Is all meat in pet food a bad idea for environmental sustainability?

Pets eating meat which would otherwise be destined for human consumption increases the overall demand for meat and therefore has a substantial environmental footprint. However, if pets eat parts of meat carcasses not typically consumed by humans - is this also an environmental challenge? We discuss below.

Dogs eating animal by-products 

Historical studies of the diets of dogs, going back to the bronze age, have consistently shown that what man’s best friend eats is closely entwined with human diet. The nutritional requirements of dogs have adapted to what parts of animal, fish or plants are available - often as scraps or potential waste material.  

This continues today, as modern production of pet food relies heavily on animal by-products (ABPs) – which are the parts of the animal carcass less used in the human food systems, such as offal, trimmings, and fat. While many people might not choose to handle or eat these products in their raw state, pet food processing converts them into nutritious and convenient feed for pets. 

Environmental implications of ABPs in pet food 

The historic integration of the food system for dogs with the human food system was due to resource availability. Now, this integration is critical in understanding, and hopefully reducing, the climate and ecological impacts of feeding pets. Given the environmental impacts associated with meat production, it is essential that all parts of the produced animals are best utilised, so that livestock production is minimised.  

To fully understand the environmental implications of using ABPs in pet food, it’s important to consider what would happen if they were not used in pet food. This involves examining the potential changes in the food system and the environmental impacts of alternative uses. For instance, if ABPs would otherwise be incinerated as waste, with minimal effect on the number of animals raised for meat, their use in pet food could be beneficial for the environment, by reducing the need for other sources of pet nutrition. Conversely, if the use of ABPs in pet food economically supports increased meat production, the environmental impacts could be increased. However, due to the wide-ranging potential uses of ABPs, we don’t yet have detailed assessments of the consequences of different use patterns. 

It’s also important to understand how emissions for different animal products are calculated. Traditionally, the “gold standard” Life Cycle Assessment approach assigns environmental impacts to different carcass portions based on their relative economic value, assigning a lower environmental impact to ABPs than higher value meats. This recognises that all cuts contribute to the value of farming, but that higher value products tend to drive the industry. Some studies may allocate emission differently, eg by mass, where the impacts of 1kg of prime steak and 1kg of intestines are judged as equal, whereas it seems unlikely the demand for intestines drives livestock production. The difference between estimates using these two different approaches can be ten-fold. This is critical, because assumption that alternative protein sources (for example plants, insects, lab grown meat) are more environmentally friendly will often differ between the different allocation approaches. It will also alter the difference in impacts between food formats: dry food typically contains more animal by-products; whereas many wet foods, grain-free foods and approaches such as raw feeding may include more meat of types that humans would consume. 

Future diets 

Many models which assess likely future human diet scenarios anticipate ongoing increases in meat production – and therefore increase in future ABPs. However, this does not guarantee availability for pet food as competing demands for ABPs, such as biofuels, are already causing challenges for manufacturers. This seems a concerning practice.  

EU and other organisations have developed “hierarchy” approaches to managing potential waste for best environmental outcomes. These approaches regard the most preferred option for ABPs would be as human food, followed by as animal food: energy recovery is the least preferred option except for disposal. The waste hierarchy approach does raise one important preferred option for ABPs to use in pet food: could humans be encouraged to eat more of the “non-prime” meat cuts?  

The above discussion highlights a range of ongoing debates in what is a relatively under researched area. An area of little disagreement is that pet food use of meat should not compete with human food. Regardless of allocation approach taken, use of prime meat which would otherwise be eaten by humans is likely to have very high environmental impacts. As societies globally aim to adjust to the challenges of rapidly reducing emissions, wider discussion of what type of meat should be eaten by pets must not be avoided.

BVA recently launched a policy position on diet choices for cats and dogs. Read now.