Horse Training Power Tip: Loading Difficult Horses
In general, whether the trailer is an angle-haul, straight-load, step-up, or ramp, a horse should follow pleasantly and comfortably behind the handler into any trailer. The horse should fit in the trailer, and not be hitting the ceiling or squished into the partitions.
To begin, most problems I have witnessed with loading have a lot to do with the horses' response to pressure on the halter. Body language is also important to recognize, as it is the horses' way of communicating with you. Some horses are terrified; some horses just say no, and have gotten away with saying no; and others have constant worries - not fitting properly, having had a bad experience, slipping or falling. (A note to all those who drive a horse trailer: from those of us humans suffering from motion sickness - many of you make us feel ill with your quick turns and rapid accelerating and heavy braking; we have to wonder how many horses suffer the same way, and endure rough rides, knocking them about and challenging their balance constantly... not a good thing for horses to want to go back in the trailer for.
The most common problems encountered with trailering involve: the horse backing up, pulling back rapidly, refusing to move at all, dodging from side to side, or a combination thereof. Again, respect for the parts of the halter will help immensely. If the handler applies pressure to the headstall of the halter, the horse should move forward. Pressure on the noseband should cause the horse to yield, and pressure on the sides of the halter should catch the side-to-side problems. The main pressure that needs to be responded to in loading is the headstall.
If the handler has a capable helper the first few times, it is enormously easier. It can be done alone, but more time and expertise is usually needed - the result may well be more thorough in the end though. Also, simple things that help immensely are: to have a horse that loads well already in the trailer, and/or to ensure the trailer looks open and inviting with lots of light. If a side door or window can be opened for more light, it is often more inviting - just be aware of any safety hazard it may cause, and be ready to close it before the horse is confined. Also, a note as I see many people doing this: it is prudent to have the bum bar and/or back door shut before tying your horse to the rings or bars of the trailer. That should be done either through the window, or after a helper has shut the back. Some trailers have enough room that an exceptionally nervous horse may try to get over or under a partition if it is not tied. Then it is very wise to have a helper, so you can have one of you holding the lead rope, preferably through a window, and one of you shutting the back enclosure. Tying a horse should mean leaving no more freedom than the length of your forearm in the rope. Horses tied too long are prone to injury as well. Common sense and good instincts apply.
Imagine a square of space that the horse has - two sides of that square are the sides flush with the sides of the trailer, a third joins the two sides a short distance behind the horse, and the fourth side is the front of the trailer, on the inside of the stall intended for the horse to be loaded. I never want to force the horse into the trailer. It may work once or twice, but it rarely leads to willingness in the future. I always want my horses to WANT to do whatever I ask, not do it because I force them to. Allocating this space is drawing or mapping out the boundary that they have to relax in, and think about the idea of walking up the ramp, or stepping up into the trailer. They are not allowed to stray out of this area, and that is the only correction they are given. When a horse starts to think about responding to the pressure of the headstall, which should be applied in accordance with each step a horse will take when it is challenging a response to it, then there has to be a release of pressure. Watching people at horse shows have trouble loading, one often sees the handler pulling as hard as they can with no give when the horse does step forward. This will often cause the horse to fly back instead.
A horse that is nervous about the trailer should be given a lot of praise and fuss with each step. Treats and feed are used with discretion - I am not a big fan of treats for every little thing. I find the horses get pushy and nippy, and the timing of the treat is not often very good. For every positive (and negative) response a horse gives, there is a three-second window to praise (or reprimand), or the horse is much less likely to make a connection to the two things. If you do use feed, however, ensure there is a positive behavior to reinforce before allowing the horse to eat a mouthful. Then wait for another positive behavior.
A horse that is saying 'no' should be pressured a little more, and perhaps with a helper encouraging safely from behind. Again, there needs to be a release, even for a moment, when a positive behavior is displayed. Then a second application of pressure is given. For the horses flying to the side, and back, try to be consistent about the box of space they are allowed, and even tighten the parameters as time goes by. Forward is the only option, but it is important to stay consistent, persistent, and methodical.
Reading the horses' body language is integral to successful loading, but there are two more points to be made about this. A horse that is not really scared and not really saying no, but also not loading may need more pressure applied - either from the headstall of the halter, or from behind - a second person may wave an arm, cautiously give the rump a slap, or better yet, use a lunge whip or corn broom to tap the horse from behind. Both tools are not used to get aggressive with, only to extend a person's arm to keep them safer if the horse is threatening to kick, or is flying sideways a lot. If the horse moves rapidly out of the imagined boundaries, the correction should be immediate to get the horse back within the boundary. If progress is made, but success is not yet achieved, the boundaries should be tightened up. If the horse starts refusing to load before it is even near the trailer, start with a bigger boundary that the horse relaxes in, and gradually move the imaginary lines closer.
When a horse is new to loading, and especially if it has been very difficult to load in the past (which is often harder to deal with than a horse new to loading), it is important to praise a lot at each stage of progress, and make a big fuss upon success. Horses that have had minimal handling, and are ultimately quite scared of people will respond to this less, but a kind tone in a voice is a source of comfort that is universal. Quitting part way is never a good plan. If necessary to do because of time of day, or lack of help, or whatever, ensure you have knowledgeable help and lots of time when you try again. Otherwise, you are reinforcing that if you ask the horse to go in the trailer and it says no, the behavior is entirely acceptable. It is exactly like people going out to catch a horse that is difficult to catch and coming back without catching the horse. The horse will never get better about being caught, and often get much, much worse.
Many of us like our horse to just walk in the trailer, slipping the lead rope over its' back as it passes us, leaving us free to close the back partitions. Then we can walk around to the side window and tie the rope. If your horse is loading well, then it is not a stretch to start them off stepping into the trailer with you, but continue on their own. Find the moment that you and your horse get to with confidence, and you then can gradually have the horse do more, and you do less. As a person that values great horsemanship, natural kindness and good rapport with a persons' horse, I always appreciate seeing a trust between horse and human that involves such things as this.