FELINE NUTRITION R. Roger Breton Nancy J Creek ------------------------------ Basic Needs Above all it is important to remember that your cat is a carnivore and requires a meat diet. This apparently self-obvious fact is all too often overlooked by people who, all well meaning, attempt to make an omnivore or herbivore out of their pet. They are slowly killing the animal with love. Dogs, while carnivores in the strictest sense, are omnivorous to a large degree, and have the ability to break down and digest vegetable as well as animal protein. A dog can survive quite successfully on the same foods humans eat, hence can live on table scraps, or even a carefully balanced vegetarian diet, especially if supplements are used. Cats, despite 5000 years of domestication, remain strictly carnivorous. They are incapable of digesting and receiving nutrition from the majority of vegetable proteins. There are no and can be no vegetarian cats. In addition, cats in the wild are equal-opportunity carnivores and devour the whole of their prey: muscles, organs, viscera, bones, offal, skin, etc. In this manner, cats ingest not only the flesh and organs of their prey but also the partially and wholly digested vegetable foods the prey had eaten. With the assist- ance of the prey's own digestive processes, the cat then is able to derive nutrition from various vegetable sources. This evolved approach to eating means that the cat has lost the ability to manufacture various vitamins, enzymes and other substances necessary to life, receiving these substances directly from its food. This "laziness" has caused the nutritional requirements of the cat to be radically different from that of the dog, which in turn has caused cat food to be considerably more expensive than dog food. Food as Fuel Food is fuel. The object of food is first and foremost to provide the body with the energy it needs to keep functioning. The greater portion of this energy is utilized to keep the body functioning as a machine. All processes in the body, movement, digestion, breathing, circulating blood, even thinking, require energy, all of which must be derived from the food consumed. This energy is measured in calories. To a scientist, a calorie is a unit of thermal energy: specifically, the amount of thermal energy necessary to raise the temperature of one cubic centimeter of water one degree Celsius. This is a distinct and definite amount. ---------------------------------------------------------------------- Feline Nutrition Page 1 To a dietitian, a "calorie" is a unit of the potential thermal energy of a foodstuff: specifically, the amount of potential thermal energy that would raise the temperature of one liter of water one degree Celsius. Since one liter is equivalent to 1000 cubic centimeters, the dietitian's "calorie" is the scientist's "kilocalorie" (the prefix "kilo" means 1000). Dietitian's calories are sometimes called "big calories" to differentiate them from the scientist's "true calories" or "small calories." To us, they will simply be "calories." The Exchange of Energy Energy is derived from food and used by the body via a series of chemical reactions. All chemical reactions require the input of energy to trigger and control them. No input of energy, no reactions. Some chemical reactions release more energy than was required to trigger and control them. This surplus of energy is stored by the body in the form of chemicals such as proteins, fats, and carbohydrates, and is available for future use. Other chemical reactions release less energy than was required to trigger and control them. This energy deficiency must be made up from the body's energy reserves by breaking down the storage chemicals and releasing their energy. The waste products of this breakdown are passed into the bloodstream and filtered out by the kidneys. Other Nutrients Besides basic energy in the form of calories, it is the task of food to provide all essential nutrients, the chemicals necessary for life. The vast majority of those chemicals required for life are derived by breaking down and rearranging the molecular structures of the proteins, fats, and carbohydrates in the foods consumed. This process is known as synthesis, and is technically defined as the forming or building of a more complex compound from elements or simpler compounds. It is important to note that virtually all organic molecules are synthesized. A glucose molecule synthesized by a cat is identical to one synthesized by an apple tree and is identical to one synthesized by a chemical laboratory. All molecules of a given type are identical: advertising claims aside, there is absolutely no difference between "natural" vitamin C and "synthetic" vitamin C. They are identical, and the terms "natural" and "synthetic" in this context are null words, without meaning. Like most higher organisms, the cat has lost the ability to synthesize