With increasing awareness of companion animals’ ecological footprint, some guardians are exploring plant-based diets for the animals who are part of their family. However, many guardians are afraid that plant-based companion animal diets may be nutritionally incomplete. This paper set out to address this fear through a large-scale study of the effect of dietary choice on dogs’ health. 

Among the 2,500 responses to the survey, roughly half of dogs were fed a conventional diet, a third were fed a raw meat diet, 13% were fed a vegan diet and the rest were fed specialized diets. Survey respondents provided information on seven general indicators of their dogs’ health and whether their dogs had 22 specific disorders, such as allergies, dental issues, and skin conditions.

According to the study, dogs on conventional diets had poorer health than those on raw meat or vegan diets. Dogs fed vegan diets were less likely to have seen a veterinarian in the last year and to be taking medication. They were also less likely to have diagnosed disorders. Guardians who fed their dogs vegan diets were more likely to believe that their dogs were healthy. They were also more likely to believe that veterinarians would think that their dogs were healthy. However, dogs fed vegan diets were not very different from dogs fed conventional diets on any of the health indicators, so there wasn’t a large effect. 

Some disorders were more common in some dietary groups than others, although no clear pattern was established. Very few dogs on any specific diet had any particular disease, so even if a real difference existed, the study might not have been able to detect it. 

Finally, dogs fed a raw meat diet had marginally better health indicators than dogs on a vegan diet. However, dogs fed raw meat were also younger on average, so they could have been healthier simply because they were younger. 

Nutritionally sound vegan diets may be healthier for dogs than conventional diets, although the effect is very small. However, because the study was correlational, it can’t prove causality. Perhaps guardians who have sickly dogs are less likely to try a vegan diet. Future research should explore the effects of a vegan diet on dogs over time and control for other factors, such as the dogs’ characteristics and the perception of health by guardians.