The cause of allergies in humans and animals are very difficult to detect by a doctor yes. My Berner Sennen dog had to suffer repeatedly from itchy paws inflamed ears and tongued skin. Drugs helped only temporarily. The attempt by the change in feed on grain-free mixes wet and dry food helped in the long run - now up for 1 year. If the animal is healthy - would be the man! THANK YOU, "forage shuttle" !!!