As opposed to what some may believe, white horses aren’t as uncommon as you might expect. You can find them across multiple breeds.
Genetically white horses feature pink skin and white fur with dark eyes; most white horses, however, are actually grays with diluted genes. This article will highlight all types of white horse colors.
Tobiano is one of four common white spotting patterns among horses. It consists of large, overlapping spots of color on animals with darker base coats – usually bay or chestnut horses, although this pattern can appear anywhere. This spotting usually extends along the topline between ears and tail, and often extends to hindquarters as well.
Hounds with tobiano gene mutations typically feature small patches of pink-skinned skin underneath white areas (referred to in this photo). If they also possess another spotting pattern or dilution gene, these additional characteristics will often become evident as well.
The tobiano gene is associated with chromosomal inversion close to the KIT gene and disrupts its proper functioning, leading to tobiano spotting patterns on horses. This dominant trait causes their eyes and coat coloration to take on this unique spotting pattern.
A horse with both tobiano and different white spotting patterns is known as a Tovero or Tobiano-overo. This breed may feature irregular or smooth markings with white face markings resembling medicine hats on its legs; additionally, its markings may be irregular or smooth and it could feature two-coloured faces with two-striped tails; for those sporting Tobiano heads there may also be colored markings in their forehead and eyes as well.
Dominant white refers to mutations on the Kit gene that are passed along as autosomal dominant traits with variable expression of depigmentation of coat hairs. While these mutations resemble maximum sabino, they do not cause its embryonic lethality when homozygous.
Patterning on horses that carry two W alleles (W1 through W20) typically ranges from spots to an all-white coat; those carrying more than one are often more heavily marked than those who only possess one allele (W4 is often responsible for leaving an “Frame” of color around the barrel and face, while other patterns such as SB-1 produce roaning or leopard complex markings).
Dominant White stands out from most extreme white patterns by not producing blue eyes; this is likely because retinal melanocytes don’t develop from neural crest cells like skin melanocytes do.
Dominant White can appear with any base coat color and can be combined with other alleles to produce various other white patterns, including Sabino, Tobiano, Splashed White Frame Overo or Roan. Like all depigmented horses, however, Dominant Whites are especially susceptible to sun exposure due to lacking melanin which protects their bodies against UV rays.
Gray horses feature white hairs that gradually turn gray as they age, keeping their manes, tails and legs the original color while their bodies and heads become increasingly grayer over time. Their manes, tails and legs retain their original hue while their bodies and heads gradually transition into grayer hues; flea-bitten horses feature small spots of dark color remaining within the gray coat while iron gray horses possess pure white coats without dapples while porcelain gray horses have darker-hued dapples than its counterparts dapples while porcelain gray horses feature both these traits within them as distinct types of grayness as do flea-bitten horses as adults do when adults.
Few horses are truly white; most carry one or more dominant white (W) genes and appear grey instead. One way to distinguish white horses from grey ones is skin color: true white horses have pink or unpigmented skin while grey ones typically have dark skin pigmentation.
Lethal White Syndrome has long been linked with the frame gene; however, other overo patterns may also contribute to its cause; though these cases tend to occur less frequently than with frame.
Though most “white” horses are grey, those carrying the frame gene run the risk of lethal white syndrome and should be monitored carefully. Double dilutes like Cremellos or Perlininos may carry this trait while some are roans or grullas like Surfer Dude were notable cases with flaxen chestnut stripes on their coats.
Named so because their function is to lighten hair and skin pigment, these genes produce paler hues such as cremello, silver dapple and palomino as well as roan and champagne-cream horses. Formerly referred to as splashed white coloration (albeit this name now being somewhat misleading as there are at least 20 mutations within KIT gene that cause less-marked whitening), KIT produces its effect through pale shades like cremello, silver dapple palomino as well as colors such as cremello silver dapple palomino horse breeding programs that produce lighter hues like these three horse colors as well.
Frame patterns, which tend to leave an “encasement” of color around the barrel and face of a horse while also adding leg white spots, is lethal when present in homozygous form but dominant when heterozygous.
Sabino is an eye-catching but more dramatic spotting pattern that typically features two or more white legs, front body spots running vertically up the body, jagged edges to their spotting pattern, jagged or roaned facial markings, jagged or roaned edges to its spotting, jagged or roaned edges to its facial markings and an irregular facial outline. While most often found on white horses, other breeds may exhibit it too. A DNA test exists for Sabino-1 which produces horses which resemble maximum white sabino maximum white while not lethal in utero; similarly produces semi-double dilute colors like champagne and cream which combine with other factors into creating an “originally” coated coat appearance.