Some horses have not had the benefit of a quiet, patient introduction to clippers and have already made up their minds that they want nothing to do with the procedure. These horses can often be improved by going through the procedure for introducing a green horse to clippers, but they have a built-in response of fear and resistance.Sometimes you will have to apply a restraint in order to protect yourself, your helper and the horse and to get the job done.
One of the easier restraints to apply is holding up a front leg. This helps to keep the horse from restlessly picking up the leg you are clipping every time the clippers touch it.
The most commonly used restraint for clipping is the lip twitch. It was long thought that a twitch quieted a horse by distracting it from clipping or a veterinary procedures by focusing its attention on pain in its upper lip. It was then discovered that horses release endorphins into the bloodstream when a twitch is properly applied, so the calming effect may have more to do with the body's chemistry than the threat of pain.
Most horses become calm when a twitch is applied; there are some that become tense, agitated or even violent, so it should be applied with judgement and care.
Many horses are easier to clip if a generous wad of cotton wool is stuffed gently into each ear. This helps deaden the noise of the clippers and also prevents hair from falling down into the ears when clipping that area. A hand cupped over the eye may also help when clipping near that area, and protects the eye from being bumped by the clippers if the horse should toss his head.
If, despite your best efforts and patience, a horse will not stand for clippers with a simple restraint humanly applied, it is better idea to sedate him than to look for a more potent restraint. A sedation is best administered by your vet, who can apply the correct dosage, so it saves him and you stress, trouble and perhaps a bad experience, and he may in time become easier to clip.