Labs are notorious for having allergy problems. Our Lab developed something called atopy. In him, it manifested as a huge blood blister between 2 toes. He never licked his feet, though. He also had nasty, smelly ears with a brown discharge that would then get infected. After fighting the battle with pred (which I HATE to use) daily doses of Benedryl and antibiotics for nearly a solid year, I said ENOUGH!
We took Bailey to a phenomenal veterinary dermatologist that is here in the Dallas area. We did skin prick allergy testing, exactly what they do for people. It is much more accurate than blood testing for allergies that is usually done on pets... more expensive, too.
We found out that our poor pooch was allergic to all types of grass, weeds, trees, dust mites, and pollen His yuchy ears were also a symptom of allergies. The infections were only secondary.
He now gets allergy serum injections every 10 days. I can give them myself. The serum has resolved nearly ALL of his ear infections, as well as the bloody blister. No more antibiotics, no more pred. Benedryl is only needed for a couple of weeks in the fall, when his allergies are the worst.
If you can afford it, this kind of testing sure as hell beats trying to figure out on your own whether it is an environmental or food allergy. Bailey was allergic to SO many things that we would never have figured it out ourselves. I am so happy that he doesn't have to have all those antibiotics & prednisone!