My Buff Orpington Rooster has developed black spots on his comb.. It's not frostbite, but looks scabby... None of the other chickens has this at all. Everyone else looks clean, even the floppy combed Brahma.. Does anyone have an idea as to what this could be? How to treat it? thank you in advance for any and all help... It doesn't seem to bother him.... Just me...