i've read through most of the threads on allergies -- well, more like skimmed -- apologies if this has been covered. my dog has had allergies pretty much his whole life (he's 7 1/2 now.) he's allergic to pretty much everything. we ran tests, he was even allergic to most of the allergy foods. he is currently on prairie and doing well foodwise. his other allergies, however, are flaring up again - that time of year, ya know. we have tried so many things for this guy, i don't even remember all of them. we have done several different antihistamines, which didn't help with the itching, we tried various holistic ideas, including vitamins and supplements (i remember trying quercetin, i don't remember which others. he has always gotten vitamin C, fish oil. we did vitamin B, but i think that might have been for something else.) so far we haven't found anything that helps, and right now he is more miserable with his itchies than i have ever seen him.