So, I’m about to rant because this keeps coming up, and I’m tired of it.
You cannot keep a cat on a vegan (or even vegetarian diet). It’s hard enough to keep yourself on one (we’re omnivores and if we cut out animal products completely we need to watch ourselves for certain deficiencies).
So, let’s explain exactly why your feline can’t be vegan.
It’s About the Taurine, Baby
Cats are true obligate carnivores (dogs are meat heavy omnivores, although they are still very hard to keep as vegetarians and doing so needs the advice of an animal nutritionist).
Cats are designed to eat meat to the point where they literally can’t taste sweet things, because meat is never sweet.
Now, here’s what being an “obligate carnivore” really means:
It’s all about one particular essential amino acid, called taurine.
All mammals need taurine. It’s used to build proteins vital for normal vision, digestion, heart function, pregnancy and the immune system.
Humans (normally) make taurine. Our bodies manufacture it from other amino acids. So, with care, humans can lead long and healthy lives without animal products (you may want to supplement Vitamin B).
Cats don’t. Cats have lost the ability to manufacture taurine and have to consume it directly from their food.
Which means meat.
Without enough taurine, your cat will go blind and develop heart problems.
Commercial cat food is balanced to make sure your cat gets enough taurine.
Ah, but can’t we synthesize taurine? Make it in a lab?
Absolutely and, in fact, a small amount of synthetic taurine is added to most cat food just to make sure. So, in theory, you could feed your cat a vegan diet and a synthetic taurine supplement. Synthetic supplements are generally less healthy than the real thing, but you could do it.
Unfortunately, while taurine is the most important issue, it’s not the only one. First of all, cats also need vitamin B12, vitamin A, and arachidonic acid, which would also have to be supplemented.
Cats and Carbs
Cats don’t need carbs. Nope, nope. Because cats have evolved to survive entirely on meat, they have no dietary requirement for carbohydrates. They just need fats and proteins.
Now, this doesn’t mean that cats can’t digest carbs, but they don’t tend to do so very effectively. Also, too many carbs for a cat can alter the pH of their urine, which results in…yup. Bladder stones. And in toms and alters, bladder stones can require emergency surgery.
Cats and Protein
Cats just plain need more protein than we do. Furthermore, while (most) humans have a digestive system that handles plant protein very well, cats just don’t.
Their system is expecting meat. Because cats don’t naturally eat carbohydrates, they turn protein into energy and thus need more protein than dogs.
Cats just need to eat meat, and it’s much easier to let them eat what their system is designed for. (And yes, this does mean you shouldn’t try to keep a cat on just dry food. I know people do, but it’s not good for them).
If you really want a vegan pet, consider a rabbit, guinea pig, or other naturally herbivorous animal. Just make sure you do all the research on their needs.