Symposium on Feline Medicine
Dietary Consideration in Feline Practice Donald R . Collins, D. V.M. *
Catowners have only one concern when feeding cats-providing a nutritionally adequate diet. The feline practitioner has three additional concerns relative to feeding cats: correcting incorrect diets, feeding cats with anorexia, and prescribing appropriate diets in the treatment of diseased cats.
NUTRITIONALLY ADEQUATE DIETS The chore of coming up with the correct diet for a cat is not nearly as difficult as it once was. Today, any commercial catfood that bears the claim "complete and balanced," "nutritional," or "adequate," must have either successfully supported the life cycle of cats in actual feeding studies, or must be able to demonstrate, by chemical analysis, that it contains the correct nutrients needed by the cat in amounts which have been suggested by the National Research Council. A problem arises when a client does not feed a cat commercial foods, or feeds it some combination of natural and commercial foods. The only way to ascertain the nutritional adequacy of these diets is to obtain a detailed dietary history, including formulas and recipes, labels, etc., and to evaluate the diet. A sample dietary history form is shown in Figure 1. Remember that a cat's diet consists of everything it eats- not just what the owner feeds it. Techniques for evaluating diets have been published. Two homemade diets that are known to be nutritionally adequate are listed:
"Director of Pet food Research. Nabisco. Inc.. Nabisco Research Center. Fair Lawn. New Jersey Ve.terina1)· Clinics oINorth America- Vol. 6. No.3. August 1976
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What type of food is fed ? (Use brand names when possible.) canned food ? _ _ _ _ _ _ _ dry food? _ _ _ _ _ _ semi-moist? _ _ _ _ __ table scraps? (list) _ _ _ _ _ _ _ __
homemade diet? _ _ _ _ _ _ _ _ __ recipe? _ _ _ _ _ _ _ _ _ _ _ __
(Labels of all commercial foods and formulas for homemad e diets should be attached to eat's record.) Comments on feeding procedure (times, amounts, containers, other cats, etc.): Does cat eat all that is fed? _ __ _ _ _ _ __ What treats or supplements are fed to the cat?
o canned tuna o canned salmon o canned sardines o bacon strips o luncheon meats
o liver strips o fresh fish o cheese o
o
o other?
0 ________________
chicken breast giblets
o ________________ o _______________ 0 _ _ _ _ _ _ __
Is cat given water?
Quantity drunk daily? _ _ _ _ _ _ __
Is cat given milk?
Quantity drunk daily? _ _ _ _ _ _ __
Does cat go outdoors?
What have you observed cat eating outdoors? (Be specific!) _ _ _ _ _ _ _ _ _ _ _ _ __
Does cat have any food allergies?
To what? _ __ _ _ _ _ _ _ _ _ __
General comments: Figure I .
A dietary history.
DIETARY CONSIDERATION IN FELINE PRACTICE
343
D'Arc)' Calle?)' Diet*
4 Ibs raw hamburger 1/2 Ib raw liver, ground 2 Ibs Purina Hi-Protein Dog Meal 1/ 4 Ib Theralint (8 tbsp.) 1/ 4 Ib Brewer's Yeast (8 tbsp.) Soak dog food in enough hot water to cover. Mix in hamburger, liver, and dry ingredients. If mixture is too dry , add a little water. If too soupy, add Gerber's Baby Rice Cereal. Should be fed at the rate of 112 ounce per pound of cat. National Research Councils Diet A (Modified)
1 Ib cottage cheese Ib whole dried milk 3/4 Ib raw liver 3 cups oatmeal (uncooked) 11/2 ozs corn oil or lard 6 ozs Brewer's Yeast (12 tbsps.) 3/ 4 oz cod liver oil Mix corn oil and cod liver oil with cottage cheese and liver (ground or blended). Mix in milk and Brewer's Yeast. Finally, fold in oatmeal, adding a little water if needed for a smooth blend. 1/ 2
INCORRECT DIETS A dietary history should be taken for every patient seen, regardless of the nature of the illness. If the cat's diet is discovered to be inadequate, the clinician should address himself to correcting the cat's diet simultaneous with other treatment prescribed. Regardless of how accurate the diagnosis, or how adroit the treatment prescribed, if the cat is suffering from even a borderline nutritional deficiency, the result of therapy will be less than optimal. Incorrect diets result in nutritional imbalances. Only a few of these imbalances will produce a specific clinical disease , however. A discussion of these imbalances follows .
Energy Imbalances Imbalances in dietary energy intake occur in two forms- too much and too little. Excessive energy intake produces obesity; too little energy produces emaciation. Obesity. The cause of obesity is simple and direct- the consumption of more food than is needed by the cat to supply its energy requirements. The prevention of obesity is equally simple and ':The D'Arcy diet forms the basis for a general hospital diet which can be modified to accommodate man y disease conditions. tLambert Kay, Santa Ana, California.