some of the chemicals it requires for life, obtaining those chemicals ready-made from the food it eats. Obviously, those chemicals must be present in the food, or the cat will fall ill and eventually die. In humans, for example, a lack of the chemical ascorbic acid, vitamin C, will result in the condition known as scurvy. Protein ---------------------------------------------------------------------- Feline Nutrition Page 2 The primary source of food energy is protein. Like all animals, a cat's body is primarily protein, and vast amounts of food protein are required to maintain it. Typically, the energy content of a cat's diet should be derived at least 25 to 30 per cent from protein, almost all of which must be animal protein. The major sources of animal protein in commercial foods are meat, fish, eggs, and dairy products. Vegetable protein is typically obtained from beans and peas, nuts, and cereals. Proteins, while providing the basic amino acids for muscle and organ tissue, do contain a high percentage of waste, which must be purged from the cat's system by the kidneys. An all-protein diet, such as a raw meat diet, will not only lack other important and even critical nutrients, but will overtax the kidneys, and may lead to urinary problems or premature renal failure. Fats The secondary source of food energy is fats. Fats have received much unwarranted bad press, mostly due to the public's preoccupation with being slim and total misunderstanding of what constitutes a good, well-balanced diet. This preoccupation and misunderstanding are both vigorously perpetuated by the advertising industry (the same people who define a Twinkie (R) as "wholesome," and who define "wholesome" as "not causing death within 48 hours"). While this tendency is bad enough for our own collective health, it can be disastrous when the same philosophies are applied to our cats. We at least have some choice in the matter. The cat requires a diet containing a lot of fat, far more than either the human or the dog. From 15 to 40 per cent of the energy content of your cat's diet should be derived from fat. Unlike proteins, fat is little wasted by the cat's metabolism, and hence does not provide a burden to the kidneys. Because of this, as a cat reaches old age, the fat content of its diet should be increased somewhat while the protein content is decreased proportionately. In this manner, the proper overall energy content may be maintained while easing the burden on the older kidneys. The key here is moderation in both rate and amount of dietary change. Sudden or rapid changes in diet are especially hard on an older cat, while an all-fat diet is as bad as a no-fat diet. Carbohydrates The tertiary source of food energy is carbohydrates, primarily starches and sugars. Like fats, carbohydrates too have received unwarranted bad press. Neither we nor our cats can live without carbohydrates: they are as essential to life as water. Only a small amount of carbohydrates is required in the cat's diet, with only about 5 percent of the total food energy being in this form. The simple carbohydrates, the sugars, are more easily assimilated into ---------------------------------------------------------------------- Feline Nutrition Page 3 the cat's system, while the complex carbohydrates, the starches, pass through virtually untouched. Cooking complex carbohydrates such as potatoes, corn, pasta, etc., start the conversion from starch to sugar and aid in the digestion process. Fiber Vegetable matter provides another important function besides energy content: it helps to keep the bowel functioning smoothly through the mildly abrasive and water-absorbing actions of its cellulose content, commonly referred to as "fiber." Note that two seemingly opposite conditions may arise from a lack of fiber: constipation, from a lack of abrasive action, or diarrhea, from a lack of water-absorbing action. While fiber is not a nutrient per se, a "regular" cat needs some fiber in his diet. As with so many other things, fiber requirements and types have been completely distorted almost beyond recognition by the advertising industry. Fiber is simply cellulose, which is the basic material from which the cellular walls (membranes) of plants are made. Cellulose is cellulose, regardless of it's source, be it from oat bran or grass. In the wild, a cat derives all the cellulose it requires from the stomach and intestines of its prey. The pampered cat, too, should receive all the cellulose it needs from its normal diet. As an interesting aside, many of the smaller wild cats subsist chiefly on insects and insectivores (lizards, etc.). At first glance, one would think that such cats would have insufficient cellulose and carbohydrates in their diet. This is not the case, as insects and other arthropods are exoskeletal creatures with a covering of chitin, a polysaccaride compound consisting of a simple