Reviving an old thread here... same issue...
I have two chicks who are about 3 weeks old -- one is growing like gangbusters (9.7 oz yesterday) but the other is small, sleepy, and only weighs 4.4 oz. They were about the same size when I brought them home 2-1/2 wks ago, but the size difference now is dramatic. Bigger is an "easter egger" (named Taco) and the smaller was sold as a buff Orpington, but is clearly an Ameraucana (muttonchops & green legs; named Ethel). Right after I got them, the smaller one was having trouble, and I finally figured out that she had not learned to drink, so once I made sure she understood the water, she was doing fine.
Both would run around, eat, climb on me when I took them out, etc. Normal poop, the smaller one's poop was a bit wetter, though not liquid.
Yesterday, Ethel's left leg seemed hurt: she could stand and walk, but preferred not to, and would "collapse" to the left as she sat. Today when I took them out of their brooder, she was kind of floppy. She did not move her legs at all. She did flap a bit at first, but has essentially been sitting on me without moving (wrapped in a towel) for the last 2 or so hours. I have been trying to get her to take liquids (water w/electrolytes & vitamins) but she's not very interested. I did get her to eat a couple bits of egg, but she's been refusing it since. I don't think she's eaten since yesterday -- no poop since I've been holding her.
<<sigh>> I already lost one little chick this spring, and if I lose this one, the other will be lonely! I've got 2 girls outside who are 7 years old, but I wanted Taco (the easter egger) to have her own pal...
I've read a bunch of "failure to thrive" threads -- it sounds like if Ethel has coccidiosis then Taco would also have it. I've been doing everything else that has been mentioned, but just wondered if there were any other suggestions anyone has come up with...
Thanks! [glad to be back on the site. Had to re-register, which is why this appears to be my first post.]