Cutting down on meat consumption helps reduce greenhouse gas emissions linked to agriculture. But what about the meat consumed by our pet dogs?
Our new study shows that feeding dogs can have a larger negative environmental impact than the diets of their owners. For a collie- or English springer spaniel-sized dog weighing around 20kg, 40 per cent of the dog foods tested had a higher climate impact than a human vegan diet, while 10 per cent exceeded the emissions of a high-meat human diet.
Dog food makes up a significant share of the global food system. We estimate that producing ingredients for dog food contributes around 0.9–1.3 per cent of the UK’s total greenhouse gas emissions. Globally, producing enough food for all dogs could generate emissions equivalent to 59–99 per cent of those from burning jet fuel in commercial aviation.
The type of animal product used in pet food is crucial. The environmental footprint varies significantly depending on whether foods use prime cuts or by-products such as offal and trimmings.
Prime cuts like chicken breast or beef mince are commonly eaten by humans and are used in some dog foods. These cuts account for about 93–98 per cent of the economic value of an animal carcass. By contrast, by-products are cheaper, less popular for human consumption, but still highly nutritious, and are widely used in pet food.
In our analysis, we assign more of an animal’s environmental footprint to high-value cuts and less to by-products. Some earlier studies assigned equal environmental impacts by weight to all cuts, effectively double-counting livestock emissions and overestimating the footprint of pet food.
A major challenge for pet owners and researchers is the lack of transparency in labelling. Terms such as “meat and animal derivatives” allow flexibility for manufacturers but make it difficult to identify whether foods rely on prime meat or by-products. Ingredients like “chicken” may refer to fresh meat, dehydrated offcuts, or a mix of both.
To address this, we used mathematical models to estimate ingredient composition based on nutritional content and ingredient lists. After running 1,000 simulations with adjusted assumptions, one result remained consistent: higher proportions of prime meat led to significantly higher environmental impacts.
Improved labelling, such as specifying the proportion of prime meat versus by-products – would allow consumers to make informed, climate-conscious choices and enable better scrutiny of sustainability claims.
Food format also matters. Wet and raw foods generally had higher environmental footprints than dry kibble, partly due to greater emissions from packaging, refrigeration, and transportation. Grain-free diets also tended to have a higher carbon footprint.
While some plant-based dog foods showed slightly lower emissions than average meat-based options, the biggest environmental differences were driven by food type (wet or raw versus dry) and ingredient composition rather than meat versus plant protein alone.
Overall, dog foods showed more than 65-fold variation in environmental impact, which is far greater than the 2.5-fold difference between vegan and high-meat human diets. This highlights the enormous potential to reduce the carbon footprint of pet food through better ingredient choices and clearer labelling, while still ensuring dogs remain healthy and well nourished.
