I have around 200 chickens that are at various stages/ages and all free range. They sleep in two different coops. One of my older hens started sneezing and coughing a few weeks ago then I noticed a couple of our birds with one eye closed. Next came many birds hunched over, with one or both eyes shut, coughing, wheezing, gurgling, and dying. I’ve lost 10 birds in just a few days. Seems like a terrible respiratory virus. Any ideas or suggestions?