I've often stated that if you are going to raise chickens you need to become accustomed to having some of them die. The same must be said with regard to protecting your flock from disease introduced by wild birds. It some times happens and there is actually very little you can do about it. Probably about the only thing you can do is food management. Never feed more scratch grain then your flock will eat in just a few minutes and broadcast it in a small area. Excess grain attracts wild birds but they are not likely to land in close proximity to actively feeding chickens. If your feeders are outdoors use covered.
