Back around 1990, when I was a brand-new vegetarian, I ran across a book that described in great detail how a vegetarian – in fact, vegan – diet could be designed to fulfill the complete nutritional needs of a cat. I leafed through it skeptically, and when it turned out that one of the key ingredients was synthesized from petroleum, I put the book back on the store’s shelf.

A few years later, I began feeding our cats a homemade organic diet, but sometimes had trouble finding organically-raised meat. (And I’ll admit I was also a little grossed out by dealing with the meat.) When I saw that a new edition of the book had been published, I ordered a copy and read it thoroughly. The petroleum derivative was no longer part of the diet, because a plant source had been found for that ingredient.

This seemed too good to be true: I could start with the same high-quality beans, grains, and vegetables that my husband and I were eating, add a specially-formulated nutrient powder, and feed our cats a nutritionally-perfect, completely-organic diet. I read the book again, and could find no flaw. Our four cats soon became vegetarians.

Everything seemed fine at first. But after a couple of years, our oldest cat began having Parkinson-like tremors that kept getting worse. After another year or so, two of the others also developed tremors. About this same time, we took in a stray who threw up every day.

Our holistic vet finally convinced me to try feeding them meat. The tremors diminished dramatically (though they never actually went away). And the cat with the “nervous stomach” stopped throwing up. That sold me, of course, but it took me several years to figure out what it might have taken to dissuade me in the first place.

Here it is: If I’m ever offered one free trip in a time machine, I’ll go back to 1990 and show my younger self a nutritionally-complete human diet that’s made entirely from animal ingredients:

Protein from meat;

Fat (both saturated and unsaturated) from meat;

Carbohydrates from milk, liver, shellfish, and caviar;

Vitamins (including vitamin C) from liver;

Minerals from bones; and

Fiber from fur!

She – which is to say I – would never even consider eating such a diet. I would have thought it was ridiculous even before I was a vegetarian. Yet I forced our cats to eat an equally-inappropriate diet, resulting in permanent nerve damage for most of them.

If you have any well-meaning friends who think that cats can be vegetarians, please tell them about the all-carnivore diet for humans. They can have a good laugh, and then maybe it will occur to them that a proper diet is more than just a list of nutrients.

Afterthoughts

All cats are not alike, of course, any more than all humans are, so it’s tempting to conjecture that the Blood Type Diet could tell us whether a few cats might have natural vegetarian tendencies. But even though cats do have two blood types called A and B, these are merely convenient labels. The blood-type antigens are not the same as in humans, so the human Blood Type Diet does not apply to them.



As I understand it, dogs are naturally somewhat more omnivorous than cats, so might theoretically do somewhat better than cats on a vegetarian diet, assuming that it included some eggs and/or milk products. Meat is, however, a substantial part of their diet in the wild, so I personally would not argue with Mother Nature.