Here's the story: https://www.backyardchickens.com/forum/viewtopic.php?id=572252 Here's the update: We are on Day 4 of having sick chickens. I've lost 4 birds out of 30 so far (one Wednesday, one Thursday, one Friday and one today). I have one still not walking well and looks like starting to slow down a bit more. I also have about 3 more that look a little tiny bit sluggish, but are still eating and drinking. They have all been on sulfadimethoxine since Thursday morning. I have only had one bird with frank bleeding (lost her Thursday am). I have a lot of birds that have very normal looking poo. I can't really tell if there are any more having bloody diarrhea. I have 3 of the sluggish looking ones isolated. I have released some of the previously isolated birds back into the coop because their poo looks normal and their behavior has perked up. (Again, all are on antibiotics). I have been giving them lukewarm water because it is pretty cold outside and that seems to increase their drinking. I've also been keeping their coop a little warmer with a heat lamp, so they are less stressed by the change in temperature. So... here are my questions... how long should I expect for this to run its full course? Can I assume remaining birds are immune? I wasn't feeding my birds medicated chick starter before this (they are about 5-6 weeks old now). Should I start medicated feed? If yes, now or after this runs it's course? (I know medicated feed can help prevent, is not used for treatment, etc). I have also read that medicated feed works differently than antibiotics and can actually interfere with antibiotics, so I'm guessing starting now is not a good idea. (And this goes back to are they immune now anyway?). I have asked some of these questions to the chicken expert at the local cooperative extension and his answers weren't as helpful as I'd hoped they would be. He just gave me a hard time for not having them on medicated feed to begin with, keep them on antibiotics, and then said just let it run it's course. I also have a friend of mine that is holding a healthy silkie that I was going to add to my flock (needed a home and I wanted a silkie). Of course, I will wait until things are well settled here, but what should I expect about my chickens being carriers now and adding a bird? I'm still trying to understand the microbiology of coccidiosis... it's something that can be in the environment in soil. It can also be passed from wild birds to domesticated birds (we have wild turkeys come through our yard on a regular basis). I did all of the recommended things to avoid general chicken illness prior to this outbreak (clean feed and water 2-3 times per day, plenty of space, clean pine shaving bedding while in the brooder, starting composting bedding when moved into the coop). Things I could (will) do differently in the future: medicated feed for the first few months for new chicks, will scrub down at minimum the nests and perches with bleach when this is done and then paint them, probably the whole coop. Have an outdoor run in the process of being constructed, but not done yet. Don't know how to feel about letting them forage in the soil now anyway, though I can't imagine not letting them, either. Anyway... all thoughts are very appreciated. I would love to hear from anyone else who has had an outbreak like this.... Thanks soooooo much.