My dog has had a strange hairless 'bulb' near his tail for about a year. I think our vet called it a 'tag' and said nothing needs to be done. Over the last week it has gotten a bit larger and he has been biting on it a bit.
I don't want to have to take him into the vet if they are doing to just say nothing needs to be done. I thought maybe I would check WebMD.