Give him plenty of time to work it out. He may get to the edge of the trailer and need to step down and back up with just his back feet or even just one back foot several times before he actually backs completely off the trailer. Offer him lots of release, praise and rubbing for every small step backward.
How do you train a horse in a trailer?
Use approach and retreat to help your horse become more comfortable walking up to the trailer. Walk your horse up to the trailer calmly until they reach a point where they become bothered and want to stop. Let him take a breath and look around. Then, walk him away and repeat the process.
How do you unload a horse by yourself?
For unloading, I untie them, throw the rope over their necks and then undo the back. Once the back of the float is undone, I tug on their tails, tell them to back and then catch their lead as they back out. They aren’t allowed out until I’ve given them the cue. Having self loading horses makes floating so much easier.
How do you make a trailer horse harder?
Work slowly and methodically
For every positive response, every step toward the trailer, pat the horse and let him take in his surroundings before asking him to load further into it. “Let him smell the trailer. Let him think,” says Alejos. “Every time he walks toward you, release.