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direct- feed the cat only that amount of food that will supply its energy needs. Treating obesity, therefore , requires reducing the food consumed to levels below that needed for energy, at least until the cat has reached its optimum weight. An effective approach to reducing obese cats is: 1. Establish an optimum weight for the cat. (Optimum weights are based on breed, sex, age, activity, etc.) 2. Determine the present weight of the cat and subtract the optimum weight from the present weight. (This gives the reduction goal, in pounds.) 3. Multiply the reduction goal by 80. 4. Divide the number obtained in step 3 by 100 for a dry food, by 85 for a semi-moist food, and by 40 for a canned food. 5. The number obtained in step 4 is the number of ounces of food to be removed from the current diet each day. (One level cupful of dry food is equivalent to 3 ozs of dry food, 4 ozs of semi-moist food, or 71/ 2 ozs of canned food .) The reduced quantity of food is fed until the cat reaches its optimum weight. Once this happens, one half of the number of ounces that were reduced can be restored to the daily diet and the cat should be fed that amount for the rest of its life, unless it has a sudden weight change, becomes ill, or becomes pregnant. Emaciation. When caused only by too little energy intake, emaciation is easily reversible and unless of long standing, causes little harm to the cat. The most satisfactory method of increasing energy intake is to increase total food consumption. A simple suggestion to the owner to feed a little more food each day may solve the problem. In other cases, however, ample food is being fed, but the calories obtained from that food by the cat are insufficient. In these cases the caloric density of the food must be increased. To increase the caloric density of a cat's diet, fats or oils should be added . About 35 calories are added for each teaspoonful of fat or oil. For example, the DArcy diet contains about 80 calories per ounce (2 .75 calories per gram). By adding two teaspoonfuls of corn oil or bacon fat to each 8 ounces of the D'Arcy diet, the caloric density can be increased to 88 calories per ounce. If the cat continues to eat the same volume of food, it will increase its caloric intake by 10 per cent. Mineral Imbalances
The most commonly seen mineral imbalance, clinically, is absolute calcium deficiency, or relative calcium deficiency produced by an incorrect calcium to phosphorus ratio. Another clinical entity seen with some regularity is deficiency anemia resulting from iron, copper, or cobalt imbalances.
DIETARY CONSIDERATION IN FELINE PRACTICE
345
Vitamin Imbalances
Among the more important vitamin imbalances in cats is that of thiamine deficiency. It is seen most often in animals fed over long periods on one food exclusively, or in cats with anorexia. Steatitis has been described as a deficiency of vitamin E, but it might also be characterized as a dietary excess of unsaturated, unstabilized fatty acids. Vitamin A toxicosis has been reported in cats fed large quantities of liver containing excessive amounts of biologically active vitamin A. Imbalances in General
In most cases, imbalanced diets do not result in a disease that resembles any of those described in nutrition textbooks. Instead, imbalanced diets produce insidious disorders with vague and inconsistent signs. Attempts to treat such disorders with a particular nutrient almost always result in atypical responses, confusing and often exacerbating the signs already present. The secret to correcting an incorrect diet, therefore, is not to correct it at all. Instead, the diet being fed should be discarded entirely, and a new, balanced diet substituted in its place. Cats are creatures of habit and easily become "hooked" on a particular diet, if their owners allow it. These "hooked" cats are of no real concern to the veterinarian unless the diet upon which the animal is hooked is nutritionally inadequate. When a diet is found to be inadequate, however, and a suitable replacement diet is recommended, the hooked cat may refuse to eat the new foods. In these instances, there is a simple procedure which, if used without shortcut, rarely fails to convert such cats to any new diet. Whenever a cat is found to be reluctant to eat a new food, proceed as follows: Replace 25 per cent of the current diet with new diet and mix the two thoroughly. This mixture is fed to the cat. When the cat is eating this 25 to 75 per cent mixture with the same enthusiasm as it did the original diet, the diet is changed to a 50 to 50 per cent mixture of old and new diets. This mixture is fed until it, too, is eaten with eagerness. Then a mixture of 75 to 25 per cent is fed and, finally, 100 per cent of the new diet is fed. The final outcome will be a cat that is eating the new diet with the same relish that it ate its old diet.
THE ANORECTIC CAT Sick cats don't eat. In fact, anorexia is the single most.common sign of illness in cats. Even a healthy cat may suffer transient anorexia from a trip to the hospital or kennel. When any cat is not eating, it devours itself to obtain the nutrients
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and fuel it needs to maintain vital functions and minimal activity. When a sick cat is not eating, it burns up stored energy and body proteins desperately needed for tissue repair, healing, and replacement. In addition to the energy and protein, that sick cat also needs about 30 other nutrients, each in proper proportion to the other. Consequently, malnutrition exacerbates bacterial, rickettsial, and helminthic infections. Likewise, such infections can convert borderline nutritional status into a full-blown deficiency disease. Every day an 8-pound cat does not eat, it burns itself up at a rate of about one pound per week, at least for the first two or three pounds. The only way to halt this drastic wasting is to immediately begin artificial alimentation. Trying a dozen different foods to coax the cat to eat only wastes precious time. Forty-eight to 72 hours of anorexia may thwart any efforts at therapy until the cat's nutritional stability has been reestablished. The first treatment for any cat that has not eaten for 48 hours or longer should be inserting a gastric tube and providing the animal with some nourishment. Numerous satisfactory diets for artificial alimentation can be made from ingredients found around the home or hospital, if a blender is available. Some of these diets are found in Table 1. In those instances where the cat also refuses to drink water, or in
Table 1. Diets Suitable fino Oral Alimentation
FORMULA
':' I jar egg yolk I jar water jar egg yolk I jar water Illz oz Karo
%
CALS
%
PER O Z
PROTEIN
% FAT
HYDRATE
34
5.3
8.9
0.3
Anorexia
14.0
Nephritis Hepatitis Enteritis
CARBO-
l/Z
45
2.6
4.4
INDICATIONS
46
5.0
13.0
6.0
Anorexia Febrile states Cachexia
2 ozs corn oil t8 ozs i/d 20 ozs water
30
2.8
7.4
5.3
Nephritis Enteritis
+8 ozs Dyne 8 ozs cottage cheese 8 ozs water
58
6.6
16.7
7.6
I jar egg yolk I jar water I tsp oil I tbsp Karo
':'Swift and Co. , Chicago, Illinois. tHills Oiv., Riviana Foods, Inc.. Topeka, Kansas . tBioLab Corp. , Kansas City, Missouri.
