I've got an 8yr old, male, white cocker spaniel (Alex) that has had allergies for the past 5 years. A couple of years ago we broke down and took him to an allergy specialist. They did the prick test to find out what he was and was not allergic to. He was allergic to most everything on the list. It seemed that everything the allergist tried Alex was not helping him. He would also scratch, dig, and bite so much he would cry. It had even gotten so bad that a few years ago I was about to have him put to sleep, just to get him out of his missery. The allergist did tell me that the allergy shots could take up to a year before they would start to work. I also had gone through a couple different premium dog foods. First it was Nutro's Lamb and Rice, then we went to Purina's LA dog food (Limited Antigens) -only sold at the vet's office at $53 for a 30lb bag. Finally, I've switched to Solid Gold Holistique dog food. I switched the foods over a two year period. I'm pretty sure he does not have any food allergies. After several years we have finally come up with a concoction of medicines and a shot (I give every other week.) He has a flare up every now and again, but I just up his dosage. Medicines are cephalexin and temril p.
I do want to warn the prednisone shots can cause liver damage over a prolonged use and it becomes less effective as your dog's immune system adjusts requiring more of the drug. Temril P also is a form of prednisone. The prednisone has also caused my Alex to gain a large amount of weight...and it doesn't come off easy. His ideal weight is around 35lbs, he had gotten up to 53lbs. I think he is now around 43lbs. Keep in mind he gets NO table scraps. The vet now has me feed him on Tues., Thurs., Sat., and Sun. I give him greenies on the days I don't feed him. I feel bad that everyone else eats except him. I hope this has been of some help.