17 day old chick who walks with a real wobble due to both legs having some kind of paralytic weakness. Can't tell if its muscular or what, but it looks somehow more like nervous system than like structural, if you know what I mean. It's as if she is 'walking on her knees,' or rather as if the bottom half of her legs don't work. She can't perch either. I do not think she was born with this symptom, though I can't be sure. I'm worried that it's not a birth defect but rather a symptom of disease. I've just never seen it before. Didn't notice it til she was over a week old- though again I can't be sure as I had a lot of chicks at the time - and it is definitely worsening. My concern isnt so much for her- she is eating, drinking and growing quite well and I don't notice anyone picking on her - the question is whether she has a contagious disease or not. Ideas? Advice? Thanks so much.