We've just gotten our flock through with having cocci & now i have one hen that is lethargic, has an empty crop on the roost tonight & appears to have vomited. she was acting normally two days ago, but has been sleeping each time I check on her today. I'm still medicating their water with "Duramyacin". Last week I lost five birds to scours. all got better once medicated, but this one is sliding down hill again. Any suggestions?