Well this is discouraging. We started keeping chickens several years ago when we lived in Tennessee, and as a total noob, I almost never lost a bird to something that I couldn't figure out. I even bought way more chicks than I needed thinking, surely I'm going to loose chicks since I have no idea what I'm doing. I didn't loose any and I ended up with way more chickens than I needed. I did all the dumb things I now know not to do. Maybe it was beginner's luck? Then, in the Fall of 2015, we moved to West Texas, and after a few months of getting settled, I built a new walk-in chicken coop and bought some juvenile birds to get a head start. One after another, they started dying. I tried giving them antibiotics, keeping things clean, treating them with Corid for Cocci, etc. but it was all to no avail. One after another, they would all die. Not all at once, but like one or two at a time every couple of weeks, just when I thought I had things under control. I bought new birds as chicks, raised them in the brooder, and would eventually integrate them into what little remained of my flock. Of the 20 or so chicks that I bought last August, I have a total of 2 birds remaining from that batch. My next-door neighbor also keeps chickens and almost never looses a bird, even though our birds are kept less than 100 yards apart (though they never have any opportunity to mingle). If it was something airborne, her birds should have been dying too, but they didn't. I kept fighting with everything I could throw at them, and then finally, as it cooled off for winter, things seemed to get better. Then about 6 weeks ago as it started to warm up again, I had a barnyard mix pullet that I hatched last October up and die on me for no apparent reason, and since then I've probably lost at least 5 more juvenile birds. About 3 weeks ago I got in a shipment of Cream Legbar chicks that I spent a pretty penny on, and they started dying on day two. Since their arrival I've lost about 7, and wouldn't you know it, all the ones I've lost have been pullets and I haven't lost a single cockerel. 3 out of 4 of the Serama chicks I hatched 10 days ago have died, and they are kept in a completely different brooder to prevent them from getting trampled by the bigger chicks. One minute they look completely fine, the next minute they're dead. I've treated my entire flock (both adults and chicks) with Oxytetracycline for respiratory infections for two weeks, and then a couple of weeks ago I started treating them with Tylosin when that didn't stop it. I've tried treating them with Corid in case it was Cocci. No dice. So yesterday I broke down and spent $65 for a gallon bottle of di-methox (Sulfadimethoxine) in case it was one of the strains of Cocci that Corid is ineffective on. I've wormed the juveniles and adults with both Wazine and Ivermectin Pour On, and I treated them with poultry dust. I'm changing out their water daily, and cleaning all of my waterers with bleach daily, making sure that they are well rinsed. I give my birds Probios in their feed, and Rooster Booster vitamins & electrolytes in their water. I've tried using different feeds, everything from Purina, to Nutrena, to DuMor, and now Bluebonnet Poultry Conditioner for adults and Bluebonnet Nature's Balance Start and Grow (medicated) for chicks. My feed is always fresh and never moldy. I'm cleaning brooders every couple of days, replacing shavings, and wiping everything down with bleach, rinse, dry, fresh shavings, repeat. The amount of time and money that I've spent over the past 6 weeks on cleaning and treating with meds is ridiculous. This is infuriating. It makes absolutely no sense. This really should not be nearly this difficult. And I'm about ready to take a very long break from keeping chickens if I can't get it under control. The next bird that dies is getting sent to the ag extension for an autopsy.