Well, I now have to make the decision to have a closed flock for a few years or cull everyone. I absolutely adore almost all of my birds (ninja rooster not so much) and the thought of culling the ones that are resisting the infection is tearing me up. We had nothing here until I brought home new chicks, which I have never done since my original 4. I bought 5 Easter Egger chicks and as they grew, one by one, they fell. They were already in the same room with my younger chicks after several WEEKS of showing absolutely no signs of illness. Yes, they were isolated first. I am down to 2, and one blue Australorp is going downhill fast despite antibiotics (I can't remember the name, but it was the one first recommended). Before I bother with another more expensive antibiotic, I just wanted to ask you guys if there is a point. If they will all be on antibiotics for the rest of their lives, then I can't justify keeping all of them. I will have to cull down to the favorite pets, because paying to feed chickens whose eggs I can't even eat or sell is just not going to happen. If I'm just needing to treat if they become symptomatic, that is something I can do. Can I vaccinate day old chicks with any success, or will they already be infected in the shell? I have two 0% hatches under my belt this month. Is that mycoplasma or the crummy little giant incubator refusing to maintain humidity and temperature? They developed fine in the older hovabator incubator but are dying in the shell in the little giant I bought for hatching. I had one chick pip and emerge from the shell partially while I was asleep, and it was dead. So I'm believing it had the respiratory illness already. The temp in the bator was warm enough that it should not have gotten chilled at all. I have eggs from another breeder in the hovabator, or I would have left the second batch of eggs in the the old bator. So incredibly sad. I love my chooks.