What Should I Feed My Cat?
Ron Hines DVM PhD
Dry commercial cat chow (kibble biscuits) are so convenient for cat owners. They help massage your cat’s gums to minimize tartar, gum disease and bad breath. (read here) They stay fresh long after you open the bag. Cat kibble is also more economical than most canned diets. But recently veterinarians and cat owners have begun questioning how wise it really is to feed your cat a diet that is so unnatural for felines in its consistency, nutrient profile and water content. One of my biggest concerns is that cats that primarily consume dry kibble rarely if ever consume enough water to compensate for the unnatural dryness of their diet. Some veterinarians believe that problem leads to chronic dehydration which in itself can lead to a number of health issues. You can read more about dehydration problem in articles on caring for elderly cats here & here . Perhaps its time to think about pulling up an extra chair at your table and cooking for your cat yourself. If that interests you go here and here. Good nutrition and a balanced diet is just as essential for your cat’s long term health as it is for yours. Take it from the FDA and its frequent pet food recalls; the only way you will ever know what is actually in the food your cat eats is to prepare it yourself from supermarket ingredients you eat as well.
House cats have not evolved from their strictly meat-eating wild ancestors in the important ways that dogs have. At least not as successfully. In their nutritional needs, house cats are much the same as their wild ancestors. They are particularly well suited to digesting animal protein. High fiber plant content is unnatural for them. Their ability to convert stored carbohydrate glycogen into needed energy is poor. (read here & here) Their liver lacks various metabolic pathways common to dogs and people. (read here) Cats seem to do well on a diet that is 30-40% percent protein, 10-15% fat, 25% percent or less carbohydrates, and a maximum of ten percent fiber. When canned, those diets are about 75-80% water. On a dry weight basis, rats and mice, the common prey of cats in the wild, are about 38-54% protein, 20-30% fat and 15-17% carbohydrate. Rodents are also about 70% water. I don’t suggest semi-moist diets because of the large amount of preservatives they contain.
Obtaining unbiased information regarding health risks related to what you feed your cat is difficult. You are not going to get it from pet food manufacturers or the “studies” they underwrite. For instance, cats are known to be much less efficient in processing the high carbohydrate content of grains-based diets than dogs are. However high carbohydrate diets earn cat food manufacturers considerably more profit than high meat diets would. As public awareness of the high carbohydrates content of commercial cat foods becomes common knowledge, major cat food manufacturers such as Nestle Purina, Hills/Colgate-Palmolive and Mars PetCare (= Pedigree, Whiskas, Nutro and Royal Canin) push back. (read here & here)
I am less certain about the relative benefits of dry cat foods now than I once was. Dry cat foods are often packed with plant carbohydrates, preservatives and compounds that cats were really not designed to metabolize. Many veterinarians associate the increased number of elderly cats with diabetes and obesity to their consumption of the excess grain, pea and other carbohydrates inserted into most dry cat chows. The only reason they are in there is that they are cheap and quality meat is expensive. You can read about diabetes in cats here.
If I Don’t Make The Food Myself Should I Feed My Cat A Canned Or A Dry Cat Food?
Given their choice, most younger cats prefer canned diets. The aroma, flavor and palatability of dry diets do not match that of canned ones. That is not always the case because cats are creatures of habit and quickly get accustomed to a flavor and consistency of diet, often to the exclusion of all others. Whichever you buy, be sure the label says that the diet meets the National Research Council’s guidelines on feline nutrition and is certified by the Association of American Feed Control Officials. Although the AAFCO is basically an industrial trade association, it is all that we currently have. The NRC got out of the business many years ago. Over the years I have seen that cats fed dry diets have less tartar build up on their teeth and less gum disease surrounding their teeth. With time, gum inflammation associated with canned diets causes the tissues surrounding the teeth to recede and their teeth to loosen. There are ways to control that you can brush your cat’s teeth, feed it a dental diet or give it carefully selected treats. ( read here & here ) Many believe that with time, chronic gum inflammation (gingivitis) allows bacteria to move through your cat’s blood stream from its infected gums and cause damage to its kidneys and liver – much as it does in human. (read here)
Should I Feed My Cat A Raw Diet?
