Hi. I'm new to this board, and new to chickens. We just got our first batch of day-old chicks 5 wks ago, and they've all been healthy, happy, and growing like crazy. This morning I noticed one of my black austalorps seemed to be having trouble with her left leg. I picked her up and examined her, and there's no sign of swelling or injury. Her eyes are clear, doesn't seem to have a fever, but when she tries to walk she seems to lose her balance, skitters sideways and falls over. When she tries to stand up her left leg starts shaking, kind of like a person's would from muscle fatigue. She's eating and drinking fine, and seems to want to run around and play with the others but she just keeps wobbling and falling over. She seems to be trying to compensate by walking along the walls of the coop. She spends a lot of time lying down with her feet tucked underneath her, not on her side. So far none of the others have been picking on her, and she doesn't seem to have any trouble getting to the feeder/waterer. She's one of a group of 27 we ordered from Welp, and they were all vaccinated for Marek's, but I've read that the vaccine isn't 100% effective. Could this be her problem? Do I need to isolate her from the rest of the flock? If it is Marek's, does she have any chance of recovering (she was vaccinated - would this increase her chances)? These chicks have quickly become my babies, and I don't want to lose her, or risk any of the others having similar problems. We kept them in the house in the brooder until they were almost 3 wks old, then moved them out to the coop about 2 wks ago. The coop is an old horse trailer that my dad and I refurbished. It was cleaned and painted before they were moved, and it's never had chickens in it before now. These gals are 5 wks old, are fed Dumor chick starter/grower that we get from Tractor Supply. Every couple days we give them some treats - 1/2 a piece of ripped up bread, 1/4 of a mashed banana, or a handful of ground up oatmeal. I clean their feeders and water out every day. They get fresh food 3 times a day. Any help or advice would be greatly appreciated. Thanks!