydrate & low fiber diet vs. moderate carbohydrate & high fiber diet. None of these approaches appears to make a meaningful difference in the small numbers of cats in any of the reviewed studies.
Diet recommendations for a cat with a sensitive gastrointestinal tract and a diagnosis of “IBD” are either a limited antigen, a “hypoallergenic” or a hydrolyzed protein diet. Some cats may tolerate a highly digestible, low residue intestinal diet. Omega-3 fatty acids may be beneficial in small quantities. Unless the GI disease is extremely mild, this condition has dietary priority as the diabetes can be regulated on any diet if used consistently and protein restriction may be unnecessary or contraindicated.
Regardless of nutritional recommendation made, we are performing a feeding trial with one subject (n=1). We need to reassess the patient to determine how suitable the diet is for him. How is his weight? How is his coat? Does he eat with enjoyment or vigour? What are his stools like (moist logs or dry pellets, cow patties or coloured water)? How energetic is he since he has been on this diet? Has there been a change in his hematocrit and proteins? Have biochemistries or usg changed? Is he proteinuric and potentially protein deficient? What about his blood pressure? Ultimately, quality of life is more important than quantity.
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Dietary Supplementation of Vitamin B12 Improves Vitamin B12 Status in Geriatric Cats ACVIM Forum 2011
SAMPLE CLIENT HANDOUT INSTRUCTIONS ON SUBCUTANEOUS FLUID ADMINISTRATION
HOW TO GIVE YOUR CAT SUBCUTANEOUS FLUIDS
Warming the fluids to body temperature 1. If you are using an unopened bag: a. Remove the outside protective bag. b. Microwave the bag for two to three minutes, depending on the microwave. c. Massage the warmed bag to distribute the heat evenly. d. Test the bag on your wrist. It should feel comfortably warm—just about body temperature. 2. If the bag has already been used and has the line attached, do not microwave it as the line will melt and seal shut. Instead: a. Boil water in a kettle or pot. b. Put the bag into a vase or tall upright container with the bulb portion up so it will remain above the water. c. Pour the hot water into the vase, taking care to not reach the bulb. d. Set the timer for about five minutes, depending on how much is remaining in used bag. e. Massage the warmed bag to distribute the heat evenly. f. Test the bag on your wrist. It should feel comfortably warm—just about body temperature.
Connecting a new line to a bag 1. Prepare the line by rolling the wheel to a closed position. 2. Take the cap off the line, being careful not to touch the end of the line. 3. Remove the end from the port on the bag. 4. Insert the pointed end of the intravenous line into the port. 5. Squeeze the bulb of the intravenous line to fill the bulb half full. 6. Open the line by rolling the wheel to the open position, and fill the line with fluids.
Giving fluids 1. Hang the bag of fluids on a curtain rod or shower rod with the still capped line hanging down. 2. Place an unused, covered needle on the line, and place the sterile cap (from the end of the line) close by. 3. Sit somewhere comfortable. (I prefer the floor so that the cat feels secure.) 4. If you want, you can wrap your cat in a towel, leaving its head and shoulders exposed, and cradle your cat. 5. Remove the cover on the needle. 6. With cat facing away from you and while holding the needle, rest your dominant hand on your cat’s back with the needle facing toward its head. 7. Lift and make a tent with the skin between your cat’s shoulders with your nondominant hand. 8. Exhale and firmly pull that skin tent over the needle. 9. Open the intravenous line wheel, and administer the volume of fluids as directed by your doctor. 10. Because the fluids are warmed, once the needle is in place the cat should be comfortable. Giving treats and praise doesn’t hurt either! 11. Close the intravenous line, and remove and discard the needle safely, recapping the line with the sterile cap. 12. Pinch the skin together with your nondominant hand when you remove the needle.
Congratulations! You’ve done it.
Notes: 1. While you are getting used to this procedure, it may help to have the fur shaved over two places at the back of the neck. That way you can be sure the needle is getting under the skin. The fur will grow back. 2. Your cat will look like it is wearing shoulder pads. The fluids will droop to one side down a leg, even to the paw. These will be absorbed over 12 to 24 hours. 3. If some of the fluids or even a bit of blood leak from the injection site, there is no need to worry.
WSAVA MUSCLE CONDITION SCORING TOOL http://www.wsava.org/sites/default/files/Muscle%20condition%20score%20chart-Cats.pdf Accessed September 3, 2016 BLOOD GLUCOSE CURVES MADE EASY Margie Scherk DVM, Dip ABVP (feline practice) Vancouver, Canada
Blood glucose curves can be very helpful to determine the dose, frequency and type of insulin needed for a given cat. They are not difficult to interpret when simple rules are followed. It is very important to get a reading every hour. Cats should have food available at all times.
