Our pullet had a black bump on her comb. We thought it was dried poop, so with a wet paper towel gently cleaned it off. It came off in one chunk and we realized it was a scab, not poop. The skin underneath was a bit slimy, like a recovering scrape. We left it be. Two days later now, it looks like this. We are separating her now but I wonder if we should put ointment or see a vet? Just don't want to cause the stress of a vet visit if it's not serious or waste time not taking care of it if we need to.