My son had cranio-sacral therapy for a year. It was a big help to him. The therapist was a horsewoman who wound up working on several of my horses. You might check with the Upledger Institute, which does much of the CST training in the US, and ask them if they can connect you with any local therapists who might be able to work on your horse.
My 87 year old mother has been getting craniosacral therapy for about 5 weeks. It has made a HUGE difference in her comfort level! So much so that she told me she was able to go to physical therapy today for the first time in months!
She has a number of physical problems and has had me very worried as I live 8 1/2 hours away. I have been after her to get CS therapy for years but it finally took a crises to get her to do it.
I am SO relieved that she is feeling better!
And, wow, this is the first time I actually got one of these icons to work.