Community
Print
We are experiencing the sixth mass extinction since fossil records began. According to a recent UN report, “current national climate plans fall miles short of what’s needed.” To avoid the most devastating effects of rapid climate change, we must swiftly and significantly reduce emissions across all sectors, including food. Discussions of the role food plays in the climate crisis tend to focus solely on how humans can eat more sustainably, but what about companion animals? The environmental impact of pet food is significant, and warrants far greater prevalence in climate conversations.
The food sector – and the animal agriculture sector in particular – is a significant and neglected contributor to rapid climate change. Latest estimates indicate that the production of animal-based foods is responsible for at least 20 percent of anthropogenic GHG emissions (though some studies put this figure much higher). This is expected to increase as animal product consumption increases globally.
The environmental impact of pet food
In wealthy nations like the US, dogs and cats consume at least 20 percent of all farmed land animals. Given its relatively high consumption of animal-based ingredients, the pet food sector is associated with substantial environmental impacts. This poses a significant challenge for environmental sustainability. But it also represents a largely untapped opportunity to mitigate the “pawprints” of our dogs and cats.
In this article, we summarise the findings of our forthcoming study, one of the first comprehensive studies exploring the environmental impacts of pet food. We examine the impacts of meat-based pet food, and the benefits of a transition to more sustainable non-animal alternatives. We conclude that the most effective measure we can currently take to mitigate the environmental impacts of companion animal diets is to transition dogs and cats to nutritionally sound vegan pet foods.
It is now clear that the importance of dietary change to combat the climate crisis is not limited to humans: we must also address what we feed to our companion animals.
Companion animal diets
The global companion animal population is vast. Over 50 percent of households worldwide have a dog or a cat – the two species which make up 95 percent of pet food sales. Global dog and cat populations have recently been estimated as reaching 1 billion animals. Domestic dogs have a collective biomass of about 20 million tonnes, roughly equal to the combined biomass of all remaining wild terrestrial mammals. Cats have a total biomass of two million tonnes. Such large numbers of animals require a huge quantity of food resources.
What’s more, we can expect these numbers to increase significantly. As countries develop, people tend to have fewer children, and have more disposable income to spend on companion animals. We can see this in pet food sales trends: the global pet food ingredients market is expected to increase from USD $32.2 billion in 2022 to $44.5 billion in 2027.
From the food they eat, to the feces they produce, to accessories and services designed for them, there are a range of environmental impacts associated with caring for a dog or cat. However, the vast majority of these impacts come from pet food, and specifically the type of pet food (i.e. the ingredients) being fed.
In other words, when it comes to the environmental impact of pets, what matters most is: what are we feeding them?
What is the climate cost of meat-based pet food?
Most pet food consumed globally is meat-based, and this comes with significant environmental impacts. Just over half – 53.1 percent – of all ingredients in pet food are animal-based. These include human grade products such as meat, fish, dairy, and egg products, and non human-consumable products (also known as animal byproducts), predominantly meat and bone meal. Globally, 74.9 percent of animal-based ingredients are animal byproducts (largely used because they are cheap), whereas this number falls to 50.8 percent in the US, where wealthier consumers are more able to afford more premium diets using higher levels of human grade ingredients.
Perhaps unsurprisingly, such a reliance on animal-derived ingredients leads to significant environmental impacts. In the US, 25-30 percent of the environmental impacts of livestock production within the US have been attributed to companion animal diets.
While estimates on the impacts of meat-based pet food vary, all studies on this subject agree these cannot be ignored. One found that, in Japan, the environmental impacts of a medium dog’s diet were greater than that of the average Japanese person’s diet. For a large dog, they were greater than the average Japanese person’s entire environmental footprint.
This is undoubtedly a challenge for environmental sustainability. But it’s also an opportunity. Because the environmental impact of pet food is currently so high, there are significant opportunities to mitigate these impacts. In countries with high rates of companion animals, like the US, the benefits achieved by transitioning dogs away from meat-based diets is equivalent to one quarter to one third of the environmental benefits achievable through human dietary change.
Read more: Is 2025 The Year Of Ethical Dog Food?
What about animal byproducts?
Until recently, the environmental impact of pet food was dismissed as negligible. Pet food relies heavily on animal byproducts, and it was generally assumed that these ingredients would be wasted if not used in pet food.
Claims like this have been repeatedly criticized. They wrongly assume that animal byproducts would be wasted in landfill if not used in pet food. The argument also assumes – crucially – that animals must be farmed in the first place.
