For several days one of my hens has been very inactive and won't eat or drink on her own. She is not gasping (like if she had a gape worm) and I wormed her yesterday. She will drink a little if I offer her water, and I have added "Sav-A-Chick Probiotics" to the water. Has anyone experience this with a chicken? I've been doing research and not having any luck pinpointing what the actual problem is.