Our chicken has not been normal for the past several days: moves slowly, doesn't peck around as usual. She has been sitting on her roost most of the day, does not want to get out of the coop. She is making very little poop, and we do not believe she has laid an egg for the past two days. Today we picked her up off of the roost, and instead of the usually chicken sounds, she made only a few sounds, and she sounded very congested, as if phlegm in her throat. We checked her for mites, and there are none. We checked vent area for pasty butt, and no paste. Any ideas?