You can teach your horse that even if he sees, hears, or feels something upsetting, his job is to tolerate it, despite his natural impulse to run. The method is simple, and so is the equipment you'll need: He wears his halter, with the longe line snapped to the ring under his jaw, and no chain over his nose; you wear gloves. Most important, you bring to your job your quiet determination to persist in each phase-without getting angry-until he gives you the response you want.
With your horse at a standstill and you facing him to begin, then moving around to his sides, gently flick the end of the longe toward him--at his neck, chest, belly, hocks, flank, groin. Take it easy--you want him nervous, not ballistic--and keep going, no matter how much he dances around, until he settles down and accepts that this isn't anything dangerous. If he tries to step away from you, follow him quietly, saying "whoa, whoa" in a soothing voice; but--very important--don't stop flicking the longe end toward him until he stops spinning and stands quietly, focusing on you (which may take several sessions if he's very sensitive). If you give him a couple of taps, then stop if he jumps and looks upset, you teach him to be afraid.
When he does stand, reward him with a pat; then repeat the process, flicking faster, until he settles again. When he tolerates that, desensitize him with the longe whip: Flick it gently (don't crack it) all over his body; then twirl it around your head once (he'll hear its whirring noise); then flick again; repeat until he accepts it. Next, move on to a paper grain bag; hold the lead in your left hand and the empty bag, folded, in your right. Rub him quietly all over with it until he settles. Then gently shake it open and rustle as you touch him all over with it until he's calm.
Desensitizing is a process you can do with anything that bothers your horse. Practically speaking, you can't duplicate every sight or sound that sets him off, of course, but once your calm persistence gets him responding to your whoa instead of to what frightens him, he'll continue responding to whoa even when the "what" is new.
Hey, congratulations! The work you've just done makes your horse a better trail partner-you've got his responses focused on you, and you've desensitized him to the scarey stuff. With just a brief review of the entire groundwork program a couple of times a week, you can keep his attention right where you want it.
This article first appeared in the July 1996 issue of Practical Horseman magazine.