In fact, only 25 percent of animal byproducts produced in high-income countries like the US are used in pet food, and the sector competes with various others for these ingredients. Animal byproducts are used in pet food not because they would otherwise be wasted, but instead because they are cheaper than human grade cuts of meat. The sale of animal byproducts helps prop up slaughtering industry profits. 11.4 percent of the gross income from beef is from byproducts, and 7.5 percent for pork.
Moreover, as we showed in 2023, animal byproducts are less efficient than human grade meat. This is because animal byproducts only make up a minority of the average animal carcass used for pet food (39.2 percent for dogs, and 31.3 percent for cats). Compared to using human grade meat, using animal byproducts in pet food requires 1.4 times more animal carcasses for dog food, and 1.9 times more for cat food. As a result, more livestock animals are required (and with them, greater environmental impacts incurred) to feed dogs and cats animal byproducts.
Given this, it is more reasonable to view these animal ingredients as coproducts rather than byproducts. In doing so, they are acknowledged as valuable commodities in and of themselves, rather than externalised byproducts that can be excluded from environmental impact calculations.
In summary, the idea that we can dismiss the environmental impacts of pet food because they use animal byproducts that would otherwise be wasted, is entirely false. It incorrectly assumes that animal byproducts would be wasted if not used in pet food, and it fails to recognise that these actually incur greater environmental impacts, compared to human grade meat.
In reality, the best way to reduce the environmental impacts of our companion animals’ diets is to transition them away from diets high in animal products, towards nutritionally sound vegan ones, or those based on cultivated meat once they become more widely available.
Read more: Plant-Based Dog Food Brand Wins Dragons’ Den Backing
Environmental benefits of vegan pet food
Fortunately, a range of alternative pet food protein sources derived from plants, fungi, cultivated meat and microorganisms are emerging, and offer huge potential to reduce the environmental impact of pet food. Various plant-based pet food companies are already widely commercially available in the UK and other countries (a non-exhaustive list is available at www.sustainablepetfood.info).
If we transitioned all dogs and cats onto nutritionally sound vegan diets, the benefits for environmental sustainability would be game changing. A global transition for pet dogs alone would save 1.5 times the greenhouse gases produced by the UK, as well as vast amounts of land and freshwater. The food energy savings would be sufficient to feed 450 million people – more than the entire EU population. At least six billion land animals would also be spared from slaughter annually, and another billion if pet cats were also transitioned.
There are also some emerging pet food alternatives that may offer even greater environmental benefits. In February 2025, Meatly, a UK-based biotech company that makes cultivated chicken-based pet food, partnered with vegan pet food company The Pack to launch the world’s first cultivated meat pet food product for retail sales. And Calysta, a company producing animal-free pet food via precision fermentation, offers a product already at commercial scale with environmental impacts reportedly a fraction of those from plant-based ingredients, let alone animal-based ones. The first nutritionally complete pet food using their protein product was launched by Marsapet in February.
What needs to change
The best thing we can do to reduce our companion animals’ environmental “pawprints” is to transition them to nutritionally sound vegan diets. Dogs and cats fed these diets seem to enjoy them as much as meat-based diets, and modern vegan pet foods are generally of equivalent, if not superior, quality and nutritional soundness to meat-based pet foods. Moreover, as we summarised recently in Plant Based News, there is a strong and growing body of evidence demonstrating that dogs and cats fed nutritionally sound vegan diets experience health outcomes as good as or better than those fed meat-based diets. Given these significant environmental and health benefits, there is no longer any sound reason not to support a companion animal dietary transition.
Other mitigation strategies include choosing to care for small rather than large animals where possible, adopting instead of buying companion animals, and preventing overfeeding (which is currently common). Importantly, however, gains from reducing overconsumption will quickly be outpaced by rising companion animal populations globally. Hence, these are supplementary strategies that should be pursued in tandem with, rather than in place of, a wider structural transition to nutritionally sound vegan diets.
Additionally, given the very significant environmental impacts associated with companion animal diets, public awareness on this topic is shockingly low. Along with governments and the mass media, those with large platforms in pet care or adjacent communities should communicate the environmental benefits of a transition towards vegan pet food to their audiences. For those resistant to the idea at first, a gradual transition (say, feeding 50 percent vegan and 50 percent meat-based pet food) would still significantly reduce an animal’s dietary “pawprint.”
Addressing the impact of companion animal diets on climate change is an environmental imperative. We now have very good evidence demonstrating health and environmental benefits associated with modern, nutritionally sound vegan diets for dogs and cats. In light of this evidence, there is no good scientific reason not to support companion animal dietary change. Given the very significant potential to mitigate climate change and environmental breakdown, support from guardians, government, and industry is clearly warranted.
Read more: Lewis Hamilton Says Bulldog Roscoe Is A ‘Different Dog’ Since Going Plant-Based
