The horse's instinct is to flee rather than try to fight. This flight mechanism explains why the horse is wary of unusual sights, sounds, smells and objects near him. Once paniced previous training is forgotten. This is where sacking out helps.
Working to overcome these fears will benefit the horse and rider. When working on this never trigger active resistance. Never stimulate him beyond his ability to cope. If he is ready to blow up or flee, ease up while working back to his curent tolerance level. Work on increasing his resistance at another time.
You can over do this, so don't carry this to extremes. If you do you'll risk producing an insensitive and unresponsive horse that ignores its environent and maybe the riders cues. Your goal is to produce a sensible and responsive mount.
To begin, either tie the horse to a post or into a small enclosed area such as a box stall or round pen. If you decide to tie the horse, wrap the leadline around the post through the bottom of the halter and back around the post. Slip the end of the leadline around bottome of the halter again and tie a knot that can be easily released in case of emergecy. Leave about 6 inches of play between his halter and the post. If you use a small enclosed area always retain control of the horse through the halter and lead rope. Do not turn the horse loose. You can use hobbles if you wish in either circumstances.
Now get an old empty feed bag, heavy shirt, cloth jacket or a saddle blanket. Stand near the horse so that you can reach him with the object , but do not stand so close that if he moves around you do not have time to move away. Proceed to sack the him by gently swinging the bag back and forth touching him in different parts of its body. He may make all kinds of noises and rear around. Stroke him with your hand and speak reassuringly to him to help with calmness. Then each time the reaction is stopped, stroke him with the object. Do this from both sides and again to every part along its side and legs. On his head, only gently put it over the face and ears. Slowly remove and repeat if desired.
You will eventually do this with your bare hands. Once he has accepted all of this without complaint and allows you to approach and catch him, reward him by taking the halter off, or some other type of reward - this is up to you.
Later on you also should take a raincoat, plastic bag and tarp (can also use other items - be creative) and go through the procedure again.(more details below)
The next step is to walk around the horse in a large circle waving the object. Increase the intensity of the flapping and decrease the size of the circle around him until he accepts the motion and sound of the object in the vulnerable areas of his head, back, belly, and hind legs.
Never slap the horse with the object you are using. This would only cause him to flinch and distrust the object. Be sure to handle the horse from both sides to prevent surprises that a one-sided horse might have in store for you later on.
If he seems ready to explode, stop and let him take a deep breath and regroup. He is ready to move on to the next phase if you can surprise him with the appearance of the jacket and he shows no fear. Remember to be fair.
As stated before you will eventually use "noisy, crackly" objects and begin again. Try to use something that is bright in color. You should ALWAYS take your time to ensure you don't panic him. Before you start useing the object leave it somewhere so that he can become acquainted with it in his own time and way. Hang it on the fence rail or somewhere in the stall. Some horses who had great fear initially will soon grab the object in their teeth and play with it.
End this by using the same objects while mounted to test him. If it is a calm day shake and flip the object throughout the ride.
Another object to use is a rope. Swing it all around him, drag it on the ground so he can see and feel it from different angels. Then touch him on the underside of the neck, the chest and belly. NEVER slap him with it.
Then run the rope around each of his legs, up around the front legs, and between the hinds. Put the rope under the tail being careful not to be in a dangerous position if he should kick in reflex. Tug on the rope. Then let your horse learn that if he relaxes, the rope will fall away from his tail. Lay the rope on the ground between his front and rear legs and slowly pull it from oneside to the other. He will probably be very jumpy with this at first, so be careful.
Other frightening objects that could be formally introduced are spray bottles, electric clippers, hats, vehicles, guns,4-wheelers, motorcycles,strange dogs newspapers, animal hides, blood, and alcohol. Take the time to teach your horse acceptance. Remember not to lose patience with him.
Although discipline may be necessary for a horse that reacts out of willful disobedience, a horse that acts out of honest fear requires time and training to overcome his apprehension. A series of "sacking out" lessons will make your horse more secure and establish a base for the safe and progressive lessons which will follow.
You can't expect your horse to never get scared, but you can teach him how to deal with his fears - in fact, you have a responsibility to do so. Here are a few ways of dealing with frightened or spooky horses.
In some situations, people may get angry because they think a horse spooked deliberately to get out of work. Or they may get upset because the horse ruined a nice performance due to his spooking. In any event, the result is a tense horse and rider. When people get angry and upset, they react badly By then of course, it's too late to prevent the spook or to help the horse learn how to better handle his fear. Taking their frustration out on their horse only makes matters worse.
Many times preventing a spook is just a matter of keeping a horse's attention focused on his rider, which also means the rider's attention is focused on the horse. A spooky rider tends to focus more on what might scare his , rather than asking his horse to concentrate on a specific job. That way the "spook" will be ignored.
To prevent spooks you must improve your own concentration and learn to be an active rider, rather than a reactive rider.
It's great to train the rider, but what about the horse? Just as we can't expect ourselves to never feel fear, we can't ask our horse to never be afraid. However, we can teach him what to do when he becomes afraid.