What I'm gathering does appear that it may partially be weather related.
And checking for pasty butt is so easy to miss sometimes and super deadly fast.
Most of the dead chicks have not had pasty butt. It's like they go from completely fine with no noticeable symptoms one minute, to dead the next minute.
How big is your coop/run and how many birds in there total? Not including brooders.
See my previous post. I will also add that my adult large fowl birds all free range most days in our very large 1 acre yard.
And is your medicated chick starter, in fact medicated with amprolium? Amprolium as well as Corid (name brand) actually is a thiamine blocker that slows the growth of coccidia. It does not actually kill them. Every sing poo has coccidia in it... warm and humid conditions help cocci to grow rapidly and sometimes out of control. And sometimes the amount int the medicated feed may not be enough to combat the load and you may still have to treat.
I assume that its amprolium, but I'll check the label when I get home from work tomorrow morning (I'm pulling a 24hr shift at the hospital today. Yay.)
But other than sudden death... we need to hear some type of symptoms.
Mostly no symptoms, except for occasionally the symptoms you'd expect from cocci- inactive bird standing over in the corner, etc. But the Corid has not seemed to stop it. Also have had some "chicken coughs", but the antibiotics seem to have stopped that. Yet they're still dying.
Do your birds have plenty of shade when it starts to warm up? And how is the ventilation on it?
Lots of shade in the areas where our coops are. For West Texas, we have a lot of trees in our yard. Coops are well ventilated, but with roosting areas where they can get out of the wind..
I'm sure at this point you know I'm not trying to find things to nit pick at just get the whole picture and try to be supportive. I agree it SHOULD NOT be this hard, and I hope you get back to the joys of keeping instead of the fear of losing real soon!
Did you have any of your original birds when you came to Texas or did you ... actually, I see you bought juvenile birds... Are those still alive? They are my first suspect to bringing something in...
Yes, with the exception of Seramas (which nobody seems to sell as chicks, only juvenile and adult birds) I will never buy juvenile birds again, only chicks or hatching eggs. We don't have any adult birds that came with us from Tennessee except for one random Mille Fleur D'uccle old lady who coops with one of my Serama pairs, but there haven't been any problems in there at all. The problems have all been with Juveniles who haven't started to lay, and suddenly now chicks. One of the juvenile birds that we bought when we first started our flock back up here in Texas started to have a "chicken cough" soon after we got her and I'm pretty sure that's where this all started. But I've treated the entire flock with antibiotics for respiratory issues (MS, MG, etc.) multiple times since then and haven't been able to wipe it out.