Vegan diets are healthier and safer for dogs than conventional meat-based diets, according to the largest study of its kind, provided they are nutritionally complete. The peer-reviewed research, published in the journal Plos One, analysed data from over 2,500 dogs over a year, assessing seven general health indicators and 22 common illnesses.
The study found that almost half of dogs fed conventional meat diets required non-routine medication, compared to only a third of those on vegan diets. Additionally, 17% of dogs on conventional diets visited the vet four or more times annually, versus 9% for vegan-fed dogs and 8% for those fed raw meat. Dogs on raw meat diets appeared marginally healthier overall, but they were also on average a year younger, which may have contributed to their better health outcomes.
Professor Andrew Knight of the University of Winchester, who led the study, said: 'Our study is by far the largest published to date. It revealed that the healthiest and least hazardous dietary choices for dogs are nutritionally sound vegan diets.' He noted that raw meat diets are often contaminated with pathogenic bacteria and parasites, as shown in prior studies.
The findings come amid growing concerns about the environmental and ethical impacts of meat consumption. The global vegan pet food market reached $9bn (£6.9bn) in 2020 and is expanding rapidly. However, the British Veterinary Association's president, Justine Shotton, urged caution: 'Although we would not recommend it, it is theoretically possible to feed a dog a vegetarian diet, but owners would need to take expert veterinary advice to avoid dietary deficiencies.'
Further research is needed to confirm the long-term effects, as the study relied on owner-reported surveys. Professor Knight acknowledged the limitation, stating the study reflects 'what real dogs in normal homes ate' rather than controlled conditions. The majority of respondents were from the UK and other European countries, with over 90% being women.
