I have a rat terrier. She is 8 years old. This summer she got a skin problem that I thought at first was the mange. All the mange treatment I gave her did no good so I ended up taking her to the vet. The vet said it was a yeast infection. She gave the dog a shot of some sort, some antibiotics, and some special shampoo to be used twice a week. I gave her all the pills and gave her a bath twice a week for a month. The problem cleared up and all the hair that had come off of her feet legs and under her chin grew back. Everything looked good. Now it appears to be coming back. The hair is coming off her again in the same locations as before. I still have some of the shampoo and have been using it, but the problem isn't getting any better. She stays outside but has access to my shop which is heated and air-conditioned if this matters. Anybody have any clue to what might be the problem before I go back to the vet?