I keep chickens primarily as pets. Three days ago, I was given two silkies, which are sick. (Sneezing and conjunctivitis, but still eating and drinking normally.) Thankfully I have had them isolated, but I am worried because my other hens got out of their pen 3 days ago and may have gotten near the sick ones. I am about 90% certain I am going to cull these sick birds (which will be super sad, but maybe the most responsible thing to do), because from my research, respiratory illnesses are chronic and not curable, but I was wondering how long it would be before my original hens would be considered "in the clear", or can I ever be sure??? I'd hate to put them down on the CHANCE that they were infected, but on the other hand, if they don't get sick but carry the germ, I'd never forgive myself if we passed this to other chicken keepers. Can you help?