Sarcoptic Mange in Dogs
above is info on scabies but if you are not itching and do not have rash as highly contagious to humans and my grandma's dog had it and she got it. Yes the revolution will rule this out as we used it in my allergy dog to rule out scabies as well.
I have an allergy dog for almost 5 years and have seen it all and this to me looks like an allergic reaction to something - i strongly recommend biting the bullet and going straight to a dermatologist and they will get to the source immediately as the vets will just keep doing the steroid thing and mask the problem and you need to get to the heart of the problem
here are some pics of my girl and what i have been through
DEE DEE ALLERGIES pictures by dwerten - Photobucket
what are you feeding as this could be a reaction to diet as well as could be a contact allergent- did you move into a new apt and maybe they cleaned carpet with a chemical that he is reacting too ?