In the last few years, raw meat diets have become a popular topic. I am hesitant to recommend them because I have seen several catteries contaminated with fatal salmonella infections which I believe were caused by feeding raw contaminated meat. Those catteries did not feed supermarket meat. They fed meat of poorer quality. However if you feed raw poultry from any commercial source, sooner or later your cat will be exposed to salmonella. All of the known vitamins present in raw meat have been supplemented in name-brand cat foods. If you do decide to feed a raw diet anyway, I suggest that all ingredients you use were intended for human consumption and that you fortified your cat’s diet with adequate sources of calcium and the vitamins that are unlikely to be found in sufficient quantity in muscle red meat (A, B & E vitamins). You can have the best of both Worlds. It doesn’t take that high a temperature to kill disease causing organisms that can lurk in uncooked meat. Read more about that here.
Moderate cooking also unlocks nutrients in your cat’s diet. Cooking at the temperatures required to produce kibble by hot extrusion destroys more of its vitamin A, B and E; but cat food manufacturers add extra in an attempt to compensate for that. (read here) I mentioned that my personal feeling is that there are more risks of bacterial and viral contamination in feeding your cat a raw diet than there are conceivable health benefits (read here) My suggestion is that you feed your cat a “close-to-raw” diet. Just heat the ingredients enough to destroy the bacteria such as salmonella and listeria. You can always supplement your cat’s diet with additional A, B and E sold by companies with a veterinary nutritionist on staff (eg Balance IT). There is no reputable scientific evidence that raw foods are any better for your cat, dog or you than lightly cooked foods are.
Recommendations you run into on the internet that suggest you feed raw food ingredients to your cat are all based on unsubstantiated conviction – not science or unbiased observation. A study conducted by the Division of Nutritional Sciences, University of Illinois (the only one I know of) found no significant difference between raw diets and cooked diets in the nutrients available to your cat, nor in its digestibility.
What About Just Buying A Raw Cat Food Sold At My Supermarket, PetSmart Or Petco?
When you purchase packaged raw cat or dog food offered by petfood manufacturers, you simply add more layers of opportunity for bacteria and toxic contamination or formulation errors to occur. More fingers have been in the pie: More low-paid employees back and forth to the rest rooms and lunch rooms, mindless machines, robots, freezer breakdowns and the opportunity for rodent contamination all add up to more risk. All you get in exchange for that extra risk is convenience.
How Much Should I Feed My Cat?
Cats differ so much in their individual metabolisms and the amount of food each needs to maintain optimal weight and health. If you have multiple cats you already know that. A large portion of adult cat are overweight. Because they store their fat under their tummies at first, your cat may not appear fat to you when seen from above or the side. It just has a deeper rectangular silhouette. By the time your cat is obviously overweight, the problem has probably been going on for quite some time. Growing cats and kittens require considerably more food per pound body weight to thrive than adult and senior cats do but you probably just kept filling its bowl like you used to. Read about ways to deal with that here.
The Nutritional Requirements of Cats
As I mentioned, cats are natural meat eaters that cannot be adequately maintained on vegetarian diets or diets that rely on grain or other plant carbohydrate sources. Grain-free is not issue-free. Diets that add plant sources of protein to save cost can be deficient in essential amino acids, fatty acids and vitamins that cats require. Since cats are finicky eaters, they choose their foods on the basis of taste, aroma, texture and moisture content rather than on meeting their nutritional and metabolic needs. In the wild when they were eating rodents, that was never an issue.
Cats are also unusual in that they cannot convert the carotenes found in leafy plants into vitamin A as us humans can. Their natural source of pre-formed vitamin A was the liver of their prey. Vitamin A is necessary for membrane health. All body surfaces are covered with a cell membrane of one form or another: the skin, the intestinal tract, the eyes, the lungs. So cats deficient in vitamin A are more susceptible to respiratory tract infections, eye and skin disease. Niacin or nicotinic acid is one of the B vitamins. It is also essential to your cat’s health. A lack of niacin predisposes your cat to inflammation of its intestines, rough skin and hair coat, oral ulcers and increased susceptibility to infections in general. Most mammals can synthesize niacin from the amino acid, tryptophan. Your cat has lost that ability so it must obtain all of its niacin from its diet. Cats must obtain the fatty acid, arachidonic acid from their diets as well. Animal fats are a rich source of arachidonic acid. Unlike most mammals, cats cannot synthesize taurine from the amino acids cysteine and methionine. They must obtain all of their taurine from the muscle meats in their diet. A lack of sufficient taurine in your cat’s diet can result in blindness, heart enlargement and heart failure. (read here) In addition to these special nutrients, cats have a higher protein and fat requirement than dogs and many other mammals.
Although high fiber diets are not natural for cats to consume, some dietary fiber residue aids in normal gastrointestinal motility. Dietary fiber also seems to aid in preventing the hyperglycemia (high blood sugar) and diabetes that are rather common in older overweight cats. That is why diets designed for cats with diabetes have increase fiber content. Increased fiber content can also be beneficial to cats with constipation problems Too much fiber can lessen the absorption of vitamins and minerals and lead to diarrhea. In the formulation of feline diabetes diets that is taken into consideration.