Anorexia Febrile states Trauma
DIETARY CONSIDERATION IN FELINE PRACTICE
347
cases where diarrhea, vomiting, or excessive fluid loss make dehydration a problem, the replacement of fluids and the restoration of electrolyte balance becomes the top priority. Most concentrated diets for anorexia do not contain enough water to supply all the cat's daily water needs. The best way to ensure an adequate water intake, therefore, is to add I oz of water to every 2 to 4 ozs of diet, before administering. Several techniques for administering liquids by oral alimentation have been described.
FEEDING DISEASED CATS The final, and perhaps most challenging, nutritional concern of the clinician is that of prescribing an appropriate diet to support the total treatment regimen for a sick cat. While normal, balanced diets are ideal for normal, healthy cats, such diets may be totally inappropriate for abnormal, diseased cats. For many of these latter cats, a special diet must be used in order to realize maximum results from a therapeutic regimen. Gastrointestinal Disease
Depending upon its location in the gastrointestinal tract, gastrointestinal disease can be characterized by vomiting, diarrhea, tenesmus, or constipation. The objectives of ordering a special diet in those gastrointestinal diseases that are characterized by the first three signs are to minimize irritation of the gastrointestinal canal and to maximize the utilization of the foods that are eaten. To accomplish these objectives, one of the commercial dietary animal foods can be used, or the client can be instructed to alter the regular diet appropriately. For example, the DArcy diet can be altered as follows : Homemade Gastrointestinal Diet
2 Ibs raw hamburger 2 Ibs cottage cheese
112
IIl.rall" Ii"er. ground
2 Ibs dry rice 1/ 4 Ib Theralin (8 tbsps.) 1/ 4 Ib Brewer's Yeast (8 tbsps.) Boil and drain rice, saving rice water, Sprinkle dry ingredients over hamburger and mix in well. Then mix hamburger, cottage cheese, and raw liver together, Finally, stir in rice, adding enough rice water to make the proper consistency for the cat. Feed at the rate of 2 ozs for every 3 Ibs of cat.
Regardless of the diet chosen, all food should be withheld for 24 hours in cases involving vomiting or diarrhea. Water can be provided in the form of ice cubes, I or 2 per hour. If the vomiting or diarrhea
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cannot be controlled, wait another 24 hours, then begin by feeding meat or chicken broth, in 2 to 3 tablespoonful portions, everyone to two hours. If this is held down successfully, add a little meat-type baby food to the broth. Twenty-four hours later expand the diet further by adding cottage cheese, soft-boiled eggs, or milk puddings that contain no sugar. If vomiting and diarrhea have remained under control for 48 hours , small quantities of the cat's regular diet can be fed at every other feeding. If this causes no untoward reaction the regular diet and normal feeding schedule can be resumed. In patients exhibiting constipation , withholding food is not as important as removal of the offending fecal mass. This mass may contain such foreign matter as hair, wool, or bone. Once removed, the prevention of recurrence is greatly assisted by feeding a diet containing moderate amounts of plant fiber, little or no bones, and plenty of energy. Such a diet is the basic D'Arcy cattery diet already discussed. An exception to the use of moderate fiber in patients with constipation will be patients with Hirschprung's disease or megacolon. In these patients, the diet should be highly digestible and as low in digestive residues as possible. The homemade gastrointestinal diet already described, or the homemade hepatic diet to be described shortly, both serve as a diet for cats with megacolon. Urinary Tract Disease
The most common condition affecting the cat's urinary tract has 20 synonyms. The most accurate one probably is feline urologic syndrome. Regardless of what name it is given - feline urologic syndrome, urolithiasis, cystitis, or simply plugged cat- the specific cause of the disease remains unknown. The objectives of feeding a special diet to the cat suffering from this complex of diseases, therefore, must be empirical. These objectives are to minimize the urinary concentrations of magnesium, and possibly phosphorus, while maintaining adequate blood serum levels of these minerals, and to maintain a urinary pH in the acidic range to keep what magnesium salts are already in the urine in solution. While most commercial cat foods do not contain extremely high quantities of magnesium (except in cases where large quantities of bone are incorporated into the diet), the things people add to their eat's diet often do contain high levels of magnesium. To assist in guiding clients in their choice of appropriate tidbits for their cat, Table 2 gives the magnesium levels of some foods commonly fed to cats. Renal Disease
As cats get older, they suffer from degeneration and reduced function of the kidneys. The objective of dietary therapy in renal disease is to reduce the workload on the kidney, thereby compensating for its
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DIETARY CONSIDERATION IN FELINE PRACTICE
Table 2.
