wont back out of trailer

Question
I have a 5 year old gelding. I can back him on the ground with a halter, or a bridle, however If I am riding I can not get him to back up. Also he loads with no problem at all, but he refuses to back out of a trailer. I really need help with this.

Answer
Hello Gin,

My solution to this is the same as my solution to not loading at all.  I would find a safe place, like a corral with a gate, drive the trailer into it, load the horse and leave him there untied.  I would give him time to figure out how to get out.  Make sure he cannot turn around and get stuck.  I feel sure than when he gets bored, hungry or thirsty, and he knows that there is food and water outside, he will back out.

This is how I play the game with my horse if he won't load.  I put the trailer in a safe place, put water and food in the trailer so that he has to get completely inside to eat or drink, and I leave him.  Sometimes it takes a long time before they will go in, and maybe you will have to wait a while until he backs out, but I feel sure that he will.  Do this a few times, and since he figured it out for himself, he will do it more easily next time.

It is certain that he had a trauma while backing at some point in his life and he needs to overcome it with no urging or hurrying.

Try this and let me know if it works or not.  If it does not, we'll find something else, but I would start here.

As for backing while mounted, that may get easier after he backs from the trailer.  

Good luck
Dorothy