So I got a couple of silver laced wynnadotes from a breeder on October 15 at 7pm. We got them home and it was bedtime for the rest of my flock and I put the new hens in the large coop with the rest. We checked on them all twice that night and everyone was fine. The next mornin I went out at 730am and put the new hens on one side of our fence and the others stayed on the other side for a bit then flew over to investigate. The silvers were doin great and eating and drinking fine. A few pecks here and there from my flock but nothin traimatic or worrisome. I went inside and came back out at 8am to check on the silvers and they were still walkin around doin fine. Came back out at 830am and one of the silvers was out in the yard pecking around while the other was lying next to our shed. I went over and picke her up to put her by her sister. When I put her down she just lay there. I sat with her a moment and noticed a gurgled breathing with her mouth opened. I got concerned and brought her in the house and put her in an opened box. I watched her for five minutes hoping it would pass but it got worse and worse. She began coughing and sneezing more and more. At this point I became worried for my original flock, who are more like pets to us, and went out to isolate the other silver. I came back in after setting up the other silver with food and water at about 915am and the sick hen was dead! I am curious to know what could have killed this little hen so quickly an if I need to be concerned for my little flock? Again she was perfectly healthy this mornin. Any help would be appreciated and I will answer any questions anyone has. Thanks!!