Vegan pet food digestibility review finds diets generally absorbed well
A review of 31 studies found nutritionally complete vegan and vegetarian diets for dogs and cats were generally well digested.
By Tom Brennan · Health & Medicine Correspondent
3 min read
A new scientific review on vegan pet food digestibility found that properly formulated plant-based diets for dogs and cats are generally absorbed well. The finding matters for owners weighing vegan or vegetarian food, because digestibility affects whether pets can use the nutrients listed on the label.
The review was published in the journal Animals and examined 31 studies on vegan, vegetarian and plant-based diets or ingredients for dogs and cats. According to Griffith University, 22 of the studies focused on dogs, two focused on cats and seven included both species.
Andrew Knight, a professor of animal welfare affiliated with Griffith University’s School of Environment and Science, said the evidence runs counter to the belief that dogs and cats cannot digest plant-derived proteins effectively.
“Current evidence indicates nutritionally sound vegan and vegetarian pet diets, and their main protein sources, are generally well digested by dogs and cats,” Knight said.
Can dogs and cats digest vegan pet food?
The review found that nutritionally sound vegan and vegetarian pet diets were broadly comparable to conventional meat-based foods in digestibility. Digestibility refers to how well an animal breaks down food and absorbs nutrients from it.
That measure is separate from whether a food is advertised as complete. Griffith University said modern commercial plant-based pet foods are usually designed to supply essential nutrients, but low digestibility could still limit how much of those nutrients an animal absorbs.
The studies covered common plant-based protein sources and ingredients used in pet food, including wheat gluten, rice protein, soy-derived ingredients, peas, lentils, chickpeas, potato protein and quinoa. Some studies also looked at proteins made through microbial fermentation.
Commercial vegan dog foods were included in some of the research reviewed. Those products contained ingredients such as peas, barley, oats, sunflower oil and lentils, according to Griffith University.
The review found that digestibility was generally high even when individual plant-based nutrients were less digestible than comparable animal-derived ingredients. Knight said the results support carefully made vegan and vegetarian diets and challenge the idea that they are less digestible than meat-based options.
What should pet owners check on vegan diets?
Knight said owners considering plant-based food should look for clear nutritional claims on packaging. “There should be a clear statement that the diet is nutritionally complete,” he said.
He also said pet caregivers should choose products from companies that can explain how they check nutritional soundness, including whether they work with veterinary nutrition specialists. The review addressed digestibility, not every possible health outcome for every pet.
Knight said more research is still needed on vegan and vegetarian diets for cats in real-world conditions. He also called for more study of kittens, older animals and pets with health problems.
The paper, “The Digestibility of Vegan and Vegetarian Diets for Dogs and Cats,” was authored by Knight and published in Animals in 2026.
This story draws on original reporting from Phys.org.