Chewing fur off

by Katie

I have a nine year old female jack and need answers!! The past couple of years shes been itching around her tail so much she chews her fur off....IT's not fleas! or from one flea bite. We've treated house, yard and other dog for fleas. Used hot spot treatment, she chews right through it. I'm sure that doesn't taste good at all. Not anal glands, had them released a couple times before. changed diet so many times... no grain...no chicken... no corn...raw food diet...you name it. Took her to dog dermitologist, did skin scrapping they found nothing. tested for fleas, mange, worms...I did more exercise with her, no change. It's not seasonal, all year long! Only relief she gets is from steriods, and that's not even 100% better.. and long term steriods is not a good idea.