Pet Food’s Environmental Impact

For years I have been thinking, talking and writing about how veterinarians can reduce the environmental impact of their practices.  It is only relatively recently, however, that I have realized that one of the biggest impacts we can have is by shaping client behaviour. One of the “dirty secrets” of veterinary medicine is that the animals we care for and love have a significant negative impact on the environment; however, the medical care we provide for a pet is only responsible for 12% of their carbon footprint.  The largest contributor to their impact, making up 60% of their footprint, is the food they eat.(1)

If the dogs and cats of the United States were their own country, they would be the 5th largest consumer of meat worldwide. (1)

Fortunately, 96% of pet owners trust their veterinarians as a source for nutrition information, so we are well suited to lead these discussions with our clients.(2) Furthermore, after cost and pet preference, pet owners place a high value on issues of animal welfare and environmental sustainability when it comes to making pet food choices.(3) As a result, veterinarians are well suited to make diet recommendations that take environmental sustainability into consideration.  Three areas of nutrition to focus on are: 1) overfeeding and obesity; 2) the format of the food (kibble vs wet vs fresh); and, 3) the source of protein used in the food.

 More than 25% of dogs and 40% cats in the US are overweight. (4)

The health concerns of being overweight are well documented, and include increased incidence of chronic disease, orthopedic disease and shorter median lifespan. It has been suggested that a 25% diet restriction leads to a longer lifespan and a reduction in markers of chronic disease.(5) In addition to individual health benefits, feeding our pets an appropriate amount of food significantly reduces their carbon footprint.  Using readily available caloric intake calculators, a 45 kg dog with a BCS of 9/9 would weigh 27 kg if it had a BCS of 5/9 and would consumes 30% fewer calories.(6) Given that diet makes up 60% of their carbon footprint, feeding an appropriate amount of kibble to this hypothetical dog would reduce their carbon footprint by 17% and save the client 30% on food costs.

 Not all Food is Created Equally

In addition to feeding our pets an appropriate caloric amount, the type of food we feed them can have a huge impact on their carbon footprint.  These days we are inundated with choice about the type of food we feed our pets, from the traditional kibble and canned wet foods to freeze dried, fresh frozen, raw, and homemade diets. A recent study looking at the environmental impact of diet choice for dogs and cats showed that wet foods result in roughly 8 times the greenhouse gas emissions than the equivalent calories of kibble(7) and a study by Royal Canin shows that commercially available prepared fresh dog food may have up to 17 times the greenhouse gas emissions of kibble!(8) This is due to a combination of ingredient choice, manufacturing, shipping (wet food is approximately 70% water by weight, while kibble is only 10%), storage and wastage of foods.

Type of Protein Matters

If we look at any given format of food, the protein source is the primary driver of its footprint. Beef and lamb generate roughly 10 times the greenhouse gas emissions of chicken or fish, so where appropriate, recommending a non-ruminant based diet may significantly reduce the diet-related impact of our pets. (9) Byproduct meal is often touted as an environmentally friendly choice, as it uses parts of the animal that are less appealing for human consumption; however because it is used for so many other purposes, only 25% of byproduct meal in the US makes it into the pet food stream, and because it is less nutritionally dense than human grade meat, more of it is needed to deliver equivalent nutrition. (10)  Alternative protein sources (insect, algae, fungal and plant) are beginning to be found in commercially available pet foods, and offer a promising reduction in the carbon footprint of pet diets, but it is important to ensure that those foods are nutritional balanced for the target animal, especially in cats, who are obligate carnivores.(11)

Fun fact: fish don’t create omega-3 fatty acids, microalgae do; as do many land plants! Broadly disseminating this information could reduce overfishing pressure. (12)

Make It A Team Effort

So, if we want to talk to our clients about the carbon footprint of their pets, there are multiple avenues we can pursue. Granted, each of these approaches takes time, which is also a precious resource in the daily life a veterinarian.  Fortunately, this work doesn’t all have to fall to the veterinarian. Although clients trust veterinarians most when it comes to nutrition conversations, they still have substantial trust in the recommendations of technicians and front desk staff, who can further the conversations about healthy weight, cost of food, format of food and also point clients towards 3rd party certifications that corroborate the conversations that we start in the exam room.(3)

We Can Also Reduce the Footprint of Our Diet

Sustainable eating is not a pet only conversation. What the humans in a clinic eat carries its own footprint, and clinics have an easy, low-stakes way to model the same lower footprint choices we are counseling clients on. Staff lunches, potlucks, and CE events are a natural place to try plant forward options alongside the usual spread, not as a replacement, just as one more thing on the table. It costs nothing to add a vegetarian dish into rotation, and it is a small, honest way for a clinic to practice what it is starting to preach.

REFERENCES

1. https://earth.org/environmental-impact-of-pets/

2. https://www.avma.org/news/normalize-pet-nutrition-conversations-every-veterinary-visit

3. Clark M, Scott D, Kern-Allely C, Koren A, Puaa KK, Delcambre J and Duncan C (2026) Veterinary clients value animal welfare and environmental sustainability in pet food choices. Front. Vet. Sci. 13:1735331. doi: 10.3389/fvets.2026.1735331

4. Mathieu Montoya, Franck Péron, Tabitha Hookey, JoAnn Morrison, Alexander J. German, Virginie Gaillard, John Flanagan, Overweight and obese body condition in ∼4.9 million dogs and ∼1.3 million cats seen at primary practices across the USA: Prevalences by life stage from early growth to senior. Preventive Veterinary Medicine,Volume 235, 2025.

5. Kealy RD, Lawler DF, Ballam JM, Mantz SL, Biery DN, Greeley EH, Lust G, Segre M, Smith GK, Stowe HD. Effects of diet restriction on life span and age-related changes in dogs. J Am Vet Med Assoc. 2002 May 1;220(9):1315-20. doi: 10.2460/javma.2002.220.1315. PMID: 11991408.

6. https://www.purinainstitute.com/centresquare/mer-calculator-for-dogs

7. Pedrinelli, V., Teixeira, F.A., Queiroz, M.R. et al. Environmental impact of diets for dogs and cats. Sci Rep 12, 18510 (2022). https://doi.org/10.1038/s41598-022-22631-0

8. Sarteel M, Daniel G. Feeding the Future: Sustainable Practices in Pet Nutrition. Doherty Sustainability Summit, 2025.

9. Our World in Data. Environmental impacts of food. https://ourworldindata.org/environmental-impacts-of-food#explore-data-on-the-environmental-impacts-of-food

10. Nicholles B, Knight A. The environmental sustainability of meat based versus vegan pet food. Front Sustain Food Syst. 2025;9:1569372.

11. Klinmalai P, Kamonpatana P, Thongpech A, Sodsai J, Promhuad K, Srisa A, Laorenza Y, Kovitvadhi A, Areerat S, Seubsai A, et al. Comprehensive Review of Alternative Proteins in Pet Food: Research Publications, Patents, and Product Trends in Plant, Aquatic, Insect, and Cell-Based Sources. Foods. 2025; 14(15):2640. https://doi.org/10.3390/foods14152640

12. https://www.openaccessgovernment.org/article/microalgae-as-a-novel-non-animal-source-of-long-chain-omega-3-fatty-acids-and-vitamin-d/193574/