I came home today to find one of my seven 4-week old chicks down on her side with legs extended. She can kick her legs, flap her wings, and move her neck and head although her neck does seem weak and she doesn't seem to control her head well. When I pick her up she puts up a protest. They have been on medicated chick feed since I got them 3 weeks ago. They were on Save A Chick Electrolytes and Probiotics for 2 weeks, then changed to acv for the last week. They are in a 50 gallon brooder with a heat lamp at one end with the temp directly underneath 75 degrees. I strip the brooder every 3 days and line it with clean paper and add kiln dried pine shavings. Their water is set up above the floor so it doesn't get dirty and it is changed once a day. I have found only one wet / diarrhea type dropping since I have had these chicks and it was dark green / brown. She ate from my hand with the other chicks last night. She has not appeared lethargic that I have noted. Her crop feels empty. What I have done so far: removed her from the brooder and put her in one of the cardboard boxes used to mail chicks with shavings and set it under the light but not directly under, sort of at the edge. I gave her water with electrolytes and probiotics via a syringe, dripping it on the side/end of her beak. She appeared to drink. I administered 2 drops of infant poly vitamins (no iron) the same way. I believe she did take some. I have given her water every hour and a half since finding her. I made a slurry with chick crumble and lots of water and got her to take a tiny amount of that. I found her 7 hours ago and she is the same or perhaps if I am not imagining it, a very tiny bit improved. Any idea of what else I can do for her or if you think I am on the wrong track, is appreciated. She does not appear to be in pain.