Magnesium Content of Treat Foods* mg
PER
1l1g PER
100 gm
FOPD
Shrimp Nuts Canned catfood Dry catfood Semi-moist catfood Canned meat catfood Codfish Potatoes (raw) Milk (whole) Saltwater fish Chicken (breast) Sardines (canned) Beef heart
100 gm
DRY MATTER
568 231-269 200 160 160 130 130 105 100 93 92 82 78
FOOD
Canned corn Beef (raw) Cheese (cheddar) Rabbit Dietary catfood Freshwater fish Hog's liver (raw) Beef liver (raw) Whole eggs Lamb Pork Rice Carrots
DRY MATTER
76
71 71
70 60 56 55 48 41 37 36 28 0.7
* Magnesium levels are given in mgs per 100 gms d,)' diet. Because there is stich a wide disparity in water content, the only way to compare a list of foods stich as these is to eliminate the water entirely, and compare nutrients by their dry weight. reduced function . The objective can be accomplished by reducing the nitrogenous wastes that must be excreted by the kidney. The most practical way of doing this is by increasing the protein quality of the diet. Doing this allows the quantity of daily protein to be reduced. In diets containing a protein blend that yields a biologic value of 80 per cent or greater, protein levels can be reduced to about 20 per cent on a dry-weight basis. (This is equivalent to about 6 per cent in a canned meat or 18 per cent in a dry food.) Because cats seem to be unique among domestic pets in their requirement that some of their calories derive from protein, the margin between the compensated and the decompensated cat with renal disease is quite narrow and the prognosis in all cases with nephritis should remain guarded. A satisfactory diet for cats with nephritis can be purchased as a commercial dietary food specially designed for cats with nephritis or it can be made at home by the client. An example of such a diet is another alteration of the basic D'Arcy cattery diet. The changes made are characteristic of those that will have to be made in most normal cat diets if it is to successfully nourish the cat with nephritis. Homemade Nephritis Diet
3 Ibs raw hamburger
112 Ib raw liver, ground
3 Ibs dry rice Ib Theralin (8 tbsps.) 1/4 lb. Brewer's Yeast (8 tbsps.) Boil and drain rice, saving rice water. Sprinkle dry ingredients over hamburger and mix in well. Then mix hamburger, rice, and liver 1/4
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together evenly, using as much rice water as needed to make the consistency proper for the cat being fed . Feed at the rate of 1 oz for every 2 lbs of cat.
Hepatic Disorders Another condition that plagues cats, both young and old, are diseases that result in reduced liver function. Whatever the cause of the liver dysfunction, the objective of feeding a special diet to patients with liver dysfunction is to reduce the workload of the ailing liver. Two of the liver s major functions that can be influenced by diet are transamination of amino acids and the conversion of purines and pyrimidines to uric acid. By restricting protein sources to those of high biologic value , levels can be lowered, and if their nucleic acid content is kept low, the need for both liver functions can be minimized. Sources such as whole eggs, dried skimmed milk, or cottage cheese will provide proteins that meet these criteria. Avoiding commercial foods containing meat by-products made up largely of glandular tissues , fish meal, shellfish, or liver will eliminate some of the worse offenders in contributing uric acid precursors. A modification of the D'Arcy diet, incorporating the protein sources suggested, can be used as a diet for cats with hepatic dysfunction. Commercial dietary foods designed to be fed to cats with gastrointestinal disorders are sometimes satisfactory in cases of liver dysfunction, as well. Homemade Hepatic Diet
1 lb hamburger 3 lbs cottage cheese 1/ 4 lb liver 2 lbs dry rice 1/ 4 lb Theralin (8 tbsps.) 1/ 4 lb Brewer's Yeast (8 tbsps.) Boil and drain rice , saving rice water. Sprinkle dry ingredients over cottage cheese and mix in well. Then mix hamburger, rice, and liver together evenly with the cottage cheese. If too thick, add some rice water to improve consistency. Feed at the rate of 2 oz for every 3 lbs of cat.
Pancreatic Disorders The pancreas furnishes both enzymes and a hormone. While enzymes produced by other organs can replace most of the enzymes lost during pancreatic disease, nothing is available to replace the hormone, insulin. Without insulin, the cat is unable to regulate glucose concentrations in the blood, and diabetes mellitus results. The objectives of special diets in diabetes, therefore, is to provide a uniform source of nutrient uptake and to provide a constant daily supply of energy, thus enabling the clinician to adjust insulin dosage. To
DIETARY CONSIDERATION IN FELINE PRACTICE
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maximize the effectiveness of this regimen a uniformity of exercise patterns should also be established. Commercial diets seldom afford the uniformity required of a diet satisfactory for treating a cat with diabetes. Consequently, a diet must either be prepared by the owner, or one of the dietary foods specially designed for patients in which strict uniformity is needed, must be fed. When homemade diets are used, the owner must be convinced of the need for the uniform diet, because it will be the owner's job to maintain that uniformity with the ingredients he chooses and the care with which he puts those ingredients together. A modification of the D'Arcy diet can be used, provided the same ingredients and exact weights are used each time the food is prepared. That modification is: Pancreatic (Diabetic) Diet
2 Ibs hamburger 2 Ibs cottage cheese 112 Ib raw liver, groun
Dietary Consideration in Feline Practice Donald R . Collins, D. V.M. *
Catowners have only one concern when feeding cats-providing a nutritionally adequate diet. The feline practitioner has three additional concerns relative to feeding cats: correcting incorrect diets, feeding cats with anorexia, and prescribing appropriate diets in the treatment of diseased cats.
