Well, Chewbacca, since you weren’t there, you don’t know, do you?
Unfortunately, opportunities to accustom her to the cart will not be consistently available, since it isn’t kept at the farm, but is hauled in to be used and then returned to a different farm. My mare is remarkably unflapped by most new stuff, and when she spooks, she usually ‘unspooks’ pretty quickly. In this case, not so much. I think it isn’t the cart, it’s the combination of horse and cart. I think we could work through it with regular and gradual exposure, but at least in this situation, that is unlikely to be possible.
I was definitely surprised by how upset she got, and how upset she stayed, and I didn’t really get any warning that the other boarder was going to be working her horse with the cart until I saw her come down the driveway. So sure, it surprised me, but I have handled my mare in a number of unfamiliar circumstances, and this is just not how she ordinarily behaves, even when something bugs her. Somehow, you will have to believe that I know what I’m talking about here, and am not just freaking out because she spooked a little. I think I will handle it better next time because I’ll have some idea what to expect, and my own surprise won’t be part of the mix. I am hopeful that she will be less bothered next time, but she may not be.