Ooooh one of my pet topics!!!
First though I have to question the setup. Do you have a trailer to practice with?
If so, you can use classical conditioning and set things up so the horse starts to looooove the trailer before you even attempt to load. I do this by using treats. Ideally you have the trailer in an area where it's safe to hang out all around the trailer but if you can only approach the rear then that can work to.
So you approach the trailer only to the point where the horse just notices it and shows some tension! This might be about 1/2 mile!!
But hopefully you can approach closer than that before the horse starts to brace and balk. Once you've found that place, back off until he's relaxed again and that will be your starting point. You might even put him away once you know that place and start again the next day or an hour later...??
So then you approach to the point BEFORE the horse reacts and give treats. You don't have to mark any behaviour just give treats. Nice treats like apples and carrots. You want the horse to associate seeing/approaching the trailer = treats and good things. So no correcting or bad language or coercion etc. Just treats. And then leave again. Do this a few times but each time see if you can go a bit closer. Never get so close that the horse tenses! Never get greedy!!
Always back off at a point before he gets worried. If you blow it and he gets worried, then leave and next time don't go so close.
If this proceeds well, then you can start making a line of small buckets with apples and carrots that lead up to the trailer. Let the horse decide how close he's willing to get to the trailer to get a treat but don't let him get too close too soon. If he seems bold and would like to go much closer than the day before, don't let him! Let him see that there are good things near and approaching the trailer but too bad he can't have them cause he's already had enough and now he has to go back to the barn. Get him so he starts pulling you towards the trailer! Does this make sense!
It really doesn't take as long as it sounds but then it depends a lot on if this is a young first timer or a horse with baggage. Either way I train it the same way.
Make the inside of the trailer as light and open as possible. Stuff the best hay in the hay net and hang buckets of treats (don't put them on the floor). When you finally get to the foot of the ramp and the horse is relaxed and showing some interest in maybe going on the ramp, start practicing backing. So you get to the foot of the ramp then ask him to back away and if he does that nicely, feed treats. I like to do LOTS of backing and walking forwards especially once they are on the ramp. I believe that if they are REALLY practiced at backing off, they feel safer going on.
So one foot on the ramp, treats, back off, treats, two feet on the ramp, back off etc and always back ALL the way off and even back a bit away from the trailer to a place of real relaxation before walking forward again. Try and just be a guide and not 'in charge'. The horse dictates the speed.
When that's all gone well and it's time to step right up into the trailer still always back off for EVERY extra step on even if the horse doesn't want to back off!!!! I do let them pause between step on and before backing but i don't let them just keep walking all the way on. I hope I'm explaining this well...??
Once they can walk all the way on and stay relaxed they get treats, have some hay if they want, hang out just a little bit but then I back them off and I then start introducing a buddy horse. So the divider gets put back to the middle and it's a narrower space to get on but there is a buddy on the trailer and that helps. I still do the walk on and back off at this stage but not so often. Maybe halfway up the ramp then back off, then two steps into the trailer then back off, then halfway into the trailer then back off, then all the way in, then back off, then all the way in and then pause and treats etc and hang out for a while. And when I back them off I continue to back them ALL the way back off the ramp and then a couple more steps. All the time being sensitive to the state of relaxation. If they are showing tension, I back up a few steps and take it slower...more treats, more sessions...
I never rush the backing...just quietly keep asking until they figure it out. If backing is really difficult I practice backing a lot more OFF the trailer. Again, lots of treats for doing it well. That is slowly, carefully and relaxed. I don't look for immediate compliance or sharp responses.
Then of course you have someone start the truck engine and turn it off before loading, and then when loaded. Then when loaded start the engine and leave it running a bit.
Then work on the door closing. (I don't tie them yet.) I use the same thinking. I have someone close the ramp(without latching) BEFORE doing the butt bar. So closing the ramp = treats! And the ramp is closed in increments and lowered again and if the horse stays relaxed, then close it up and hold it closed of a bit then back down and take the horse off. Then next time I do the butt bar (same thinking - butt bar = treats) and if that goes well, take the horse off. Next time butt bar and ramp, then take the horse off.
Doing it this way there is LOTS of loading and unloading but it's really kind of fun. If you do it keeping the horse under threshold, it's safe and pleasant for all involved. The slightly hairy time comes when you've loaded, put up the butt bar, closed the ramp, tied the horse and it's time to move! So...I have someone move the truck just 2 feet and stop, ramp opened, butt bar down, and take the horse off.
Then the first trailer ride is about 200 yards and stop and unload. With a young horse, I want to be careful that I unload still in familiar territory so ideally it's nice just to drive around a circular driveway. I also always try and include a good travelling buddy.
Phew...sorry to go on but it's hard not to get wordy!!! The most important part is that at no time is there any growling or correcting or coercion so that they learn the trailer game is FUN!
Some horses load fine but they are nervous on the trailer. What I do then is load them a lot but don't go anywhere. Just load them, feed apples etc have a yummy hay net available (cable tv, popcorn, party hats, champagne...
) then get off.
I've also worked with lots of problem loaders/travellers who improved dramatically with all the backing off practice. Sometimes I wonder if they just get so sick of having to back off that they just say jeeeez can I just stay on the damn trailer and have some peace!!!
But I also believe that they feel safer knowing they can get off easily?? I think that because I think every problem loader I've dealt with was really bad at backing. They were bad at backing just in general usually too. They didn't know where their feet were etc.
So...hope that is some help...??? Obviously so much depends on the setup and the horse but I've always found the above a good basic recipe for both young and problem horses.
