I had this happen a long time ago and lost all of my flock. I moved from that location and recently started my flock again. I noticed today I have some red. Comets snezzing and running nose. I tried vetrex last time and the powder you put in their water. This didn't help last time. I lost everything. I. Have read about tylan 50. I never have used it. Please if you know of something I can do to fix them let me know. I don't want to lose any. Cost is not a issue. To see them sick makes me sad.