[anonymous]

The blood test, that’s what I thought.
Most allergies are environmental. Ask your vet if a referral to a veterinary dermatologist for intradermal skin testing is indicated if he doesn’t have a positive response to the diet changes and treatment in a reasonable amount of time.
Especially if the symptoms have been going on for 4 seasons/1 year without significant relief from symptoms.
Hope this helps

Evidence Update- Evidence-based Canine Allergy Treatment