So I have 3 chickens that have been congested, eyes and nose running. 1 of the roosters couldn't crow for a couple of days and his eye was swollen. We have been using tetracycline (I think is the name) for 2 days and vet Rx. What else should I be doing for them? All but 1 seem to be getting better. Should I cull since they will now be carriers or let it be? Thanks in advance.