Is It Possible (Or Safe) to Make Your Pet a Vegetarian?

Pug with her head tilted surrounded by vegetables

Dr. Justine Lee is adamantly against vegetarian pet diets. Read more to find out why. For more from Dr. Lee, find her on Facebook!

Ever hear of the saying “You are what you eat”? I’m an omnivore (although I honor “Meatless Mondays”), but I’m fully supportive of you choosing to eat healthy – whether it’s as an omnivore, vegetarian, or vegan.  That said, when it comes to your pet, I’m going to take the stance and say that you should never make your pet a vegetarian…especially for cats.

About 15 years ago, I treated a young, 15 month-old cat for a severe, rare type of heart disease called dilated cardiomyopathy (DCM) – thankfully, we hardly see this type of heart disease anymore in cats. This kitten had an extremely loud heart murmur (meaning the sound was abnormal when I listened with a stethoscope). The severity of the heart murmur was graded a 6/6 (with 1 being the softest and 6 being the worst). The cause of the heart murmur? Inappropriate diet. The cause of this kitten’s heart disease was the owner’s fault, as the owner made the kitten a vegetarian (forcing his dietary beliefs on his pet).  

We don’t see this type of heart disease as much as we used to thanks to better nutrition. Veterinarians were able to link certain types of DCM to the lack of taurine, an essential amino acid (essential means that the body can’t make it, and it’s imperative that the diet contain it).

What should you learn from this? Don’t make your pet – especially your cat – a vegetarian.

While dogs are omnivores (they can eat both plant and animal sources of protein), cats are strict carnivores. While there are cat vegetarian and vegan diets commercially available, these are never recommended by veterinarians (well, at least the good ones). 

Please don’t make your cat a vegetarian. If you want to cook for your cat (and can deal with having meat in your vegan refrigerator), then that’s OK, as long as you realize that it is very difficult to make a homemade, nutritionally balanced diet for your cat without screwing something up. If you want to attempt it, make sure it’s recommended by a board-certified veterinary nutritionist (that does not mean trying whatever you stumble upon on the Internet!), as it will require appropriate electrolyte, vitamin, and mineral supplementation (especially focusing on phosphorous, calcium, Vitamin A balance, among a few other things!).

Without appropriate supplementation, cats that are fed vegetarian or vegan diets are at high risk for other life-threatening deficiencies in amino acids and vitamins (e.g., lysine, tryptophan, etc.). It's not worth the fatal risk. 

Dogs, on the other hand, can handle vegetable-based protein sources, so it is possible to make your dog a vegetarian. That said, dogs won’t like it. That’s because meat-based protein sources taste better (If you offered Fido a piece of corn versus a piece of steak, guess which one he’ll choose?). If you feel adamant about it, talk to your veterinarian or a veterinary nutritionalist about it. It’s OK to make your dog vegetarian if you feel strongly about it – just make sure it’s a balanced diet (with the correct amino acids and multivitamins again). Same goes for a homemade diet – it’s OK to do, just make sure you consult your veterinarian – or better yet – a veterinary nutritionalist.

As an emergency specialist, I’m pretty adept at treating congestive heart failure… but I prefer not to see DCM even again. So help me out: feed your pet a balanced, medically appropriate diet!

If you have any questions or concerns, you should always visit or call your veterinarian – they are your best resource to ensure the health and well-being of your pets.