Please help, I have had 2 hens die and a third who I am trying to keep from dying! Hen 1: Fine in the morning, acting normal with everyone else, found dead in the afternoon, I autopsied her and found no worms, no mites or lice, no nothing, looked like a totally normal healthy bird. Hen 2: Had trouble walking for a couple days, I was giving her extra vitamins, extra protein, immune support. We had a rough rooster and I was thinking he threw her back out or damaged her back. She seemed mentally totally fine, just had trouble walking well, but was still able to walk and was hanging out with the other birds. Eating and drinking on her own. Then found her dead on the 3rd morning. Hen 3: Was totally fine this morning, this afternoon I found her laying down, fluffed out, breathing with her mouth open and unable to walk. I checked her, she isn't egg bound as far as I can tell, she doesn't have any mites/lice, her eyes and nose are clear. Her crop feels normal. I gave her a direct couple drop dose of Corrid followed by some water to wash it down. She is barely swallowing what I am giving her. I put her in a quarantine tote in a warmer room with food and water. History: I got all of them vaccinated for Mariks and Cocci from the hatchery, they have never been wormed but I have autopsied a couple now recently and have found no trace of worms, nor have I seen any signs in their poop. No bloody stool as far as I can see. I give them water via water nipples so it is always clean water. They are in a large enclosed pen, so they haven't gotten into anything weird. They are eating good organic layer feed, with optional grit and oyster shells. What should I do? I don't want to loose this girl, and I don't want to keep finding mystery dead girls!!!!! What can kill this many girls this quickly? By the way all my other hens are acting totally normal. And the rough rooster was separated yesterday morning so it wasn't him this time.