Food Allergies in Dogs: Signs & Elimination Diets
Vet-reviewed via PetHealth+ · Last reviewed June 2026
True food allergies cause itchy skin, ear infections, or GI upset year-round. Diagnosis uses a strict elimination diet for 8–12 weeks — the only reliable method.
Allergy vs intolerance
Allergies involve the immune system; intolerances may cause diarrhoea without itching.
Common triggers
Beef, chicken, dairy, wheat, and soy are frequent culprits — but any protein can trigger allergy.
Elimination trial
Feed one novel protein and carbohydrate source only; no treats or flavoured medications.
Related: Dog allergies and itching
Frequently asked questions
What are signs of food allergy in dogs?
Itching, recurrent ear infections, paw licking, and sometimes vomiting or diarrhoea.
Are grain allergies common in dogs?
Protein allergies are more common than true grain allergy.
Do allergy blood tests work?
Elimination diet remains the gold standard; blood tests alone are unreliable for food allergy.
Can puppies have food allergies?
Yes, though they can develop at any age after repeated exposure.