Cat and dog owners could significantly reduce their environmental impact by simply using more dry food. According to a new study, pet food has seven times the carbon emissions of dry food.

Pet food has its own carbon footprint but there is a considerable difference between the carbon emissions resulting from dry and wet pet diets. The new study, recently conducted in Brazil, revealed that the dry food consumption of a 10 kg dog (the equivalent of 534 calories per day) releases about 828 kilograms of carbon dioxide annually. 

Meanwhile, on a wet diet, the carbon footprint of the same animal increases by a whopping 689%, taking the released CO₂  amount to 6,541 kgs per year. That’s about 2000 kgs more carbon dioxide than what is released by a gasoline-powered car in a year. The researchers suggest that by taking care of what our pets eat, we can significantly reduce the negative impact they have on the environment.    

A sustainable pet diet can make a difference

The population of pet dogs and cats stands at 76.8 million and 58.4 million respectively in the US alone; globally, the number is harder to estimate, but the number of cats and dogs seems to be growing worldwide. This large population is fed mostly meat-based wet and dry food products, while some feed their animals with homemade food.

Previous research has already suggested that pet food may be a significant source of greenhouse gas emissions — not a decisive one, but one that’s worth considering. For instance, a study conducted by researchers at the University of Edinburgh in 2020 showed that the carbon footprint of the global pet food industry affects land twice the size of the UK. If the pet food industry is considered a country, it would rank at the 60th position in greenhouse gas emissions worldwide — the rough equivalent of a mid-sized country.

However, as the current research suggests, most of the emissions produced by pets result from wet diets, possibly due to their high water and meat content. The authors of the study performed an interesting experiment before coming across these findings.

The researchers examined land usage, greenhouse gas emissions, and water consumption for 320 diets of cats and 618 diets of dogs. The food consumed by the pets included dry products, wet products, and pet food that is prepared by pet owners at home using ready-made pet recipes. Pets who lived on wet diets released the maximum amount of CO₂  (6,541 kgs) per year.

Pets on dry and homemade diets led to almost equal amounts of water consumption, dry food still managed to emerge as the best diet due to its lower environmental impact and the high energy and nutritional value it offered to pets. The researchers claim that dry diets provide more energy per gram than wet and homemade pet food.

“Dry diets for both dogs and cats presented the highest metabolizable energy (kcal/g) (p < 0.001) and nitrogen-free extract (NFE) content (g/1000 kcal) (p < 0.001). As for protein content (g/1000 kcal), wet diets for dogs presented the highest amounts, followed by homemade diets (p < 0.001),” the authors note.

Most of the nutrition that wet diets provide comes from their high meat and water content which leads to high emissions. Although wet diets are rich in protein, they are not the only source of protein for pets. Some companies have also started to offer protein-rich insect-based pet food that could also help owners slash their pet’s carbon emissions to a large extent. 

For instance, the amount of carbon dioxide that is released into our atmosphere during the production of every 100 gms of animal protein-based wet food can be up to 14 times higher than for producing the same amount of insect protein. Explaining this further the researchers said:

“As protein-rich ingredients can be one of the main sources of environmental impact, the choice of protein type is very important. A change of inclusion or ingredient should be considered depending on the nutrient requirement and diet composition as a whole. Furthermore, the inclusion of alternative ingredients, such as insects, could improve the sustainability of a diet.”

Ultimately, the researchers conclude that feeding your pet a balance of dry pet food and sustainable foods such as insect protein could help us fight climate change and provide our loved pets with all the nutrition they need in the most sustainable way possible — while keeping them healthy and energetic at the same time.

The study is published in the journal Scientific Reports.