Should Fluffy and Fido go vegan?

A new study says yes — for the environment.

The United Nations Food and Agriculture Organization estimates that livestock are responsible for 14.5% of the greenhouse gas emissions. In response, some experts say eating vegan — meaning a nutritionally sound diet without animal proteins or products — for two-thirds of meals could slash food-related emissions by 60%.

“Vegan pet food is clearly associated with very large savings in greenhouse gas emissions, land and water use, and a range of other environmental parameters,” said Dr. Andrew Knight, a professor of philosophy at Griffith University in Australia, who led the new study. “If implemented globally, such diets would also save the lives of billions of ‘food’ animals annually, and enable the feeding of billions of additional people (and dogs and cats), with the food energy saved.”

The new study said American dogs and cats consume about one-fifth as much meat as their human counterparts and about one-tenth of that worldwide.

Recent research suggests that nutritionally sound vegan diets — lacking meat, eggs and dairy — are safe for pets and may have comparable health benefits, the study noted.

If all U.S.-based dogs and cats went vegan, researchers estimated that the lives of 2 billion livestock animals a year could be saved, along with billions of aquatic animals.

If pets around the world stopped eating meat, around 7 billion livestock animals a year would be spared from slaughter, according to the study.

Knight also estimated that switching pets to plant-based foods could also lead to significant reductions in land and water use, greenhouse gas emissions, use of biocides, and emissions of other pollutants.

For scale, the study said that dogs going vegan could free up an area of land equivalent in size to Saudi Arabia or Mexico; cats, the size of Japan or Germany; and humans, all of Russia and India combined.

It estimated that an all-vegan dog diet could result in a reduction of greenhouse gas emissions greater than the amount from the United Kingdom, and for cats, from Israel.

For the research, Knight used U.S. pet population data from 2020, and 2018 data for the worldwide estimates. Other numbers were derived from prior studies and government databases.

Dr. Joseph Wakshlag, a professor of nutrition and sports medicine at Cornell University’s College of Veterinary Medicine in Ithaca, N.Y., reviewed the findings.

Asked if he would change his pets’ diets given the study’s findings, the answer was a firm “no.”

“Why would you? The whole rest of the world isn’t changing their diets and doing anything about sustainability,” he said.

“What would be the difference based on the recommendation from an epidemiologic, utopian society point of view when there are so many other things that are contributing to the sustainability crisis that are so much more egregious?” Wakshlag continued. “As soon as we start changing the human patterns, then we can change the dog and cat patterns.”

Still, about 17% of Americans say they are “alarmed” about climate change. About 5% are vegetarian and 3% are vegan, according to a 2019 Gallup poll. Researchers have estimated that vegans are responsible for 75% less in greenhouse gases than their meat-eating counterparts.

So if people did want to feel like they were moving the needle even slightly, they might consider switching both their own and their pets’ diets over to plant-based foods.

For fur baby food, Knight said care is needed.

“To safeguard health, it is important that people feed only commercial diets labeled as nutritionally complete, produced by reputable companies with good standards,” he said.

The findings were published online Oct. 4 in the journal PLOS ONE.

More information

For more on livestock’s contribution to climate change, visit the World Resources Institute.

SOURCES: Joseph Wakshlag, DVM, PhD, professor, clinical nutrition, sports medicine and rehabilitation, and section chief, nutrition, Cornell University College of Veterinary Medicine, Ithaca, N.Y.; Andrew Knight, DPhil, veterinary professor of animal welfare, adjunct professor, School of Environment and Science, Griffith University, Queensland, Australia; PLOS One, Oct. 4, 2023, online