My 5 month old Easter Egger, Elsa, suddenly developed paralysis last week. Since then I have separated her from the other hens. None of my other chickens show any symptoms. She eats, she drinks, doesn't have diarrhea, but can't walk! She can't really stand well and will just roll over on her side if you push her a little. I'm not sure what it could be?? I have been giving her vitamins daily along with her normal layers feed, oats and cracked corn and her daily greens. Suggestions?