Nutrition PDF

Nutrition 20 CHA P TE R Patricia A. Schenck...

Nutrition 20 CHA P TE R Patricia A. Schenck 1. Calcium NUTRIENTS a. Deficiency: Decreased bone mineralization, I. Water bone fractures A. Water is the most important nutrient b. Excess: Nephrosis, enlarged costochondral B. Requirement (mL/day) roughly equals 1.6 * rest- junctions ing energy requirement (RER) in dogs and 1.2 * 2. Phosphorus RER in cats a. Deficiency: Pica, rickets, poor growth II. Carbohydrates b. Excess: Bone loss, calcification of soft A. Includes sugars and starches tissues B. Utilized as a source of glucose 3. Potassium C. Carbohydrate ingredients include grains a. Deficiency: Anorexia, heart and kidney (e.g., wheat, corn, rice, barley, oats) lesions D. Cooking increases the digestibility of b. Excess is rare carbohydrates 4. Sodium, chloride III. Fiber a. Deficiency: Inability to maintain water A. Resists enzymatic digestion; is fermented in the balance colon b. Excess: Thirst, seizures, death B. Fiber promotes and regulates normal bowel 5. Magnesium function a. Deficiency: Muscular weakness, irritability, C. Fiber sources differ in their fermentation decreased bone density, seizures properties b. Excess: Uroliths, paralysis D. The amount of fiber in the diet impacts the 6. Iron digestibility of the food a. Deficiency: Anemia, poor coat IV. Protein b. Excess: Anorexia, decreased liver function A. Proteins are composed of amino acids. Ten amino 7. Zinc acids are essential in a dog diet, and 11 are essen- a. Deficiency: Alopecia, depigmentation of hair tial in the cat b. Excess: Rare B. Catabolism of protein produces waste nitrogen 8. Copper and generates ammonia, which can be toxic a. Deficiency: Depigmentation of hair, C. Protein is required in the diet because amino neuromuscular disorders acids are continually being used in metabolic b. Excess: Increased activity of liver enzymes pathways 9. Manganese D. Most commercial diets contain excess protein a. Deficiency: Crooked legs, fatty liver V. Lipids b. Excess: Rare A. Certain fatty acids (linoleic acid in the dog, lin- 10. Iron oleic and arachidonic acid in the cat) are required a. Deficiency: Goiter, reproductive failure, in the diet myxedema B. Fats are an important source of energy, providing b. Excess: Goiter, decreased appetite more than twice the energy per gram compared 11. Selenium with protein or carbohydrate a. Deficiency: Muscular dystrophy, subcuta- C. Dietary fat improves the absorption of the fat sol- neous edema, renal mineralization uble vitamins (A, D, E, and K) b. Excess: Vomiting, staggering, salivation, VI. Minerals nail loss A. Required for many important functions in the 12. Chromium body a. Deficiency: Impaired glucose tolerance B. Minerals from meat sources are typically better b. Excess: Dermatitis, lung cancer utilized than minerals from plant sources VII. Vitamins C. A variety of medical problems can result from de- A. Vitamins A, D, E, and K are fat-soluble vitamins. ficiency or excess of minerals Intestinal absorption requires bile salts and 290  CHAPTER 20 Nutrition 291 micelle formation; absorption is by passive 12. Cobalamin (vitamin B12) transport. They are stored in fat; thus deficiency a. Deficiency: Poor growth, anemia is less likely; however, they are more likely to b. Excess: Altered reflexes cause toxicity 13. Vitamin C: No signs of deficiency or toxicity in B. The remaining vitamins are water soluble and are dogs or cats absorbed by active transport. They can be de- 14. Choline pleted, rapidly causing deficiency; toxicity is un- a. Deficiency: Thymic atrophy, poor growth, common anorexia, fatty liver C. A variety of medical problems can result from de- b. Excess: No toxicity ficiency or excess of minerals 15. Carnitine 1. Vitamin A a. Deficiency: Cardiomyopathy, hyperlipidemia a. Deficiency: Anorexia, poor growth, weak- b. Excess: No toxicity ness, fetal resorption b. Excess: Tooth loss, poor growth, cervical ENERGY REQUIREMENTS spondylosis 2. Vitamin D I. Dogs a. Deficiency: Rickets, osteomalacia, bone A. Resting energy requirement (RER) fractures, enlarged costochondral 1. RER (kcal)  70*(body weight [BW] [kg])0.75 junctions 2. If BW is between 2 and 45 kg, RER (kcal) is b. Excess: Hypercalcemia, calcinosis, an- approx 30*(BW [kg])  70 orexia, lameness B. Maintenance energy requirement (MER) depends 3. Vitamin E on physiologic state and ranges from 1.0 * RER in a. Deficiency: Steatitis, dermatitis, anorexia, obese individuals to 1.8 * RER in intact adults myopathy, immunodeficiency, sterility C. Work energy requirement ranges from 2 * RER for