I have a lovely Speckled Sussex pullet that is about 9 months old. She is otherwise completely healthy as far as I can tell, but yesterday I noticed she was carrying her tail off to one side a bit. Today it seems a little more so. I have checked her over - no wounds, no feather loss, no pain or swelling in the area or at the base of her tail or over her back. She was vaccinated for Marek's at the hatchery. She is one of 47 chickens in our flock, including a few roosters. They get commercial layer feed - always fresh - and free range all day long. Everybody else seems fine and dandy. Any thoughts on what this might be from or what, if anything, I should do?