My Cocker Spaniel has numerous food allergies. We feed him grain free only, currently he gets Orijen fish formula. We noticed fish and potato formulas tend to work better than poultry or red meats.

From my understanding, injections are doses of the allergens themselves and that is why his allergies are worse. The goal is for him to build an immunity to it, so it will get worse before it gets better.

Good luck with your pup! Cocker Spaniels are such a wonderful breed, I'm sad that they often come with many health issues!