There is no justification for allowing a horse to continue the habit of kicking. He will be a danger to people, other horses, and even to himself since he can cause injuries to himself as well. For a horse, if there is no physical reason to justify it; kicking is an acquired bad behavior that needs to be nipped at the bud. For instance, he may have had to protect himself against aggression from other horses in the past, or wasn’t trained properly, or he is just bored or stressed. There are many approaches you can take to break the bad habit of kicking, but you will need to exercise a lot of patience.
As expected with any negative habits, rule out any physical issues, especially if your horse kicks during a ride when no other horse is around him, or if he tries to kick under saddle but not when on the ground. Be sure to note the exact instance of kicking when you are riding. If he kicks when you apply leg pressure on him, or when you want him to transit to a faster gait like a canter or lope, then you need to check for hind-end issues like sore stifles, lower back or hocks.
Horses are instinctive herd animals, and therefore behave according to their herd’s pecking order. A horse that is striving for dominance over other members of its herd will display a number of aggressive habits, including kicking, until its competitors have backed down and shown respect to the “boss”. Move your horse around a circular pen severally, changing directions every time. If he tries to turn to face you or attempts coming towards you without permission, wave a lunge whip or rope at his hindquarters to scare him. However, do not hit him. He should change direction by turning his face away from you until he has sopped his aggressiveness. Do this a number of times using a rope halter equipped with a long lead till he has accepted you as dominant in his relationship with you.
If your horse is fond of kicking at other horses as you ride, consider “ponying” him with another friendlier horse. If you don’t have expertise or experience in ponying, it is very important that you seek help. Mount another, more calm horse that yours likes, riding them as you lead him alongside it. Keep the two about 4-6 feet apart. Coil your horse's lead rope around your palm in such a way that you can easily let go in case he pulls at you violently. Perform several short practice rides as you watch out for any aggressive signs on him. In these maneuvers, progressively perform turns and halts till you are satisfied that he has started to behave perfectly. Lastly, try riding him alongside other horses and if he is still kicking, take him through another round of these ponying lessons.
You can use some simple negative reinforcement to help you break your horse’s kicking habits too. The key here is that your horse should prompt that negative consequence. For example, if he routinely uses kicking inside his stall to get your attention or demand for food, you can try a kick chain. A kick chain refers to a leather bracelet that has an attached chain which can be buckled to your horse's kicking leg. When he kicks, the chain will hit him on the leg. There is another device that operates via sensors that are attached to stalls. When he kicks, the sensors will detect it and he will be squirted with water. Progressively, your horse will learn to associate kicking with pain and stop doing it to save his skin. However, if you suspect that he is simply bored, you can provide him with stall toys that are specially designed to help relieve boredom.
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