So, I was just putting my chickens away for the night when I turned around to find one hen still out. All day, she had been acting completely normal—she was dust-bathing, eating, drinking, laid an egg—everything a healthy chicken would do. But, when I approached her and picked her up, she was somewhat limp, and was gulping a lot. I checked to see if she was choking on something, or something was stuck in her crop or throat. Nothing. I checked for mites and broken bones—nothing was to be found. She was also shaking badly, and her eyes were also half closed. There really isn’t anything that she could have eaten that would’ve made her sick . . . So, what is it? Is there anything I can do to help her?