An analysis of commercially available dry dog foods in the UK has revealed that plant-based formulations generate lower environmental impacts compared to meat-based alternatives, according to research published in Frontiers in Nutrition-Nutrition and Sustainable Diets.
The University of Nottingham study examined 31 dry dog foods across five categories: plant-based, poultry-based, beef-based, lamb-based and veterinary renal diets. Researchers found that plant-based options consistently required fewer resources and produced lower emissions across all measured environmental metrics.
According to the study, the environmental differences proved substantial when scaled to real-world feeding scenarios. Per 1,000 kilocalories of dry food produced, beef-based diets required an estimated 102.15 square meters of land compared to just 2.73 square meters for plant-based alternatives. Greenhouse gas emissions followed similar patterns, with beef-based foods generating 31.47 kilograms of CO2 equivalent versus 2.82 kilograms for plant-based options.
"Plant-based diets had the lowest impact across all measures of environmental impact," the study reported. "Beef-based foods generated 7.1-fold higher acidifying emissions and 16.4-fold higher eutrophying emissions, compared to plant-based foods."
Calculating canine lifetime environmental impacts
The researchers calculated lifetime environmental impacts for a typical 20-kilogram (44-pound) Labrador Retriever over nine years. The analysis showed feeding exclusively plant-based food would require approximately 8,964 square meters of land, equivalent to about 1.4 football fields. In contrast, beef-based diets would demand 334,851 square meters, roughly 52 football fields worth of land.
Poultry-based and veterinary diets fell between these but remained substantially more resource-intensive than plant-based alternatives. Lamb-based foods showed the highest environmental impact, requiring 365,409 square meters of land over the dog's lifetime.
The study methodology employed life cycle assessment datasets to evaluate environmental metrics including land use, greenhouse gas emissions, acidifying emissions, eutrophying emissions and freshwater withdrawal. Researchers adjusted calculations for ingredient composition, energy density and moisture content differences across the 31 commercial products analyzed.
The analysis focused exclusively on adult dog food formulations, representing the largest segment of the UK dry dog food market where 50% to 70% of pet owners choose kibble either alone or mixed with wet food.
The research noted that bioavailability and nutritional adequacy assessments fell outside the study's scope, with environmental impact serving as the primary evaluation criterion.
