I have an 8 month old bantam hen that has an ongoing nasal congestion but is otherwise healthy and energetic. Eats well, drinks, runs, plays, sleeps, etc. The congestion is yellow, hard, and smelly. An older hen of ours would every once in a while have the same issue (like once every year or two and she lived to 9), and she was in the same area as this hen. No other chickens have this issue. I had treated the older hen with Tylan 50 but am wondering if this is the right course? We don't have a knowledgeable chicken vet in the area. Thanks!