Your cat is a carnivore and requires a meat diet. Dogs, while carnivores in the strictest sense, are omnivorous to a large degree, and have the ability to break down and digest vegetables as well as animal protein.

Cats, despite thousands of 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. Cats in the wild 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. The cat then is able to derive nutrition from various vegetable sources thanks to the prey's digestive processes.

This is why cat food is more expensive than dog food, more meat!

The ideal diet would be one which meets all 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.

Some cats require special dietary consideration: kittens, pregnant and nursing cats, elderly cats and convalescent cats. Some commercial feed is processed to suit these special needs.

The vast majority of us will be feeding regular commercial cat foods. These come in four specific types: dry foods, soft-moist foods, canned foods and gourmet foods.

The scientifically-balanced foods available from pet and feed stores and from your veterinarian usually contain supplements and additives to guarantee the best nutritional balance possible. 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.

Dry foods are the least expensive and being dry, have the advantage of an abrasive action which helps to keep the teeth and gums clean and healthy. These foods have a long shelf and bowl life and the food may be left out at all times. The cat may help himself to many small meals thus improving tone and digestion.

One theoretical disadvantage is a predispositon among male cats to develop Feline Urological Syndrome (FUS). Veterinarians are sharply divided on whether the dry dog food's low water content contributes to the problem if the cat has a predispostion to FUS.

Soft-moist foods have more appeal than dry foods and also cost more. They are good for about a day in the bowl and should not be left out longer than that. Be aware that most soft-moist foods contain an abundance of preservatives so labels should be read carefully.

Canned foods are the most expensive. Their biggest drawbacks being cost and odor. Canned foods do nothing to inhibit dental tartar. However, the same argument that gives dry foods a predispostion towards the development of FUS implies a lack of predisposition in canned foods. Again, this has not yet been determined one way or another.

If a cat has already suffered a bout with FUS a low magnesium diet is often prescribed by the veterinarian.

Gourmet or premium foods are usually not balanced and must not be used as the basis of your cat's diet. Think of them as treat foods.

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 6 hours. If diarrhea develops, the cat cannot digest milk, if the stool remains normal, it can.

Excerpts from FELINE NUTRITION