How do I get a horse to load in a trailer?

Trailer loading is a trust exercise before it is a training exercise, and the horses that load reliably are the ones that have learned the trailer is a safe, low-pressure place rather than a trap. Begin with the trailer parked in a familiar location, doors open, ramp or step well secured so it does not shift or rattle underfoot. Walk the horse to the trailer and allow it to look, sniff, and investigate without pressure. Ask for forward movement toward the opening using a light lead rope cue and a cluck — release any pressure the moment the horse takes a step toward the trailer, even one step. That immediate release is the lesson. Progress in increments: front feet on the ramp, halt, reward, step off. Front feet inside, halt, reward, step off. The horse learns that entering the trailer is its own reward because pressure releases there and nowhere else. Never try to force a horse into a trailer by pushing from behind with multiple people — that creates a frightening experience that becomes the horse's permanent association with loading. Sessions should end on the horse's best effort of the day, not at a predetermined endpoint. A horse that walks to the ramp confidently and puts two feet in calmly has had a successful session even if it never fully loaded that day. Consistency across multiple calm sessions builds a horse that self-loads willingly.