There are some legitimate reasons why horses do not like horse trailers. To a horse, even the most open, spacious trailer is still a small, confined space. Being a flight animal, nature has wired horses to be claustrophobic in order to protect them from predators. Because trailers are off the ground on wheels, climbing inside is a bit unnerving to a horse as the trailer moves around. Once inside the trailer, horses are further confined with the closing of the divider, and the shutting of the door. Finally, after being locked inside, the trailer starts to move. It bumps along the road, eventually stops, and then the doors are opened, and by this time the horse is thinking “Get me out of here!”