Sabino describes a distinct pattern of white spotting in horses. In general, Sabino patterning is visually recognized by roaning or irregular edges of white markings, belly spots, white extending past the eyes or onto the chin, white above the knees or hocks, and "splash" or "lacy" marks anywhere on the body. Some sabinos have patches of roan patterning on part of the body, especially the barrel and flanks. Some sabinos may have a dark leg or two, but many have four white legs. Sabino patterns may range from slightly bold face or leg white markings—as little as white on the chin or lower lip—to horses that are fully white.

The known causes of the sabino patterns are the SB-1 allele and several other dominant white (W) alleles on the KIT gene. The genetics behind some types of sabino, such as that found in Clydesdales, have not yet been identified. Some genes, such as Sabino-1, are incomplete dominants, producing irregular spotting when heterozygous, but when homozygous, can produce a horse that is almost completely white. Some forms of sabino are thought to be a reason for solid-colored horses with bold white markings on the face and high white leg markings.

Prior to the development and widespread use of DNA testing to determine equine coat color, the term broadly encompassed pinto patterns that did not clearly appear to be tobiano or frame overo. Some breed registries still use the term to describe spotting phenotypes that include roaning or irregular spotting, regardless of the precise genetics involved.

Horses described as Sabino can have varying amounts of white, from bold white face and leg markings all the way up to fully white coats. Sabino patterns often have speckling and roaning. The different white spotting patterns usually have some consistency in which areas of the horse are white and which are pigmented. At the minimal end, there will typically be white on the legs and face, and the horse may also be lightly roaned. In horses with a bit more white, it usually extends above the knees and hocks onto the belly. At the other end of the spectrum, nearly white sabino horses may still have scattered flecks of color, though it is also fairly common to have color on the ears, lower neck and chest, flanks, tailhead, and back.

Unlike white markings on non-sabino horses, the white leg markings of the sabino pattern often have a strip of white extending up the front or the back of the legs toward the belly. Some people call these "lightning strikes".

The term "sabino" was in use prior to the mapping of the horse genome to describe a wide range of pinto spotting patterns that are characterized by irregular edges, and is used by some breed registries. For example, the American Paint Horse Association still groups sabino patterns in its "overo" family of color patterns, even though sabino, splashed white, and frame overo are produced by different genetic mechanisms and are visually distinct. Since the APHA classification system was created prior to modern genetic studies, it was based on physical description and not genetics.

In Welsh ponies and some other UK breeds, sabino patterns are sometimes called "blagdon." To confuse matters further, in Spanish-speaking countries, the term "overo" refers to horses with what are called "sabino" patterns in English; meanwhile, in these countries the term "sabino", which literally translated from Spanish means "speckled" or sometimes "roan", refers to a flea-bitten gray.

Breed standards that recognize the sabino pattern include the Mustang, American Paint, Miniature horse, Morgan, Hackney (and Hackney pony), Tennessee Walking Horse, and the pinto color breed registries. Horse breeds that are generally solid-colored and do not allow most pinto coloring in their breed registries, but who may have representatives with sabino-style patterns (such as the Arabian, Thoroughbred, and Clydesdale) have at times classified sabino horses as roan or even gray.