My two oldest (9 months) are now sick, I didnt notice for about a week or maybe longer. My light Brahmin is wasting away, she was plumpy but now super light, and weak, my heathiest BSL has red streaks down her butt, I dont see blooody poop, but maybe I'm not looking hard enough. I know that the cause is my lack of avian biosecurity, they share (but separated) a run with 7 week old silkies and they are doing fine. The outside birds are coming in to the run and eating the food of the older hens, as I have netting around most of the area for the younger ones. The poop has a strong smell, not at all the "usual" smell. What should I do? Tetracyclene or Sulmet? I am not sure whats hitting the older hens. Help!!!!