Ok, well I am on bird number 2 now. First one died, found a 2nd. she is pooping bloody stool. I just feel like I am standing on the tracks and the big train is coming.... they had two dripper bottles of W. milk then saw others looking for water so I opened up the water to them figured being dehydrated is not going to help me at all. Completly cleaned out a new pen, sprayed it with 10% solution of Ammonia, let it sit for a long while, then rinsed out. Hooked up a dedicated water system with probiotics powder in the water, the packets were old but I used what I had, including a small packet of electrolytes that was also old. Hung a light for warmth, will wash out food containers next with the Ammonia solution and wait. Meds should be here by 12-noon tomorrow.
While moving chicks to new home some are very light, some don't look good to me. I think this stuff moves quickly. I didn't notice anything but regular poop on the towels (from the move) that is the very good news of it.
So don't treat the whole pen?