Hello! Im a newbie to keeping chickens and have a sick hen! I got my hens two and a half weeks ago from an acquaintance. They are 8 months old and laying--two gold sex link and two black. Very suddenly, a week and a half after getting them, one died overnight. She went into her coop early that night and hunkered down. I put Immune Boost in the water and she passed overnight. Very sad. Another hen started to look down on Sunday and I noticed some mucus and foam in her poop, so I immediately started treating them with Corid. It's been three days and they perked up considerably and their appetites have increased. This morning I went to check on them and the hen that was looking down is down again. She is hunkered and not very active, but upright. Her red bits look good, eyes clear, no mites... Any thoughts? I have some Duramycin and Tylan is on its way. I am at a loss and frustrated. Can I give Duramycin and Corid at the same time?