b. Excess: Minimal toxicity, impairment of ab- light work to 8 * RER for heavy work sorption of other fat soluble vitamins, pro- D. Gestation longed clotting times 1. First 42 days, feed as an intact adult (1.8 * RER) 4. Vitamin K 2. Last 21 days, feed 3* RER (or more if needed) a. Deficiency: Prolonged clotting time, hemor- E. Lactation energy requirement ranges from 4 to 8 * rhage RER, depending on the number of puppies nursing b. Excess: Minimal toxicity, anemia F. Growth energy requirement 5. Thiamin (vitamin B1) 1. First 4 months of life about 3 * RER a. Deficiency: Anorexia, weight loss, ventri- 2. After 4 months  about 2 * RER until adult size flexion in cats, paresis in dogs is reached b. Excess: Hypotension, bradycardia II. Cats 6. Riboflavin (vitamin B2) A. RER is calculated as for dogs a. Deficiency: Ataxia, retarded growth, derma- B. MER ranges from 0.8 * RER in obese individuals titis, ocular discharge, bradycardia, fatty to 1.6 * RER in active intact adults liver in cats C. Gestation b. Excess: Minimal toxicity 1. Energy requirements increase linearly during 7. Niacin (vitamin B3) gestation a. Deficiency: Anorexia, diarrhea, poor 2. Feed at 1.6 * RER at breeding and gradually growth, ulceration of mucosa and necrosis increase to 2 * RER by parturition of tongue, drooling 3. Free-choice feeding is recommended b. Excess: Melena, convulsions D. Lactation energy requirement ranges from 2 to 8. Pyridoxine (vitamin B6) 6 * RER, depending on the number of kittens a. Deficiency: Anorexia, weight loss, poor nursing growth, microcytic hypochromic anemia E. Growth energy requirement is about 2.5 * RER b. Excess: Anorexia, ataxia until adult size is reached 9. Pantothenic acid a. Deficiency: Fatty liver, emaciation, poor PET FOODS growth, tachycardia, coma b. Excess: No toxicity I. Federal and state agencies regulate pet food labels 10. Folic acid and ingredients. The Association of American Feed a. Deficiency: Anorexia, weight loss, glossitis, Control Officials (AAFCO) has regulations regarding leucopenia, megaloblastic anemia in cats, the ingredients that can be included in commercial hypochromic anemia pet foods. They also regulate what may be stated on b. Excess: No toxicity the pet food label 11. Biotin II. Pet food labels a. Deficiency: Hyperkeratosis; alopecia; A. The display panel must include the manufacturer’s crusty secretions around eyes, nose, and name, the name of the product, net weight, which mouth; drooling; diarrhea stage of life the food is designed for, a description b. Excess: No toxicity of the product, and the nutrition claim 292 SECTION II SMALL ANIMAL B. The information panel must include a list of ingre- E. Vegetarian diets can be developed for dogs but dients, the guaranteed analysis, a nutritional ade- are difficult to develop for cats because of their quacy statement, feeding guidelines, and manu- unique nutritional requirements facturer or distributor F. Vitamin and mineral supplements should be 1. Ingredients must be listed in descending added to the diet, but only after the other ingredi- order by weight in the formula. Ingredient ents have been cooked names must conform to AAFCO guidelines. G. Small batches of food should be made because The ingredient list gives information regard- these diets do not contain preservatives. Food ing relative amounts, but it does not provide should be kept in the refrigerator between feed- any information as to the quality or digest- ings, and larger batches can be frozen ibility of the ingredients. Also realize that H. Patients consuming homemade diets should be wet ingredients will be at the beginning of the evaluated by a veterinarian at least 2 to 3 times ingredient listing because water in the wet per year. Special attention should be paid to the ingredient contributes to the weight, making skin and hair. Calcium and vitamin D status it heavier should be monitored, as nutritional secondary 2. The guaranteed analysis panel must include the hyperparathyroidism is not uncommon in animals minimum percentages for protein and fat and receiving a diet deficient in calcium or vitamin D maximum percentages for crude fiber and mois- or excessive in phosphorus ture. These percentages are the percentages “as-fed.” They do not give any indication as NUTRITION UNIQUE TO THE CAT to the caloric density or digestibility of the product I. Cats are strict carnivores; dogs are omnivores 3. The nutritional adequacy statement tells II. Nutrient requirements whether the product is designed for adult A. Energy metabolism: Cats have a low liver glucoki- maintenance or growth