Need to switch from Innova

My 15 month old golden, Jack, had been doing well on Innova large breed food when I started switching him to regular Innova adult. In a short time he started to chew his feet and developed some sores on top. I initially thought it might be the start of fall allergies, but I put him back on the lg breed formula. His feet improved a lot with only a little redness left now. The only ingredient difference between the two is herring meal in the reg adult. They do both have herring oil. Since I'm suspecting a herring allergy, I'm looking to switch to another food without fish meal (not sure if I need to avoid all fish or just herring?).

California Natural might be an option, but I'm not sure if the protein is high enough for a young dog. Has anyone tried Pinnacle chicken formula? My 10 year old allergy golden is doing well on the Pinnacle duck & potato since we switched him from Natural Balance duck & potato.

Thanks for your help!