A scientific review concluded that vegan and vegetarian foods formulated for dogs and cats can be as well digested as conventional meat-based diets, provided they are nutritionally complete and balanced.
The study, published in the scientific journal Animals, analyzed 31 investigations into the digestibility of plant-based diets and ingredients intended for companion animals. In total, 22 studies conducted in dogs, two in cats, and seven that included both species were evaluated.
Digestibility is a fundamental indicator of a diet’s quality, as it measures the body’s ability to absorb and use the nutrients present in foods. Even when a food contains all essential nutrients, reduced digestibility can compromise its absorption.
According to the authors, the currently available scientific evidence indicates that nutritionally adequate vegan and vegetarian diets, as well as their main protein sources, are generally well digested by dogs and cats.
Among the ingredients analysed are wheat gluten, rice protein, soy derivatives, peas, lentils, chickpeas, potato protein, quinoa and proteins produced by microbial fermentation. Some of the studies also evaluated commercial vegan dog foods, formulated with ingredients such as peas, barley, oats, sunflower oil and lentils.
Although some plant sources showed slightly lower digestibility than animal-origin ingredients, the review concluded that, overall, the levels of digestibility remain high.
The study’s lead author, Andrew Knight, Professor of Animal Welfare at Griffith University, believes the results counter the widely propagated notion that dogs and cats cannot effectively digest plant-based proteins.
“These conclusions support the use of carefully formulated vegan and vegetarian diets and challenge the notion that they are less digestible than conventional meat-based diets,” says the researcher.
However, the expert recommends that owners always verify whether foods on the label indicate they are nutritionally complete and whether they are produced by companies able to demonstrate that they developed the formulations with the backing of veterinary nutrition specialists.
The researchers also stress that more studies are needed to better understand the digestibility of these diets in cats, especially under real-use conditions, as well as in kittens, older animals, and animals with health problems.
