Can Dogs Thrive on a Plant‑Based Diet? New Study Says Yes — With Caveats
For years, the idea of feeding dogs a plant‑based diet has been met with scepticism. After all, our canine companions descend from carnivorous wolves, and meat has long been considered the cornerstone of their nutrition. But as more people embrace vegetarian or vegan lifestyles — for health, ethical, or environmental reasons — the question has become harder to ignore: can dogs be healthy without meat?
A new study from the University of Nottingham offers one of the most comprehensive answers yet. The research, published in 2025, analysed 31 commercially available “complete” dry dog foods in the UK — 19 meat‑based, six plant‑based (four vegan, two vegetarian), and six veterinary prescription diets for dogs with kidney or urinary issues. The results challenge some long‑held assumptions, while also highlighting serious gaps in the pet food industry.
Plant vs. Meat: More Similar Than Expected
The researchers measured protein content, amino acid profiles, fatty acids, minerals, and vitamins, comparing them to the European Pet Food Industry Federation (FEDIAF) nutritional guidelines.
The surprise? Plant‑based diets stacked up remarkably well against meat‑based ones. Protein levels were virtually identical, and the quality — measured by the presence of essential amino acids — was often just as good. In fact, four of the six plant‑based foods met all essential amino acid requirements, and average concentrations of some high‑quality amino acids were even higher than in many meat‑based diets.
This finding directly counters the common belief that only meat can provide dogs with the full spectrum of essential amino acids.
The Weak Spots: Iodine and B Vitamins
While plant‑based diets performed well in protein quality, they consistently fell short in two key nutrients:
- Iodine: Only one of the six plant‑based foods met the recommended levels.
- Vitamin B12: Virtually absent in plants, B12 is essential for nerve function and red blood cell formation.
These deficiencies mirror challenges seen in human vegan diets. The good news? They’re easily fixed. The one plant‑based food that met iodine requirements included seaweed and dried algae — both rich natural sources. Supplementation, either by manufacturers or owners (with veterinary guidance), can close these gaps.
A Bigger Shock: Veterinary Diet Deficiencies
Perhaps the most alarming discovery wasn’t about plant‑based foods at all, but about specialised veterinary diets prescribed for dogs with kidney disease. These “renal diets” are intentionally low in protein to reduce strain on the kidneys, but the study found that four out of six failed to meet essential amino acid guidelines. One was deficient in six different essential amino acids.
For already sick dogs, such deficiencies could worsen health outcomes. In human medicine, low‑protein kidney diets are often supplemented with essential amino acids — a step that appears to be missing in many canine formulations.
No Perfect Score
The study’s most sobering conclusion: none of the 31 foods met 100% of the FEDIAF guidelines for all nutrients. Only 55% met all amino acid requirements, 24% met all B‑vitamin guidelines, and just 16% met all mineral requirements.
While most shortfalls were minor and unlikely to cause immediate harm, the findings suggest that “complete” on a pet food label is more aspiration than guarantee.
Why This Matters Beyond Nutrition
Feeding dogs a plant‑based diet isn’t just about health — it’s also about sustainability and ethics. With over 500 million pet dogs worldwide, their collective meat consumption has a significant environmental footprint. Reducing meat in pet diets could help lower greenhouse gas emissions and reduce demand for livestock farming.
As co‑author Rebecca Brociek noted, “Plant‑based diets, when properly formulated, can be a healthy and viable alternative to meat‑based options… perhaps the alternative isn’t only better for the planet, but also beneficial for our four‑legged companions”.
Practical Advice for Dog Owners
If you’re considering a plant‑based diet for your dog — or simply want to ensure their current diet is truly “complete” — here are some steps to take:
- Consult Your Vet First
Every dog is different. Age, breed, activity level, and health conditions all affect nutritional needs. - Check for Supplementation
Look for plant‑based foods that include iodine (from seaweed or algae) and vitamin B12. If not present, ask your vet about safe supplements. - Read the Label Critically
“Complete” doesn’t always mean nutritionally perfect. Compare the ingredient list and nutritional breakdown to FEDIAF guidelines. - Monitor Your Dog’s Health
Watch for changes in coat quality, energy levels, digestion, and weight. Schedule regular check‑ups and blood work. - Don’t Ignore Meat‑Based Gaps
The study showed that meat‑based diets can also be marginal in certain nutrients. Apply the same scrutiny to all foods. - Be Extra Careful with Prescription Diets
If your dog is on a veterinary diet, especially for kidney disease, discuss these findings with your vet. Ask whether amino acid supplementation is appropriate.
The Bottom Line
The University of Nottingham study offers a nuanced answer: yes, dogs can thrive on a plant‑based diet — but only if it’s carefully formulated and supplemented where needed. The bigger takeaway? Whether plant‑ or meat‑based, no commercial food is perfect, and owners should be proactive in ensuring their dog’s nutritional needs are met.
In the end, the best diet for your dog is one that balances health, lifestyle, and values — and that you choose with eyes wide open, armed with good information and professional guidance.