cellulose-like base molecule (chitin and cellulose are chemically related) coupled with various simple sugars, thus providing both fiber and carbohydrates simultaneously. Good things, those bugs! Vitamins Vitamins and related compounds are complex organic molecules used as catalysts or agents in various metabolic processes. In the wild, the cat derives all the vitamins it requires from its prey and from sunlight. The domestic cat must receive all its vitamins in its diet. Under some conditions, your veterinarian may prescribe a vitamin supplement. A warning is in order here. If the diet is properly balanced and the cat is young and healthy, vitamin supplements are unnecessary. Giving vitamin supplements to a healthy cat may actually lead to a condition of vitamin toxicity, which can be very dangerous, even deadly. In a like manner, a vitamin deficiency can also be very serious. The best solution is a well-balanced diet without supplements unless prescribed by a veterinarian. Each vitamin plays its role in the health of a cat. Vitamin A is fundamental to good vision, proper growth, and a healthy skin. ---------------------------------------------------------------------- Feline Nutrition Page 4 Vitamin B1 is needed for growth and overall body function. Vitamin C is important for a healthy skin, coat, and gums, but is not required in the diet as the cat synthesizes all it needs. Only very small amounts of vitamin D are required for regulating the use of calcium and phosphorus, necessary for good bones and teeth. Vitamin E is required for a healthy skeleton and reproductive system. Vitamin K is required for proper blood clotting, but like vitamin C is wholly synthesized by the cat. Vitamin B12 is not required by the cat except in very small traces. Minerals In addition to the proteins, fats, carbohydrates, fiber, and vitamins, all of which are complex organic molecules, certain small amounts of various inorganic substances are required for life. Life is often though of as being composed of six elements: carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorous; the same elements that make up DNA. The "big six" are the overwhelming components of life, com- prising all but a fraction of a percent of all living tissue. That fraction of a percent is crucial. The elements iron, sodium, iodine, magnesium, potassium, manganese, and a host of others are also required in varying amounts. All these inorganic substances are lumped together under the general term "minerals." Again, atoms are atoms, and there is no such thing as "organic calcium," advertising claims notwithstanding. The calcium extracted from limestone is identical to the calcium extracted from seashells or bone. Limestone was once seashells, after all. By the same token, calcium is an element, as are iron, sodium, iodine, etc., and cannot be artificially produced. All elements, with the exception of a few short-lived and highly radioactive ones such as plutonium, are found only in nature (the short-lived ones are also found in nature, but not on Earth). Like the vitamins, the minerals are necessary for overall body function. The three most important minerals are iron, calcium, and phosphorus. Iron is crucial to proper blood function: it is the "heme" in hemoglobin, which carries oxygen from the lungs throughout the body (making the blood red as it does so). Calcium and phosphorus are required by the bones and teeth, which together contain over 99 per cent of the body's calcium and phosphorus, and for proper muscle action. Unclassified Nutrients Like everything else, there are a few nutrients that do not fall neatly into the major groups: proteins, fats, carbohydrates, vitamins, and minerals. These nutrients are nonetheless essential to life. One such nutrient is linoleic acid, a fatty acid midway between the fats and the carbohydrates in chemical composition, which is necessary for healthy skin and fur, among other things. There are many such unclassified but required nutrients. ---------------------------------------------------------------------- Feline Nutrition Page 5 Cat-Peculiar Nutrient Needs It is important to remember the at cat is a cat, it is not and is never a dog, or a human, or any other living creature. Cats are unique, and have unique needs. Just as a cat needs little or none of some of the nutrients required by us, such as vitamin B12, it has a definite need for others that we do not, as well as differing proportions of those nutrients we have in common. Inositol, one of the B-complex vitamins, for example, is definitely required by the cat to be present in its diet, but is synthesized by dogs and humans. In a similar manner the compound taurine is required for good vision in certain nocturnal animals, such as cats. It is believed to be required for a healthy tapetum lucidum, a lining inside the eye that acts as a sort of "light-amplifier," greatly increasing