Interest in plant-based diets is on the rise, despite only 3% of Americans identifying as vegan and 5% as vegetarian, according to a Gallup poll.

Vegan meats such as the Beyond Burger and Impossible Burger have disrupted the meat industry, even infiltrating fast food chains such as KFC and Burger King. Vegan restaurants are gaining popularity and Americans are spending billions on dairy-free milks and plant-based products.

And now, some people are extending their plant-based lifestyle to their dogs by feeding them a vegan diet. Pet diets tend to reflect the choices of their human counterparts, according to the American Veterinary Medical Association.

"Interest in, and availability of, plant-based diets, are growing in popularity in the North American pet food market," the AVMA notes in a study.

Even major pet food companies such as Purina, Pedigree, Natural Balance and PetGuard have entered the vegetarian and vegan realm by offering plant-based options. They use protein from ingredients such as brown rice, barley, peas, spinach and potatoes.

James Scott, a vegan who founded the Texas Veggie Fair, started feeding his Chihuahua mix, Betsy, a plant-based diet when he first found her roaming the streets as a puppy. Scott's girlfriend, Joy Lindsay, also gives her schnauzer mix, Ami, vegan dog food and has been doing so for the past three years. Ami is currently 9 years old and Betsy is 6.

Though there is some debate on whether dogs are omnivores (eating both meat and plants) or carnivores (only meat), many veterinarians and pet food companies consider them omnivores.

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Research has shown that dogs "can live and thrive on a vegan diet," Scott says. "I think that was my main driver for going ahead and picking out vegan dog food."

Scott noted that he has concerns that some of the mass-produced pet food could contain meat from diseased or dying animals, which he wouldn't want to give to his dog.

Though Scott says he can't definitively say whether a plant-based diet has made either Betsy or his girlfriend's dog Ami any healthier (Ami was already a pretty healthy dog before going vegan), he does believe it helped his Chihuahua recover faster from living on the streets.

"She started getting bigger and filled out," Scott says. "She was smaller than she should've been as a puppy. I feel like it contributed to her getting healthier faster."

According to a study in an AVMA journal, there is little scientific evidence to back up claims that a vegan or vegetarian diet is beneficial to dogs. Lindsay Rubin, vice president of V-Dog, a vegan dog food company, provides anecdotal evidence of its benefits.

"We’ve seen dogs live into their 20's on our formula," Rubin says and lists the benefits of vegan pet food as being "increased mobility, decreased allergies, better bowel movements and excellent weight maintenance."

Megan Shepherd, doctor of veterinary medicine and a clinical assistant professor at Virginia-Maryland College of Veterinary Medicine, says it's important to remember that dogs are omnivores and not herbivores (which eat only plants). If you're going to feed your dog a plant-based diet, it's important to make sure you're picking foods formulated with the proper nutrition to sustain your dog.

Just looking at the label isn't enough, she said.

"There’s information that’s important to consider that’s not on the label, like contacting the company and finding out the credentials of people formulating the diets," Shepherd suggests. "Do they have formal training in vet nutrition? Do they have formal training in food science and manufacturing food?"

Shepherd notes that there's also been less research done around plant-based diets so the effects on dogs aren't widely known yet. She suggests consulting with your vet before switching your dog to a plant-based diet, as nutritional requirements vary from dog to dog.

"Plant-based diets are generally going to have a lower digestibility just because of the inherent high fiber nature of the diet and so it’s just important to make sure that both enough protein as well as all the essential amino acids are included," Shepherd says. "One amino acid in particular that is of concern with vegetarian diets is methionine."

Other important nutrients to consider when picking food for your dog are omega-3 fatty acids, vitamin B12 (cobalamin) and fat-soluble vitamins, specifically vitamin A and vitamin D. Shepherd says while these nutrients can be found in plant-based diets, they're generally easier to find in meat diets.

She also notes that while plant-based sources may be rich in certain nutrients that doesn't necessarily mean your dog will be able to digest those nutrients.

"While it’s important that pet owners feel comfortable with what they're feeding them, it’s important to keep in mind that dogs aren’t tiny humans and they have different requirements," Shepherd says.