Sneezing and coughing

[Gbear74]

I have 8 hens and a roo. The roo and about half of the hens are sneezing or coughing. No change in behavior and there combs are bright red so I treated them with 1/2 cc Tylan injected and will continue for 3days. The question I have is, should I treat the other 11 pullets I have in the same coop seperated by chicken wire? The pullets are not showing any symptoms.

 

[Gbear74]

LOL... guess I will reply to my own post. Maybe someone can help me with this one too, I suspect marke's in my flock. I have been getting about one hen every month or so that gets sick.... becomes unable to walk and of balance doesn't got to roost any more, then dies. There have been three of these in the last 5 months. My hens are about 9 months old. I bought some mareks' vaccine for a batch of chicks I have in the incubator now. When I vaccinate the chicks can I vaccinate the older birds the will just have been treated with Tylan 50 5 days before the vaccine?