Teach loading on days when you are not going anywhere. Break it into small steps the horse can already do, reward each one, and end while it is still going well. The published comparisons favor positive reinforcement and habituation over pressure, and a New Zealand survey of more than a thousand horse people found that whip use during loading doubled the likelihood of transport-related problem behavior. Before any of it, have your vet check the horse, because balancing in a moving box is physical work and a horse who finds it painful will refuse.
Loading is where handlers get hurt. It is a confined space, a solid structure, and a flight animal being asked to walk into a box. The order below is deliberate: health, then setup, then training, then the day.
Scope, stated plainly. This page is about the horse. Whether your vehicle can legally and safely tow your trailer, what it weighs, and how it is hitched are separate questions with separate answers, and they are not covered here. Take those to your vehicle manufacturer's handbook and your state or provincial licensing authority before you tow anything.
Start with the vet
A horse who has never loaded well may simply never have been taught. A horse who used to load and now does not is a different case, and the Merck Veterinary Manual's guidance on diagnosing behavior problems in horses puts it in the right order: the veterinarian rules out health problems with a physical examination and diagnostic testing before a behavioral history is taken, with pain named among the causes of behavior change.
For loading specifically, the things worth naming to your vet:
- Foot and limb pain. Stepping up onto a floor, or walking up a ramp, and then bracing against motion for an hour is demanding. Being able to report a digital pulse gives your vet one more data point.
- Back, neck and sacroiliac pain, which makes balancing against sway painful.
- Gastric ulceration. The European College of Equine Internal Medicine consensus statement, Sykes and colleagues, Journal of Veterinary Internal Medicine, 2015, reports equine squamous gastric disease in 37 to 59 percent of pleasure horses and 17 to 58 percent of show and sport horses.
- Vision. A horse who does not adapt quickly between bright daylight and a dark interior is not refusing a trailer, he is refusing a hole.
- Respiratory disease, because the air in a closed trailer is not the air in a field.
Take his resting temperature, pulse and respiration before you call. If that is not routine, how to take a horse's vital signs covers the method, and a running health record is what turns one reading into a trend your vet can use.
What the research actually supports
There is more published work on trailer loading than on almost any other groundwork problem, and it points consistently in one direction.
Habituation is protective and whips are not. Padalino, Rogers, Guiver, Bridges and Riley surveyed the New Zealand equine industry and published "Risk factors for transport-related problem behaviors in horses" in Animals, volume 8, issue 8, article 134, in 2018. From 1,124 valid responses, 22.2 percent reported at least one horse showing transport-related problem behavior over the two-year period, and 31.3 percent of those problems occurred during loading. Whip use during loading doubled the likelihood of transport-related problem behavior. Training that combined negative reinforcement with positive punishment was a significant risk factor, as were fewer than five years of handler experience and a lower ability to recognize equine distress. Habituation training was associated with lower odds of problem behavior than other methods.
Target training and shaping work on horses who already refuse. Ferguson and Rosales-Ruiz published "Loading the problem loader: the effects of target training and shaping on trailer-loading behavior of horses" in the Journal of Applied Behavior Analysis, volume 34, issue 4, pages 409 to 423, in 2001. Working with mares who would not load, inappropriate behaviors dropped to zero immediately after target training, and every horse completed the shaping sequence.
Positive reinforcement produced less stress than pressure. Hendriksen, Elmgreen and Ladewig, in the Journal of Veterinary Behavior in 2011, took twelve horses with severe loading problems and split them between two methods. The negative reinforcement group met degrees of pressure, including lead rope pulling and whip tapping, released when the horse complied. The positive reinforcement group was clicker trained to follow a target into the trailer. Heart rate was recorded every five seconds and discomfort behaviors were sampled throughout. For horses who refused to load, positive reinforcement gave the fastest solution with the lowest stress response.
That is an unusually consistent evidence base for a training question, and it is the reason this page is built the way it is.
Set the trailer up so the horse can say yes
Half of loading is arranging the situation. Do this before the horse is anywhere near it.
- Park on level ground, with the trailer stable and not free to move when the horse steps on.
- Open everything you safely can. Front unload doors, windows, vents. A trailer that reads as a tunnel is far more inviting than one that reads as a cave.
- Look at the light. Loading with the sun behind the trailer makes the interior a black rectangle.
- Check the footing on the ramp and the floor, and again on the ground in front of it. A horse who slips once will remember it.
- Remove or move a partition if the configuration allows it safely, so the entry is wide.
- Park so the horse is not being asked to load toward a road, a gate or an open field.
- Reduce the noise. Loose bars and chains banging on a ramp is a startle waiting to happen.
The training ladder
Every step below is a behavior the horse can already do or can be shaped into. The rule that makes it work is that you stop while it is still easy.
- Lead calmly past the trailer, at whatever distance keeps him relaxed. That distance is the starting point, and it is set by the horse, not by you.
- Stand near it, doing nothing.
- Touch the ramp or the doorway with a nose or a foot, and get rewarded for it.
- One foot on, then off, calmly and on your cue rather than in a rush.
- Two feet on, then off.
- All the way in, with the back left open.
- Stand inside with the back left open, with hay if he wants it.
- Back off on a cue, calmly and straight. Unloading is a trained behavior too, and a horse who rushes backward off a ramp is dangerous.
