Straining to Rationalize Vegan Cat Food

By nature, cats are killers, not vegans. Veterinarians will tell you that they are obligate carnivores. Biologically, they require nutrients that come only from the flesh of other animals. But about 12% of pet owners are vegans or vegetarians. So some vegans in particular may find a dilemma in feeding cats meat-based products while they consume none of that because of personal convictions. Hence, there is a growing interest in vegan cat food.

This interest is understandable, based on personal values. But when we see authors of a new study in PLOS ONE straining to rationalize this choice, it’s puzzling. Is the rationalization really necessary?

An Unfounded Claim of Health Benefits

Quite clearly, Andrew Knight, Alexander Bauer, and Hazel Brown have a story to tell. They conclude in their new paper that “cats fed vegan diets tended to be healthier than cats fed meat-based diets.”

Unfortunately, though, their study does not support such a bold conclusion. For one thing, it is merely a survey of pet owners, who tell the researchers how healthy they think their cats are. Not only is it uncontrolled and purely observational, it has no objective data on the actual health of the cats.

There is no surprise in finding that cat owners who go to great lengths to feed their cats a vegan diet might believe their cats are enjoying extra health because of it.

But there is one surprise. The only statistically significant finding in all of the comparisons between cats on vegan diets and those on meat-based diets did not favor the vegan diets. It seems that owners were more likely to report kidney problems in cats receiving a vegan diet.

Certainly, given the observational nature of this study, this is not proof of a problem with the vegan diets. But even more certainly, this study offers no evidence for health benefits from vegan cat food. None.

We are having a hard time understanding why PLOS ONE editors saw sufficient merit in this study to publish it.

Evangelizing Nutrition

The only learning we take from this study is that the impulse to evangelize one’s own beliefs about nutrition is strong. So long as the pets will not be harmed by their diet, conjuring up health benefits for vegan cat food is not necessary. But it is misleading.

Virtue is its own reward.

Click here for the study in PLOS ONE and here for more on consumer beliefs and behaviors about vegan diets for their pets. For a sampling of the misleading reports that this misleading publication prompted, click here, here, and here.

Woman with a Cat, painting by Fernand Leger / WikiArt

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.

September 15, 2023