Allergies

My doggie Goose has been pretty itchy, got him on Apoquel because the testing is so expensive. Cleaned ears, oatmeal bath, no changes. He doesn't have fleas or anything. He's 2, neutered, all shots current. Tried elimination diets, salmon oil, and probiotics he's on currently. We're currently feeding him Acana Lamb and Pumpkin which he's been eating for about 6 months at this point. We have cats, other allergens maybe, just looking for advice on things that you all found helpful. TIA.