We've seen all the "duck and potato" foods but I feel like in trying other foods we're just changing too many variables with each test. We'll never figure out which thing it is or was. That's why we wanted to get down the the simplest diet and see, whether it's rice and beef, chicken, turkey, eggs, whatever. And then add to that one thing at a time. I want to be rid of the ingredient lists full of who knows what additive.
Those foods are actually quite simple, though. And you need to try them AT LEAST a month each. Doesn’t matter what kind of food you’re talking about - a month on just that food, even if it’s “just real steak”. It’s time-consuming, period. For most allergic dogs, it doesn’t happen overnight.
Of course, that’s if the dog is allergic to anything catastrohic (dust, anyone?). You can also check into “bug” allergies from when they are bitten by fleas, mosquitoes, etc.
But you may have other things going on that aren’t allergies. Just sounds like it could be.