Vegan Pet Food ‘Most Effective’ Measure to Tackle Climate Footprint of Dogs & Cats

A new review suggests that pets have a significant climate footprint, and the best way to lower their impact is to feed them nutritionally sound plant-based food.

Globally, a tenth of all meat is consumed by cats and dogs, a share that rises to 20% in some high-income countries, like the UK and the US. In the latter, in fact, up to 30% of the environmental impact of livestock production has been attributed to pet diets.

Shifting our furry friends towards plant-based meals formulated to be nutritionally sound is the “most effective” way to mitigate their climate impact, a new review has found.

The research was carried out by Bryant Research’s Billy Nicholles and University of Winchester’s Prof Andrew Knight (who has led a number of studies exploring veganism, pet health, and climate change).

The two researchers included 21 studies in their review, assessing the meat- and plant-based ingredients in commercial pet food, the role of animal byproducts, and emerging innovations like cultivated meat and microbial proteins for cats and dogs.

“Given the very significant and comparatively neglected environmental impacts of the pet food industry, measures to reduce the dietary ‘paw prints’ of our companion animals warrant urgent adoption,” the authors write in the Frontiers in Sustainable Food Systems journal.

Where do pet food emissions come from?

The review found that a diet solely comprising wet pet food is linked to nearly eight times more emissions than dry food.

Studies have found that manufacturing and energy costs are among the most carbon-intensive processes in pet food production, while packaging and distribution are among the least impactful factors.

Food waste was identified as an exacerbating factor, particularly due to overconsumption. Consumer demand and perceptions of pet health have led to some pet foods having much more protein than required, which can contribute to overfeeding by their guardians. The study points out that pet obesity is a major problem, with around half of cats and dogs in various geographies overweight or obese.

Impacts from animal urine and faeces have a significant contribution to absolute emissions, especially via freshwater eutrophication and disposal via landfill.

However, ingredient selection has the largest impact on pet food’s climate footprint. One life-cycle assessment (LCA) from Brazil found that these make up at least 70% of the industry’s impact.

The problem with animal byproducts in pet food

Knight’s previous research has found that 53% of ingredients used in pet food are animal-derived, including both those that can and cannot be consumed by humans. The latter group (think byproducts like bones, meat meal, or intestinal linings) comprises 75% of all animal-based ingredients in the sector.

“There is a widespread and commonly accepted misunderstanding that animal byproducts are associated with reduced environmental impacts due to their status as waste products from human meat production, that would otherwise be discarded,” the authors say, even noting some studies that suggest pet food offsets the impact of the human food industry.

However, only around a quarter of animal byproducts produced in wealthy nations go towards the pet food industry, which competes for these ingredients with the likes of the livestock, energy and pharma sectors.

To that end, some studies have contended that byproducts actually have a worse environmental impact because of their poor nutritional content.

“For dog food, using animal byproducts rather than human-grade meat requires 1.4 times more livestock carcasses, and for cat food, 1.9 times more,” the authors added. This is because the industry needs more livestock carcasses on average to produce the same amount of ingredients it would with human-grade meat.

“Hence, animal byproducts are less efficient to produce, than human-grade meat. Their production requires significantly more livestock carcasses. This has the potential to increase the number of livestock animals required, and the associated environmental impacts,” the study explains.

How vegan pet food can mitigate these impacts

According to Nicholles and Knight, plant-based pet food has been controversial in the past because of nutritional concerns. But over the last few years, various studies (including some by Knight) have proven that vegan food can be safe for both cats and dogs, and can have better health outcomes than meat in some cases.

It’s not just pet wellbeing that can benefit from animal-free food – it’s the planet’s health too. A global transition towards vegan diets for cats and dogs could save an area of land larger than Mexico and Germany combined, and emissions higher than the yearly collective total of the UK and New Zealand.

These findings are based on conservative estimates of dog and cat numbers and energy requirements. “In reality, the environmental impact reductions associated with a transition to vegan companion animal diets can be expected to be even larger,” the researchers note.

Microbial proteins and cultivated meat, meanwhile, “offer significant, and in some cases extremely large, reductions in environmental impacts”. One LCA found that cultivated meat for pet food can generate 84-95% fewer emissions than beef, and 47% fewer than chicken.

“There is no longer any sound reason not to support such a dietary transition, particularly given the strong and growing body of evidence demonstrating equivalent or superior health outcomes when nutritionally sound vegan pet diets are used,” the study noted. Even the British Veterinary Association has ended its objection to plant-based dog food.

The study calls for several policy measures to help decarbonise food for our furry friends. This includes informational campaigns for pet owners to prevent overfeeding and food waste, and communicating to them the substantial climate footprint of pet diets and the best way to mitigate them (which is a transition to animal-free proteins).

It also urges investors and government funds to ramp up their activity in alternative protein production for pets. “These responses – in particular, a rapid transition away from animal-based ingredients to sustainable alternatives – represent an opportunity to substantially mitigate the environmental impacts of the large and increasing global pet food industry,” it states.

Another idea is to encourage gradual transition, feeding them 50% vegan and 50% meat-based diets first. “Even a 50% reduction in meat-based pet food consumption would still significantly mitigate the environmental impacts of pet food production,” the authors said.