A miniature horse is a breed or type of horse characterised by its small size. Usually it has been bred to display in miniature the physical characteristics of a full-sized horse, but to be little over 100 cm (40 in) in height, or even less. Although such horses have the appearance of small horses, they are genetically much more similar to pony breeds such as the Shetland. They have various colors and coat patterns. They are commonly kept as companion animals. Some are trained as service animals, and others for sporting activities such as driving and other competitive horse show events.