It could be genetic or it could be a toxin. If it is genetic there isn't much you can do. If it is a toxin again their isn't much you can do except to try to limit potential exposure.
I know that in the case of botulism, wry neck can appear to be a symptom and death can follow quickly. I heard one person claim that giving vitamin B complex mixed at the rate of 1/2 capsule dissolved in one gallon of water may be helpful. It should be the only source of water and should be made fresh daily.
Good luck.
