A new study published in the journal Animals reveals that dogs, on average, consume more farmed animals annually than humans – approximately 13 terrestrial animals per dog compared to nine per person globally. The research, conducted by veterinary professor Andrew Knight of Griffith University, suggests a shift towards sustainable and nutritionally balanced canine diets could significantly reduce greenhouse gas emissions, animal slaughter, and pressure on global food resources.
The study highlights the environmental costs associated with meat-rich, egg-based, and dairy-inclusive diets. However, it posits that altering canine diets may yield a greater positive impact than modifying human consumption patterns. The discrepancy stems from a larger proportion of a typical dog’s dietary energy – around 34 percent – deriving from animal-based ingredients, compared to approximately 19 percent for humans.
These figures represent global averages, with consumption varying by country. In high-income nations like the United States, overall consumption is higher. In the U.S., the average person consumes 24 farmed terrestrial animals annually, although a dog consumes 20, representing a smaller difference of around 20 percent.
Traditional meat-based pet foods, have a substantial impact on both the environment and animal welfare. Increasingly, alternatives based on plant proteins, microbial proteins, and cultivated meat are becoming available. Fully vegetarian or vegan pet foods are readily accessible online in many countries. As of early 2026, 14 studies and a systematic review have reported positive health outcomes in dogs and cats fed these types of diets, though responsible manufacturers must fully supplement these diets to ensure complete nutritional profiles.
The potential benefits of widespread adoption are considerable. If all domestic dogs were transitioned to nutritionally adequate vegan diets, the study estimates that six billion farmed terrestrial animals could be spared each year. The resulting reduction in greenhouse gas emissions would equate to 1.5 times the annual emissions of the United Kingdom, and the conserved food energy could feed 450 million people – the population of the European Union. These calculations are based on 2018 data, and given the faster growth rate of the canine population compared to the human population, the potential benefits are even greater today.
Professor Knight estimated that at least 150 million dogs and cats could realistically be transitioned to nutritionally appropriate vegan diets, based on survey responses from thousands of pet caregivers. He noted, however, that this analysis assumed only one dog or cat per household, suggesting the actual number could be significantly higher.
The study evaluated sustainable pet diets using principles of effective altruism, a philosophical approach prioritizing issues based on their scale, neglect, and tractability, aiming to maximize benefits. The analysis concluded that sustainable pet diets are significantly neglected, with only two full-time researchers worldwide outside of animal feed companies and less than one percent of the annual budget of the farmed animal advocacy movement dedicated to this area.
Knight concluded that plant-based diets for pets represent a powerful, yet largely overlooked, means of reducing the use of farmed animals, improving food security, and addressing climate and biodiversity challenges. He urged environmental and animal advocates to move beyond a focus solely on human diets, stating, “It’s ironic that the animal advocacy movement has largely overlooked the diet of its own companion animals.”
