A new study from the University of Nottingham shows that in the U.K., no commercially available dog foods—plant-based, meat-based, or veterinary—fully meet all adult dog nutritional guidelines. Published in PLOS One on September 3, 2025, researchers analyzed 31 dry dog foods labeled “complete,” including 19 meat-based, 6 plant-based, and 6 veterinary diets designed for dogs with kidney concerns.

While dogs are omnivores capable of thriving on a variety of diets, the study revealed gaps across all types of dog foods. All products met vitamin D requirements, but compliance dropped significantly for amino acids (17/31), minerals (5/31), and B-vitamins (4/31). Plant-based diets were particularly prone to deficiencies in iodine and B-vitamins, but supplementation can help cover these gaps. Veterinary diets, despite being specially formulated for renal support, often lacked essential amino acids.

Lead researcher Rebecca Brociek emphasized: “Dogs don’t need meat—they need the right nutrients. Our study shows that plant-based diets can be viable with supplementation, but every type of dog food has nutritional gaps that veterinarians and owners should be aware of.”

These findings underscore the importance of evaluating nutrient intake, especially for dogs on plant-based or therapeutic diets, and may guide veterinarians in recommending supplements or dietary adjustments.