Like badrinker, I could watch it while eating cottage cheese or yougurt, Feel sorry for the horse though!
While eating yogurt, no problem, but that's a hazard of the job.
They need to open that up more, and establish ventral drainage, or it's going to re-occur. (IMHO)
Most likely gave him a couple cc's of ace, or a local.
I've got performance cow horses, more than I need, but really still not enough, and I don't know wtf caused that, but I don't want any.