I have a 9 month old Ameracauna hen who was perfectly fine yesterday and last night, laid an egg yesterday, I locked them up in the coop at about 7 pm and all was well. This morning at 8 am, she is down in the corner of the coop, I thought she was dead. I picked her up and she was totally limp and she is not a chicken who likes being petted or handled much. I thought she had broken her neck or back, but she can move some but not enough to get up. I checked all over for injuries/blood, can't find anything wrong. The only thing I notice is a thin mucus in and around her beak. I moved her to a screened porch away from the others, and made her a pen. I was able to hold her head up, it seems she doesn't have the strength, and got some electrolyte water down her, as well as 1cc of Tylan, as recommended by my neighbor, who has kept chickens for many years. Any ideas? Do they go down overnight like this? Anything else I should do? At this point, I am very upset, it doesn't look good.