My chicks are dying how do I identify the disease or cause

[danalister]

I have two hens who have had two clutches of chicks about 2 weeks apart. The first clutch all the chicks (5) were fine for about 3 weeks, then the second clutch hatched and one of new chicks died on the second night, I then scrutinized all the chicks and noticed that two chicks, one from the first clutch and one from the second clutch did not look so well, they were not eating and seemed sleepy, they were following their moms around but often getting left behind and closing their eyes. I suspected coryza as my chickens have had that before and I believe it remains in a flock??I noticed one of the mums shaking her head and what looked like a small amount of mucus flying out, but she was not wheezy or clogged up with snot and the babies were not snotty or wheezing in any way either. I began treatment for coryza/coccidios (ESB3). 3 days later another 2 chicks died (the sickly ones) and last night another one that had seemed perfectly well also died. I forgot to mention that just after the first clutch hatched another one of my teenage chicks (4months old) just dropped dead in the night, literally fell off his perch, and that seemed a perfectly healthy chicken, one of her siblings contracted what I think might be Maericks disease when he was little as he slowly seemed to develop slight paralysis of the legs, and is unable to roost and now walks upright like a penguin,but he is a perfectly happy, friendly little guy, with his place in the flock and has lived like that for about 3 months now. I just don't know where to start trying to find out what is wrong! My chickens 1 rooster, 6 layers, 2 mummies, 2 teenagers and the remaining chicks are all free range in a 2 acre plot, they roost at night in a spacious house, which is cleaned every day. Does anyone have any ideas : (

 

[CMV]

You are seeing the long term implications of having a flock with CRD. When you opted to treat instead of culling, this is what you signed up for. Your morbidity and mortality rates are going to be much higher than in a healthy flock. Your expenditures of resources are going to be much greater than in a healthy flock. And the flock itself is going to frequently be ill.

I am sorry.