Should your pet switch to a vegan diet?

A researcher has carried out a study into the potential environmental benefits of pet owners switching their dog or cat’s meat-based diet to a vegan one.

Looking at factors such as reduced freshwater consumption and greenhouse gas emissions, Lead Researcher, Andrew Knight of Griffith University, Australia, published the findings in the journal PLOS ONE.

Previous studies have put a microscope over livestock impacts in relation to human diets, however Knight explained that few have considered the relative role of cat and dog diets. Recent research suggests that nutritionally sound vegan cat and dog diets (ones that are lacking meat, eggs, and dairy) are safe and may have comparable healthfulness to meat-based diets.

Questioning the environmental benefits of vegan pet diets, Knight calculated a series of estimates of the potential impacts of a hypothetical scenario in which all cats and dogs in the US or around the world were switched to nutritious vegan diets. Using pet population data from 2020 for the US and 2018 data for the worldwide estimates, Knight also considered other inputs from a variety of prior studies and governmental databases to carry out his research.

The estimates suggest that the amount of livestock consumed by dogs and cats in the US “may be about one fifth of that consumed by humans, and about one tenth globally”. If all US dogs and cats switched to vegan diets, the model estimates that nearly two billion land-based livestock animals might be spared from slaughter yearly, and nearly seven billion if all cats and dogs around the world switched. Knight also claimed that “billions of aquatic animals would also be spared”.

Going further, the estimates also suggested that there was the potential for significant reductions in land and water use, greenhouse gas emissions, use of biocides, and emissions of other pollutants.

“For instance, switching all dogs worldwide to vegan diets could free up an area of land larger than Saudi Arabia, and for cats, larger than Germany; for comparison, if all humans became vegan, an amount of land larger than Russia and India combined might be spared,” explained Knight.

“Switching all dogs’ diets could result in an estimated reduction of greenhouse gas emissions greater than the amount of all emissions from the UK, and for cats, Israel,” he continued.

However, Knight pointed out that the pet population and animal energy requirement data used might underestimate true numbers, so the true environmental benefits of vegan diets “might be greater than estimated”. In addition, he noted that the calculations “required making some assumptions”, and that more research is needed to bolster confidence in the estimates.

“This study shows environmental benefits when vegan diets are used to feed not just people, but dogs and cats as well. However, to safeguard health, it’s important that people feed only vegan pet food labelled as nutritionally complete, produced by reputable companies with good standards,” concluded Knight.