Tobiano
Tobiano is probably the most well known and easily identifiable Paint/Pinto pattern. It's considered separate from the other three
patterns and is very different in physical appearance.
Tobianos are easily identified by their white legs and solid coloured head. This combination is unique because generally leg and
face markings are seen on the same horse. If the head does have a white marking it is caused by Sabino, Frame or Splash.
Contrary to popular belief blue eyes are not a characteristic of Tobiano. If a Tobiano looking horse has a one or two blue eyes, it
would be beneficial to have a OLWS test done on it to be sure that it does not carry Frame. Tobiano does a good job of "hiding"
Frame characteristics and the horse may only have a small star and one blue eye. Splash can also be the cause for blue eyes on
otherwise Tobiano looking horses. A facial marking as small as a snip or strip can be an indicator of Splash or Sabino. Horses that
are only Tobiano are much rarer than some may think, most are a combination of Tobiano and one of the other patterns.
The white on the body is arranged in a vertical pattern and will usually cross the horse’s topline somewhere between the ears
and tail. The spots of a Tobiano are a rounded shape with clean, sharp edges. The tail can be two colours but the colour will be
at the bottom and the white will be at the top.
Small spots of colour commonly called, Ink Spots, Paw Prints, Cat Tracks, etc., are another peculiarity of the Tobiano pattern.
These small spots occur in the white patches anywhere on the body of the horse; they are usually small, round and occur in
groups so they are easily seen as different from the larger patches of colour that makes up the Tobiano pattern. These spots are
the same colour as the other coloured parts of the body. This marking is associated with homozygosity of the Tobiano pattern
but not necessarily mean that the horse is homozygous.
On some Tobiano horses the pigmented skin extends a short way beyond the patch of colour into the white area. The result is a
shadow or halo which causes horses to be commonly called shadow paints, ghost paints, ribbons paints or halo paints. These
are very distinct when the horses are wet. This effect also occurs in other types of spotting as well.
Another characteristic associated with the Tobiano pattern are ermine spots or distal leg spots. Ermine spots are small to large
spots of colour in the white close to the hoof. Distal leg spots are small to large spots of colour that occur in the white on leg
above the ankle, these could just be in spots or paw prints that are occurring on the legs rather than the body. Ermine spots are
not necessarily a true characteristic of Tobiano as they do occur on horses that do not have this pattern.
Another trait of Tobiano that occurs on the leg is spots of colour around the chestnuts, on a leg that is white in this area.
Genetic Information
The Tobiano pattern is caused by a dominant gene. Homozygous Tobianos do occur and are gaining population as breeders gain
knowledge and insight into the requirements and genetics of this colour pattern. To get a homozygous Tobiano both parents
must be Tobiano. The amount of white in the coat pattern is not a reliable way of determining whether a horse is homozygous or
not as very minimal Tobianos do occur a lot more often than people think.
Occasionally horses with the tobiano gene do not have any body spots. These minimally marked horses will have white leg
markings of varying size; the head will be dark, unless another pattern is also present. Sometimes this is referred to as a
"slipped Tobiano". There are even horses that have only a couple short socks that test homozygous for Tobiano.
This combination is usually thought to be just your basic solid horses with basic white leg markings. The specific combination of
extensive leg white and no facial white is consistent with the Tobiano gene and is not consistent with the combination leg and
face markings otherwise common in horses. Though these horses are genetically Tobiano they do not look so physically because
they are missing the body spots. These are the minimally marked Tobianos and these horses can and do go on to produce
Tobiano offspring as reliably as any other horse with the Tobiano gene.
Sabino
Sabino (Sah-BEE-no) is a white spotting pattern that is usually included with Frame and Splash and given the generic
name, Overo. This is because it displays pattern characteristics which can be very similar to either of these patterns.
Interestingly enough, in South America when the term Overo is used, this is the pattern they are referring to. The term
Sabino comes from northern Europe and in Spanish means "pale red" or sometimes "roan". Sabino in South America
specifically means flea bitten Grey, especially Grey that has red flecks instead of black. In the United States it is a term
used for this particular pattern and although it may resemble Roan or Grey at times, it should not be confused with either
as it is totally separate.
