I had 17 hens, they are 7 months old. Tuesday night everyone of them looked fine, eating and drinking fine. Wednesday morning I found one hen fluffed up and gasping for air. I picked her up to take her in the house and she died by the time we reached the door. I could see thick clear mucous in her mouth. Nothing else abnormal. I believe that she suffocated from this thick mucous. Last night, all the hens looked great. This morning, one hen was puffed up and refused to scratch for grain when I threw down some scratch. Everyone else was very lively. I've brought her in the house to isolate her. Does anyone know what could be wrong? What medications I can get? No vets in the area will treat chickens, so I am on my own. Also, I heat the coop to about 40 - 45 degrees. There have been no changes in feed, or otherwise. Any help is appreciated.