On Vegetarian Pets | Vol. 3 / No. 35.3

This cat eats meat-based kibble | Photo: Richard Ford Burley


Recently, Distractify summed up a 2015 Tumblr thread in which a woman shared how “excited” her dog looked about a vegan meal she was about to receive, and someone with some apparent expertise in veterinary science and animal welfare suggested in no uncertain terms that said dog was not doing well on said diet. This created quite the debate about feeding animals vegetarian or vegan diets when, in nature, you can be certain they’d be eating at least some meat.

Now, cats are what you’d call an “obligate carnivore.” They require at least 20% of their diet to be protein, require high quantities of the amino acid known as arginine, and cannot produce the amino acid taurine. Cats need meat, and despite attempts to develop vegetarian or vegan feed for cats, I am unaware of any that are considered anything but risky for your pet. You must feed your cat meat or meat-based feed.

Dogs, like cats, are a part of the order Carnivora, so you would expect them to absolutely require meat. And the responder in the Tumblr post does seem to have expertise on his or her side, claiming to work at a prestigious animal hospital (all, of course, anonymized). S/he certainly has a point that the idea that dogs are omnivorous (unlike their wolf antecedents) is still in its infancy. That said, there is some scientific evidence pointing to the possibility that dogs may also thrive on very specifically formulated vegetarian diets.

Take this study, in which six dogs were given a diet with 43% poultry meal and another six were given a diet with that poultry meal replaced with 43% soybean meal and corn gluten. These dogs were racing-grade Siberian Huskies, and they were testing to see whether after twelve weeks on the diet it would negatively affect their health, specifically looking for anemia but testing a wide range of health indicators. By the end of the 12 weeks, all the dogs were in good health, and both groups’ blood iron went up over the course of the study.

But on the other hand, a single n=6 study in one breed of dog for twelve weeks is hardly a green light for feeding your dog your own brand of vegan diet with supplement pills. It’s the very beginning of a body of scientific research that would need to be a lot bigger for me to take any kind of a chance on a dog I’m taking care of.

And of course I’d never feed my cat a meat-free diet.

If you still want to feed your dog a vegetarian diet, talk to your veterinarian. I’ve heard stories that it’s possible, and I think many vets will probably admit the possibility, but they’ll also probably admit that it’s something that should only be done with professional consultation and regular check-ups. Do not try to feed your dog a vegetarian diet of your own making. Please.

Animals can’t tell us what they’re feeling, so please, be really really conservative in trying to make your animal follow your own personal moral code.


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Richard Ford Burley is a human, writer, and doctoral candidate at Boston College, as well as an editor at Ledger, the first academic journal devoted to Bitcoin and other cryptocurrencies. In his spare time he writes about science, skepticism, feminism, and futurism here at This Week In Tomorrow.