The US bans domestic horse slaughter but exports horses to Mexico and Canada where welfare standards are lower, creating a welfare crisis across borders.
American horses exported for slaughter face 24-48 hours of transport in crowded trailers across borders without adequate food or water. Lance killing at Mexican plants involves inserting a lance into the spine rather than captive bolt stunning, causing prolonged suffering. The drugs routinely given to US horses including bute (phenylbutazone) are prohibited in food animals and pass into the human food supply.