I have a few friends who are vegetarian or vegan, who have considered putting their pets (mainly cats, which is why I specified in the title) on a similar diet.

I feel like that might not be good for the animal, but I feel like I can't discuss it with them without being throughly educated on the topic.

Is it safe to feed a cat a vegetarian or vegan diet? Why or why not?

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    There is no conclusive evidence that it is impossible. I've found a study about nutritional deficiencies in veg(etari)an cats, but it didn't compare the cats to omnivorous cats. In general vegans tend to watch their diet much more closely than non-vegans, still most of them I know consider it to be too hard to feed a vegan diet to a cat (as the margins of error are very small) and in consequence feed them omnivorous. Only a comment as I have no experience with cats myself (besides scratches).
    – Baarn
    Commented Dec 10, 2013 at 14:51
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4 Answers 4


Although PETA seems to say that it's perfectly healthy, cats are not vegetarian and thousands of years of evolution has made them into carnivores. They have a specific requirements for nutrients that vegetarian diets just cannot provide. With the exception of special situations where the cat requires a modified diet, vegetarian diets should be avoided.

As noted below, cats have issues producing Vitamin A & D as well as taurine, which are difficult to get from a vegetarian diet.

Vitamins A and D: Dogs and cats cannot make vitamin D in their skin, so it needs to be in their diet. And the vitamin D needs to be D3, which comes from animal sources, not D2, which comes from plant-based sources. “People and dogs can use D2 to some extent, but cats really need D3”, Heinze says.

Taurine. Dogs can make taurine if provided the right building blocks through dietary protein. Cats cannot make their own taurine at all, so it is regarded as an essential amino acid in this species and must be present in adequate amounts in the diet. Both species can suffer taurine deficiencies.

If attempting a vegetarian/vegan diet, consulting a vet first is crucial, and then only going with cat food that has been specifically formatted in order to provide the required nutrients. Attempting a 'home grown' vegetarian diet is not healthy for cats and can kill them or cause serious harm. In no conditions should a vegetarian/vegan diet be attempted with a kitten.


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    PETA, as opponents to scientific testing with animals, are far from being acceptable authorities on any scientific matter related to animals, specifically including nutrition. If you need authoritative advice, the more rational SPCA agencies, veterinary schools, and the like -- biologists rather than philosophers, to put it kindly -- would be more reasonable places to go.
    – keshlam
    Commented Jul 19, 2015 at 6:52

Short answer: No.

Cats are obligate carnivores. Note the "obligate". While they can process and obtain nutrition from some vegetable/plant matter, they cannot receive or produce all the nutrients they need this way.

Omnivores (like humans and dogs and many others) have certain metabolic pathways available to them that mean that they can make use of both plant and animal matter fairly well. We need vitamin A. We can get this directly from other animals (meat), but our bodies can also manufacture it from beta-carotene which is found in many plants. Cats cannot do this. Vitamin A does not occur in plants, only vitamin A precursors, which cats cannot adequately make use of. Same story with taurine, vitamin D, and many others.

Cats have a carnivore's digestive tract and a carnivore's metabolic system. With very careful balancing and supplementation, it might be possible for a cat to survive on a vegetarian diet. However, there is a difference between surviving and thriving. Cats should not be forced to eat a vegetarian diet.

If your friends wish to maintain a vegetarian/vegan household, that's fine, but they should look into pets who are suited for such a diet in that case. Cats, unfortunately, are not one of them.


Cats require an amino acid called Taurine, since they are unable to synthesize it themselves. This particular amino acid is only found naturally in animal tissue. Because Taurine is destroyed by heat, a Taurine supplement is added to commercial food.

There are vegan websites that claim you can give your cat a vegan diet, however it may not be appropriate for all cats. Depending on the pH of your cat's urine on this type of diet, it may allow the formation of bladder stones (I can tell you from experience, this is not fun to deal with).

Urinary tract problems are fairly common in cats, and because of the relative acidity of meat to vegetable protein, some vegan cats suffer from them.

Because of the greater risk to males, you may want to give your cat some canned meat-based foods (a veternarian-prescribed pH balancing formula is ideal) be given along with vegan food, particularly if they have had any past history of urinary tract issues or crystal formation. Cats who have never displayed any tendencies to develop urinary tract problems can often get by with a fully vegan or nearly all-vegan diet, but you must be vigilant with males due to the urgency of needing proper care if there is blockage due to the formation of crystals in the urinary tract. Those who have had problems in the past may need as much as 1/2 to 3/4 of their food consist of meat in order to completely mitigate this risk.


Note that the only treatment for this type of urinary problem is diet. If your cat is prone to crystal formation, your vet will instruct you to switch foods.


Vegan diet is not suitable for cats. It could result in a deficiency of taurine, vitamin B12 and arginine. Your cat might have health problems like cardiomyopathy, blindness, feline lower urinary tract disease, urinary obstruction, bladder crystals, etc. If you are still feeding her on vegan diet, then to ensure her good health you are advised to take her to a veterinarian check up.

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