Vegan diets are just as healthy for cats and dogs as meat-based animal feed, according to research that will further spark a controversy over whether owners should feed their pets plant-based foods.

Andrew Knight, a veterinary professor at the University of Winchester, said his research showed that cats and dogs had better or better health outcomes on plant-based diets, as they did when fed meat-based animal foods, provided they had been carefully formulated additional synthetic nutrients.

Knight’s findings came after warnings that pet owners could be in breach of the Animal Welfare Act 2006 if they do not eat a “proper diet” that meets their dog’s nutritional needs – a 20 20,000 fine or a fine of me 20,000. 51 weeks in prison.

Although the act does not define vegan or vegetarian foods as inappropriate, Justine Shotton, president of the British Veterinary Association, said: “We would not recommend feeding a dog on a vegan diet as it is much easier to get the nutritional balance of wrong than you properly understand, leading to the risk of dietary deficiencies and comorbidities. ”

She added that any changes in pet diets “should only be undertaken under the advice of a veterinarian with in-depth nutritional knowledge” and that people had a “duty to care for their pet”, including ensuring a proper diet.

The head of veterinary services at the Blue Cross charity also advised not to feed pets vegan food. “Pets need a balanced diet, cats in particular have very specific nutritional needs which are unlikely to be met by a vegan diet,” she said.

The unpublished findings of Knight’s research are part of a larger study that found that plant-based pet food was at the same time equivalent to meat-containing products, as well as satisfying for pets to eat.

“Dogs, cats and other species have nutrient requirements, they do not need meat or any other special ingredients. They need the group of nutrients, and provided they are supplied with a fairly tasty diet, “As much as they are motivated to eat it and digest it, we would expect them to thrive. And that’s what the evidence seems to show,” Knight said. “The claim is that animals on vegan diets will necessarily get sick and it is somewhat cruel to keep them, it is contrary to the scientific evidence in this area and it is ignorant.”

Cats are carnivores and need some protein in their diet, such as taurine. However, Knight said these were usually degraded into highly processed pet food and had to be added back to the feed synthetically.

He added that it was easier to turn dogs into plant-based diets, as they were ubiquitous — the result of evolving alongside humans and eating chunks of food cooked during prehistoric times.

Guy Sandelowsky, a veterinarian and founder of the vegan dog food company Omni, said his products, which typically included sweet potatoes, brown rice and squash, contained 30% more protein than most meat-based diets and were carefully formulated to meet all of the dog’s nutritional needs. “It’s totally ridiculous to make a comprehensive statement about plant-based diets,” he said. “When people do the food themselves they run into problems.”

According to market research firm Mintel, 34% of dog owners are interested in regularly feeding their dogs plant-based foods. Sandelowsky said this reflects a growing interest in sustainable living, as according to a UCLA study, animal feed generated about 25% of the environmental damage associated with the meat industry, equivalent to 64 million tonnes of carbon dioxide per year, or that had the same climatic impact as a year-long drive of 13.6 million cars.

He added that the option entered into a growing trend towards treating pets as children, including encouraging them to eat better quality food, and reflected concerns about the link between processed meat and cancer and obesity in humans.

Elisa Allen, director of People for Ethical Animal Treatment, said consumers were increasingly concerned about eating meat-based animals because they contained “very much the same hormones, pesticides and antibiotics found in commercial meat products for humans.” -along with animal parts. are considered unfit for human consumption ”.