I went out to see why I couldn't find a bird and she was inside laying down wyes closed. I picked her up and her legs and wings were floppy. She opened her eyes. She had a greenish/yellow ooze on her bottom. Her vent actually looks good. Pink and moist. Smelt a bit vinegary. Her breast bone was really protruding. I left her for 2 hours and she seems worse. She was upside down and a bit twitchy. I'm like 98% sure she'll die. Just curious why. I separated her from the flock (unfortunately it's out in the cold, but I put her out of the wind and snow) but it's just kinda sucky. I feel awful What do I do? Do I just have to put her out of her misery or does it sound like she'll die soon and I should just let nature take its course? Will my other hens be ok? What can I do for them? Blah. This is the sad side to chicken keeping.