night vision and, incidentally, making the eyes very reflective. The metabolism of a cat is vastly different from dogs and humans in its ability to purge various chemicals from the system. It is this metabolic difference that causes cats to be easily poisoned by things that a dog or human would shrug off. Common aspirin metabolizes (is broken down and purged) in a human in about four to six hours, but requires 38 hours in a cat! This difference makes the cat highly susceptible to salicylate toxicity. An overabundance of certain nutrients or substances, or a deficiency thereof, can and often does lead to various medical conditions and problems. Water People don't often think of water as a part of the diet, but without water there is no life. About 70 per cent of a cat's body is water. A cat requires about one fluid ounce of water per pound of body weight per day. In the wild, the majority of this water comes from the cat's prey. In the home, this may also be true if the diet consists of canned food, but with semi-moist or dry foods this is not the case. Fresh water must always be available to your cat, regardless of its diet. Do not substitute milk or other liquids for water. To a cat, milk is a food, not a beverage. The only cat beverage is water. Many people are distressed when their cat will drink from a scummy puddle, the gutter, a pond, even the toilet, but won't touch its nice, clean water dish. There is a simple cause for this behavior: the water dish tastes bad to the cat, or used to taste bad (cats have good memories). If we think in cat terms for a moment, algae, mud, fish- bits, even feces are all natural, normal things it rather expects in the wild. But chlorine! Feh! Remember that your cat has a sensitive ---------------------------------------------------------------------- Feline Nutrition Page 6 sense of smell and taste (plus another sense midway between the two) and can readily detect odors and flavors lost on us, while even we can taste the chlorine in our tap water. This foul taste is what makes the sale of bottled water profitable. You may find that your cat will also appreciate bottled water. Barring that, you may try boiling your pet's water first, as boiling will drive out the highly-volatile chlorine. Even letting it stand out a few hours before serving will allow the majority of the chlorine to evaporate. Often, adding an ounce of club soda (carbonated water) to 16 ounces of ordinary water will do the trick. Cats love car- bonation. The Natural Diet There is always controversy as to what establishes an ideal diet. Putting aside such controversies, at least for the moment, we may safely say that an ideal diet would be one which meets all the evolved criteria of the cat. In other words, a wild diet: whole mouse, sparrow, cricket, lizard, etc. It is unlikely that Purina or anyone else will be producing canned chopped whole mouse in the near future (the government would probably prohibit sale because of excessive mouse hairs), so we must look to actual wild cats and actual wild prey for the ideal diet. The actual long-term diet of a wild or feral domestic cat breaks down as follows: Total Dry Fuel Energy ------------------------------------------------- Water 70.0% ----- ----- ----- Protein 14.0% 46.7% 50.0% 35.7% Fats 9.0% 30.0% 32.1% 51.5% Carbohydrates 5.0% 16.7% 17.9% 12.8% Ash 1.0% 3.3% ----- ----- Calcium 0.6% 2.0% ----- ----- Other 0.4% 1.3% ----- ----- The "total" column indicates the percentage breakdown of the diet with water included among the nutrients, while the "dry" column indicates the percentage breakdown excluding water. The "fuel" column indicates the percentage relationship of the fuel foods to each other: protein, fats, and carbohydrates. The "energy" column indicates the percentage of total food energy (caloric) intake among the three fuel foods. Note that while fats account for only 9% of the total diet, 30.0% of the dry diet, and 32.1% of the fuel diet, they account for 51.5% of the total energy input. This is because fats contain 9 calories per gram, while protein and carbohydrates each contain 4 calories per gram. The Natural Kitten Diet ---------------------------------------------------------------------- Feline Nutrition Page 7 The natural diet for a kitten is its mother's milk. Cat's milk is radically different than that of most other mammals, especially cows. The basic components of cat's milk per deciliter, compared against an equivalent adult cat diet, dog's milk, cow's milk, and 20% liquid reconstituted evaporated cow's milk (canned milk) is as follows: Adult Cat Dog Cow Canned Diet Milk Milk Milk Milk ----------------------------------------------- Water 70% 72% 77% 87% 80% Solids 30% 28% 23% 13% 20% ----------------------------------------------- Calories 187.2 147.9 119.5 68.7 115.4 Protein 16.8 11.4 7.5 3.5 5.8 Fats 11.6 7.9 8.3 3.9 6.6 Carbohydrates 3.9 7.8 3.7 4.9 8.2 