Wait a second, I wouldn't start treating for Cocci unless you know they have it. Have you seen any blood in their stool? I think they just had a rough trip, unfortunately that happens sometimes. When I have a weak chick I do these things: 1) Poly-Vit-Sol (without added iron) baby vitamins: couple of drops, a couple times a day (you can find them at pretty much any pharmacy, drug store, wal-mart, etc) 2) ACV in the water 3) Make a hard boiled egg/plain yogurt/chick starter slurry and then very patiently try to get them to eat as much of it as you can by wiping a tiny dab on the corner of their beak and letting them lick it up. Good luck!