1. Start by looking at the shape of whole curve. Identify the nadir (lowest BG value), time to nadir, starting and highest BG value, duration (Figure 1).
Figure 1. Blood glucose curve elements 500 Duration 450 450 450 Glucose differential differential Glucose 396 400 360 350 324 288 300 270 234 250 198 198 180 200 162 Glucose mg/dL Glucosemg/dL 150
100 Time to nadir
50 Nadir
0 1 2 3 4 5 6 7 8 9 10 11 12
Hour
This graph is in mg/dL (convert to mmol/L by dividing by 18)
Check if the blood glucose (BG) level decreases for a reasonable period of time. This indicates that cells see and respond to the insulin? • If the curve merely wobbles around the starting level (e.g., curve D in Figure 2), then either: • The cells do not see/respond to this insulin; • The client is not administering the insulin correctly. This could be technique (intra-fur, intradermal resulting in poor absorption) or lack of comprehension (giving air, wrong dose); • The insulin is damaged (dropped, client wiped vial with alcohol, bacteria introduced into vial); • Counter-regulatory phase of Somogyi response to overdose.
2. Time between BG at time zero (just before insulin is given) to time at which BG level is the same = duration of action. This value tells you how long the insulin lasts in this individual. • If duration is 9-12h, then BID administration is appropriate; • If duration is 6-8h, then TID administration is appropriate.
3. Time to reach nadir indicates how rapidly insulin is being absorbed and taking effect. If peak insulin effect is between 2-4h after administration, be suspicious of Somogy over-swing (too much insulin). This will be followed by a rapid increase in BG with the curve exceeding the starting BG. 4. BG level at nadir indicates maximum effect of insulin. IMPORTANT In order to determine nadir, one must have hourly BG readings. In fact, to really identify the nadir, we would need even more frequent readings, however with less than hourly measurements, we could easily miss a Somogyi, both at nadir as well as the over-swing.
5. Glucose differential/delta is the difference between starting BG and nadir BG. If this difference is small (<7 mmol/L; 126 mg/dL), it is easy to decrease the starting BG without dropping the BG too low at nadir. This is a safe insulin to use for this patient. If the difference is large, it becomes difficult to increase the dose without risking hypoglycemia at peak effect.
6. Goal range for BG (not to be confused with differential) of 5.5-12 mmol/L; 100-215 mg/dL throughout the day provides good glycemic control and normalizes fructosamine levels.
Spot checking should only be done to determine whether a lethargic, wobbly cat is hypoglycemic (and needs glucose) or hyperglycemic (and needs insulin) before rushing the cat to the clinic. Using spot checks (i.e., anything less than hourly measurements) does not provide useful information and can result in making inappropriate recommendations.
Fructosamine reflects glycemic control, or time that BG is above ideal range over approximately the preceding 10-14 days. It is elevated if too little insulin is given but will also be elevated during Somogyi over-swing, i.e., when too much insulin is being given. Glucosuria will occur under both situations as well.
Figure 2. Examples of blood glucose curves A Ideal curve => continue dose and type of insulin B Short duration => give insulin more often or change type of insulin C Somogyi overswing: rapid drop in glucose with counter-regulatory overcorrection => decrease insulin dose or change type of insulin D Poor response due to client misunderstanding, poor technique, damaged insulin, attempt to correct from Somogyi response, extremely low dose => Client education, recheck curve. If no change, change insulin.
600
500 D
400
300 B
Glucose mg/dL Glucosemg/dL 200 A
100 C 0 1 2 3 4 5 6 7 8 9 10 11 12
Hour
Margie Scherk
Board Certification • American Board of Veterinary Practitioners (ABVP) Feline Practice, 1995
Education • Doctor of Veterinary Medicine (DVM), Ontario Veterinary College University of Guelph, 1982
Current Professional Activities • Active in Research Grant Proposal Review • Reviewer - Journal of Veterinary Behavior: Clinical Applications and Research • Reviewer - Canadian Veterinary Journal • Lecturer in Feline Medicine • Active in American Association Feline Practioners, American Board of Veterinary Practioners, North American Veterinary Licensing Examination • Editor - Journal of Feline Medicine and Surgery • Reviewer - Journal of the American Animal Hospital Association • Reviewer - Clinician's Brief • President AAFP 2007
Marital Status • Happily married to Jim
Children • Two (one of each flavor)
Pets • A large clowder of cats
Hobbies • Gardening • Cooking • triathlon (swim-bike-run) • Thinking • Reading
Favorite Quote • There is no such thing as impossible; Impossible just takes longer.