Horses die decisively. They thud to the ground thunderously, try a few times to get up and then just stay down, panting. The sound of a horse falling is horrific, final. There is no way to push it back where it came from. If you are watching it, it happens in slow motion, and the sight precedes the sound, like thunder gathering force behind the lightening bolt. Then it hits your eardrums and you shriek despite hands over your ears.
The vet helps with a giant needle in the neck, administering enough drugs to kill a horse, literally. Its eyes lose focus, its muscles lose tone, breaths become shallow, raspy, rare. All movement ceases, but the skin stays warm for a while yet.
You kneel by the dying animal and caresses its flaccid neck. The chestnut fur is matted and muddy from the recent crash, her belly rising and falling, the wait between breaths excruciating. This horse is all horses, you think. Warm, accommodating, apprehensive, sometimes funny. Your whole life has been spent with these gentle giants, and here is another one leaving you behind.
Pauses between breaths are getting longer until no more follows. You pick up a thick lock of mane and braid it.