There are twelve minerals that are essential for your cat. One of these, calcium, is essential for the formation of its bone and teeth and the construction of signaling or messenger compounds that allow communication between individual cells of the body. Kittens that do not receive sufficient calcium have pinkish, translucent teeth, a bowlegged stance and knobby painful joints. (rickets) Partial bone fractures and lameness in these kittens are common. Most of the kittens I see with this condition were the offspring of nutritionally deprived feral (wild) or homeless cats. But others received a diet that was unsupplemented meat or fish. Meat is low in calcium and high in phosphorus. High phosphorus foods interfere with the absorption of even the little calcium that meat contains. Older cats on low calcium high phosphorus meat diets are likely to suffer from tooth, bone and joint problems.
How Often Should I Feed My Cat?
An average sized adult cat weighing nine pounds is said to normally consume about 240 kilocalories a day. That means little to me and probably very little to you as well. But veterinary nutritionists like to mention it so I will as well. Neutered cats generally need less calories per day than intact cats but they are inclined to eat more. Cats enjoy munching on and off throughout the day. So I suggest food be available to your cat all the time or in multiple small meals throughout the day. Frequent small feeding and exercise could conceivably less the likelihood of digestive tract problems such as triad disease. And small meals seem to lessen their tendency to obesity as well.
When food is available to your cat all the times, cats are said to generally eat ten to twenty small meals per day. Younger cats tent to self-regulate their caloric intake and stay lean. But twenty to forty percent of cats become overweight over time when food is always available (=free choice). As your cat ages and sleeps more, it might be better to feed it a diet that is less caloric. One always needs to consider a cats age and body condition when planning its diet. Problems occur more in multi-cat households because it seems that there is always one cat that needs to eat more and another that needs to eat less. The only way I have found to solve this problem is to feed different cats in different closed rooms of your home several times a day. Give them about twenty minutes at a feeding.
Thin cats should be encouraged to eat one-and-a-half times your normal cat’s ration. Be sure your thin cat get checked out by your veterinarian for cause. Increased food consumption is best accomplished with delightful odors and smells, treats and pungent flavors. Your vet sells various “energy drinks” such as a/d®. I never found a need for them unless the cat had to be tube-fed, suffered from a head/mouth injury or generalized weakness. Feed chubby cats foods that are advertised as lower caloric or just feed them less if you can stand their begging and meowing. If your cat is fed only two thirds of the food it presently consumes, weight loss will be gradual and gentle.
What Brand Should I Buy?
Cat foods differ primarily in their source of protein. Generic cat foods use less expensive sources of protein. Because of this, the quality of protein in generic and house brand cat foods is usually poorer. Protein content is misleading. Not all protein is digestible. Chicken feathers are about 80% protein. But unless subjected to chemical modification, the protein in feathers is not available to your cat. (read here) Excluding “niche” and specialty brands sold through pet shops, groomers and online which generally cost more, the quality of your cat’s diet is reflected directly in the price you pay for that food.
Cats love the taste of fish. However, an overactive thyroid gland (hyperthyroidism) as well as premature aging have been associated with feeding fish-flavored cat foods. It is unclear if the problem is the poor quality of rancid fish that sat too long on the dock and often end up in cat food or if there are constituents in fish themselves capable of causing a problem. (read here, here & here) Some nutritionists theorize that the high level of unsaturated fatty acids in fish lend themselves to the formation of free radical groups upon spoiling. If you must frequently feed fish or fish-flavored cat food, supplement your cat with vitamin E and thiamine as they do for the sea lions and seals at SeaWorld. ( read here) It might even be chemicals associated with the can linings themselves that contribute to fish-related health problem. (read here & here)
How Much Water Does My Cat Need?
Cats are not big drinkers. They tend to drink considerably less than dogs do. That is possibly because some of our cats descended from the desert sand cats of Egypt. (read here) In addition to that, all the ancestors of our domesticated cats lived primarily on rodents that were over 75% water. (read here) This tendency to drink less water than they should, particularly when they consume mostly dry cat food, might also be the cause of their high susceptibility to urine crystals and subsequent lower urinary tract disease. (read here) Your cat should have access to water in several places at all times. If it is eating canned food, it will naturally drink less because canned food is so high in water. Adding water to your cats food (up to 40%) is an excellent way to help chubby cats consume more water, loose weight and encourage their activity. (read here)
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