I have a vet that works both Eastern & Western Meds for dogs, PLUS he has 30+ yrs behind. He has started his own supplement company called 2docs. You can find it on the internert and he has a great natural formula for allergies. I would make sure it is not a food allergery, something as simple as changing him to a fish and potatoe food, several companies make them. THAT"S ALL HE GETS during the test. NO treats!
Check out 2docs web site Randy is the BEST of the BEST and the allergery formula is great, you can also get support from them on their website
Sparkling Blu Yorkies!!!