NUTRITIONALLY ADEQUATE DIETS The chore of coming up with the correct diet for a cat is not nearly as difficult as it once was. Today, any commercial catfood that bears the claim "complete and balanced," "nutritional," or "adequate," must have either successfully supported the life cycle of cats in actual feeding studies, or must be able to demonstrate, by chemical analysis, that it contains the correct nutrients needed by the cat in amounts which have been suggested by the National Research Council. A problem arises when a client does not feed a cat commercial foods, or feeds it some combination of natural and commercial foods. The only way to ascertain the nutritional adequacy of these diets is to obtain a detailed dietary history, including formulas and recipes, labels, etc., and to evaluate the diet. A sample dietary history form is shown in Figure 1. Remember that a cat's diet consists of everything it eats- not just what the owner feeds it. Techniques for evaluating diets have been published. Two homemade diets that are known to be nutritionally adequate are listed:
"Director of Pet food Research. Nabisco. Inc.. Nabisco Research Center. Fair Lawn. New Jersey Ve.terina1)· Clinics oINorth America- Vol. 6. No.3. August 1976
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What type of food is fed ? (Use brand names when possible.) canned food ? _ _ _ _ _ _ _ dry food? _ _ _ _ _ _ semi-moist? _ _ _ _ __ table scraps? (list) _ _ _ _ _ _ _ __
homemade diet? _ _ _ _ _ _ _ _ __ recipe? _ _ _ _ _ _ _ _ _ _ _ __
(Labels of all commercial foods and formulas for homemad e diets should be attached to eat's record.) Comments on feeding procedure (times, amounts, containers, other cats, etc.): Does cat eat all that is fed? _ __ _ _ _ _ __ What treats or supplements are fed to the cat?
o canned tuna o canned salmon o canned sardines o bacon strips o luncheon meats
o liver strips o fresh fish o cheese o
o
o other?
0 ________________
chicken breast giblets
o ________________ o _______________ 0 _ _ _ _ _ _ __
Is cat given water?
Quantity drunk daily? _ _ _ _ _ _ __
Is cat given milk?
Quantity drunk daily? _ _ _ _ _ _ __
Does cat go outdoors?
What have you observed cat eating outdoors? (Be specific!) _ _ _ _ _ _ _ _ _ _ _ _ __
Does cat have any food allergies?
To what? _ __ _ _ _ _ _ _ _ _ __
General comments: Figure I .
A dietary history.
DIETARY CONSIDERATION IN FELINE PRACTICE
343
D'Arc)' Calle?)' Diet*
4 Ibs raw hamburger 1/2 Ib raw liver, ground 2 Ibs Purina Hi-Protein Dog Meal 1/ 4 Ib Theralint (8 tbsp.) 1/ 4 Ib Brewer's Yeast (8 tbsp.) Soak dog food in enough hot water to cover. Mix in hamburger, liver, and dry ingredients. If mixture is too dry , add a little water. If too soupy, add Gerber's Baby Rice Cereal. Should be fed at the rate of 112 ounce per pound of cat. National Research Councils Diet A (Modified)
1 Ib cottage cheese Ib whole dried milk 3/4 Ib raw liver 3 cups oatmeal (uncooked) 11/2 ozs corn oil or lard 6 ozs Brewer's Yeast (12 tbsps.) 3/ 4 oz cod liver oil Mix corn oil and cod liver oil with cottage cheese and liver (ground or blended). Mix in milk and Brewer's Yeast. Finally, fold in oatmeal, adding a little water if needed for a smooth blend. 1/ 2
INCORRECT DIETS A dietary history should be taken for every patient seen, regardless of the nature of the illness. If the cat's diet is discovered to be inadequate, the clinician should address himself to correcting the cat's diet simultaneous with other treatment prescribed. Regardless of how accurate the diagnosis, or how adroit the treatment prescribed, if the cat is suffering from even a borderline nutritional deficiency, the result of therapy will be less than optimal. Incorrect diets result in nutritional imbalances. Only a few of these imbalances will produce a specific clinical disease , however. A discussion of these imbalances follows .
Energy Imbalances Imbalances in dietary energy intake occur in two forms- too much and too little. Excessive energy intake produces obesity; too little energy produces emaciation. Obesity. The cause of obesity is simple and direct- the consumption of more food than is needed by the cat to supply its energy requirements. The prevention of obesity is equally simple and ':The D'Arcy diet forms the basis for a general hospital diet which can be modified to accommodate man y disease conditions. tLambert Kay, Santa Ana, California.
