I’ve been asked several times whether I think it’s OK to feed a dog a vegan diet. The short answer is that dogs can survive and even thrive on a vegan diet, but it’s not easy and it’s not the optimal diet. Cats cannot be vegan, by the way.

A recent article in Wired addressed this question from the perspective of dog owners’ conflicting beliefs: They are vegan because they oppose using animals for human benefit but they also want to provide the best lives for their dogs (which means letting the dogs eat meat …). I understand the dilemma.

Premium pet food companies understand the dilemma, too. More and more, they are advertising the humane and sustainable nature of the ingredients they use. Is the advertising accurate? I don’t know; my hunch is that some companies are better than others, as with human food producers. Maybe the Whole Dog Journal will add sustainability to its list of criteria in future dog food evaluations (wouldn’t that be great?).

From a nutritional standpoint, I’d advise choosing this path very carefully. Consult with a canine nutritionist or a vet who has studied pet nutrition extensively. That is not a given; many vets take one or no courses on nutrition in vet school and many vet schools receive a lot of funding from large pet-food companies. That is to say, what many vets “know” about nutrition is heavily influenced by the makers of often not very good kibbles. I’ve gotten truly terrible nutritional advice from many otherwise excellent veterinarians.

If your vet is on board and knows a lot about canine nutrition, you can probably work out a vegan or mostly vegan diet that will work for your dog. But it’s not something to do casually; don’t just switch to a vegan food and forget about it. For example, your dog might need more frequent blood work done to test for key nutritional elements, as the recent scares over taurine levels illustrates.

One hypothesis with the many dogs showing low taurine levels is that foods with high levels of vegetable-based proteins and low or no carbohydrates made it harder for the dogs to get full nutritional benefit from the meat-based proteins in those foods. While I haven’t yet seen a definitive answer to that question, it suggests that boosting the amount of plant-based proteins in a dog’s diet has implications beyond whether she’s getting enough protein … which means going vegan or mostly vegan could have health effects that you’re not anticipating, and that even if the dog is a healthy weight and seems to be fine, serious problems could be developing.

So. The long and short answers get us to the same place, which is this: If you’re serious about moving your dog to a more vegan diet, proceed carefully and make sure you’ve got a knowledgeable vet’s supervision and guidance.