My dog does too and she gets a shot of some kind of cortisone/steroid from the vet. This helps tremendously with her itching, as does Benadryl. I have a lab and a great dane, so they are huge and under the care of the vet when taking meds. Also, I’d try a different vet. Additionally, there are vets who specialize in allergies and dermatological issues, which may be worth a visit. Your current vet may know of one in your area. Also, using stainless steel dishes helps and bathing regularly with a hypoallergenic shampoo. There is also a very expensive brand of food called Hills, only available at Vet’s I believe, but I just can’t justify the cost. It’s like $70.00 for a 30 lb bag or something ridiculous.