Tobiano is a spotted color pattern commonly seen in pinto horses, produced by a dominant gene. The tobiano gene produces white-haired, pink-skinned patches on a base coat color. The coloration is almost always present from birth and does not change throughout the horse's lifetime, unless the horse also carries the gray gene. It is a dominant gene, so any tobiano horse must have at least one parent who carries the tobiano gene. Other spotting patterns seen in pinto horses include frame overo, splashed white and sabino. In the United Kingdom, tobianos are frequently referred to as "coloured" or as "pied": piebald if black and white, skewbald if white and any base color other than black. Sometimes "painted" is also used. Bay and white tobiano horses are also referred to as tricoloured. Characteristics Tobiano traits generally include the following: White legs from the hocks and knees down White crossing the back between the withers and the dock of the tail White is arranged in a vertical pattern Facial markings are similar to those of a traditionally solid-colored horse. i.e. star, snip, strip, or blaze. Extreme white facial markings suggest the presence of additional color pattern genes beyond tobiano White patches which are usually rounded or oval in shape, rather than jagged (see overo) Dark color extending down the neck, giving the appearance of a shield The word tobiano is of Portuguese origin, first used in Brazil to describe horses brought to Farroupilha's War by Brigadeiro Rafael Tobias de Aguiar. (HOUAISS, A. VILLAR, M. de S. Dicionário Houaiss da Língua Portuguesa. Rio de Janeiro: Objetiva, 2001. p. 2727). Genetics Tobiano is a dominant gene, designated TO. Therefore, one parent must be a tobiano for the pattern to occur, and the coat pattern will occur with a single copy of the tobiano gene present (i.e. the horse is heterozygous for tobiano). Furthermore, when a horse is homozygous for tobiano coloring, all of that horse's offspring will be spotted, with only a few exceptions: if either parent passes the dominant gray gene to the foal, then its spots will be visible while it is young, but will gradually become lighter until finally, as the gray gene acts upon all coat colors, the entire horse's coat fades. In the case of horses that are born tobiano but turn gray, the skin will retain pigmented and unpigmented skin beneath its hair that may produce "ghost" markings.