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direct- feed the cat only that amount of food that will supply its energy needs. Treating obesity, therefore , requires reducing the food consumed to levels below that needed for energy, at least until the cat has reached its optimum weight. An effective approach to reducing obese cats is: 1. Establish an optimum weight for the cat. (Optimum weights are based on breed, sex, age, activity, etc.) 2. Determine the present weight of the cat and subtract the optimum weight from the present weight. (This gives the reduction goal, in pounds.) 3. Multiply the reduction goal by 80. 4. Divide the number obtained in step 3 by 100 for a dry food, by 85 for a semi-moist food, and by 40 for a canned food. 5. The number obtained in step 4 is the number of ounces of food to be removed from the current diet each day. (One level cupful of dry food is equivalent to 3 ozs of dry food, 4 ozs of semi-moist food, or 71/ 2 ozs of canned food .) The reduced quantity of food is fed until the cat reaches its optimum weight. Once this happens, one half of the number of ounces that were reduced can be restored to the daily diet and the cat should be fed that amount for the rest of its life, unless it has a sudden weight change, becomes ill, or becomes pregnant. Emaciation. When caused only by too little energy intake, emaciation is easily reversible and unless of long standing, causes little harm to the cat. The most satisfactory method of increasing energy intake is to increase total food consumption. A simple suggestion to the owner to feed a little more food each day may solve the problem. In other cases, however, ample food is being fed, but the calories obtained from that food by the cat are insufficient. In these cases the caloric density of the food must be increased. To increase the caloric density of a cat's diet, fats or oils should be added . About 35 calories are added for each teaspoonful of fat or oil. For example, the DArcy diet contains about 80 calories per ounce (2 .75 calories per gram). By adding two teaspoonfuls of corn oil or bacon fat to each 8 ounces of the D'Arcy diet, the caloric density can be increased to 88 calories per ounce. If the cat continues to eat the same volume of food, it will increase its caloric intake by 10 per cent. Mineral Imbalances
The most commonly seen mineral imbalance, clinically, is absolute calcium deficiency, or relative calcium deficiency produced by an incorrect calcium to phosphorus ratio. Another clinical entity seen with some regularity is deficiency anemia resulting from iron, copper, or cobalt imbalances.
DIETARY CONSIDERATION IN FELINE PRACTICE
345
Vitamin Imbalances
Among the more important vitamin imbalances in cats is that of thiamine deficiency. It is seen most often in animals fed over long periods on one food exclusively, or in cats with anorexia. Steatitis has been described as a deficiency of vitamin E, but it might also be characterized as a dietary excess of unsaturated, unstabilized fatty acids. Vitamin A toxicosis has been reported in cats fed large quantities of liver containing excessive amounts of biologically active vitamin A. Imbalances in General
In most cases, imbalanced diets do not result in a disease that resembles any of those described in nutrition textbooks. Instead, imbalanced diets produce insidious disorders with vague and inconsistent signs. Attempts to treat such disorders with a particular nutrient almost always result in atypical responses, confusing and often exacerbating the signs already present. The secret to correcting an incorrect diet, therefore, is not to correct it at all. Instead, the diet being fed should be discarded entirely, and a new, balanced diet substituted in its place. Cats are creatures of habit and easily become "hooked" on a particular diet, if their owners allow it. These "hooked" cats are of no real concern to the veterinarian unless the diet upon which the animal is hooked is nutritionally inadequate. When a diet is found to be inadequate, however, and a suitable replacement diet is recommended, the hooked cat may refuse to eat the new foods. In these instances, there is a simple procedure which, if used without shortcut, rarely fails to convert such cats to any new diet. Whenever a cat is found to be reluctant to eat a new food, proceed as follows: Replace 25 per cent of the current diet with new diet and mix the two thoroughly. This mixture is fed to the cat. When the cat is eating this 25 to 75 per cent mixture with the same enthusiasm as it did the original diet, the diet is changed to a 50 to 50 per cent mixture of old and new diets. This mixture is fed until it, too, is eaten with eagerness. Then a mixture of 75 to 25 per cent is fed and, finally, 100 per cent of the new diet is fed. The final outcome will be a cat that is eating the new diet with the same relish that it ate its old diet.
THE ANORECTIC CAT Sick cats don't eat. In fact, anorexia is the single most.common sign of illness in cats. Even a healthy cat may suffer transient anorexia from a trip to the hospital or kennel. When any cat is not eating, it devours itself to obtain the nutrients
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and fuel it needs to maintain vital functions and minimal activity. When a sick cat is not eating, it burns up stored energy and body proteins desperately needed for tissue repair, healing, and replacement. In addition to the energy and protein, that sick cat also needs about 30 other nutrients, each in proper proportion to the other. Consequently, malnutrition exacerbates bacterial, rickettsial, and helminthic infections. Likewise, such infections can convert borderline nutritional status into a full-blown deficiency disease. Every day an 8-pound cat does not eat, it burns itself up at a rate of about one pound per week, at least for the first two or three pounds. The only way to halt this drastic wasting is to immediately begin artificial alimentation. Trying a dozen different foods to coax the cat to eat only wastes precious time. Forty-eight to 72 hours of anorexia may thwart any efforts at therapy until the cat's nutritional stability has been reestablished. The first treatment for any cat that has not eaten for 48 hours or longer should be inserting a gastric tube and providing the animal with some nourishment. Numerous satisfactory diets for artificial alimentation can be made from ingredients found around the home or hospital, if a blender is available. Some of these diets are found in Table 1. In those instances where the cat also refuses to drink water, or in
Table 1. Diets Suitable fino Oral Alimentation
FORMULA
':' I jar egg yolk I jar water jar egg yolk I jar water Illz oz Karo
%
CALS
%
PER O Z
PROTEIN
% FAT
HYDRATE
34
5.3
8.9
0.3
Anorexia
14.0
Nephritis Hepatitis Enteritis
CARBO-
l/Z
45
2.6
4.4
INDICATIONS
46
5.0
13.0
6.0
Anorexia Febrile states Cachexia
2 ozs corn oil t8 ozs i/d 20 ozs water
30
2.8
7.4
5.3
Nephritis Enteritis
+8 ozs Dyne 8 ozs cottage cheese 8 ozs water
58
6.6
16.7
7.6
I jar egg yolk I jar water I tsp oil I tbsp Karo
':'Swift and Co. , Chicago, Illinois. tHills Oiv., Riviana Foods, Inc.. Topeka, Kansas . tBioLab Corp. , Kansas City, Missouri.