Calories are per deciliter of milk or equivalent adult diet. Protein, fats, and carbohydrates are in grams per deciliter (one deciliter is 1/10 of a liter or 100 milliliters: about 3.38 fluid ounces). The carbohydrate content of milk is virtually all lactose, commonly called milk sugar. Special Requirements Some cats require special dietary consideration. The obvious would be kittens, pregnant and nursing queens, elder statescats, and convalescent cats. If your cat is or has been ill, you should follow the dietary guidelines prescribed by your veterinarian. Normal cat conditions should require only normal dietary variations. There is a strong tendency these days for people to follow the advice of others in the matter of diet, even the very strangest of diets have their adherents. This is not always wise, even for humans. When it comes to our cats, one rule is very simple: unless the advice giver is well-schooled in veterinary medicine and/or feline nutrition, take all such advice (especially if radical) with great hesitation. Remember that some components of food are critical but not obvious, and that more is not always better. When in the least doubt concerning a new cat diet, ask your vet. The normal diet of any mammal changes with age. Obviously, a nursing kitten requires milk, whereas an older cat does not: the myth of cats and milk is just that, some older cats will in fact become ill if they drink milk. Less obvious is the fact that the total caloric intake per pound of body weight and the ratio of protein to fat in the diet changes with age and other conditions. Following is a simple table giving requirements versus age and condition: ---------------------------------------------------------------------- Feline Nutrition Page 8 Cals Protein Fats Carbs ------------------------------------------ Newborn 190 42.1% 29.2% 28.8% 5 weeks 125 47.2% 27.5% 25.3% 10 weeks 100 50.0% 26.1% 23.9% 20 weeks 65 51.9% 30.0% 18.1% 6 months 50 51.3% 33.3% 15.4% 1-10 years 40 52.0% 35.9% 12.1% 15 years 35 44.0% 42.0% 14.0% 20 years 35 43.3% 41.5% 15.2% Pregnant 125 45.7% 31.8% 22.5% Nursing 125 44.9% 31.1% 24.0% Daily Requirements A good many of us humans are counting calories, the same may be done for a cat. A healthy adult cat requires approximately 40 calories per pound of body weight per day (for an 8-pound cat this would be 320 calories per day). Of these 40 calories, about 12-16 should come from protein, 20-25 from fat, and 3-4 from carbohydrates. Protein 3600 mg -- 14 calories Fat 2500 mg -- 23 calories Carbohydrate 840 mg -- 3.3 calories Linolic Acid 250 mg ---------------------------------------------- Vitamin A 250 I.U. Vitamin D 13 I.U. Vitamin E 10 I.U. Choline 25 mg Niacin (B3) 560 ug Pantothenic Acid 130 ug Riboflavin (B2) 63 ug Pyridoxine (B6) 50 ug Folic Acid (B9) 13 ug Thiamin (B1) 7.8 ug Biotin 0.63 ug Vitamin B12 0.25 ug Vitamin C * trace only Vitamin K * trace only ---------------------------------------------- Calcium 125 mg Phosphorus 100 mg Potassium 38 mg Sodium Cloride 25 mg Magnesium 2.5 mg Iron 1.3 mg Zinc 380 ug Manganese 130 ug Copper 63 ug Cobalt 25 ug Iodine 13 ug Selenium 1.3 ug ---------------------------------------------------------------------- Feline Nutrition Page 9 There are, of course, many other subtle and necessary components of food that are not obvious in these tables. Commercial Foods The vast majority of us will be feeding our cats commercial cat foods. These foods come in four specific types: dry foods, soft-moist foods, balanced canned foods, and specialty or "gourmet" canned foods. As a simple rule of thumb, the nutritional content of 3 ounces (one level cup) of dry food is the same as that of 4 ounces of soft-moist food and the same as that of 7.5 ounces of canned food. Specialty or gourmet foods are seldom a balanced diet by themselves, and must not be fed without supplements or another, balanced food. They are best used as treats or "Sunday dinner." The scientifically-balanced foods available through pet and feed stores and from your veterinarian usually contain supplements and additives to guarantee the best nutritional balance possible. Most of these foods are further classed into pediatric/nursing, maintenance, and geriatric blends, assuring a proper protein-fats-carbohydrate mix for the specific cat. Specialized diets (weight loss, low sodium, etc.) are also available from these same sources and through your veterinarian for the problem cat. Commercial supermarket-type cat foods vary little in nutritional content between brands. Assuming the food is complete in nutrition and the cat is a young-to-middle-aged healthy adult, almost any of these foods will suffice. One should be wary of non-nutritional additives and fillers used in commercial foods. Most dry foods, for example, use corn meal as a bulk filler, while canned foods often use gelatin. Since these substances effectively pass right