I feel your pain. My horse would do most things cheerfully except load. But then I had a major attitude adjustment and some training and I fixed the problem. I used to be so stressed about it!
First, I had an expert come work with me on loading. I really learned how to drive him into the trailer. But I was still really stressed about it. It was always his choice, not mine and fortunately he’s a really good Doobie and usually we got where we wanted to go.
Second, I watched Greg Eleil load a really bitchy mare onto a trailer and it was freaking life altering. Forget all this crap about ropes and whips and extra people. Greg had a rope halter and a 12 foot solid lead rope and an absolutely confident, unflappable attitude. Now, keep in mind that Greg can tie a knot in a rope by flipping it in a circle so he has excellent control over the rope. (which is why I use a dressage whip to perform the same function). Greg stood behind the trailer and swung the rope at the mare’s flank. Tap, tap, tap. Not hard enough to hurt her, just hard enough to piss her off. She reared, she turned. He pretty much stood still and immediately took the pressure off the second she even contemplated getting on the trailer. Within ten minutes that mare was self loading. Greg’s demeanor never changed. Loading a horse = Waiting for a bus mentally.
The third attitude adjustment happened when I was taking my kids to the dentist. A three year old in the next cubicle was having a tooth pulled and he was HYSTERICAL. After he left, I asked the head dentist if they ever used laughing gas. He said, no because you don’t know how all kids are going to respond and often you end up with a drunken hysterical kid. He said, “We just keep going. We know we’re not hurting them.”
A lightbulb went off in my head with regards to my trailering issues. “Keep going. I’m not hurting him.” When my horse gets balky about loading, tap, tap, tap, with the whip. If he doesn’t move forward (if he’s backing up) I get firmer with it. He must go forward when the whip taps him on the back.
Don’t do up the butt bar until you know he’s made a choice and is standing quietly. Even if you have to load twenty times.
Forget the treats and the bribes and treat this like any other riding exercise. You wouldn’t bribe your horse to get him to jump a ditch or a spooky looking fence. You’d use your aids and praise him to all get out when he does the right thing.
I do give my horse treats once he’s loaded on the trailer so he knows it’s a happy place to be, but they are not linked to proper loading.
My proudest moment came at a show last month when I applied these techniques to a cranky loader at a show for a friend and got her mare on the trailer on the first try.