While brushing out my mare, Magic, today, I discovered an odd lump on her tail. It doesn't seem to bother her any, even if I push on it, and it's a solid mass, not squishy or anything. I took some pictures on my cell phone... sorry if it's a little hard to see.
Does anyone have any idea what it might be? I've never noticed it before, but it may have still been there awhile, because I almost didn't notice it today. Does it seem like something the vet should look at?