I have a Daschund that is about 2 and a half years old. She was a stray that dropped into our laps when she was less then a year old, she still had a puppy tooth or two. Anyway, I have noticed that she seems to go through cycles of itching on her back. She does not have fleas. IF I let her she gets under the bed and rubs the hair right off her back. It lasts for 2 or 3 weeks and then it stops and her hair grows back. Does anyone know what this could be? Her name is Gretchie. She is red.