Since my daughter was born April 2013, Luna has been licking and biting the hair off her belly till it is raw and infected. Her vet has treated her for a potential autoimmune disorder but she has failed all diet changes and medications and supplements. He said we could do a biopsy of the area but even he doesn't believe we would gain much information from that and the $400 would be a waste. It is either autoimmune, cancerous, or behavior related. I have two feliway diffusers going in different parts of our house. I have tried making her wear an e-collar but she always manages to wiggle out of it. We recently started her on amitriptyline. Does anyone else have experience with this behavior.