Treating a sick hen & Roo w/Tylan. What for the flock?

[sarahandbray]

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!!

 

[Eggcessive]

You don't want to be treating birds who are not showing symptoms, since it won't help to prevent symptoms. Separate any birds showing symptoms, and treat if you wish. Respiratory diseases can be from viruses (infectious bronchitis, ILT, and others,) while others are from bacteria or mycoplasma (MG, coryza,) and others can be from mold (aspergillosis.) Antibiotics will only treat bacterial and mycoplasma, but not viruses or mold. Air sacculitis is the biggest complication in respiratory diseases. If you lose a chicken, send the refrigerated body into the state vet for a necropsy, to determine what disease you are dealing with. MG can cause facial swelling, but coryza can also with a bad odor. Both make your whole flock carriers for life. Adding new birds is always risky for introducing chronic diseases, and they should be quarantined for at least a month to look for symptoms of disease.

 

[sarahandbray]

Ugh. And I was SO CAREFUL! I've only introduced chicks that I've hatched myself or bought from reputable hatcheries. Twice I've gotten adult birds, but have quarantined in my garage for over a month.

I have the two birds separated (separately!) and if one dies, I will send it for necropsy, but it's around $100 here. Cornell Coop Extension was not as helpful as I thought they would be. Oh well.
I'll push to get more directive about where to send for necropsy. My big show rooster isn't getting any better, so it might be his time if he doesn't respond to the Tylan 50 in a few days.
We have a vacation coming up in two weeks and I'm not having the chicken sitter babysitting a sick ward as well!!