Anorexia Febrile states Trauma
DIETARY CONSIDERATION IN FELINE PRACTICE
347
cases where diarrhea, vomiting, or excessive fluid loss make dehydration a problem, the replacement of fluids and the restoration of electrolyte balance becomes the top priority. Most concentrated diets for anorexia do not contain enough water to supply all the cat's daily water needs. The best way to ensure an adequate water intake, therefore, is to add I oz of water to every 2 to 4 ozs of diet, before administering. Several techniques for administering liquids by oral alimentation have been described.
FEEDING DISEASED CATS The final, and perhaps most challenging, nutritional concern of the clinician is that of prescribing an appropriate diet to support the total treatment regimen for a sick cat. While normal, balanced diets are ideal for normal, healthy cats, such diets may be totally inappropriate for abnormal, diseased cats. For many of these latter cats, a special diet must be used in order to realize maximum results from a therapeutic regimen. Gastrointestinal Disease
Depending upon its location in the gastrointestinal tract, gastrointestinal disease can be characterized by vomiting, diarrhea, tenesmus, or constipation. The objectives of ordering a special diet in those gastrointestinal diseases that are characterized by the first three signs are to minimize irritation of the gastrointestinal canal and to maximize the utilization of the foods that are eaten. To accomplish these objectives, one of the commercial dietary animal foods can be used, or the client can be instructed to alter the regular diet appropriately. For example, the DArcy diet can be altered as follows : Homemade Gastrointestinal Diet
2 Ibs raw hamburger 2 Ibs cottage cheese
112
IIl.rall" Ii"er. ground
2 Ibs dry rice 1/ 4 Ib Theralin (8 tbsps.) 1/ 4 Ib Brewer's Yeast (8 tbsps.) Boil and drain rice, saving rice water, Sprinkle dry ingredients over hamburger and mix in well. Then mix hamburger, cottage cheese, and raw liver together, Finally, stir in rice, adding enough rice water to make the proper consistency for the cat. Feed at the rate of 2 ozs for every 3 Ibs of cat.
Regardless of the diet chosen, all food should be withheld for 24 hours in cases involving vomiting or diarrhea. Water can be provided in the form of ice cubes, I or 2 per hour. If the vomiting or diarrhea
348
DONALD
R.
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cannot be controlled, wait another 24 hours, then begin by feeding meat or chicken broth, in 2 to 3 tablespoonful portions, everyone to two hours. If this is held down successfully, add a little meat-type baby food to the broth. Twenty-four hours later expand the diet further by adding cottage cheese, soft-boiled eggs, or milk puddings that contain no sugar. If vomiting and diarrhea have remained under control for 48 hours , small quantities of the cat's regular diet can be fed at every other feeding. If this causes no untoward reaction the regular diet and normal feeding schedule can be resumed. In patients exhibiting constipation , withholding food is not as important as removal of the offending fecal mass. This mass may contain such foreign matter as hair, wool, or bone. Once removed, the prevention of recurrence is greatly assisted by feeding a diet containing moderate amounts of plant fiber, little or no bones, and plenty of energy. Such a diet is the basic D'Arcy cattery diet already discussed. An exception to the use of moderate fiber in patients with constipation will be patients with Hirschprung's disease or megacolon. In these patients, the diet should be highly digestible and as low in digestive residues as possible. The homemade gastrointestinal diet already described, or the homemade hepatic diet to be described shortly, both serve as a diet for cats with megacolon. Urinary Tract Disease
The most common condition affecting the cat's urinary tract has 20 synonyms. The most accurate one probably is feline urologic syndrome. Regardless of what name it is given - feline urologic syndrome, urolithiasis, cystitis, or simply plugged cat- the specific cause of the disease remains unknown. The objectives of feeding a special diet to the cat suffering from this complex of diseases, therefore, must be empirical. These objectives are to minimize the urinary concentrations of magnesium, and possibly phosphorus, while maintaining adequate blood serum levels of these minerals, and to maintain a urinary pH in the acidic range to keep what magnesium salts are already in the urine in solution. While most commercial cat foods do not contain extremely high quantities of magnesium (except in cases where large quantities of bone are incorporated into the diet), the things people add to their eat's diet often do contain high levels of magnesium. To assist in guiding clients in their choice of appropriate tidbits for their cat, Table 2 gives the magnesium levels of some foods commonly fed to cats. Renal Disease
As cats get older, they suffer from degeneration and reduced function of the kidneys. The objective of dietary therapy in renal disease is to reduce the workload on the kidney, thereby compensating for its
349
DIETARY CONSIDERATION IN FELINE PRACTICE
Table 2.
