Today I noticed that my Easter Egger has white foamy material in the corner of both of her eyes. My research points to Chronic Respiratory Disease caused by a bacterium, usually introduced from new birds or visitors. I am treating her now and have her quarantined from the rest of my flock. My question is this: This is a closed flock. The last birds I introduced were chicks that are now five months old (I've had them since they were 3 weeks old). I have not introduced new hens, nor have we had any visitors. If I am able to treat this hen, should I keep her separated from the flock forever? How can I prevent the spread of this to my other girls and how can I prevent this from occurring again? My frustration is that I am very careful with my girls and we still got a bad disease! I will post pictures if anyone would like to see. Thanks for any help or advice you can give.