Seems to me that this mare needs some body work
done. My gelding acted in a similar manner after being saddled, although he
would stand to be saddled, he'd act like he was afraid to move afterwardsm, and
then he'd finally start dancing around with his back a bit hunched. He was
afraid.....of the pain. After an adjustment, he was fine. The adjustment also
started the change in his trailering behavior. Prior to the adjustment,
he'd damce constantly and bite the trailer while inside. After the
adjustment his behavior began to change to quiet loading & riding.
BTW, the vet hadn't found any medical problem either. I had him adjusted
anyway.