Magnesium Content of Treat Foods* mg
PER
1l1g PER
100 gm
FOPD
Shrimp Nuts Canned catfood Dry catfood Semi-moist catfood Canned meat catfood Codfish Potatoes (raw) Milk (whole) Saltwater fish Chicken (breast) Sardines (canned) Beef heart
100 gm
DRY MATTER
568 231-269 200 160 160 130 130 105 100 93 92 82 78
FOOD
Canned corn Beef (raw) Cheese (cheddar) Rabbit Dietary catfood Freshwater fish Hog's liver (raw) Beef liver (raw) Whole eggs Lamb Pork Rice Carrots
DRY MATTER
76
71 71
70 60 56 55 48 41 37 36 28 0.7
* Magnesium levels are given in mgs per 100 gms d,)' diet. Because there is stich a wide disparity in water content, the only way to compare a list of foods stich as these is to eliminate the water entirely, and compare nutrients by their dry weight. reduced function . The objective can be accomplished by reducing the nitrogenous wastes that must be excreted by the kidney. The most practical way of doing this is by increasing the protein quality of the diet. Doing this allows the quantity of daily protein to be reduced. In diets containing a protein blend that yields a biologic value of 80 per cent or greater, protein levels can be reduced to about 20 per cent on a dry-weight basis. (This is equivalent to about 6 per cent in a canned meat or 18 per cent in a dry food.) Because cats seem to be unique among domestic pets in their requirement that some of their calories derive from protein, the margin between the compensated and the decompensated cat with renal disease is quite narrow and the prognosis in all cases with nephritis should remain guarded. A satisfactory diet for cats with nephritis can be purchased as a commercial dietary food specially designed for cats with nephritis or it can be made at home by the client. An example of such a diet is another alteration of the basic D'Arcy cattery diet. The changes made are characteristic of those that will have to be made in most normal cat diets if it is to successfully nourish the cat with nephritis. Homemade Nephritis Diet
3 Ibs raw hamburger
112 Ib raw liver, ground
3 Ibs dry rice Ib Theralin (8 tbsps.) 1/4 lb. Brewer's Yeast (8 tbsps.) Boil and drain rice, saving rice water. Sprinkle dry ingredients over hamburger and mix in well. Then mix hamburger, rice, and liver 1/4
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together evenly, using as much rice water as needed to make the consistency proper for the cat being fed . Feed at the rate of 1 oz for every 2 lbs of cat.
Hepatic Disorders Another condition that plagues cats, both young and old, are diseases that result in reduced liver function. Whatever the cause of the liver dysfunction, the objective of feeding a special diet to patients with liver dysfunction is to reduce the workload of the ailing liver. Two of the liver s major functions that can be influenced by diet are transamination of amino acids and the conversion of purines and pyrimidines to uric acid. By restricting protein sources to those of high biologic value , levels can be lowered, and if their nucleic acid content is kept low, the need for both liver functions can be minimized. Sources such as whole eggs, dried skimmed milk, or cottage cheese will provide proteins that meet these criteria. Avoiding commercial foods containing meat by-products made up largely of glandular tissues , fish meal, shellfish, or liver will eliminate some of the worse offenders in contributing uric acid precursors. A modification of the D'Arcy diet, incorporating the protein sources suggested, can be used as a diet for cats with hepatic dysfunction. Commercial dietary foods designed to be fed to cats with gastrointestinal disorders are sometimes satisfactory in cases of liver dysfunction, as well. Homemade Hepatic Diet
1 lb hamburger 3 lbs cottage cheese 1/ 4 lb liver 2 lbs dry rice 1/ 4 lb Theralin (8 tbsps.) 1/ 4 lb Brewer's Yeast (8 tbsps.) Boil and drain rice , saving rice water. Sprinkle dry ingredients over cottage cheese and mix in well. Then mix hamburger, rice, and liver together evenly with the cottage cheese. If too thick, add some rice water to improve consistency. Feed at the rate of 2 oz for every 3 lbs of cat.
Pancreatic Disorders The pancreas furnishes both enzymes and a hormone. While enzymes produced by other organs can replace most of the enzymes lost during pancreatic disease, nothing is available to replace the hormone, insulin. Without insulin, the cat is unable to regulate glucose concentrations in the blood, and diabetes mellitus results. The objectives of special diets in diabetes, therefore, is to provide a uniform source of nutrient uptake and to provide a constant daily supply of energy, thus enabling the clinician to adjust insulin dosage. To
DIETARY CONSIDERATION IN FELINE PRACTICE
351
maximize the effectiveness of this regimen a uniformity of exercise patterns should also be established. Commercial diets seldom afford the uniformity required of a diet satisfactory for treating a cat with diabetes. Consequently, a diet must either be prepared by the owner, or one of the dietary foods specially designed for patients in which strict uniformity is needed, must be fed. When homemade diets are used, the owner must be convinced of the need for the uniform diet, because it will be the owner's job to maintain that uniformity with the ingredients he chooses and the care with which he puts those ingredients together. A modification of the D'Arcy diet can be used, provided the same ingredients and exact weights are used each time the food is prepared. That modification is: Pancreatic (Diabetic) Diet
2 Ibs hamburger 2 Ibs cottage cheese 112 Ib raw liver, groun
