II have been avoiding making suggestione here, since I cetainly don't know your horse, but I had a nice thoroughbred mare that was coming along very well in her training suddenly get very tense and reactive. I jumped right off and removed the saddle. She was so sore right behind the withers that she practically went down when I touched her.
I had to lay her off for awhile until she was no longer sore. For her it was a saddle fit problem. Nancy
