Kicking a horse with spurs is almost never acceptable! Spurs are only appropriate for inexperienced riders on horses who need more precision. Spurs are not intended to make horses go faster or to punish horses. This cannot be stressed enough. To make a horse go faster or work more obediently you should use other methods of disciplines such as training, groundwork, or even crops. Spurs, however, have a negative effect when used to discipline. It is very easy to sour a horse by kicking it with spurs. If you need to kick a horse with spurs to get the results you desire, something is lacking in your ability as a rider or the horse's training, and it should be addressed through education, not by inflicting pain. If spurs are kicked upon a horse without the correct timing, discipline, and education it only confuses a horse and will cause a horse to misbehave in ways such as rearing, bucking, or bolting. A horse kicked with spurs without the education to understand what the spur means will react, not respond. It is very important to never kick horse with spurs. Even talented riders who have earned the right to wear spurs never kick a horse with spurs, but will carefully apply them in measured amounts to achieve the desired affect.