Dealing With The Rearing Horse
What Is A Rear?
A horse is said to rear when it stands up on its hind legs. In general, the horse will shift its weight backwards and bend its hind legs while it lifts its front end off the ground.
In extreme cases, a horse may rear so high that it loses balance and falls over backwards.
Because rearing looks so dramatic, some horses are trained to do it on command. I don't recommend doing this unless you really know what you are doing, and if you do, make sure you choose a very clear signal that cannot be mistaken for anything else.
Movie horses are often trained to rear on command. Circus horses may rear in the ring and it is a maneuver sometimes used in competitive liberty work.
In classical dressage, the 'levade' is one of the three airs above the ground, all three of which are based off of battle maneuvers. It is a controlled rear, with the ideal being a 45 degree angle of the body and the forelegs tucked. Most rearing horse sculptures are actually of horses performing a levade.
Why Does A Horse Rear?
Assuming that you are not asking your horse to rear, there are three common reasons why the horse might do so:
1. Pain in the mouth. Rearing can be a symptom of over-bitting or of the rider using heavy hands. Many habitual rearers are made this way. If a horse that has never reared before suddenly starts doing so, then it should have its teeth checked as soon as possible.
2. Fear or aggression. A horse that feels cornered or trapped may rear. Horses that encounter a rattlesnake or similar predator will often rear and threaten the animal with the front hooves. (I have also seen a horse rear and stomp on a rat that got into its stall). A horse that has become terrified of its handler may, indeed, rear and strike out.
3. Excitement. Sometimes a horse that is being held back from a race will do a half-rear, or a horse might rear up in a cross country or barrel racing chute. These little rears are generally not particularly dangerous.
A horse generally does not rear in order to throw its rider. In most cases, a horse determined to unseat a rider will buck, rather than rearing. I did know one evil-minded cob who would start to rear and then turn it into a buck for a combination that was very hard to sit...
Dealing With A Rear - On The Ground
If your horse rears when leading, you are in an extremely dangerous situation. This is one of those situations where just letting the horse go may be essential to preserve your safety. You need to get away from the hooves. Move towards the horse's shoulder, where he cannot get you with a forward kick. Do not try to pull him down - it will not help and might make the situation worse.
The best tactic I have seen for a horse that habitually rears when led (stallions will often pop little half rears and even full rears when being led to the breeding corral) is the following:
1. Replace the lead rope with a lunge line. Either use a chain or lead in a bridle - if you do the latter, thread the lunge line through the near bit ring and secure it to the far one.
2. Lead the horse as normal with your right hand. In your left hand, fold the lunge line tightly and hold it inside your hand. (Do not, under any circumstances, wrap it around your hand or arm).
3. If the horse rears, let go with the right hand and let the line 'play' through your left before stopping it with the right. This means that although the horse will still rear, you will still have hold of him.
A horse that has developed the habit of rearing while led will often stop after only a few sessions of realizing that he cannot get away. Note, though, that this behavior is most often triggered by fear of the handler or of something else in the area. In addition to breaking the rearing habit, you need to establish what is triggering the behavior (obviously, it could be something a previous owner did).
Dealing With A Rear - In The Saddle
If your horse rears when you are riding him, then the paramount concern is to make sure he does not go over backwards.
Drop the reins and shift your weight forward...I would almost go as far as to 'throw' your weight forwards as this will encourage the horse to get back down. If insecure, grab a bit of mane. As soon as the front feet touch the ground again, drive the horse forward.
Any horse that rears unexpectedly should have its teeth checked at the earliest opportunity. If the horse is simply excited, then you may want to tweak its routine. Don't always canter in the same place on trail rides. If rearing in a chute, then make up a chute and make the horse walk into and out of it, so that chute doesn't always mean 'run like whatever'.
An unexpected rear out on the trail may mean that the horse perceived a threat. Snakes are particularly likely to make a horse rear.
Most habitual, evasive rearers are or have been over-bitted. I recommend using the lightest bit you can control the horse in and, if possible, avoiding a curb. Sometimes a rearer can be cured by switching to a bitless bridle. Make sure you are not the problem - have an instructor check that you are being quiet and light in your hand.
Fixing The Habitual Rearer
I do not recommend anyone but an expert work with a horse that has got into the habit of rearing as an evasion under saddle. Period. In the bad old days, habitual rearers were routinely euthanized - it was considered a dangerous and incurable habit. Or, people would try to fix them by breaking a bottle over their head to make them too scared to rear. Never do this - it can actually kill the horse.
In my mind, there is only one way to fix a rearer, and that is for a calm, experienced rider with a good seat to take the horse on. The rider should work primarily on forward and calm. When the horse rears, the trainer will reach forward and gently but firmly push down between the horse's ears. If that does not work, they may graduate to a light slap. Some trainers use a rolled up newspaper. In very extreme cases, breaking a water balloon over the horse's head might be the only solution, but that is generally a last resort (some people use an egg).
This requires confidence, a sense of timing, and being completely calm when the horse goes up. If you don't have all of those things, then do the horse and yourself a favor and hire a professional to solve the problem.