i found a 9 month old easter egger had foamy eyes and was sneezing. i immediately isolated her and watched her for a day but she was gone next morning. i cleaned out my coop and disinfected with acv. i gave the remaining 14 hens probiotic yoghurt and acv in their water next day nothing. day after maran was suddenly dead, fine in the morning when i let them out and then gone by lunch when i went to check. next day an orpington dead in the morning when i opened up the coop. olive egger sneezing next day barred rock 3yr old sneezing next day different hen dead, barred rock puffed up - expected the worst today fine in the morning, and lunchtime my last green egger just dead. mouth open ive checked all for mites, nothing. ive just turned off my winter lighting but surely that cant be taking them out one by one. theres no sign of predator entry to the coop what can i do? its almost time for the spring worming but if they are already fighting off something i dont want to stress them more. theres no evidence of worms ive stood int he coop for an hour and examined the poop of all 9 left. the barred rock is now fine but another marans is acting weird. the olive eggar has also recovered ( she was the second to have bubbly eyes, none of the others have had that) any ideas what it could be and how i can stop it. i dont want to lose all my hens. i also have three baby chicks in the house brooding, 4 weeks old, but i practice bio security procedures and they all appear healthy. worried also as i have friends with coops and i dont want to carry anything courageous to their area so have been avoiding them.