I have 2 dogs, one a bicheon pommerian mix and the other a bicheon, pommerian terrier. Small hairy dogs. I keep them clipped and well groomed. My problem is they both scratch to the point of sores and hair lose. They do not have fleas, ticks or mites. I use sensitive dog shampoo. My vet prescribed a topical cream and suggested children's benadryl. Which cost me 167.00 including vet visit, but offered the little relief that only lasted a few days. Any suggestion? I'm open to anything.