What did the vet suggest? If the symptoms have been going on for 1 year/4 seasons without a significant response to treatment by the regular vet, the next step would be to go to a veterinary dermatologist and get intra dermal skin testing, you need an accurate diagnosis.
Hair and saliva mail in tests are not allergy tests, don’t be fooled. use the search engine here to search allergies. This subject comes up frequently.
Has your vet referred you to a veterinary dermatologist? That is where I would start.
Have you checked the search engine here, example:
/forums/topic/candida-in-dogs/
/forums/search/allergies/
