URBANA, Ill. — Take a stroll down your local supermarket’s pet food aisle, and you’ll see endless options. It seems there’s a dog food available nowadays for every pup and any occasion – including vegan dog food. While a vegan diet for a dog may sound silly at first, researchers from the University of Illinois say that at least two human-grade, lightly-cooked vegan diets provide adequate nutrition for dogs.
“The trends of vegan foods and human grade foods are increasing for dogs. Because people are feeding these diets to their pets, it’s important they be tested like all other foods to make sure they’re safe and ‘complete and balanced,’” says study co-author Kelly Swanson, professor in the Department of Animal Sciences, part of the College of Agricultural, Consumer and Environmental Sciences at U of I, in a university release.
The research team analyzed two human-grade vegan formulas (with and without a grain ingredient) made by the plant-based pet food company Bramble. They compared those vegan diets to a leading brand of chicken-based kibble. Researchers fed the diets to a group of beagles for three weeks, sampling the dogs’ blood chemistry, fecal quality, and microbiomes (the collection of microbes present in their droppings) along the way.
Both diets make the grade
The team analyzed the actual dog foods as well. Results confirm that vegan diets for pets are veterinary nutritionist-formulated mixtures of whole foods which include lentils, garbanzo beans, sweet potatoes, butternut squash, apples, blueberries, peas, and carrots. Additionally, both vegan diets and the chicken diet met the standards set by the Association of American Feed Control Officials (AAFCO) for “complete and balanced” nutrition.
“One thing to remember is that animals don’t have ingredient requirements, they have nutrient requirements. As long as they’re consuming the essential nutrients in the correct amounts and ratios, dogs can be vegan, vegetarian, or meat-eaters,” Prof. Swanson adds. “Knowledge of ingredient composition and nutrient needs are critical, however. Anyone can slap together a vegan meal for their dog, but without careful formulation, you might have something that’s really imbalanced.”
Earlier studies conducted by Prof. Swanson’s team concluded that human-grade, fresh dog foods are highly digestible — meaning they produce less stool. However, this wasn’t exactly the case for vegan diets. Scientists in this study deemed all three diets highly digestible, and the vegan diets didn’t generate any more or less stool than the chicken diet.
“It’s not a surprise, really. With these ingredients, there’s more fiber and oligosaccharides, which could be good for dogs that need to stay regular,” Prof. Swanson notes.
Vegan pet food could help overweight dogs slim down
Study authors say it was surprising to see different blood metabolites, or chemicals in the blood that can indicate strong or poor health, among pups depending on the diet they were eating. Blood triglycerides and cholesterol, measures of circulating fats, were significantly lower in dogs on the vegan diets. This could be a plus for overweight pets, researchers note, as it could help maintain a healthy weight.
When the team analyzed fecal microbiome and the chemicals produced by those microbes, they discovered additional positive traits.
“There were some interesting and beneficial changes in the microbial community that I think reflect the blend of fibers that were present in the vegan diets. The fecal metabolites phenol and indole, both of which contribute to fecal odor, were dramatically decreased in those diets too. It’s still going to smell, but probably less,” Prof. Swanson comments. “Overall, it looked like there were some beneficial shifts from a gut health perspective in dogs fed the vegan diets.”
Prof. Swanson adds that he’d like to perform head-to-head comparisons between human-grade diets, both with and without meat and dairy products. Still, considering this is the first study showing how fresh vegan diets perform in dogs, the results are promising.
“No one had tested digestibility of these diets in dogs before this. We showed that these vegan diets resulted in desirable fecal characteristics, high nutrient digestibilities, and positive changes to certain blood and fecal metabolites,” he concludes. “For people who are interested in feeding their pets a vegan diet that aligns with their personal values, the diets we tested are a good choice.”
Prof. Swanson stresses that veterinary nutritionists created all the diets in this study, and that homemade vegan dog foods may not provide the same complete and balanced nutrition levels for dogs.
The findings appear in the Journal of Animal Science.