My hen has been in distress for a few hours. She was fine all day, layed an egg this morning. Found her lying in coop, unable to stand and struggling to breathe.. She can't hold her head up. Her chest had swollen up like a huge water balloon, gave her some olive oil, massaged a little. There is a hard spit in her neck, not sure if it's impacted crop. Just gave her a warm bath to get poo cleaned off, she has been in a crate last few hours. Her legs are sticking straight out, like she can't bend them, she can't put any weight on them and her head has been twitching to the right side. Her breathing is slow but steady now. Her body is stiff but she is breathing, eyes are open. When I touch her stomach or move her, she screeches, a sound she has never made before. Also just noticed when lying with her on her side, there is a pronounced bone down her middle, I don't recall it being like that before, it's exposed. Please help.