I Knew it!
There was a reason for Sparkler's crow hopping/bucky behavior! I think we proved it.
Dawna came out tonight to do some bit fitting. I've not been sure whether to ride through her behavior or not. If it's just that she's learned I'll get off when she kicks then I need to do ride it through. If there's a reason for the behavior, that's another thing.
The first thing Dawna did was work on a big knot in Sparkler's neck, massaging it out. We walked her some and she was fine. Then I put on her sweet-iron snaffle bridle and within a few seconds of walking she kicked out with her left leg. We tried a JP-type bit on the headstall and she seemed to take it well walking her but holding onto the halter underneath. To be sure, though, we put the reins on and bang - as soon as I picked up the left rein, the leg kicked out and she bucked with both feet. It sure looks like something in her mouth -- activated by pressure from the rein -- makes her buck.
What to do? We tried Dawna's side pull but ran out of time to really test it. So I'm going to get one -- a Liz Graves model, very reasonably priced. There's no bit! If this theory is correct, it should solve the problem. Stay tuned!
Some interesting links related to these topics:
