Global Review Finds Properly Formulated Vegan Pet Diets Can Match Meat-Based Diets in Digestibility

Analysis of 31 Scientific Studies Suggests Modern Plant-Based Pet Foods Can Deliver High Nutrient Digestibility When Properly Formulated

A comprehensive scientific review published in the journal Animals has concluded that properly formulated vegan and vegetarian pet diets are generally as digestible as conventional meat-based diets, challenging one of the most common criticisms of plant-based nutrition for companion animals.

The review, led by veterinary researcher Dr. Andrew Knight, analyzed 31 peer-reviewed studies evaluating the digestibility of commercially formulated vegan and vegetarian diets in dogs and cats. The authors found that most nutritionally complete plant-based diets achieved high levels of nutrient digestibility, comparable to traditional animal-protein formulations in many studies.

A copy of the Publication can be accessed here – animals-16-01454-with-cover

Modern Processing Improves Digestibility

The review highlights that advances in pet food manufacturing—including extrusion, thermal processing and precise amino acid supplementation—have significantly improved the nutritional quality of plant-based pet foods.

Commercial vegan diets commonly use ingredients such as soy protein, pea protein, lentils, chickpeas, potato protein and microbial proteins. When formulated to meet established nutritional standards, these ingredients can provide highly digestible protein and energy for companion animals.

Several experimental studies included in the review reported protein digestibility exceeding 80%, with digestibility values comparable to premium meat-based products.

Complete Nutrition Remains Essential

The researchers caution that the findings apply specifically to nutritionally complete commercial diets formulated to meet recognized nutritional requirements.

Cats remain obligate carnivores, meaning plant-based diets must be carefully supplemented with essential nutrients such as taurine, arachidonic acid, vitamin A, vitamin B12 and certain amino acids that are naturally abundant in animal tissues.

Similarly, vegan diets for dogs must provide balanced amino acid profiles, vitamins and minerals to ensure long-term nutritional adequacy.

Challenging Long-Held Assumptions

For decades, critics have argued that plant proteins are inherently less digestible than animal proteins for companion animals.

According to the review, the available scientific evidence does not consistently support this assumption. While digestibility varied among ingredients and formulations, overall digestibility remained high across most commercially produced vegan diets evaluated.

The authors conclude that modern formulation techniques allow manufacturers to produce plant-based diets capable of delivering nutrient digestibility comparable to conventional pet foods in many cases.

Growing Interest in Sustainable Pet Nutrition

Interest in alternative protein sources continues to grow as the global pet food industry explores ways to reduce environmental impact while maintaining nutritional quality.

Plant proteins, fermentation-derived ingredients and other novel protein sources are increasingly being investigated as sustainable alternatives to traditional animal-derived ingredients.

However, veterinary nutrition experts emphasize that diet selection should always prioritize nutritional completeness, ingredient quality and evidence-based formulation rather than whether the protein source is animal- or plant-derived.

What This Means for Veterinarians and Pet Owners

The review does not suggest that every vegan pet food is nutritionally equivalent or suitable for every animal.

Instead, it reinforces that commercially formulated diets meeting recognized nutritional standards can achieve high digestibility, provided they are carefully designed and balanced.

Veterinarians continue to recommend regular health monitoring for pets consuming alternative diets, particularly cats, to ensure appropriate body condition, blood parameters and long-term nutritional status.

As research continues, the study adds to a growing body of evidence suggesting that nutritional adequacy depends more on formulation and nutrient balance than on whether protein originates from plants or animal tissues.