The Genetics of Color in Miniature Horses

The Genetics of Color in Miniature Horses

Why Does a Minature Horse With Pinto Coat Color Throw Pinto Offspring At A Higher Rate
Than Do Parents With Other Coat Colors?

The answer is in the genes.












Scientific Fact: The pinto coat color pattern is controlled by a dominate gene.

This is why when you breed a horse that is pure pinto to a mini with a solid color most offspring will
appear pinto, although they will be hybrid or mixed for the pinto coat color gene. But, there is
another genetic phenomena which can help you produce 100% pintos. (Please breed pintos with the
best conformation and personality).

Research Fact: Scientists found that the pinto color (also called tobiano), is associated with an
inversion of a large chromosome near the KIT gene. This inversion has an effect on the function of
the KIT gene causing “paw prints” or splashes of color to appear in the white areas of a pinto‘s
coat. KIT definition: it is a multipurpose gene that is essential to the function of the coat color
genes.

Researchers at the University of Kentucky determined that the gene inversion effect on the KIT
gene was linked to the tobiano pinto coat color in horses (including miniatures). They discovered
that a pinto with the “Paw Print” or splashes of color in the white areas of their coat were
genetically pure pintos, and they had the gene inversion effect.
Conclusion: Pintos with paw-prints are pure for the pinto coat color gene.

So, if your tobiano colored horse is a pinto with “Paw Prints,” as seen in the photos above, its most
likely a pure pinto and will always have pinto offspring as shown below.

Pure Pinto bred to a Pure Pinto= 100% of offspring are pure pinto.
Pure Pinto bred to a solid color= 100% of offspring appear pinto.
Pinto Mix bred to a Pure Pinto= 100% of offspring appear pinto.
Pinto Mix bred to a solid color= 50% of offspring appear pinto and 50% are solid.
Pinto Mix bred to a Pinto Mix= 75% of offspring appear pinto and 25% are solid color.

However, if you want to be certain, the Veterinary Genetics Laboratory at the University of
California, Davis, will test the DNA of your pinto for $25 to see if it has the gene inversion
effect. All they need is 30-50 hairs with intact roots (hair pulled out of the skin). The results
come in 5-10 working days.

Here is the link to the form: UC Davis Veterinary Genetics Laboratory

Scientific Fact: Scientists who have studied coat colors in horses have found many color patterns
are associated with genetic malformations. Happily, the pinto color is not! This genetic phenomena
of passing the pinto coat color on was noticed by the developer of the Falabella breed of horse in
the 1800s.
Cruz Mountain Miniature Horses- Home Page
Both of these pintos are pure
genetically for the pinto coat
color. Notice the color
splashes in the white areas.
Some pintos have a smaller
splash as seen at right, but
they are also pure for the
pinto gene.