One of my 2 1/2 yr. old hens , started acting sluggish and started staying to herself. Stopped eating and drinking, and just sat all humped up with her eyes closed. When I went to pick her up she just layed over on her side. All this just started yesterday morning, or thats when I first noticed her not eating, and not running around with the other hens. She is very thin and her breast bone is protruding. Anyone have an idea as to what the cause is. This is the second hen Ive lost like this. It happens so fast, by the time you see something wrong, their all but gone. No lice,mites, and see no worms in her poo.