Q: I have heard that cats need to eat animal protein or they will get ill. What is it in animal protein that they require and what happens to them if they do not get it?
A: Cats do have a unique metabolism. They are truly carnivorous animals and are dependent upon ingesting animal flesh on a regular basis, while dogs can do well on a vegetarian diet.
A great deal has been learned about feline nutritional needs in the last few decades. In the late 1970s, it was learned that cats required the amino acid taurine, which is only found in animal protein. House cats actually produce taurine, but in quantities too small to meet their metabolic needs. If a cat does not regularly ingest meat, its retina degenerates causing an irreversible blindness.
A minimum taurine requirement was established for feline diets. It should be noted that retinal degeneration can also occur in cats due to an inherited defect.
In the mid 1980s, it was learned that cats fed a diet deficient in taurine were also at increased risk of a disease of the heart muscle known as dilated cardiomyopathy. This disease can be life-threatening, as it makes the hear muscle flaccid and renders the heart a less-effective pump. Fortunately, this form of heart disease can actually be reversed if diagnosed in time and the cat's diet is supplemented with taurine.
In addition to heart and retinal disease, taurine deficiency can also reduce fertility in cats. Fortunately, taurine deficiency is now rare, since the feline requirement is widely known and cat foods are supplemented with taurine. Current cases are generally limited to cats fed dog food diets.
Timm Otterson, DVM
Prepared as a public service by the Niagara Frontier Veterinary Society. Send questions to Pets, P.O. Box 403, East Aurora, N.Y. 14052-0403. Sorry, personal replies cannot be provided.