I have 17 hens and 1 rooster. Last week I thought that I heard my rooster crow funny. Today I am sure, it sounds like he is congested. They all seem to have a cold. The older ones sound weezy, No discharge from the nose. They are all acting fine, eating, laying, coming out of the coop and such but they seem to have a cold. This is my first winter with chickens. Help.