There has been a 360% spike in vegans in the UK since 2006, as people are swayed by the pros of a lifestyle free from all animal products. This year alone, 150,000 people signed up for the Veganuary challenge to give the diet a go for the whole of January.
But as us humans ditch the steak for the tofu, we might start to feel a little uncomfortable with scraping meat out a tin and slapping it in our pet's bowl.
So, can a pet owner feed their animal a plant-based diet without it harming their health? Or would it see those concerned by animal welfare actually harming their pets?
It depends on whether the animal is a carnivore, herbivore or an omnivore. Most rodents are herbivorous, including hamsters, mice and guinea pigs, but rats are omnivorous.
Dogs are also omnivores and can eat a wide variety of food types, RSPCA spokesperson Ginny Read told IBTimes UK.
"They can survive on a vegetarian diet as long as the diet is well-balanced," said Ginny Reid.
"If an owner is considering switching their dog's diet to a vegetarian option, they should consult with their vet to make sure that it will meet all their pet's nutritional needs, which will depend on many factors such as age, health and lifestyle," she added.
"We would not recommend feeding a dog a vegan diet," Gudrun Ravetz, the senior vice president British Veterinary Association, told IBTimes UK. "Owners would need to take expert advice to avoid dietary deficiencies and associated disease, as it is much easier to get the balance of nutrients wrong than to get it right. A dog on a vegan diet may also need synthetic supplementation."
Cats, meanwhile, are strict carnivores and need very specific nutrients to stay healthy and survive. These include taurine, vitamin A and arachidonic acid. "They can become seriously ill if they are fed a vegetarian or vegan diet," warned Read.
"It is important to remember that meat contains vital vitamins and nutrients needed by your cat or dog," chimed Ravetz.
Pet owners concerned about the welfare of the farm animals used in pet food can check if it has an ethical sourcing policy, added Read.
But some vegans aren't entirely comfortable with this and will to keep pets with diets like their own. Tap "pets that are herbivores" into Google, and dozens of articles appear listing the pets that match their ethics with headlines including: "Top 10 Pets for Vegan Households".