Respiratory infection help

[riverlane91]

I just got 6 new chickens, all are healthy but I think they may have carried in a respiratory illness. 2 days ago I noticed my aloha Hawaiian hen was sleeping standing up by my car, she just wants acting right. Yesterday i came home and she was worse and my polish hen was having trouble breathing, both had a snotty nose and drool. My Hawaiian also has runny eyes. I started the flock on tetracycline hydrochloride and disinfected the whole coop. The polish is better but the Hawaiian is still falling asleep standing or keeps going back into the coop to sleep. If I wake her she perks up and will walk around and drink a little but not eating. Any ideas on what more I can do? And how long does tetracycline take to start working? Is her sleeping a way of fighting off infection or is she giving up?

Thank you!