That was interesting SueNH
The horse there looked more to be suffering from lack of blood flow to the heart maybe - certainly no sign of a panic or anxiety attack
We had a horse that was eventually found to have a tumour growing by his heart that behaved like that - though not when the girth was tightened - just would stop occasionally, stagger and almost pass out then be perfectly fine.
He was retired from riding because of it but the vets couldn't find a cause until the tumour got large enough that the blood flow was always restricted
I wish I could remember...Long time ago when the net first opened up I remember somebody talking about this same kind of thing. I almost think it was like squirrelfood said. The nerve is running in just a hair bit different a spot than most. Gets aggravated from repeated pressure and eventually *poof* the horse winks out for a minute or two.
I watched the video. The girth was a little too close to the elbow. Still, I can understand a nerve problem. Maybe the US Cavalry knew what they were doing when they used a quarterstrap that puts the girth farther back. 2CavSgt.jpg Photo by deddygetty | Photobucket
Even if you tack up wrong, and put the saddle too far forward, like THIS example, http://img503.imageshack.us/img503/4369/jake3.jpg
you still girth farther back than an English or Western saddle does.
Can you get an English saddle that girths farther back? That might help.
I agree. I didn't see any signs of panic or behavior. And yes, the cinch was forward a little. I would like to see what happens if the saddle is set back and the cinch is tightened a few inches to the back.