We have been and are going through the same allergy battle with Cincy. We found food was not improving her condition and as soon as she was off the antibiotics she was back to itching. Benedryl and Claritin didn't really help too much.

One thing tht did help was a new shampoo called Kertalux. The other thing that seems to be helping is immunotherapy. We have a blood test run that said yes, it is an allergy (tht took about 15 min in the vet's office) they then sent the blood out for further testing (both food and airborne) and found she is allergic to dust mites. We have begun giving her shots at home and she has had her first 5 which were 4 days apart. She will be given one a week for the next 2 months, then go to every other week, and eventually one a month, where she will stay for the rest of her life.

Getting started on this was expensive, but when we get it under control, it should only be $75-$100/year. (less then we were spending on antihistamines!) So far it is helping. We are not thre yet, and she is not as full dose yet, but we are making headway. If you have any questions feel free to PM me.

Good luck with Jasper. I hope you find relief for him soon!