For this reason, veterinarians may need a backup. A .22-caliber pistol is a good choice. The gun should be placed perpendicular to the forehead in the center of an X formed by drawing a line between the horse's right ear and left eye and left ear and right eye. If done correctly, death is instantaneous. To make sure the horse is dead, the veterinarian will listen for a heartbeat and may check the eye for a reaction by touching it.
Horses have a very sensitive corneal response.
If there is any sensation, it will be felt in the eye. If a horse needs to be put down during transport due to illness or a trailer accident, it's best to call the state police. They can put you in touch with a local veterinarian, or in extreme emergencies can shoot the horse to end its suffering. Most large competitions have a veterinarian on the grounds for emergencies, but some smaller ones do not. In the latter case, competition management can put you in touch with a veterinarian, and if he must euthanize the horse, he can give you the best advice on removing the body for burial or disposal.