try putting some electrolyte/vitamin in their water. You could also try the poly-visol without iron. I work at a feed store and had a little sebright do that when they came in. She was very weak. I give all my chicks at home and at the store the electrolye in their water. After getting her warm I started dribbling the water along her beak. I did this off and on all evening and by the time I left work she was drinking on her on and eating some. The next nmorning when I came in to work I couldnt tell which chick it was that was sick. She was up running eating drinking with everyone else. Also since doing this we hardly have any pasty butts at work now.