I purchased 12 BCM chicks last October. I was wondering if someone could give me some advice. The chicks are around 14 weeks old now. About a week ago, I noticed the smallest pullet lying down all fluffed up. I figured she was just trying to stay warm. She was like that for a couple days. I tried to touch her and she got up and started limping really bad toward the feeder. I separated her and brought her back into the garage with a heat lamp. She could stand but she couldn't walk well and we looked at both her legs and couldn't see anything wrong with them. We figured maybe she sprained one of her legs or something. She has been inside for 2 or 3 days now and she can't stand at all and one of her legs is stuck straight out behind when she lays down. I can roll her on her back and move her legs and she just lays back and closes her eyes. She doesn't move either of her legs or toes. If I try to stand her up she falls on her face or on her wing or side and just lays there. She will eat and drink at least if I put it under her nose, but she seems sleepy. We looked on the internet to see if we could figure out what is wrong and unfortunately it sounds a lot like Mareks. They keep saying paralysis of the legs, one sticking back and one forward. Now she is definitely sticking one straight back but the other one is floppy underneath her belly. She is being kept in a box right next to my new chicks that are only 1 week old as we thought this was an injury. Now I am worried we may have exposed the chicks to a highly contagious disease. Although I read on a website that the Mareks vaccine would only stop the paralysis and tumors. The lady I bought them from said that she vaccinated them, so does that mean that this couldn't be Mareks? Sorry for the long post, but we are getting to the point that we think she needs to be put down, but I would rather not if I didn't have to. Any help would be greatly appreciated. We are fairly new to chickens and have never had a sick one before. P.S. No one else is showing any signs of illness or paralysis. Thanks!