One of my hens has had what seems like a cold for a month now. She started off with a lot of sneezing, coughing,mouth breathing, and nasal discharge. Soon after she stopped laying and started molting. We tried to treat her naturally for two weeks, but put her on clavamox when she didn't improve. Her symptoms are less now. She is not breathing through her mouth and the nasal discharge is lighter, but she is still sneezing and coughing. She still isn't laying, but aside form these symptoms seems healthy. She has a great appetite, is drinking, and has energy. My vet doesn't know what is wrong with her. I feel bad because she has been isolated from the flock for a month now. Any ideas what this might be?