Vegan Cats Are Healthier, Finds Largest Study to Date

Health outcomes in 1,369 cats fed vegan or meat-based diets

Seven general indicators of illness were studies, as well as 22 of the most common feline health disorders.

Cats are carnivores, or so we thought. However, a major new study has found that cats are healthier, when fed vegan diets. The study, just published in leading scientific journal PLOS ONE, is the largest such study to date. It resulted from an international collaboration led by veterinary Professor Andrew Knight (UK) and co-authored by statisticians Dr Alexander Bauer (Germany) and Hazel Brown (UK). It studied 1,369 cats fed vegan or meat-based pet food, for at least one year. Cats fed vegan diets had better health outcomes for each of seven general health indicators studied. 

First, differences between diet groups in age, sex, neutering (desexing) status and primary location (outdoor vs. indoor) were all controlled for statistically. Next, risk reductions were calculated for cats of average age and characteristics. For average cats fed vegan diets, risk reductions were:

  • increased veterinary visits (possibly indicating illness) - 7% reduction
  • medication use - 15% reduction
  • progression onto a medical diet (after being fed a vegan or meat-based diet) - 55% reduction
  • reported veterinary assessment of being unwell - 4% reduction
  • reported veterinary assessment of more severe illness - 8% reduction
  • pet guardian opinion of more severe illness - 23% reduction.
  • Additionally, the number of health disorders per unwell cat decreased by 16%.

No reductions were statistically significant, but collectively they reveal a strong trend. Additionally, the prevalence of 22 of the most common feline health disorders was studied. Forty two percent of cats fed meat, and 37% of those fed vegan diets suffered from at least one health disorder. 15 disorders were most common in cats fed meat, and seven most common in cats fed vegan diets.

Veterinary Professor of Animal Welfare Andrew Knight, the study leader, stated: 

"For every single general health indicator studied, these cats had better health outcomes when fed vegan diets. This represents a strong and consistent trend. It indicates that pet food manufacturers are now designing and creating vegan pet foods to include all necessary nutrients, but with fewer of the dietary hazards that are prevalent within meat-based pet foods. Cats consuming vegan diets have better health outcomes, as a result." 

These results concur with those of other, recent studies. In 2021, leading veterinary nutritionist Dr Sarah Dodd and colleagues published a study of 1,026 cats, of whom 187 were fed vegan diets. Cats fed vegan diets were more frequently reported by their guardians to be in very good health. They had more ideal body condition scores, and were less likely to suffer from gastrointestinal and liver disorders, than cats fed meat. No health disorders were more likely, for cats fed vegan diets. These studies are available via > health. 

Prof. Knight stated:

"This offers exciting potential to improve not only feline health, but also to address the very significant environmental impacts of the livestock sector created through pet food production. However, to safeguard the health of our feline friends, it is important that pet guardians feed only commercial vegan pet foods labelled as nutritionally complete, produced by reputable companies with good standards."


- link to the study, which will go live upon publication:


Andrew Knight
Veterinary Professor of Animal Welfare
- Adjunct Professor, School of Environment and Science, Griffith University, Queensland, Australia
- Visiting Lecturer, University of Winchester, UK
- EBVS® European & RCVS Veterinary Specialist in Animal Welfare Science, Ethics and Law; American Veterinary Specialist in Animal Welfare
- Fellow, Royal College of Veterinary Surgeons, & Member, Australian and New Zealand College of Veterinary Scientists (Animal Welfare chapter)
Southampton, UK


Contact Information:
Andrew Knight
Veterinary Professor of Animal Welfare

Original Source: Vegan Cats Are Healthier, Finds Largest Study to Date