and reproduction. nase activity and thus cannot metabolize a large There are two methods for determining nutri- amount of simple carbohydrate tional adequacy: B. Protein metabolism a. Formulation method: With this method, the 1. Cats have a much higher protein requirement manufacturer guarantees that the formula- than do dogs because of the high activity rate tion on paper meets the nutritional needs of liver transaminases and deaminases. Dogs either for adult maintenance or for growth (omnivores) and herbivores can decrease this and reproduction enzyme activity when low-protein diets are fed, b. Feeding trial method: With this method, the but cats cannot manufacturer has conducted feeding trials 2. Arginine is required in the cat for conversion to guarantee that the product actually of ammonia to urea. Arginine-deficient diets meets the nutritional needs for maintenance rapidly result in ammonia toxicity or growth and reproduction. This method is 3. Taurine is required in the cat preferred to the formulation method, but it a. Cats have a low rate of taurine synthesis; is more expensive and, unlike other species, cats can utilize III. Calorie content taurine only for conjugation with bile acids. A. The kcal/g of diet (metabolizable energy [ME]) is Thus taurine is lost at a high rate typically not provided on the pet food label but b. Deficiency of taurine leads to central retinal may be obtained either from product literature or degeneration, reproductive failure, and the directly from the manufacturer development of dilated cardiomyopathy B. Two diets can appear very similar in percentages c. Taurine is abundant in animal tissues but of protein and fat but can be quite different in absent in plants terms of ME. Diets should not be compared on 4. Methionine and cystine the basis of percentages, but they should be com- a. Sulfur-containing amino acids required in pared using ME. ME takes into account the caloric high levels by the cat density and digestibility of the diet b. Signs of deficiency include poor growth IV. Homemade diets and crusting dermatitis at mucocutaneous A. Recipes should be chosen from reputable sources junctions or formulated by a veterinary nutritionist who c. About 20% of a cat’s diet should be animal offers this service protein to supply adequate methionine B. All foods should be cooked to destroy any bacte- C. Lipid metabolism ria present in raw products. Cooking also im- 1. In addition to linoleic and linolenic acid, the proves the digestibility of the starch in the diet cat also requires arachidonic acid in the diet. C. Recipes need to be strictly followed with minimal The cat cannot synthesize arachidonic acid substitution to ensure that the diet is nutrition- from linoleic acid (as can the dog) ally adequate. A gram scale for weighing ingredi- 2. Arachidonic acid is found in animal tissues, ents is recommended but not in plants D. Periodically a sample of the diet should be D. Vitamins submitted to a laboratory for analysis to ensure 1. Niacin is required by the cat in higher amounts nutritional content than in the dog because cats do not have sufficient  CHAPTER 20 Nutrition 293 conversion of tryptophan to niacin. Niacin is IV. Urolithiasis: Canine found in high quantities in animal tissue A. Calcium oxalate uroliths (prevention) 2. Pyridoxine is required in higher quantity in the 1. Encourage water intake cat compared with the dog because of the high 2. Avoid excess dietary protein transaminase activity 3. Avoid excess dietary calcium and sodium 3. Vitamin A is required by the cat because 4. Avoid both an excess or deficiency of cats cannot convert vitamin A precursors magnesium (-carotene) to vitamin A, as can the dog. 5. Avoid foods high in oxalates (asparagus, spin- Vitamin A occurs naturally only in animal tissues ach, broccoli, peanuts, soybeans, sardines, E. Water: Cats do not have a strong thirst stimulus, green beans, corn, apples) and thus they are able to form highly concen- 6. Avoid excess vitamin D trated urine 7. Maintain urinary pH between 6.8 and 7.2 III. Feeding practices B. Calcium phosphate uroliths (prevention) A. Cats typically eat 10 to 20 small meals per day 1. Encourage water intake B. Cats may be more difficult to transition to a new 2. Avoid excess dietary protein diet. Transitioning should be done slowly for best 3. Avoid excess dietary phosphorus, sodium, success calcium, and vitamin D C. Cats develop food aversions easily, especially if C. Struvite uroliths the food is associated with GI upset. This can be 1. Encourage water intake important if introducing a