Sick pullet, and I'm almost positive cocci is the culprit. Been doing the chicken thing for a few years, but this is the first time I've had an outbreak/overload of this parasite, and of course have no corid/amprol on hand, so it's ACV in the water and off to TSC in the morning, hoping the pullet is okay until then. First, a big THANK YOU to casportpony for the excellent information on dosing. I was tempted to just pm you with my story/questions, but decided it is better to not fill up your pm box and maybe the answers to my questions will be helpful to someone else reading in the future. These are 9 hatchery birds from MPC (Meyers), hatched June 3rd. Had them in a brooder in the house (extra bathroom) feeding medicated starter. At about 2 weeks, brought in dandelion clumps from my yard (4 adult chickens free range the yard) with the dirt. At about 4 weeks, started putting them out in a rectangular hardware cloth cube for a few hours/day. At about 8 weeks old, attached a 2"X4" welded wire no floor dome shaped run to the cube and let them out all day (moved brooder to deck and put them back in brooder at night to sleep). Moved cube/run around the yard each day. Changed food to flock raiser (not medicated) at about 9 weeks. Adult chickens roamed around area, checked out new flock, etc. Aug 17th (one week tomorrow, so at almost 11 weeks old) moved them to pen area sharing a chain link 'wall' with adult chickens. This pen area was a garden last year and adult chickens were in there frequently this year before moving the younger ones there. Have not yet allowed the younger ones out to free range. Everything seemed fine, everyone doing well until Tues, Aug 20th. That day spent about 15-30 minutes just watching them before we left to run some errands and everyone seemed fine; we left about 2:30pm. Took a quick look/count when we got back home around 6pm, didn't notice anything out of the ordinary, but didn't spend much time then. Went out around 8pm and had one dead pullet in the pen. No obvious signs of injury, really couldn't figure out what happened. Pullet was in rigor mortis (not sure how long that takes to set in, so not sure if she was gone at 6pm and I just thought she was sitting on the ground, they all do that alot and always have) and her head was at an odd angle, thought it looked broken. Spent all day Wednesday checking on them (about every 15-20 minutes, I was nervous!) and watching them and saw no signs of anything. Did the same on Thursday, but checked them about every hour (except I was gone for about 3 hours, home by 1pm) and by the time they went to bed last night I had decided it must have just been a freak accident/injury/death. This morning everyone looked fine, I left for about 2 1/2 hours, came home and had another pullet down. When I went to pick her up, she was still alive, no obvious injuries, but she would lay down with her legs out to the side. Brought her inside, put her in a chicken crate on a clean old dust ruffle that was mostly white so I could see if there was any bleeding, etc. about 2:30pm. Gave her water(with ACV) and feed. She remained sitting, but by about 4pm was back to sitting on her feet normally. Up until about 8pm there was nothing on the dust ruffle, she had been drinking the water and at least picking at the food based on the scattered feed. At 8 pm, there was alot of watery poop and alot of blood. She was standing and looked like her feathers were fluffed out and she was hunched. Neither of those symptoms were present when I found her/put her in the crate. She's staying in the crate in the bathroom tonight. Have seen no symptoms in any other chicken. So, here are my questions: 1. Do you think it's anything other than cocci? 2. Do you think this is a good treatment plan? I plan to treat as for a 'severe' infection. I believe my TSC only carries the Corid powder, so was going to go with 2 teaspoons/gal for 5 days. My thinking is this seems to be a fast moving strain with the blood in the poop showing up before any other symptoms. I saw no evidence of any bloody poop in the pen and I was walking around in there looking for it Wed and yesterday, but I'm guessing this was the cause of the other pullet's death which seemed asymptomatic until death or at least until a few hours before death. I will treat all 8 remaining 12-week old chickens. 3. Should I treat the 4 adult chickens? Based on the first death occurring at 3 days in the pen, and a 5 day incubation period (from what I could find), I'm worried the overload was in the young chickens' poop that was throughout the yard from where I kept moving the dome run. I'm concerned the adult chickens would have been exposed, because when I'd move the run, the adults would spend an inordinate amount of time pecking around in the spot the run had been moved from. I'm sure they were exposed, but unsure if they have developed an immunity already. 2 of them have been here for 19 months and 2 others have been here for 3 1/2 months. The adults range from 19-24 months and are not showing any symptoms, but my feeling is treat them, it can't hurt. My only hesitation is that they will not be able to free range while on the medication because I would not be able to limit them to only having the water with the corid. They will not be happy about this development at all, but better safe than sorry. 4. Am I missing anything? I will use vitamin/electrolyte supplements AFTER 5 days of treatment, not during. If she makes it until morning, I will monitor and make sure the sick pullet is eating/drinking (as well as everyone else). I think I'll keep the sick one in the house for a couple of days or at least until she is looking better. Since there's nothing else I can do tonight, and it's 11:50pm here, I'm heading to bed so I can get up and get to TSC when it opens. I will check here before I go to see if anyone has any other ideas/input as to other supplies I may need to get. I'm about a 45 min drive from TSC, so it would be best to get anything I need while I'm there. I may also try to ask in the store, but they hire college kids mostly (it's Athens, GA, a college town) and I'm not sure they can help with more than where to find stuff in the store. Thanks to anyone who took the time to read this novel, and thanks in advance for any ideas/suggestions.