What Should Vegetarians and Vegans Feed Their Pets?

Source: Photo by Александр Ермолаев /123RF

I was once accused of picking up unwanted kittens from my local animal shelter and feeding them to my son’s baby boa constrictor. The charge, of course, was preposterous. But as I wrote in a commentary in The American Psychologist, it got me thinking about ethical implications of what we feed our pets.

Take, for example, the relative moral calculus of having a pet cat versus a pet snake. Most authorities agree that cats are “obligate carnivores” that need to consume some animal flesh to thrive. Even dried cat food contains processed meat. If my cat Tilly eats only three ounces of meat a day, she will consume 70 pounds of flesh over the course of a year. By comparison, Sam, my son’s boa constrictor ate only one mouse a week. As the average mouse weighs only half an ounce, this translates into slightly less than two pounds of mouse meat a year. Hence the moral burden of owning a cat is roughly 30 times greater than that of living with a pet snake.

The Vegetarians Dilemma

I don’t have any angst about living with a cat, but my vegan friend Lisa who owns two cats does. She is not alone. The psychologist Hank Rothgerber found that morally motivated vegetarians and vegans who owned pets, particularly cats, often feel guilty about the diets of their companion animals. He calls the conflict that comes with loving a pet that eats meat “the vegetarian's dilemma.”

Lisa, of course, would love to feed her pets a vegan diet. But even though meatless cat and dog foods are available (see here), she is not convinced her pets would thrive if they did not consume some animal protein. A recent study in the journal PLOS One (full text here) explored the degree to which pet owners like Lisa try to resolve the vegetarian’s dilemma by feeding their companion animals plant-based diets.

A team of researchers from the University of Guelph in Canada surveyed 3,673 dog and cat owners about their pets' diets. They recruited the participants through social media sites for animal enthusiasts and pet owners and breeders. As is usually the case with surveys of pet owners, most of the respondents were women, and the bulk of them was from the United States, the UK, Australia, and New Zealand. The researchers were primarily interested in the pet-feeding practices and preferences of omnivores, vegetarians, and vegans. Eighty-four percent of the participants were omnivores, 5.8 percent were vegans, 6.2 percent were vegetarians, and 4 percent ate fish but no other meat (pescatarians).

What Do People Feed Their Pets?

Source: Graph by Hal Herzog

The researchers obtained information on the diets of 2,940 dogs and 1,542 cats. Ninety-seven percent of the dogs and 99 percent of the cats ate food that contained some form of meat. As you can see in this graph, all the omnivores and pescatarians and nearly all of the vegetarians fed meat-based foods to their pets. Conversely, 10 percent of the vegan cat owners and 30 percent of vegan dog owners raised their companion animals on completely plant-based pet foods. (With the exception of one vegetarian, only vegans in the sample maintained their pets on completely meatless diets.)

What Would People Prefer to Feed Their Pets?

Source: Graph by Hal Herzog

The researchers asked owners what they would prefer to feed their pets if there were healthy alternatives to meat-based dog and cat foods. Three-fourths of vegan pet owners were enthusiastic about plant-based pet foods compared to half of the vegetarians in the study. While a third of the vegans said they presently fed their pets exclusively on plant-based food, 78% of them indicated they would shift their dogs and cats to a vegan diet if they were convinced it would meet their dietary needs. (Not surprisingly, only 20 percent of omnivores said they would like their pets to become vegans.)

Concerns About Meat-Based Pet Food

Source: Graph by Hal Herzog

The participants were also asked about their concerns with both vegan and meat-based pet foods. Among all the participants, the most common concern about meat-based pet food was farm animal welfare (39 percent of participants). Naturally, more vegans and vegetarians were concerned about feeding their pets meat-based food than were omnivores. Indeed, most of the omnivores did not have any concerns about feeding pets meat-based foods, while the vegans had more concerns about meat-based diets than either vegetarians or the omnivores.

Concerns About Vegan Pet Food

Source: Graph by Hal Herzog

Ninety-one percent of the participants had at least one concern about plant-based pet foods. While most vegan pet owners did not have concerns about plant-based pet foods, the other groups did. For example, 70 percent of vegetarians and omnivores were concerned that it was unnatural for dogs and cats to live on a vegan diet. And over half of them thought a vegan diet would be unhealthy for their pets. As you would expect, cat owners were more concerned about vegan pet foods than were dog owners.

Is There a Future for Vegan Pet Food?

The researchers concluded that even if a nutritionally viable plant-based option were available, most dog and cat owners would not make their pets go vegan. However, they point out that there is a potentially large market for plant-based pet chow. For example, as many as 20 million vegetarian and vegan pet owners live in the U.S. If the results of this study apply broadly, and if the health concerns about meat-less pet food can be alleviated, this means that roughly 10 million American dog and cat owners might be interested in giving vegan pet chow a try.

Stay tuned.