Muscle spasms

Dr. Lowder:
I have a 7 year old paint mare that has developed a major twitch/muscle spasms in her chin when exercised. You can stand by her and watch her chin spasm out and if you feel that area it is just like a clock ticking in there. This cause her to jerk her head up.

Could she have head shaking syndrome or what other possible causes could there be? It makes it very hard to train or ride her as she can't concentrate on what you are trying to teach her.

I've had her teeth checked.

Ê Thanks for any help.
Diane in Oregon

Diane,
You will see this in horses that become sore on their training and the worst is that once they start it is near impossible to stop them. I would consider riding the mare with a bosal (hackamore) and see if that helps.ÊÊ

Thank You,
Dr. Lowder