[Keiko]

Hi, i have a mixed goup of 7 chickens. One of the hens is always sneezing and has discharge coming from her nose, she sometimes gapes too, though this hasnt effected her laying at all and there is no signs of swelling but she does have a stunted top beak (could this be the problem?). This has been going on for sometime with no effects to the other birds, she was like it when we got her, but now a young cockerel has developed the same symptoms. I was wondering if anyone could help tell me what it may be and how to get rid of it? Thanks