My dog is a 3 year old american bulldog, since he was young he has had anditchy right ear which I concluded could just be yeast (since he is rather large). But he also gets black spots along his stomach and down his legs, when I pat the black spots he shows me they are very itchy with his hind legs. They are crusty and small, about the size of a dime, and not completely black but also a fungus type colour. When they are scratched they peel away but I dont peel them in fear of hurting him. I know this can be caused by fleas but none of my other dogs suffer from it. Pictures are available upon request. Please help.