Pacing is a lateral two beat gait displayed by horses and some other animals, such as camelids. As a general rule, an animal will not pace unless it comes from a species or breed which paces naturally; among horses, the Standardbred is probably most famous for its pacing ability, although a few other breeds pace as well. Pacers, as horses which can pace are known, are often highly prized for their ability to perform this somewhat unusual gait.
When horses pace, they bring both legs on one side of the body forward at the same time. This generates a rocking motion for the rider which can become very uncomfortable at high speeds, so riding horses are often trained to pace more slowly, for greater enjoyment on the part of the rider. At any given time while a horse is pacing, at least two legs are in contact with the ground, and the horse can cover a lot of ground, especially if it has long legs.
This gait falls between a trot and a canter in speed. Horses which can pace are said to be “gaited horses,” reflecting that they are capable of a gait beyond the familiar walk, trot, canter, and gallop. Pacing is generally encouraged in breeds which are bred to drive, with Standardbreds also being raced at the pace in harness races.
Among horses used for riding, the Icelandic is a well-known pacer. Icelandics have a gait called the skeið, or “flying pace,” which is actually quite comfortable to sit, despite the speed. Not all Icelandics develop this gait, and some develop a slower version, known as the “piggy pace,” which is generally considered undesirable.
In horses which have a natural ability to pace, the trait must often be brought out. Some trainers use special shoeing or gear to encourage their horses to pace, and once the gait has been established, they work on refining it. In the case of horses used in racing, the pace must be developed so that it is rapid enough for the horse to win, but it does not slip into a canter or gallop, and the endurance of the horse must also be built up so that it can compete on long traits. In riding horses, development of pacing abilities is focused on making the gait as smooth as possible.