I have one SLW hen that is rubbing her head on her back. She is eating and walking around but will stop, sit and rub the back of her head . I have been giving her vitamins for the last two weeks on and off. I even banded her leg at one point just so I could id her as she was getting so much better, I couldn't find her in the flock. She does sound "raspy" when I hold her. Now I think she has an upper respiratory problem. How should I treat this? All the other hens are just fine..??