prescription diet while 2. Maintain an acidic urine a cat is hospitalized a. For prevention, maintain pH between 6.2 D. Most cats prefer solid, moist foods that resemble and 6.4 flesh and prefer foods close to body temperature b. For dissolution, maintain pH between 5.9 and 6.1 3. Restrict protein intake. Feed lower protein in- DIETARY MANAGEMENT IN DISEASES take for dissolution as opposed to prevention I. Obesity 4. Restrict phosphorus and magnesium intake A. Decrease the caloric density of the food D. Ammonium urate uroliths B. Increased dietary fiber can dilute the caloric con- 1. Encourage water intake tent of the food and provides bulk 2. Avoid excess dietary protein C. Feed low to moderate dietary fat 3. Maintain an alkaline urine pH (pH 7.0 to 7.5) D. Maintain adequate dietary protein to prevent lean E. Cystine uroliths body mass 1. Encourage water intake II. Diabetes mellitus 2. Avoid excess dietary protein A. The water requirement is increased in diabetes, 3. Maintain an alkaline urinary pH (pH 7.1 to 7.7) so make sure adequate water is provided V. Urolithiasis: Feline B. Avoid simple sugars, and provide complex carbo- A. Struvite uroliths hydrates 1. Encourage water intake C. Feed a diet moderate in fiber 2. Avoid excess dietary protein D. Feed a moderate quantity of protein; protein 3. Avoid excess dietary phosphorus and should be highly digestible magnesium E. Semi-moist foods have a hyperglycemic effect and 4. Avoid obesity, but an increased energy density should be avoided can decrease mineral intake F. Electrolytes may become depleted because of in- 5. Maintain an acidic urine creased urinary losses B. Calcium oxalate uroliths G. Chromium supplementation may improve glucose 1. Encourage water intake tolerance 2. Avoid excess dietary protein H. Many cats with diabetes are obese and should be 3. Avoid obesity, but an increased energy density moderately calorie-restricted to cause weight loss can decrease mineral intake but prevent the development of hepatic lipidosis 4. Avoid excess calcium III. Chronic renal failure 5. Avoid either an excess or deficiency of A. Make sure adequate water is available at all times magnesium B. Avoid excess protein intake, but make sure that 6. Maintain a slightly acidic urine (pH 6.6 to 6.8) adequate protein is provided. In later-stage renal VI. Adverse reactions to foods disease, protein may need to be further restricted A. Use a novel protein source, or limit dietary C. Restrict dietary phosphorus protein to one or two protein sources D. Avoid excess dietary sodium B. Avoid excess levels of dietary protein. Protein E. Ensure adequate caloric intake should be highly digestible F. If hypokalemia occurs, provide potassium supple- C. In dogs with diarrhea, avoid foods containing mentation (especially in cats) wheat, barley, or rye G. -3 fatty acid supplementation may be beneficial D. Avoid foods that contain tuna or mackerel H. Calcitriol levels decrease in renal failure and may E. Feed a food that has reduced or no food additives need to be supplemented to prevent secondary VII. Congestive heart failure hyperparathyroidism A. Avoid excess sodium intake 294 SECTION II SMALL ANIMAL 1. Prescription diets formulated for cardiac dis- 3. Antioxidant vitamins such as vitamins E and C ease have the lowest concentration of sodium may have benefit to prevent lipid peroxidation 2. Many geriatric foods and renal diets also con- D. Feline hepatic lipidosis tain lower amounts of sodium compared with 1. Provision of adequate calories is most impor- regular adult diets tant. Many cats are fed via feeding tube B. Potassium, magnesium, and phosphorus 2. Protein deficiency may play a role in the patho- 1. Electrolyte abnormalities may occur as a result genesis of hepatic lipidosis. Moderate amounts of the administration of cardiac drugs of protein should be fed and should contain a. Diuretics may cause a loss of potassium and adequate taurine and arginine magnesium 3. Potassium supplementation should be consid- b. Angiotensin-converting enzyme inhibitors ered because many cats with hepatic lipidosis may cause hyperkalemia are hypokalemic 2. Restrict phosphorus if chronic renal failure is 4. Carnitine supplementation is beneficial in obese also present cats undergoing weight loss. It may also have C. Taurine some benefit in those with hepatic lipidosis 1. Taurine supplementation may be beneficial, es- E. Portal hypertension pecially if there has been a taurine deficiency 1. Sodium chloride should be restricted in those 2. In dogs, taurine deficiency in association with with ascites or hypoproteinemia