7 month old barred rock. Late Sept to Mid october she was in isolation. It started with running crooked (in a straight line, but her feet were about 30 degrees off to the right). She progressed to whether she couldn't stand at all and lay on her side for a week while I spoon fed her eggs and her regular feed with Vit E, selenium, poly vi sol, electrolytes. She started making gradual progress, and a week and a half later she was back in the coop. Her balance wasn't back 100%, but she wasnt falling. Now, after a couple of weeks of somewhat normal, she started losing her balance again, occasional tremors in her legs, her neck is tucked back into her chest. Poop ranges from loose to normal. Brown. After the first episode, I thought it sounded most like West Nile (which had been in our area). Now that is reoccurring, I don't know! I've read about Mareks, Newcastle, EE, but if it's one of those, it definitely isnt a classic case. No other birds are showing signs of illness. I know this chicken was not vaccinated (and three others in my flock are not), but I'm not sure about the other 9. The person I got them from is hard to contact, and she hasn't emailed me back. Your thoughts? TIA!