You might ask the vet for some amitryptilline. It is an antidepressant (for humans) and also pain relief. As a "side effect" it has excellent anti-histamine properties and is very sedating. My Jake (golden retriever) has had long term problems with allergies, and when they get really bad, they amitryptilline helps, if for no other reason than it is a great sedative and he doesn't itch if he's sleeping. Good luck. Jake's mom.