cardiomyopathy has been shown in cocker 2. Adequate calorie intake needs to be main- spaniels and golden retrievers tained 3. Some cardiac diets include high levels of tau- F. Other nutritional factors rine, and supplemental taurine is not neces- 1. An increase in dietary fiber may be beneficial sary if one of these diets is being consumed by reducing the production of nitrogenous D. Carnitine waste in the gastrointestinal (GI) tract 1. Carnitine supplementation will be most benefi- 2. Iron supplementation may help in those with cial in those with carnitine deficiency GI ulceration or hemorrhage associated with 2. Significant improvement is usually seen on the liver disease echocardiogram within 8 to 12 weeks of sup- 3. Vitamin K may become deficient in those with plementation chronic liver disease, leading to altered coagu- E. Fish oil lation. Vitamin K supplementation is helpful in 1. Fish oil is high in -3 fatty acids those patients 2. Fish oil may decrease tumor necrosis factor IX. Primary lipid disorders and interleukin-1 concentrations that are A. Animals with a primary lipid disorder should be associated with cachexia placed on a low fat diet. Fat intake should be de- VIII. Hepatic disease termined on a g/kcal basis, not just on the per- A. Copper-associated hepatotoxicosis centage of fat in the diet 1. Maintain adult protein requirements unless B. The addition of -3 fatty acids in the form of fish there are signs of hepatic encephalopathy oil supplementation can be very effective at low- 2. Restrict copper intake. Diets should not contain ering triglyceride concentrations more than 5 ppm copper on a dry matter basis X. GI disorders 3. Zinc supplementation can be used partially to A. Pharyngeal and esophageal disorders block copper absorption 1. A high dietary fat content can help maintain 4. Antioxidant vitamins such as vitamin E and adequate calories. A lower fat content is a vitamin C may be beneficial to prevent lipid better option if there is esophageal reflux peroxidation that occurs in copper-associated 2. Dietary protein content should be greater than hepatotoxicosis 25% dry matter B. Portosystemic shunt 3. A gruel consistency is best if there is esopha- 1. Protein geal obstruction or esophagitis. Dry food or a a. Should be from a highly digestible source bolus of moist food is better if there is mega- b. Protein content may need to be moderately esophagus restricted if signs of hepatic encephalopa- 4. Feeding small amounts of food in an upright thy are present position is recommended 2. Fat is an important source of calories in ani- B. Hairballs mals with portosystemic shunt 1. Larger kibble size increases the passage of C. Chronic hepatitis or cirrhosis hairballs out of the stomach and decreases 1. Protein vomiting a. Hypoalbuminemia is an important problem 2. An increase in dietary fiber can help prevent with hepatitis, and protein intake should be hairballs maintained at normal adult levels C. Gastritis b. If signs of hepatic encephalopathy are 1. Feed only one or two novel protein sources, present, protein should be restricted and keep protein to a minimum 2. Adequate caloric intake is important to pre- 2. Do not feed high-fat diets as these delay gas- vent tissue catabolism tric emptying  CHAPTER 20 Nutrition 295 3. Maintain adequate potassium in those that are 2. Feed a highly digestible diet, with a highly di- vomiting gestible protein source 4. Iron, copper, and B vitamin supplementation 3. Restrict protein to one or two sources may be helpful in those with GI blood loss 4. Moderate-fat diets are best, though some can D. Prevention of gastric dilatation or volvulus tolerate higher fat diets if calories are needed 1. Feed multiple small meals per day rather than 5. Folic acid supplementation may be beneficial one large meal 6. -3 fatty acid supplementation may also be of 2. Increase the amount of time to consume a benefit meal to prevent ingestion of air. Feed from a 7. Either low dietary fiber or a moderate amount of very small container, feed a large kibble-sized mixed soluble-insoluble fiber is recommended. food, or add obstacles to the food bowl Beet pulp, fructooligosaccharides, or inulin may 3. Feed a mixture of dry and moist food be beneficial fiber sources E. Acute enteritis 8. If colitis is acute, withhold food for 24 to 1. Withhold oral intake of food and water for the 48 hours first 24 to 48 hours J. IBS: Feed a diet with an increased level of insolu- 2. Preventing dehydration is most important. ble fiber Provide adequate fluids either orally or K. Constipation parenterally 1. Encourage