The Appaloosa is an American horse breed best known for its colorful spotted coat pattern. The breed has a wide range of body types, stemming from the influence of multiple breeds of horses throughout its history. Each horse's color pattern is genetically the result of various spotting patterns overlaid on top of one of several recognized base coat colors. The color pattern of the Appaloosa is of interest to those who study equine coat color genetics, as it and several other physical characteristics are linked to the leopard complex mutation (LP). Appaloosas are prone to develop equine recurrent uveitis and congenital stationary night blindness; the latter has been linked to the leopard complex.

Source: Wikipedia