on through a cat, there is no harm in them, but you are paying for them, sometimes dearly. As with everything else, read those labels. Several popular brands of catfood use excessive food coloring to enhance the appearance of the food. One extremely popular brand uses so much red dye that it will make your cat's stools orange. The claim is that the dye is FDA approved and does the cat no harm. Frankly, we feel that the color of the food is of no interest to the cat (texture, shape, taste, and smell are different matters). It is put there solely for the benefit of the cat owner (who is the purchaser, after all) to make the food appear more like meat. Who needs it! If the food is good and appeals to the cat, what else matters? A common misconception about cat foods is that dry foods derive their protein from cereals and other vegetable sources while canned foods derive their protein from meat and other animal sources. In reality, all commercial cat foods derive their protein from both animal and vegetable sources, with animal sources dominating. Most vegetable products in commercial foods, however, may be considered as filler. Please remember that in the wild the cat does consume vegetable ---------------------------------------------------------------------- Feline Nutrition Page 10 protein in the stomach and viscera of its prey, and can utilize this protein with the assistance of its prey's own digestive processes. These processes are in part duplicated during the manufacture of commercial cat food allowing digestion of some vegetable proteins. Unfortunately, an understanding of the molecular structure of proteins and the digestive process itself is required to produce the "partially-digested" vegetable protein used in cat foods, thus making it virtually impossible for home-kitchen duplication. There are still no vegetarian cats! Dry Foods Dry foods are the least expensive of the four types and, being dry, have the added advantage of an abrasive action which helps to keep the teeth and gums clean and healthy and minimize the buildup of dental tartar. They derive their protein and fat from meat, fish, poultry, and/or dairy products blended into a cereal base, usually corn meal. Careful balancing and the addition of vitamin and mineral supplements have made the modern dry food a good and well-balanced diet. These foods are typically about 10% water (no matter how dry they appear), and thus have long shelf and bowl lives. This means the food may be left out at all times and the cat may help himself to many small meals rather than one or two large meals. This improves tone and digestion. One theoretical disadvantage is a predisposition among male cats, especially neuters, to develop Feline Urological Syndrome (FUS). This predisposition has not been substantiated at this time (neither has it been disproved) and veterinarians are sharply divided on the issue. If such a predisposition exists, it would probably be due to the low water content of the dry foods. Providing an adequate source of good- tasting fresh water will often negate any such problem. Dry foods tend to lose their nutrition slowly over time, especially upon exposure to air and light. Avoid using any dry food more than six months old. If dry food must be stored for long periods (as on board ship), store the food in air- and light-tight containers. Soft-Moist Foods Soft-moist foods have more appeal than dry foods, also more cost. They are intentionally designed to make the cat think they are meat, both in texture and taste, and do a fairly good job of it. Like dry foods, they derive their protein and fat from a variety of sources. Additionally, one particular source, meat, fish, whatever, is often emphasized to establish flavor. They run to about 30-35% water, as contrasted to dry food's 10% and canned food's 70%. Unlike dry foods, they do not inhibit dental tartar. They also have the advantages of minimal odor and long shelf life. They are good for about a day in the bowl, and should not be left out ---------------------------------------------------------------------- Feline Nutrition Page 11 longer than that. Shelf life is extremely long, as they are usually packaged in air-tight pouches. Be aware that most soft-moist foods contain an abundance of preservatives to prevent spoilage, so labels should be read carefully. Canned Foods Canned foods are the most expensive of the three types, but are still the most popular. Their biggest drawbacks being cost and odor. Canned foods are primarily protein and fats from meat, fish, dairy and vegetable sources with added vitamins and minerals. Except for the specialty or gourmet varieties, most are nutritionally complete. Many canned foods contain 70% water or more, often gelatin is used as a filler and literally to trap and hold more water (one brand is 78% water). The purchaser pays for this water and gelatin, naturally. Read