A new life cycle assessment of 31 dry dog foods in the UK reveals that plant-based diets consistently outperform meat-based alternatives across every major environmental measure. Conducted by University of Nottingham veterinary researchers Rebecca Brociek and Professor David Gardner, and published in Frontiers in Sustainable Food Systems, the study underscores a major opportunity for pet owners and the pet food industry to shrink their ecological “pawprint.”
Key Results
- Greenhouse gas emissions: Plant-based foods produced just 2.82 kg CO₂-eq per 1,000 kcal, compared to 31.47 kg for beef-based formulas – over ten times higher.
- Land use: Plant-based diets required 2.73 m² per 1,000 kcal, versus 102.15 m² for beef-based products.
- Water use: Plant-based options consumed 249 L of freshwater per 1,000 kcal, far less than beef (575 L) or lamb (684 L).
- Nutrient and acidification pollution: Beef-based diets generated 14-16 times more acidifying and eutrophying emissions respectively, than plant-based equivalents.
- Middle ground: Poultry-based and semi-synthetic veterinary formulas had lower impacts than red meat, but still much higher than plant-based foods.
Over a typical nine-year lifespan, feeding a 20 kg Labrador exclusively on plant-based dry food would require 8,964 m² of land and emit greenhouse gases equal to 2.8 London-New York return flights. The same dog fed on beef-based food would need 334,851 m² of land and emit the equivalent of 31.3 such flights.
Why It Matters
With pet ownership on the rise worldwide and demand for pet foods increasing, the environmental impact of animal-based ingredients can no longer be overlooked. The researchers conclude that increasing plant-based ingredients in pet diets provides a practical and scalable way to reduce land use, emissions, nutrient pollution, and water stress – without compromising caloric value.
They note, “feeding your dog plant-based will significantly improve a households’ environmentally sustainability”, and that, “… lower-impact pet food ingredients will be essential in reducing the [pet food] sector’s ecological paw print.”
While some suggest that using meat by-products like ‘meat meals’ is more sustainable, the study found these often ranked among the highest-impact ingredients, failing to bridge the gap.
Broader Context
This work supports earlier research. In 2023, veterinary professor Andrew Knight demonstrated that switching pet dogs worldwide to nutritionally sound vegan diets could save greenhouse gas emissions equivalent to 1.5 times the UK’s annual output, while providing enough food energy to feed 450 million people, equivalent to the EU population. By late 2025, at least 11 peer-reviewed studies had also shown positive health outcomes for dogs fed plant-based diets.
As Prof. Knight explained, “Higher proportions of plant-based ingredients, or nutritionally complete plant-based diets, can substantially reduce the ecological footprints of companion animals. As awareness grows, such diets may shift from niche to mainstream – aligning our care for pets with responsibility for the planet.”
Contact Information
Andrew Knight
Veterinary Professor of Animal Welfare
andrew.knight@murdoch.edu.au
+44 7577 899 61
SOURCE: Sustainable Pet Food Foundation