When mine came down with cocci, I didn't know until i walked into the coop and found one dead. I started looking around and there was bloody poop EVERYWHERE. I don't know how I didn't notice it before. I immediately switched them to medicated feed and put Corid in their water. I didn't have any more die after that, to which I was very surprised and thankful. My friend was over and she kept saying "Let's go check on the chicks." I refused, not wanting to go in there and see who had died next. (I didn't neglect them or anything. I checked on them often enough to know they had feed/water and were okay. I was just so nervous to see who else had died, and she asked ever 10 minutes or something.) They are all healthy free-ranging chickens now. (Well, I take that back. Some of them have fowl pox, but I'm not counting on that killing them.) So if it is Coccidiosis, would recommend medicated feed and Corid. It seems to have kept mine from dying. I was watching them grow weak and poop blood, and they still managed to perk up and survive. If you haven't, check for bloody poop though. Like I said before, it's really hard to miss.
Chicks have something called shed intestinal lining come out in their poop naturally. It looks like bloody poop, but much less severe than coccidia. If it's Cocci, there will be no doubt in your mind that it's Cocci. If it looks like poo with a bit of bloody flesh in it, it's not cocci. If it looks like blood with a little bit of poo in it, it'd probably cocci.
Chicks have something called shed intestinal lining come out in their poop naturally. It looks like bloody poop, but much less severe than coccidia. If it's Cocci, there will be no doubt in your mind that it's Cocci. If it looks like poo with a bit of bloody flesh in it, it's not cocci. If it looks like blood with a little bit of poo in it, it'd probably cocci.