Sabino is very prevalent and occurs in many, many breeds such as: purebred Thoroughbreds, Tennessee Walkers, Akhal-
Tekes, American Baskir Curly, Spanish Mustangs, Quarter Horses and Morgans, just to name a few. There are actually very
few breeds in which Sabino does not occur - Icelandic Horses being one.
One Sabino characteristic is a white marking on the face which can vary from a few white hairs to a large blaze. Another
very common characteristic of Sabino is white on the lower lip and/or chin, ranging from small to large. Some very minimal
Sabinos may not have this characteristic white spotting but will have other traits of the pattern. Even though facial white
is common, even to the point of causing a "bald" or "apron" marking at times, blue eyes are not considered a trait of the
pattern and if it does occur in conjunction with Sabino it is usually a trait of a certain line of horses and these horses
usually only have one blue eye, not two, or it is being caused by another gene.
Leg white that ranges from a coronet to a high stocking is also common. There really is no rule as to how many legs are
white, but generally at least one will have some white on it. Patches on the knees, which are not connected to any other
white, are also a trait that can occur with Sabino.
Another common characteristic of Sabino is roaning, this is the most minimal expression of Sabino. This can vary from a
small amount of roaning concentrated in an one area of the horse to roaning that covers the entire body. It's also common
for roaning to be found on the head and legs, especially if a white marking is present. This roaning will vary in extent from
very minimal to very extreme and occurs to some extent in all breeds which have Sabino.
Body spotting is can range from very minimal that usually begins in the belly area to maximum effects involving the entire
body. The minimal expressions can be seen as roaning, to speckled areas to larger white patches. Most Sabinos are
flecked or roan and this is especially true when a horse has extensive spotting. Towards the more maximum expression of
the pattern, some Sabinos can look very similar to Splashed Whites, the difference being that Sabinos generally have
some roaning to the edges of their white. Splash spots (without Sabino present) should be crisp and clean.
At it's most maximum expression Sabino will cause the horse to be totally white, if any colour remains it's usually as roan
or speckled on areas such as the ears, tail base, chest and flanks, these areas may not have coloured hair, it may just be
the coloured skin showing through the white hair. In the past, a horse coloured like this was said to be "Dominant White".
This dominant gene, labled W, was thought to be lethal when homozygous, like Frame. The problem with this theory was
that many horses who were "Dominant White" didn't have the necessary "Dominant White" parent; the rule of dominant
genes being that at least one parent must have it for the foal to have it. Research has shown that these "Dominant
White" horses who are usually born from non-white parents are really Sabinos with the maximum expression of the pattern.
The theory of the "Dominant White" gene has been left in the past, especially since there has never been any scientific
evidence to support that it exists.
Sabino is the most common cause of solid coloured horses with "chrome" or horses that have lots of facial white and high
leg white but no body spots, although it's common to see small to large belly spots. These horses are thought to be "solid"
with "normal" white markings, but are in fact Sabinos and depending on the horse they are mated with they could be just
as likely to produce a Sabino foal as another Sabino with more pattern expressed. An example of this is the many Quarter
Horses that are minimal expression Sabinos, these horses can and do produce full patterned "Paint" foals that are called
"crop-outs". Sabino also very commonly mixed with Frame and Splashed White in Miniature Horses, American Paints and
Pintos.
Some in the equine genetics community that believe that Sabino is a polygenic trait which means there are more than just
one gene controlling it's expression. This group also is inclined to believe that Sabino is the cause for all white markings in
horses; the polygenic theory would support this claim. After studying Sabino in many different breeds, I am inclined to be
one of those that believe both theories.
Further research by breeders and scientists will hopefully shed some more light on this fascinating pattern.
Due to Clydesdales & Shires being exclusively Sabino, it's very unlikely that Sabino is lethal in homozygous form as many
horses in those breeds are very sure to be homozygous for the Sabino allele.
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