Planning a healthy, nutritious diet is a challenge for most humans, but it can be even more stressful to figure out what pet owners should feed their dogs.
In recent years, more dog owners have leaned into feeding their pooches plant-based diets, despite the lack of concrete data on whether these vegan diets are actually good for canines. But new research on the health impacts of different dog diets could either put owners’ minds at ease — or ignite a new slew of controversy over canine chow. The findings were published Wednesday in the journal PLOS ONE.
“This is the first time health outcomes have been studied, in a very large-scale study,” Andrew Knight, lead author on the study and founding director of the University of Winchester’s Center for Animal Welfare, tells Inverse.
What’s new — The researchers compared the health outcomes of conventional, raw meat, and vegan diets, finding that the most “nutritionally sound” diet for dogs, is, in fact, a vegan diet.
Dogs on vegan diets suffered from far fewer health disorders and allergies than pets fed conventional diets. On average, dogs fed vegan diets in the study had half the risk of suffering from health disorders — such as gastrointestinal issues — as pups raised on conventional diets.
“Conventional” diets refer to meat-based products produced by commercial pet food companies. On the whole, “dogs fed conventional diets appeared to fare worse than those fed either of the other two diets,” according to the study.
“We have sufficient confidence scientifically, that dogs can be healthy (and indeed, thrive), on nutritionally sound vegan diets,” Knight says.
But to be clear: the researchers aren’t necessarily suggesting people should start making their own plant-based meals for their dogs. Instead, Knight suggests dog owners rely on nutritionally balanced, commercially available vegan dog food from a reputable company. Home-made plant-based diets may not contain the right proportions of nutrients — such as proteins, carbohydrates, minerals, and vitamins — even if pet owners add nutritional supplements.
“Guardians should always aim to use diets of good quality, from reputable companies, and check that the diet is nutritionally complete,” Knight says.
It’s also important to know that while the raw meat diets performed better on certain health indicators than conventional diets, the researchers still do not recommend raw meat diets at this time due to concerns over pet safety. The American Veterinary Medical Association also does not recommend raw meat diets for pets, though the website states its policy is currently under review.
“A very sizeable body of studies have clearly shown that raw meat diets are associated with significant hazards, notably, pathogens such as bacteria and parasites,” Knight says.
How they did it — Some pet owners believe vegan and other plant-based diets are unnatural and may harm pet health, requiring further research to help pet owners make informed decisions when it comes to their dog’s diet. So Knight set out to conduct that research. The recent PLOS ONE study is part of a larger body of research that explores the environmental sustainability and behavior implications of different pet diets.
Knight’s team surveyed more than 2,500 dog guardians about their pets’ diets and health. The researchers looked at three types of dog diets: conventional, raw meat, and vegan. Out of the dog owners surveyed, 54 percent chose conventional diets for their pets, 33 percent fed raw meat, and 13 percent selected vegan diets.
To draw conclusions about the impact of diet on pet health, the scientists analyzed the prevalence of 22 health disorders in the dogs, as well as other indicators of poor health such as the number of veterinary visits or medication use. Common health disorders include gastrointestinal issues, problems with muscles and bones, mobility and dental issues, and cancer.
There are some limitations that could impact the study’s findings. For example, the research was not conducted in a laboratory setting where pets were fed a controlled diet, but instead relied on data from dog owners whose pets were fed normally at home with some snacks, scavenging, and supplements on the side.
“Hence, our results show the outcomes that can be expected, when normal pet guardians feed vegan or meat-based diets to dogs, in normal homes,” Knight says, but adds that their study is a large-scale effort with “a broad range of objective data” that makes it reliable.
Why it matters now — The study’s findings are timely as the vegan pet food industry is booming. Experts estimate the vegan pet food market will grow to $15.65 billion by 2028.
“There is increasing interest in alternatives to conventional meat-based diets, due to concerns about pet health, environmental sustainability, and the welfare of farmed animals used to produce meat-based diets,” Knight says.
Contrary to popular belief, dogs are not carnivores but omnivores by nature, so it’s never been a totally outlandish idea to cut meat out of dog diets. But there’s still little consensus on the topic among pet owners and even many veterinarians. A 2018 publication in the Journal of the American Veterinary Medical Association says that dogs can obtain most essential nutrients from plant sources, but also cites the lack of scientific data on the “benefits of feeding plant-based diets to omnivorous and carnivorous pets.”
“The results — that the healthiest and least hazardous diets for dogs are nutritionally sound vegan diets — will probably prove very controversial, for the sizeable group of people who erroneously believe that dogs need meat,” Knight says. (Cats, on the other hand, are obligate carnivores.)
Inverse spoke with Chyrle Bonk, a veterinarian at Petkeen.com, to get the opinion of a veterinarian who was not affiliated with the study. Bonk says any pet owner choosing to feed their dog a vegan diet should consult with a qualified veterinary nutritionist before moving forward.
“The main concern for any dog diet is that it is complete and balanced. This goes for commercial dog foods, homemade diets, raw diets, and vegetarian or vegan diets,” Bonk says.
She adds, “Any homemade, raw, or vegan diet is going to take considerable supplementation with vitamins, minerals, etc, so being sure that these are high quality and digestible is a must.”
The Inverse analysis— Pet owners accustomed to feeding their dogs conventional meat-based diets may still be uncertain about taking their pet on the vegan journey with them.
When in doubt, consult your veterinarian and read the label on any commercially-sold pet food closely to make sure your pup is getting all the essential nutrients they need to live their best lives. Healthy vegan diets still need to provide all the necessary nutrients from plant, mineral, and synthetic sources.
“I won’t recommend any diet, vegan or otherwise, to a dog without making sure it is complete and balanced,” Bonk says.