In the largest study yet to examine the environmental footprint of dog food, scientists found that certain pet diets were linked to far higher greenhouse gas emissions than dry kibble or even meat-heavy human meals.
Researchers estimate that the production of ingredients used in British dog food accounts for around 1 per cent of the UK’s total greenhouse gas emissions.
John Harvey, principal investigator of the study at the University of Edinburgh’s Royal (Dick) School of Veterinary Studies, said the results showed a striking disparity between different types of dog food.
“Our findings reveal that the environmental footprint of dog food is both significant and highly variable,” he said.
The study found that the highest-impact diets, including wet and raw foods rich in meat, were responsible for up to 13,000kg of carbon dioxide emissions per year for a 20kg dog. By comparison, the lowest-impact diets, such as dry kibble, produced as little as 178kg of CO₂ annually.
For context, researchers estimated that a human consuming a meat-rich diet generates about 2,624kg of CO₂ per year, while a vegan diet produces around 1,055kg.
“The dog diets with the biggest impacts are those that rely heavily on prime cuts of beef,” Harvey said. “Most people do not get such a large proportion of their nutrition from beef, and even high meat consumers typically eat a wider range of foods.”
The research analysed ingredient labels from almost 1,000 dog food products sold in the UK. Using emissions data published in the journal Climatic Change, the team calculated the carbon footprint of dry, wet and raw foods, including grain-free and plant-based options.
The researchers warned that if feeding patterns seen in the UK were replicated for dogs worldwide, the resulting emissions would be equivalent to more than six months of global jet fuel consumption from commercial aviation.
Dr Rob Williams, president of the British Veterinary Association, said the findings highlighted the environmental benefits of using animal by-products in pet food.
“Organ meat and other by-products may be less appealing to people but are perfectly safe and very nutritious for dogs,” he said. “Using them reduces waste in the food industry and generally has a much lower carbon footprint than pet food made with human-grade ingredients or some raw diets.”
Williams added that dry dog food typically has a smaller environmental impact because of the ingredients used and because it is easier to store and transport than wet or raw products.
