My boy Flint is allergic to chicken, he gets really bad hot spots on his skin if he eats even the smallest amount. It might have to do with the poor quality of dog food here in the US, but that's the only problem he has. I feed him a good lamb & rice kibble and he does fine on it, healthy skin, fur, teeth, keeps on weight etc. Plus I add lots of fruits, veggies, grass, treats etc to his diet. He's kinda like a vaccume cleaner, I'm sure you're used to that with your AmStaffs.
What allergy's do they have??