Since last weekend, I noticed that my two year old Thuringian hen was crouched down quite a bit but I didn't think too much of it, she was still acting normally, running to meet me and eating and drinking. Then on Thursday I noticed she was struggling to walk. Over the weekend, her right foot has become completely curled up and paralysed and her left, whilst not as bad is also a bit useless. She shuffles about on her elbows. She's still alert, eating, drinking and chatting. I've separated her from the rest of the flock and started giving her vitamin b in her water. There's no sign of injury or bumblefoot. Has anyone any idea what this could be? What else can I do? She's a lovely, friendly girl, I'll be really sad to lose her.