Hello: I have approx. 500 Black Sex-Links chicks (BSLs) who are split up into 3 different groups. We're still recovering from Hurricane Ike which destroyed a lot of my bird housing, (AND much damage to MY house) so things are less than ideal. When I first got the chicks, I had them housed in a trailer in litter, in two equal groups. During the hurricane, they were moved inside into my business building on litter, in two different groups. (Yes - I'm STILL cleaning up!) The hurricane wrecked the chick's housing. Therefore, I'm "making-do" with what I could pull together, once I got them out of my place of business! Two groups are on "ancient" litter, and are doing fine. The third group are on pasture with the protection of a "Chick-Inn" from Farm Tec. They've been there for approx. 2-3 weeks. The chicks will be 8 weeks old on Wednesday. The "problem" group is approx. 150 being kept in the above 12' by 18' structure. They have "baby" roosts, and the water is kept VERY clean. Fresh food is given twice daily. The weather has been mostly dry since the hurricane, and although confined, there is plenty of sunshine, ventilation, etc. and their area is very dry. However, it IS on grass. About 5 days ago, I noticed 3-4 chicks standing around, not interested in food, with kind of ruffled feathers. One of them had mustard yellow poops - no blood noticed. I started that group on Sulmet, and followed the instructions on the bottle. They are already on medicated feed. Unfortunately, I've lost 3 chicks since I first noticed a few "not acting right", and one is still acting droopy. I'll be dumping several bales of fresh pine shavings into their area this evening. I'm ASSUMING that 1. the problem really IS coccidia, and if so, that the grass became overwhelmed with contaminated feces and thus overwhelmed the chicks immune system? 2. That it isn't something else? The other curious thing is that I STILL don't notice blood in poop, and the ones that have died have clean vents, and except for the first one, were some of the biggest chicks. I haven't bleached out their feeders, but will do this evening. Any suggestions? Would it be worth dosing the sick chick with an alternative? From prior posts I've learned that protozoa don't respond to antibacterials, but my Merck's manual lists stuff like oxytetracycline. Is it worth giving this a try? If so - what is the dose? Thanks for any help or insights people can give me.