misdiagnosis of red mange?

Question
Thank you for your answer yesterday.  Well, we took our 8 month lab puppy to the vet yesterday (Tuesday).  Sunday, we were told she has red mange based on a skin scrape done at an emergency clinic.  Yesterday, the regular vet did another skin scrape and says that it is not red mange.  He believes it is heat spots and general allergies and really does not feel that her symptoms are at all consistant with demondex mite problems.  Now I really do not know what to do.  She has lost a lot of hair on her belly, between her hind legs and in various places on all 4 legs.  She is missing about a quarter size splotch of hair on her back.  She does not have any hair loss on her muzzle or near her eyes.  She has scratched the area around her ears enough to cause large open sores.  Do you have an opinion on which vet I should trust?  Right now, she is taking 1000 mg of Cephalexin 2 times a day and 20 mg of prednisone 2 times a day.  I really hate to bother you again with this.  I'm thinking of looking for a vet with a speciality in skin disorders.  Do you think I should just wait to see if the two medicines she is on helps before seeking out a specialty doctor?

Answer
If the emergency clinic veterinarian saw demodex mites on a skin scraping, then that's what it is.  I would be sure to ask if that was the case because you really don't want your dog on prednisone if there is demodex mange on the skin.  That can make it much worse. Sometimes we can scrape the skin and not find any mites.  If the emergency clinic vet found them and your veterinarian didn't, that doesn't mean that the dog does not have them.  It just means that your vet did not FIND them.