My hen that I hatched 6 months ago showed some signs of lamness already as a chick. It has progressed to her shaking and burying her head under her breast as if she is dizzy. She seems so shake it off when I offer her food and water, but then goes back to tucking her head under her body and walking backwards and slightly shaking. I have separated her from the flock, due to them walking on top of her. Help! I have raised chickens for about 6 or 7 years and have never had this happen. Any ideas??