[Draygor]

Hi everyone, I hatched out 6 chicks of various breeds at the end of September (2 light Sussex, 1 cream legbar, 1 wyandot and the other 2 I think are Marans). All has been going well until a week or so ago. 

1 of the light Sussex ran up to the feeder 1 day and was very unstable on its legs. Concerned, I scoured the internet looking for possible causes and watched videos on Mareks disease, Newcastle disease etc, but could find nothing that matched what this looked like. 

I quarantined it for a week, gave it vitamins every day, and it is and has always been eating and drinking fine, although seems to be a little underweight compared to the other chicks. 

The main symptoms are that it shakes its head from side to side like something is irritating it. For all the world it looks like when a human has an inner ear problem and it affects their balance. I did find something about ear mites in chickens and wondered if this might be the issue? 

Can anyone shed some light on this for me please? 

Thanks
Tim