Gaited Horse Saddles
In most "gaited" breeds, an ambling gait is a hereditary attribute. However, some representatives of those breeds might not continually gait. Conversely, some naturally trotting breeds could have ambling or "gaited" ability, significantly with specialized coaching. Several horses will each trot and amble, and a few horses pace additionally to the amble, rather than trotting. However, pacing in gaited horses is usually discouraged. Some horses don't naturally trot or pace, but simply like their ambling gait for his or her intermediate speed. It has become habit or comfortable for the horse to achieve the pace or trot rather than the correct gait.
A 2012 study of movement in harness race horses, Icelandic horses, and mice, determined that a mutation on the factor DMRT3, that controls the spinal neurologic circuits associated with limb movement and motion, causes a "premature 'stop codon'" in horses with lateral ambling gaits. This mutation is also a gene, therein even one copy of the mutated gene can turn out gaitedness.