those labels! Unlike the dry foods but like the soft-moist foods, canned foods do nothing to inhibit dental tartar. However, the same argument that gives dry foods a predisposition towards the development of FUS implies a lack of predisposition in canned foods. Again, this has not yet been determined one way or the other. If a cat has already suffered a bout with FUS, especially repeated bouts, a low magnesium canned-food diet is often prescribed as the preventative of choice. We wish to emphasize here that the low magnesium canned-food diet is for animals who already have an FUS history, and is not indicated in healthy animals. Gourmet Foods Premium or gourmet foods are usually not balanced and must not be used as the basis of your cat's diet. Think of them as treat foods. These foods have two distinguishing characteristics. First, they are terribly expensive, and second, the tend to be of the "100% beef" variety, all one substance. The higher price does not necessarily mean better. Using 100% beef as an example, the food may contain lung and udder, which have no real nutritional value but are still beef, and most certainly will contain hoof, also still beef, in the form of gelatin, also of minimal nutritional value. What we're saying here is that if it's part of a cow it's "beef," but some "beef" is really bull. With gourmet foods, if you don't mind the price and your cat likes them, use them as treats. Fresh Foods We in the U.S. have been almost totally brainwashed into the concept ---------------------------------------------------------------------- Feline Nutrition Page 12 the "fresh is best." This holds true if and only if fresh is balanced, which it often is not. A well-balanced fresh-food diet for a cat would consist of meat (muscle tissue) for protein; saturated and unsaturated fats for protein (polyunsaturated fats, such as those in margarine, are not usually found in a carnivore's diet); sugars, starches, and other carbohydrates; cereals, grass, and certain leafy vegetables for fiber; various organs for vitamin content; bones for calcium and phosphorous; blood and vegetables for iron and mineral content; and small amounts of this and that for trace elements and pleasure. All these requirements are contained in the average mouse. Since few of us will raise mice specifically for cat food, we may feed our pets a varied and well-balanced fresh-food diet with a little thought. The following foods have the characteristics and effects listed: Meat (muscle tissue): this is the basic food of any carnivore. The meat may be beef, horse, pork, lamb, chicken, whatever (even mouse). Most meats should be lightly cooked to kill parasites, especially pork and fresh-water fish. The cheaper, fatty cuts of meat will also provide the fat the cat requires (buy the cheap hamburger, it's better for the cat). As a special treat, try giving your cat a mouse-sized gobbet of almost-raw body-temperature rabbit or chicken when he is not especially hungry and watch the hunter come out. He will probably stalk it, throw it in the air, pounce on it, and eventually eat it. This is all part of the natural order of life. Liver: cats have a weakness for liver. This is an evolved trait to guarantee that the liver of the prey will be eaten and the cat will obtain sufficient vitamin A and iron. In the home, the cat will take all the liver it can get. If too much liver is given, the cat will succumb to vitamin-A toxicity, which can be fatal. As in all things, moderation is the key. The liver (especially beef liver) should be very lightly cooked. When eaten raw it often causes diarrhea, when overcooked, constipation. Kidneys: usually quite inexpensive, kidneys (especially beef kidneys) provide a good source of iron and several critical vitamins. Because the uric acid content is high, kidneys should be soaked in cold water for a hour or two prior to cooking and serving. Heart: heart in general but especially poultry and rabbit hearts are a favorite among cats and provide top-notch protein. Do not remove the fatty tissue and paracardial sack, as they provide a source of needed fats. Lung: lung has little food value and should not be served. Most cats won't eat lung by itself. ---------------------------------------------------------------------- Feline Nutrition Page 13 Udder: like lung, udder has little food value and should not be served. Spleen: spleen will often cause diarrhea and should be avoided. Tripe: fine for dogs and large cats, tripe is usually too tough for our small cats. Tripe stew, on the other hand, is excellent, as the meat is softened by stewing and the broth is good all around. Offal: the offal of small animals, such as rabbits, is fine if cooked lightly to kill parasites. It is, after all, what they eat in the wild. Bones: bones are good food. The bones of larger animals, such as beef bones, are usually too big for a cat to get a handle