I just picked up 6 barred rock chicks today. They look to be about 1 month old. As I got them home, I noticed two of them are....very sick. They both have crooked neck. There necks are bent upside down and all they do is try to walk, fall over and go into seizures. I'm new in the chicken thing, and I have no idea what is wrong with them. What can I do? Do they have a disease, birth defect or what?