Cats thrive on vegan diet in peer-reviewed study

A new study has suggested cats fed a plant-based diet are less likely to suffer from a range of adverse health consequences, including gastrointestinal and hepatic disease.

Published in BMC Veterinary Research, the study – conducted by Ontario Veterinary College, at the University of Guelph in Canada – also reported cats fed a plant‑based diet had more ideal body condition scores than their carnivorous counterparts.

The study was based on 1,325 owner questionnaires – and while most cats were fed a meat-based diet, almost 20% received entirely plant‑based food.

Cats ranged from 4 months to 23 years old – and in their conclusions researchers reported no differences in lifespan between diet types, and that more owners of cats fed plant‑based diets reported their cat to be in very good health.

Important contribution

The results have been welcomed by Andrew Knight – European and RCVS specialist in animal welfare science, ethics and law, and a long‑time advocate for plant‑based pet food.

He said: “The veterinary profession has generally held the view that cats in particular cannot thrive on a vegan diet. Many worry about feline inability to adequately digest plant-based ingredients, or similar factors.

“However, evidence to support such concerns is lacking. In any case, the gold standard is always the effects on the animal itself.

“This recent study is limited by its reliance on owner opinions, but it is nevertheless a very large-scale study and makes an important contribution to this field. It adds to limited smaller studies which utilised veterinary examinations and blood results.

“The combined results of this growing evidence base indicate that cats and dogs maintained on nutritionally sound vegan diets suffer no adverse health consequences, and may experience certain benefits, such as reduced obesity, GI and hepatic disease in cats.”

Prof Knight said he believes this latest work and other studies in the area show that evidence is mounting for plant‑based diets to be considered a viable source of nutrition for both cats and dogs.

He added: “Recent searches indicate there are no studies showing contrary results – neither population studies, nor even a single case study.

“Hence, while acknowledging the limitations of studies to date, it is undeniable that the balance of evidence now supports the feeding of nutritionally sound vegan diets to both cats and dogs.

“This also makes sense nutritionally. Cats, dogs and all other species have requirements for specific nutrients. They have never needed any particular ingredient. People often mix up these two concepts.”

More research needed

However, the Pet Food Manufacturers’ Association (PFMA) believes there is still not enough evidence to suggest feeding cats a plant-based diet has any health benefits.

Sarah Hormozi, PFMA’s head of science and education, said: “At the PFMA we encourage research into pet food and diets as this contributes to the overall knowledge and better understanding of pet nutrition and health.

“Plant-based diets are still relatively new, the numbers of cats fed this way is relatively low and the historic-use information is limited. As a result, there is currently not enough evidence to suggest that feeding cats a plant-based diet has health benefits for them.”

She added: “Cats are obligate carnivores, and have very high requirements for proteins and certain amino acids that are mainly found in animal proteins. Feeding a solely plant-based diet to cats has, therefore, been subject to debate.

“A well-designed plant-based diet with added nutrients, that is complete to meet all the nutritional requirements of cats, has the potential to allow them to maintain health. However, a wealth of animal nutrition expertise is required to formulate and deliver such products.

“For this reason, we advise owners to think very carefully before choosing a plant-based diet for their cats, consult a veterinary nutritionist, and source the food from reputable manufacturers.

“The PFMA’s fact sheet on vegetarian and vegan diets is a useful resource for vets to use in practice to inform pet owners.”