on, but a cartilagineous knuckle or tail bone may be just the ticket. The bones of small animals may be served lightly cooked to kill parasites, but do not serve the cooked bones of birds, especially the long bones, as cooking makes the bones brittle and they may shatter and become lodged in the throat or puncture the esophagus or stomach wall. Bones of any size may be pressure-cooked until soft, but this destroys the marrow, which the cat considers the best part. Bone meal may be used to provide needed calcium and phosphorous. Fish: cooked, boned fish is almost always welcome. Avoid raw fish in quantity as a vitamin-B toxicity may easily develop, especially with cod, tuna and other oily fish. Do not feed fish organs, especially fish livers. Milk: milk is a food, not a drink (the only cat drink is water). This food will provide an excellent source of calcium and phosphorus needed for strong bones and teeth, as well as many other vitamins and minerals. Unfortunately, a large percentage of cats lose the ability to digest milk as they grow older. To test your cat for milk tolerance, give it a small bowl of milk, then watch its stools for the next six hours. If diarrhea develops, the cat cannot digest milk, if the stool remains normal, it can. An acidopholus-enriched milk, available at most large supermarkets, can often be consumed by cats (or people) that cannot tolerate normal milk. Acidopholus is the symbiotic bacterium that lives within the intestine and produces the enzyme that metabolizes lactose (milk sugar). The most common cause of milk intolerance is an acidopholus deficiency. Acidopholus- enriched milk carries its own acidopholus culture with it. Yogurt: many cats like plain yogurt and, like milk, it is an excellent source of calcium and phosphorus. Unlike milk, yogurt is one-step removed from fresh. It has already been consumed by a ---------------------------------------------------------------------- Feline Nutrition Page 14 bacterium, and is therefore partially digested. This makes it very easy for cats and people to finish digesting. Being sensitive to terms like "digested," the dairy industry calls yogurt a "cultured" product. Butter: an excellent source of fats, good for growth and coat, butter is a good but somewhat expensive treat upon which a cat will gladly pig out. We suggest the occasional small pat as a special treat. Cream: combining the tastes and benefits of butter and milk, sweet cream is kitty champagne! Treat it as such. Cheese: most cheeses will cause constipation if fed in large amounts. The occasional small piece is healthful and appreciated. Cats don't seem to care much for the exotic cheeses, such as limburger, brie, or bleu, possible they are put off by the smell of the mold (we humans eat the damnedest things!). Margarine: since most margarine taste pretty much like butter, cats will usually treat them like butter and take all they can get. Unfortunately, margarine is not butter, and does not contain the calcium and phosphorus that makes butter so beneficial to cats. The polyunsaturated vegetable fats used in most margarines go straight through a cat. Think of margarine as a mild and good- tasting cat laxative (really a lubricant), and use a small pat of it as a loving treat/preventative/cure for hairballs and constipation. Eggs: raw egg yolk is beneficial and tasty, providing protein, sulfur, calcium, phosphorus, and a host of other vitamins and minerals. The raw egg white, on the other hand, contains avatin, which breaks down and destroys the B vitamins. If you must feed your cat whole eggs, cook them first, which congeals the white and destroys the avatin. Vegetables: cats are carnivores, but they do eat the vegetable contents of their prey's stomach and viscera. Small amounts of vegetable matter such as potato or pasta, about 5% of the total diet, can be consumed providing the vegetables have been cooked first (cooking breaks down complex carbohydrates into simple carbohydrates and aids digestion. If you are feeding too much vegetable matter, or not cooking it enough, it will show up as constipation or diarrhea, depending upon the vegetable. Fruits: unlike vegetables, fruits contain primarily simple carbohydrates and need not be cooked. The author had a calico cat, Gigi, who loved melon: watermelon, honeydew, cantaloupe -- she loved them all! Like vegetables, be moderate and beware intestinal distress. Cereals: many cats like cereals. Again, in moderation, cereals such ---------------------------------------------------------------------- Feline Nutrition Page 15 as oatmeal, wheat farina, corn-meal mush, etc., are quite beneficial as providers of carbohydrates. Avoid raw cereals, as cats cannot digest the starches. Absolutely avoid grits (and hominy in general), as the residual lye is toxic to a cat. ---------------------------------------------------------------------- Feline Nutrition Page 16