I’d like to recruit some owners of headshakers to try a treatment that has worked for mine. Two things up front: I will make no money from this and you should consult with your vet before trying it.
I have a now 18 year old OTTB mare that stated severe headshaking 4 years (or so) ago. We think that neurologic Lyme may have been the initial cause, but it went on to have a seasonal life of its own. It was so bad that each year we would consider euthanasia to end her suffering and she was unsafe to ride.
When she became symptomatic this spring I decided, in consultation with my vet, to try oral CBD (cannabidiol) oil. I gave her a 10 mg dose three days in a row, using a product made for human use. Day 1, she seemed more comfortable within 30 min or so. Days 2 and 3 there were no symptoms. I skipped day 4: no symptoms, but I gave an additional dose on day 5. That was over two weeks ago and symptoms have not yet recurred.
I don’t know if the effects will last or if they can be generalized to other headshakers. In my horse the change has been so striking that I will not hesitate to give her additional doses should symptoms recurr.
If anyone else has experience with this or is interested in trying it, I’d love to hear from you!