My flock (13 hens, now) free ranges for about half the day on a one third acre fenced in yard. I've had 3 deaths in the past 2-3 months: The first was a sudden death in a previously healthy 3 year old hen who had laid an egg the day before. The next morning, she was dead under the roost with no external injury. The 2nd was a 3 yr old hen who was never very robust to begin with, but developed what looked like respiratory distress, beak almost always open and panting, even when weather not hot. The third was a rooster -- we just put him out of his misery last week, because he developed a staggering gait with neck starting to twist off to one side. He had been sleepier and less active for several weeks prior to the gait disorder. After doing some reading, I learned that Newcastle disease could account for all these deaths. And, since that can be acquired from wild birds, and mine free range, it seems like a strong possibility. Another hen is now starting to pant with beak open most of the time, even when it is not hot here. Questions: Do you think this is Newcastle? Is it likely to kill the whole flock, if it is Newcastle? Should I put down the whole flock and disinfect the place? Is it possible to prevent it in a free range situation? ...Or is it likely to run its course, affecting a few birds, with the rest of them able to fight it off?