Food Allergies

I believe that one of my cats has a food allergy because he had sores on his head. He is wearing an inflatable ecollar which seeems to help. My vet recommended switching the cat food to Hills z/d which seems to be helping. I am also giving him probiotics. I am hoping that I can have him go back to Blue or Blue Freedom. Any suggestions?

Maybe your cat is allergic to chicken. Hill's Z/D uses hydrolized protien, so even though it contains some chicken your cat's system won't react to it, even if it is what's causing the allergy. It also includes a lot of ingredients you don't really want to be feeding your cat. If your cat is allergic to chicken it may be why he was having a reaction to Blue, which is a high quality food. All Blue formulas contain some form of chicken. My oldest cat is allergic to chicken, she can't eat anything that contains chicken or chicken fat. She's also allergic to grains and peas, so it's very difficult to find a food she can eat. Hopefully this won't be the case for you. I would wait until he's healed completely then try him on a grain free food without chicken. I ended up putting my cat on Simply Nurish Sweet Potato and Salmon, you can buy it at Petsmart. She does well on it and it's not very expensive. I would also keep up the probiotics.

I suggest trying a diet with a single novel protein sources (rabbit, duck, venison, lamb...)

I have 3 cats with food allergies (1 to grains and pork; 1 to beef and rabbit; 1 to chicken/all chicken products.)

I used all 3 hydrolyzed foods (Purina HA, Hills z/d and Royal Canin.) I had switch from HA to z/d due to GI issues associated with the food and then had to stop using z/d for the same reasons. My cats didn't particularly care for the Royal Canin (all of these were the DRY formula.)
Royal Canin makes dry/canned limited ingredient prescription diets in Venison, Duck and Rabbit.

Nature's Variety Instinct makes dry/canned LID diets in Rabbit, Duck and Turkey. They also make a LID canned Lamb formula.

Both the Instinct and the Royal Canin LID are Grain-free (both use Green Pea in them.)

I now use Instinct (dry/canned,) Royal Canin Prescription PV (venison)/PD (duck) and various other grain-free canned food that doesn't contain their individual allergens.

Thanks so much for the info.