baby chick deaths

[mlivly]

Over the past 3 weeks I have had chicks dying. The currently sick one is about 4 wks old. The chick was fine yesterday and this morning is having trouble standing up-very wobbly, off balance-kind of walks like someone who is really drunk. The others looked like this too-they continued to eat and drink but by the third day after the "wobbling" gait, were dead. It has affected both Rhode Island Reds and Golden Sex Linked. They are on medicated food. Normal looking stools. Don't appear to have rapid or labored breathing-any ideas.