What Should I Feed My Cat?

Ron Hines DVM PhD

Health problems and feeding decisions?

A home-cooking for my cat?here and here

Feeding mature & elderly cats 

A special kidney diet for my cat? 

A low-iodine diets for my hyperthyroid cat?     

Quality of mass-marketed cat food? 

Preservatives in your cat’s diet? 

Fat Cat?

Give My Cat Wisely-Selected Bones? 

Shouldn’t my cat be a vegan too?   

Dry commercial cat chows (kibble) are so convenient for pet owners. They help stimulate your pet’s gums, stay fresh when opened and they are economical. But recently, veterinarians have been questioning how wise it really is to feed a diet that is so unnatural to dogs and cats. The chief concern at this time is that pets on dry foods, particularly cats, never consume enough water to compensate for the dryness of kibble. You can read more about that theoretical problem in an article on caring for elderly cats here. If you decide to pull up an extra chair at your table and cook for your cat, go here.

Good nutrition and a balanced diet are essential for your cat’s health. People often ask me what they should feed their cats. Over the years, I have made some observations on the health of cats fed an enormous variety of diets. Here are some of my conclusions.

Cats have not evolved from strict meat eaters in the way dogs have. In their nutritional needs, cats are much the same as their wild ancestors. They are particularly well suited to digesting animal protein but unable to utilize dietary fiber. Cats do best on a diet, which is twenty percent protein, nine percent fat thirty-five percent carbohydrates and a maximum of ten percent fiber.

Should I Feed My Cat A Canned Or A Dry Cat Food?

Given their choice, most cats prefer canned diets. The aroma, flavor and palatability of dry diets do not match that of canned. Cats are creatures of habit and quickly get accustomed to a flavor and consistency of diet to the exclusion of all others. Which ever 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. Over the years I have found that cats fed dry diets have less tartar build up on their teeth and less gum disease surrounding the teeth. With time, gum inflammation associated with canned diets causes the tissues surrounding the teeth to recede and the teeth to loosen. With time, it is thought that bacteria can move through the blood stream from infected gums cause damage to the cat’s kidneys and liver (see the tests). Dry cat foods have greater caloric density – that is they are richer. This is because canned food contains about 75% water. I do not suggest semi-moist diets because of the large amount of preservatives they contain.

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 not designed to metabolize. Many veterinarians associate the increased number of elderly cats with diabetes and obesity to their consumption of excess grain carbohydrates found in dry cat chows. You can read about diabetes in cats 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 meat. All of the known vitamins, present in raw meat, have been supplemented in name-brand diets. If you do decide to feed a raw diet, the ingredients must be intended for human consumption and you must fortify the diet with sources of calcium and 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. To read more about that, go here.

I am not a big fan of fad diets or any kind. Cooking unlocks many nutrients in foods (but it also destroys a few (ref)). 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  (ref) You can always supplement your cat’s diet with additional vitamins. There is no reputable scientific evidence that raw foods are better for your pet but we do know that cooking can make available more food energy from the meat protein your pet eats. 

Recommendations you run into on the internet that suggest you feed raw food ingredients to your cat are 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 digestibility. 

How Much Should I Feed My Cat?

Cats differ allot in the amount of food each one needs for optimal weight and health. Most adult cats I see are overweight. Overweight cats store their fat on their tummies so they may not appear fat to their owners. Growing cats and kittens require considerably more food per pound body weight to thrive than adults or senior cats do.

The following table is an estimate of how much your cat should eat. It is not precise because the compositions of various brands differ.

Age Body Weight Ounces of Dry Food Ounces of Canned Food
10 weeks 2.0-2.4 lbs 2.5-3.0 oz 7.3-8.9 oz
20 weeks 4.2-5.5 lbs 2.8-3.7 oz 8.0-10.5 oz
30 weeks 5.5-8.4 lbs 2.8-4.2 oz 8.1-12.4 oz
40 weeks 6.4-8.4 lbs 2.6-3.4 oz 7.6-9.9 oz
Adult Active 4.8-9.9 lbs 2.0-4.0 oz 5.7-11.8 oz
Adult Inactive 4.8-9.9 lbs 1.7-3.2 oz 5.0-10.3 oz
Senior Adult 4.8-9.9 lbs 2.3-4.3 oz 6.7-7.7 oz
Pregnancy 5.5-8.0 lbs 2.8-4.4 oz 8.1-13.0 oz
Giving Milk* 4.8-8.8 lbs 6.1-11.1 oz 17.8-32.4 oz

The Nutritional Requirements of Cats:

Cats are natural meat eaters and cannot be maintained on vegetarian diets or diets that rely heavily on grains. Such diets are deficient in essential amino acids, fatty acids and vitamins. Cats are finicky eaters who choose their foods on the basis of taste, aroma, texture and moisture content rather than meeting their nutritional needs.

