respiratory infection: do i treat or cull?

[milillion]

Looking for some help with a sick chicken. She seems to have an upper respiratory infection. Rattle in her breathing. Does a head bob to swallow and she has white liquid draining from her beak (not nose and eyes look normal. no swollen face either) Ive got her isolated and on some antibiotics. Trying to determine what i should do next..... Does having any sort of respiratory issue mean she is a "carrier" and will infect the rest of my hens OR is it just having Coryza that does that? I was hoping to get more chicks this spring but if I treat her and keep her then I will have to have a closed flock. Any and all advise welcome.

 

[Eggcessive]

The most common respiratory infections are infectious bronchitis (IB,) mycoplasma (MG or CRD,) coryza, and ILT. It is up to you to cull or not, but she may infect the rest and any new chickens, and all will become carriers for life. How is her crop? Is the white liquid mucus or crop contents? Coryza may have a bad odor around the head. You can always contact your state vet to get one tested, or get a necropsy done or a sick or dead bird. Many times they will euthanize for no extra cost. Here is some info about finding your state vet, and a good link on diseases including the ones above:
http://www.aphis.usda.gov/animal_health/animal_dis_spec/poultry/participants.shtml
http://edis.ifas.ufl.edu/ps044