About a year and a half ago, my pit bull Gotti, had a small case of mites.  The vet scraped him to test for the mites.  "Scraping" involved actually scraping, with a razor, a small amount of skin cells from the bald spots where the mites were.  We got rid of the mites and all the hair on the places the vet scraped grew back, except for on the top of Gotti's head.  The hair has never grown back, and he's got this nickel-sized bald spot right on the top of his head.  I took him to another vet this winter, and he checked for mites, but there were none.  So, we're not really sure what to do.  It's only a superficial thing, the dog is 100% healthy. We were just wondering if anyone had any suggesstions for growing back patches of hair, like any good topical ointments. Everywhere else, he's got thick, healthy fur. Thanks for any input.