The problem may not be the protein source. Dogs can react to any ingredient that has protein in it, including peas, beans, lentils, corn, alfalfa, flax, etc. So it could be the other ingredients that all Orijen formulas share.
My dog reacts to chicken, many grains, tomato, and flax, which is kind of funny, because when I first started trying to figure out his issues, I used DinOvite with great results and it has a lot of flax in it, but he reacted strongly to chicken and grains and only had a very minor reaction to flax, so it took me another year to figure out that he was also reacting to that.
