Dry Pet Food May Be Greener Than Wet Food
Pet owners may have a new reason to seek out kibble.
Dry food for cats and dogs tends to be better for the environment than wet food, report veterinary nutritionist Vivian Pedrinelli of the University of São Paulo in Brazil and her colleagues. Their analysis of over 900 pet diets shows that nearly 90% of the calories in wet food come from animal sources. That’s about twice the share of calories from animal ingredients in dry foods.
The team factored the cost of different pet food ingredients into several environmental metrics. The conclusions, described on November 17 in Scientific reportssuggests that wet food production uses more land and water and emits more greenhouse gases than dry food.
Scientists already knew meat-rich human diets lead to greenhouse gas emissions (SN: 05/05/22). But when it comes to environmental sustainability, “we shouldn’t ignore pet food,” says Peter Alexander, an economist at the University of Edinburgh who was not involved in the work.
The impact of various pet foods on the environment is unclear, says Alexander. Commercial fare for cats and dogs is generally not made from premium cuts of meat. Instead, ingredient lists often include animal byproducts — the gristle and bits that people aren’t likely to eat anyway.
How to calculate the carbon cost of these remains is an ongoing debate, says Gregory Okin, an environmental scientist at the University of California, Los Angeles who was not involved in the study.
Some argue that pet food by-products are essentially free because they come from animals already raised for human consumption. Others note that every calorie requires energy and therefore carries an environmental cost. Also, animal-derived ingredients in pet food may not just be leftovers. If they contain even a small amount of human-edible meat, it could have a big impact.
Knowing that there is an environmental difference between moist cuts and crispier cuisines could be helpful for environmentally conscious pet owners, Okin says. Having this information at the ready at the grocery store is “super important when people are making decisions,” he adds. “There are consumers who want to be careful.”
