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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