water intake 3. Electrolyte disorders are common; monitor po- 2. Feed a diet with an increased level of insoluble tassium, sodium, and chloride especially fiber 4. Feed a moderate fat level XI. Pancreatic disorders 5. Feed a diet that is highly digestible A. Exocrine pancreatic insufficiency 6. Either feed a diet low in fiber, or feed a moder- 1. Feed a highly digestible food with added pan- ate mixture of soluble and insoluble fiber creatic enzymes 7. Glutamine supplementation is beneficial 2. The diet should be very low in fiber F. Inflammatory bowel disease (IBD) 3. Fat content should be low to moderate. MCT 1. Limit dietary protein to one or two sources. oil may be added if additional calories are 2. The diet should be a highly digestible protein needed source 4. Fat-soluble vitamin supplementation should be 3. Hypokalemia and dehydration are common, considered so make sure there is adequate water and B. Pancreatitis potassium consumption 1. Discontinue oral intake of food and water until 4. Feed a moderate fat content. High-fat foods vomiting stops. Provide parenteral nutrition if contribute to diarrhea necessary 5. Fiber should be fed at a moderate level. 2. Avoid excess dietary protein because free Fiber sources such as beet pulp, fructo- amino acids can stimulate pancreatic secre- oligosaccharides or inulin produce volatile tion. Maintain adequate protein ingestion fatty acids that may be beneficial 3. Ensure adequate water intake 6. Zinc deficiency can occur in IBD, so assess 4. Feed a diet low to moderate in fat zinc consumption XII. Cancer 7. Omega-3 fatty acid supplementation may have A. Cancer cachexia is an important issue. In addi- benefit tion, chemotherapy and radiation therapy may 8. Feed multiple small meals per day impact the ability to consume food. Nutritional G. Lymphangiectasia or protein-losing enteropathy support may need to be provided early during the 1. Feed a diet high in dietary protein. The protein course of therapy to prevent weight loss source should be highly digestible B. Carbohydrate metabolism may be altered in some 2. Feed a diet relatively low in fat cancers, and carbohydrates might not be utilized 3. Medium-chain triglyceride (MCT) supplement as efficiently as a result of insulin resistance. may be beneficial in providing calories. MCT Carbohydrates should supply only about 10% of oil is not very palatable, however the daily energy requirement 4. Feed a diet low in fiber C. Many cancer patients have decreased muscle 5. Fat-soluble vitamin supplementation may be mass and decreased protein synthesis. Protein needed should exceed levels normally needed for mainte- 6. Feed multiple small meals per day nance. Additional arginine may decrease tumor H. Small intestinal bacterial overgrowth growth and metastatic rate. Additional glutamine 1. Feed a highly digestible diet with a highly di- may also be beneficial where there is intestinal gestible protein source injury 2. Feed a moderate fat diet. High-fat foods con- D. A large proportion of daily calories should come tribute to diarrhea from fat. -3 fatty acids may inhibit tumorigenesis 3. Fructooligosaccharides can reduce the bacte- and metastasis, and additional -3 fatty acids rial load (such as from fish oil) may be beneficial I. Colitis E. Vitamins A, E, and C have been shown in some 1. Correct dehydration and electrolyte abnormalities studies to be beneficial during cancer therapy 296 SECTION II SMALL ANIMAL F. Zinc or selenium deficiency has been associated Supplemental Reading with increased incidence of cancer. Low levels of iron may be beneficial to slow tumor growth Hand MS, Thatcher CD, Remillard RL, Roudebush P, eds. XIII. Skin and hair disorders Small Animal Clinical Nutrition, 4th ed. Topeka, KS, A. Avoid protein and energy deficiency. Feed a mod- 2000, Mark Morris Institute. erately to highly digestible diet Pibot P, Biourge V, Elliott D, eds. Encyclopedia of B. Avoid fatty acid deficiency. Dogs and cats require Canine Clinical Nutrition. Aimargues, France, 2006, linoleic acid, and cats additionally require arachi- Royal Canin. donic acid Pibot P, Biourge V, Elliott D, eds. Encyclopedia of Feline C. Provide adequate dietary zinc, copper, and iron Clinical Nutrition. Aimargues, France, 2009, Royal D. Some skin diseases are responsive to vitamin A Canin. supplementation, but excesses can be toxic Case LP, Carey DP, Hirakawa DA, Daristotle L, eds. Canine E. Some diseases (such as lupus) may respond to and Feline Nutrition: A Resource for Companion Animal vitamin E supplementation Professionals, 2nd ed. St Louis, 2000, Mosby.