I have a hen that was pecked on the head real bad by another hen. Then the Roosters jumped on her. She has a hard time walking , she falls to the side. Then I brought her in the past two nights (very cold temps out) She started throwing her head back onto her back and shaking vigorouly back and forth. I gave her water with eyedropper and very little apple sauce. Any ideas of what I can do for her and what does the neck thing mean. Thank you.