I have taken in a rescue dog--a small, two-to-three year old Shih Tzu mix--and she has a strange, unpleasant rash on her hind-legs and belly. It itches terribly which causes her to scratch it incessantly (and I can only assume this opens opens up the problem for infection, bacteria, etc).
I have taken her to a vet and they (kinda) confirmed that it wasn't some kind of mange; pushing a $50 bottle of shampoo the size of my thumb onto me that has yet to of improved the poor dog's quality of life.
My best guess is that perhaps it is a very severe allergy to fleas/flea-bites (and, being no vet or animal expert, I only say this because the few times i have given her antihistamines from the pet store she stopped itching (of course this is probably because they simply put her to sleep...)).
Any advice will be greatly appreciated!