I have a relatively large flock--about 65 birds in three coops in a large pasture. One of my prize SLW roosters showed signs of a respiratory infection 3 weeks ago, so he's been in quarantine in my basement. I've been giving him Oxytetracycline, but it hasn't helped. He's about the same--wheezy, hard to stand, mouth-breathing. Flock was fine until last night I noticed a BCM hen with a closed eye. Checked her this morning and it was closed and goopy. She was out for a moment but went back to her roost. I brought her up to the garage and have her in a dog crate. Now what? Ok, so it seems like Tylan 50 injections for both of them? 3-5 days? How do people with big flocks stop the spread of this? Do I buy the jug of $70 Tylan water soluble powder on Amazon? I can't possibly treat that many birds any other way. And do real farmers actually cull ALL their birds if one or two is sick like this? I just can't imagine!!