- Close the back, once every step above is boring.
- Only then, a short journey to somewhere pleasant and home again.
Two rules on top of the ladder. Never move up while the horse is tense. ISES's fourth First Principle is regard for current emotional states, and the practical version is that a horse with a high head, a fixed eye and no chewing is not learning anything useful. And stop on a success, even a small one. Poor shaping, ISES notes, leads to confusion, and finishing on a refusal teaches the refusal.
Target training deserves a specific mention because it is what the JABA paper used. You teach the horse to touch an object with his nose for a reward, away from the trailer, then use it to lead the movement. The horse walks forward because he is following something he wants, not because he is escaping pressure from behind. That is exactly the difference the Christensen work on voluntary versus driven approach describes.
Practice with a horse who has never traveled before you need to. For a newly bought horse, this belongs alongside everything else in the first two weeks with a new horse: find out what he already knows, on a day with no appointment at the end of it.
Methods to refuse, and the reason each one is on the list
These appear across the search results for this phrase. Every one of them either injures horses, injures handlers, or trains the opposite of what you want.
| Method | Why it is not on this page |
|---|---|
| Two people hauling on the lead rope | It applies force to the head of an animal who is already braced, and it puts hands in a loaded rope. This is the mechanism in the hand-injury data below |
| A lunge line or rope run behind the quarters, held by two people | The handlers are inside a loop with a panicking horse, and a horse who leaps forward into a trailer has not been trained, he has been startled |
| A whip, a broom, or anything waved or tapped from behind | Whip use during loading doubled the odds of transport-related problem behavior in Padalino and colleagues' survey |
| A rope around the barrel, or over the poll | Force on the exact structures a panicking horse can injure, with the handler in the middle |
| A blindfold | Removes the horse's information and your warning, and increases panic |
| Loading with a chain over the nose or gum | Pain-based restraint, and it does nothing about the reason for the refusal |
| Standing directly behind the horse to push | There is no version of this that is safe |
| Sedation arranged without your vet | Sedatives are prescription medicines. A partly sedated horse on a ramp is unsteady, and the decision is your vet's |
| "Just get him tired first" | Fatigue is not training, and it makes a horse less able to balance in transit |
The equipment rules, plainly
- Gloves, always. Ritter and colleagues, in Archives of Orthopaedic and Trauma Surgery in 2024, reported that 53.8 percent of equestrian hand injuries occurred while leading the horse, through traction from a lead rope or bridle on the fingers, with avulsion amputations in 23.1 percent of patients. Gloves were associated with a significantly reduced amputation risk.
- Never wrap the rope around your hand, wrist or fingers. Fold it.
- A properly fitted halter, and a lead long enough that you are never underneath him.
- A helmet is a reasonable choice for this job, and it is normal in professional settings.
- Do not tie the horse until the back bar or ramp is secured, and untie before you open it. A horse tied to a trailer with nothing behind him is a horse who can back out against a rope.
- Never be inside a trailer with a horse without an escape route. No standing in front of a horse in a straight stall, no closing yourself into a space where he can move forward.
- Do not put a child, or anyone who cannot let go, on the rope.
- Have a rope cutter or knife accessible, and know you will use it from the side.
When this is not a self-help project
Stop, and get professional help, if the horse:
- rears at the ramp or in the doorway
- strikes out with a front foot
- bolts away from the trailer while being led
- has already injured someone at a trailer
- goes down, scrambles or panics inside
- has a sudden change from loading easily to refusing
Get the vet first, then an instructor accredited by a recognized national body or a qualified equine behavior consultant. In Padalino and colleagues' data, fewer than five years of handler experience and a lower ability to recognize distress were both risk factors, which is a polite way of saying that this is a job where knowing what you are looking at matters.
We are not publishing a number of sessions, a timeline or a success rate. The studies above measured particular horses under particular conditions, and turning them into "most horses take X" would be inventing a figure.
A note on what this page is. It is a framework built from the named veterinary and equine-science sources above. We are not describing our own horses in it.
FAQ
Should I feed him in the trailer?
Food in the trailer is standard practice and it supports the counter-conditioning this page describes. One caution from the research: Padalino and colleagues found food provision during loading and transport among the factors associated with transport-related problem behavior, which is a reminder that it is not a substitute for training and that it can go wrong if it becomes bait. Use it as reinforcement for a behavior you asked for.
Ramp or step-up, straight-load or slant?
Horses differ and it is worth finding out which your horse handles better before you commit. Padalino and colleagues did report that two-horse straight-load trailers were associated with a higher likelihood of transport-related problem behavior than small trucks. That is one survey and it does not settle the question, but it is worth knowing.
Can I practice with a companion horse loaded first?
Often yes, and it uses the horse's social nature rather than fighting it. The risk to manage is two horses and two handlers in a small space, so plan the sequence, the exit routes and who is where before anyone leads a horse anywhere.
How long before a trip should I start teaching this?
Long enough that no session ever has a deadline attached. The one thing every source agrees on is that training under time pressure is where it goes wrong, which is the entire reason this page exists separately from the article about the day it goes wrong.
He loads and then will not come off.
Unloading is its own trained behavior and it deserves the same ladder. Do not pull. Give him time, give him a cue he knows, and if he is stuck and frightened, get help rather than escalating in a confined space.