Pet owners may be more keen in having a vegan diet for their cats or dogs than we thought, according to a study out of the University of Guelph.

University of Guelph's Ontario Veterinary College (OVC) surveyed more than 3,600 dog and cat owners from around the world, asking them about what kinds of foods they eat and what foods they feed their pets.

Researchers found a "surprising" number of pet owners, particularly those who are already vegan, that are interested in switching to a plant-based diet for their pets.

Lead researcher Sarah Dodd, a PhD candidate at OVC's department of population medicine, said about six per cent of those surveyed said they were vegan, with more than a quarter of them stating they already feed their pets a plant-based diet.

"It's a significant number of animals when you look at the number of individuals and considering how new and niche these diets are. I think that's quite a large number," Dodd told CBC News.

More surprising to Dodd, was the number of non-vegans who said they would be interested in a plant-based diets for their pets. More than a third said they would make the switch, she said.

Dodd said if vegan or plant-based diets were affordable, accessible and met their pet's nutrition and dietary needs, 35 per cent of those surveyed said they would make the switch and of those people, 55 per cent said there were some stipulations, such as the food had to be affordable, accessible and met their pet's nutritional and dietary needs.

'Weird problems'

It is much easier and possible to implement a vegetarian or vegan diet in dogs than cats, according to Ted Morris, a veterinarian with Bloor Animal Hospital in Toronto.

Cats are obligate carnivores, which means they have to get certain nutrients from animal protein, whereas dogs don't share that restriction

"It's really challenging to create a balanced vegan diet for cats," Morris said.

For cats, not accessing those nutrients can cause heart diseases, problems with eye function and affect the PH in their urine.

Dogs, on the other hand, can get those nutrients from plant sources, as long as they are balanced. Morris did note that there have been cases of dogs experiencing heart disease when on grain-free diets, however.

"The more things people experiment with, the more weird problems pop up," he said.

More research needed

Though her research didn't delve into whether or not vegan diet for pets are increasing, she said she wouldn't be surprised if it did become a trend.

"As we start to consider diet and nutrition being crucial for our own health, we then start to implement those things as well to our pets," Dodd said.

There is not a lot of research that looks at the health implications of vegan and vegetable-based diets in cats and dogs, she adds, though it is a field that her team will be looking into.

"This is a thing and we ought to be looking at how does this affect animals and can this be done in a healthy manner for them?" she said.

Dodd said if pet owners are serious about making the switch, they should talk to their vets about it.

Morris seconded that, adding that it's also better if you make the vegan or vegetarian diets for your pets yourself, as some store-made vegan diets are not balanced.