Tobiano

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 present from birth and does not change throughout the horse's lifetime, unless the horse also carries the gray gene. (see below) 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, or 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 Tri-Coloured.

Tobiano traits generally include the following:

The word tobiano is of Spanish origin, probable first used in South America to describe horses brought in by a Dutch emigrant named Tobias.

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 born Tobiano but turn gray, the skin will retain pigmented and unpigmented skin beneath its hair that may produce "ghost" markings. A homozygous Tobiano that also carries a dilution gene, such as a Pinto with a base color of palomino or buckskin may not reliably produce spotted offspring if bred to another horse with a dilution gene, as a double-dilution may "wash out" the base color.

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