That black screen they’re pulling out in the video isn’t some random piece of equipment. It’s a big portable curtain the track crew keeps ready for exactly these moments. When a horse breaks a leg or gets wrecked out there from running full tilt on that hard surface, they rush it into place fast so nobody in the stands or on TV has to watch what happens next. What it actually means (most of the time) is that the horse is done. Once that screen goes up, a vet steps in and puts the animal down right there on the grass with a shot. These horses aren’t getting loaded into some fancy ambulance and rushed off for surgery like many people want to believe. Most of the time the injury is too bad and they just end it quick behind the curtain so the crowd doesn’t see.