True. At the moment I have a vegetarian Poodle. He is not amused but it is necessary in order to let his system "reset". Evidently something we were feeding him caused an allergic reaction and it was causing ear infections, etc.If none of it helped, it could be there's some underlying problem suppressing the immune system or affecting nutrient absorption. A lot of skin conditions arise when the body struggles to meet other "more important" basic needs (i.e. keeping the organs functioning optimally).
Of course, the solution could be as simple as taking a look at what you're feeding - not all commercial feeds are properly balanced, and a lot of dogs are sensitive to particular ingredients (chicken is a common culprit). If they're not getting the nutrients they need, or not absorbing them because the digestive tract is irritated, skin conditions are a typical outcome.
Once his system calms down we can "peel the onion" and figure out what he can,and cannot, eat.