Slaughtering
In most countries where horses are slaughtered for food, they are processed in industrial abattoirs in similar fashion to cattle. Typically, a penetrating captive bolt gun or gunshot is used to attempt to destroy the animal's higher brain tissue. The blow is intended to either kill the horse instantly or stun it, with immediate exsanguination (bleeding out) being used to both ensure death and to begin the process of meat harvesting. Saleable meat is removed from the carcass, with the remains rendered for other commercials uses.
Horse welfare advocates have raised concerns that the particular physiognomy of the horse cranium means that neither the penetrating captive bolt gun nor gunshots are reliable means of ensuring that is horse is in fact killed or stunned, and that the animal is more likely to be simply be paralyzed, and to therefore experience the full pain and awareness of being skinned and butchered alive during the final phase of the slaughter process.
Blood of the Beasts (Le Sang des bêtes) is a 1949 short French documentary film written and directed by Georges Franju featuring the slaughter of a horse (and other animals).
Read more about this topic: Horse Slaughter