Cats are unusual in that they cannot convert the carotenes found in leafy plants into vitamin A as humans can. Their natural source of vitamin A is liver. Vitamin A is necessary for membrane health. Cats deficient in vitamin A are more susceptible to respiratory tract infections, eye and skin disease. Niacin or nicotinic acid is also essential to your cat’s health. A lack of niacin causes inflammation of the intestines, rough skin and hair coat, oral ulcers and increased susceptibility to infection. Most mammals can synthesize niacin from the amino acid, triptophan. Cats have lost that ability and must obtain all their niacin from their diet. Cats must obtain the fatty acid, arachidonic acid from their diets. Animal fats are a good source of arachidonic acid. Unlike most mammals, cats cannot synthesize taurine from cysteine and methionine. They must receive all of it through the muscle meats in their diet. Lack of sufficient taurine causes blindness and heart enlargement. 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, some dietary fiber is important for gastrointestinal motility. Dietary fiber also seems to aid in preventing hyperglycemia and diabetes that are common in older cats. Too much fiber can prevent the absorption of vitamins and minerals and lead to diarrhea.

There are twelve minerals that are essential for cats. One of these, calcium, is essential for the formation of bone and teeth and as a signal between cells. Kittens that do not receive sufficient calcium have pinkish, translucent teeth a bowlegged stance and knobby painful joints. Partial bone fractures in these kittens are common. Most of the kittens I see with this condition were the offspring of nutritionally deprived feral (wild) cats. Others received a diet that was primarily meat or fish. Meat is low in calcium and high in phosphorus. High phosphorus interferes with the absorption of the little calcium that meat contains. Older cats on low calcium high phosphorus meat diets suffer from tooth and bone problems.

How Often Should I Feed My Cat?

An average sized adult cat weighing nine pounds should consume about 240 kilocalories a day. Neutered cats need less than intact animals. Cats like to munch on and off throughout the day so I suggest food be available at all times or in multiple small meals. Frequent small feeding and exercise could, conceivably, less the likelihood of digestive tract problems such as  triad disease, etc.

When food is available at all times, cats will eat ten to twenty small meals a day. Younger cats tent to self-regulate their caloric intake and stay lean. But twenty to forty percent of cats become overweight when feed free choice. As cats age, feed them a diet that is less caloric. One needs to consider at cats age and body condition when planning a diet. Problems occur 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 the house several times a day. Give them about twenty minutes at a feeding. Thin cats should be encouraged to eat one-and-a-half times a normal ration. This can be done with treats or pungent flavors. Feed chubby cats foods that are advertised as lower caloric or just feed them less. Chubby cats are more susceptible to diabetes and liver disease. If these cats are fed only two thirds of the food they presently consume, weight loss will be gradual and gentle. One can also feed a lower caloric cat chow to accomplish the same thing.

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 poorer.

Do not be led astray by considering only the percent protein. Percent protein tells nothing about the quality and digestibility of the product. Excluding premium, niche and specialty brands sold through pet shops, the quality of cat diets is reflected directly in the price you pay for the food.

Cats love the taste of fish. However, an overactive thyroid gland or hyperthyroidism as well as premature aging have been associated with feeding fish-flavored cat foods. It is not clear if the problem is that poor quality, rancid fish are used in animal foods or if there are constituents in fish themselves that cause the problem. It might even be a chemical associated with the can itself that causes the problem. 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 feed fish-flavored cat foods, supplement your cat with 25-50 units of vitamin E per day and one milligram of thiamine.

How Much Water Does My Cat Need?

Cats are not big drinkers. They drink less than dogs do – possibly because they descend from desert sand cats. This may also be the cause of their susceptibility to urine crystals and subsequent lower urinary tract disease. Your cat should have access to water at all times. If it is eating canned food , it will drink less. Adding water to your cats food (up to 40%) is an excellent way to help chubby cats loose weight and encourage activity. (ref)

You are on the Vetspace animal health website