Should Dogs Eat a Vegan Diet?

Golden Cali watches puppy Orly bite an ice cream cone
A decidedly non-vegan treat!

A friend recently shared with me an article about feeding dogs a vegan diet. The article referred to two studies done in the UK with the same lead researcher. The upshot is that these articles say that dogs can live healthy lives on a vegan diet and that they find vegan diets palatable. In fact they claim that “vegan pet foods are generally at least (emphasis added) as palatable to dogs and cats as conventional meat or raw meat diets, and do not compromise their welfare.”

Color me skeptical. But I’m willing to consider the evidence.

Both studies were published by PLoS One (Public Library of Science), which means they are freely available:

The first issue with these studies is evident from their titles: Both are based on an online survey of dog and cat owners. The ‘indicators of health’ paper used a subset of the data used in the palatability study. Using a self-selected group of pet owners answering an online survey is not a scientifically sound method, and there’s no way to know whether the responses are accurate.

The questions are also problematic. To gauge dogs’ health, for example, they asked the owners to give their opinion of their dog’s health — and to also guess what their vet would say about their dog’s overall health … even for dogs whose owners report not having taken them to a vet in over a year (or ever).

There are other issues with the questions, such as the limited response choices for the kind of diet a dog ate — “conventional” meat-based, which covers an enormous variety of foods; raw, which could be homemade or commercial; and vegan, which also could be homemade or commercial — and not accounting for treats. A combination wasn’t an option, but I — and many people I know — feed some raw and some kibble.

Based on their data, though, the authors are certain that they know that dogs both enjoy their vegan diets and are generally perfectly healthy while eating vegan. (I haven’t seen a study on whether the cats on vegan diets were healthy … but it’s trickier with cats.)

I’m still very skeptical.

I actually do think that dogs can be healthy on a vegan diet, but it’s not easy. I think that, for an active dog, it would be challenging to provide sufficient protein from sources that dogs can easily digest without feeding so many carbs that the dog would become obese. (The study authors never actually saw the dogs, so we don’t know if the vegan-fed dogs were healthy weights.)

But what I am really skeptical of is the claim that the dogs (& cats) found the vegan diets “at least” as palatable as a meat-based diet. I simply do not think that dogs (or cats) want to be vegan.

As any trainer knows, some treats are “higher-value” than others.

While each individual dog will have different preferences, the highest-value treats tend to be the ones that are closer to fresh: fresh meat, fresh fish, cheese, even some fresh veggies. A close second is “jerky” type treats — dried meat or fish — or the soft treats. These smell and feel more like meat, and they probably taste more meaty (or fishy). Low-value treats are biscuit-type treats — cookies, kibble, Charlee Bears. These are hard and dry. They’re nicely crunchy, but I doubt they taste like much.

Within my dogs’ varied diet, they have favorite foods. Their behavior is very different when I am preparing them fresh food or mixing in canned sardines with their kibble than if I’m giving them plain kibble.

But they’re golden retrievers, so they greet any and all food eagerly, exhibiting some behaviors described in the study as indicating palatability and enjoyment, such as eating quickly, wagging their tails, and licking the bowl or their lips. Even non-golden-retrievers tend to eat quickly in multi-dog households, so this is not necessarily an indication that the dog likes the food.

Some of the other behaviors listed as indicating palatability are … at best, questionable. They’re also behaviors that I would not tolerate, no matter what they meant. These include vocalizing for food, stealing food, raiding food bins, waking the owner during the night for food, showing aggression around food, or staying near the food bowl. The last two indicate resource guarding, a whole separate problem that has nothing to do with the taste of the food.

The authors also say that the fact that the dogs ate the food they were served means that the food was palatable to them. But it could just mean that the dogs were hungry and knew that they weren’t getting a menu to choose their dinner from.

Or maybe it meant that the dogs were hungry because their vegan or kibble-only diet wasn’t satisfying. How do the authors know that the vocalizing dogs were asking for food? Or for more of the same food? Maybe they were literally crying for better food? And, how many dogs wake their owners up at night because they love their dinner so much they want more? Is that a thing?! Or were these dogs so hungry they couldn’t sleep?! Or they heard a strange noise or they were scared by the thunder or just wanted to cuddle …?

(In case you’re still wondering, I am pretty sure that the the study does not show what the study authors say it does.)

I’m also pretty sure that my dogs don’t want to be vegan.

To be fair, I am strongly in favor of a vegan diet. I am not vegan, but I inch closer to that ideal all the time. I also agree with the authors’ statements about the unsustainability of the way we feed pets. The whole food animal industry is unsustainable (and, I believe, problematic in so, so many ways).

Cali's pawprint looks like a smiley face
Cali’s pawprint; she’s a very happy girl

So, finally, we get to the real dilemma: Should I work toward my dogs’ happiness by feeding them a diet they enjoy and thrive on? Or should I follow the study authors’ ideals, which I share, of seeking a more sustainable option?

Cali and Orly vote for happiness.

Can my dog be vegan?

Cali turns away from her food bowl and faces a fence
Cali doesn’t want to be vegan!

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.