They would be the genes which cause a horse to have particular markings (usually
certain locations on its coat, while diluting the rest of its body color.
If science could locate them. As of April 2009, they have still only
located "markers" that indicate that horses have them, and that only
for one form of striping with dilution.
Old vs. New Definitions
Just a generation ago in America, and still in many countries to this day, "dun" in horses was defined according to the
dictionary definition of the word: a muted, tan, or mousy,
color, usually with darker points.
In the horse world, this is changing, as equine color genetics knowledge has
changed. Horses once lumped together under the old definition of
"dun" are now recognized as being champagne, buckskin, dun, pearl, and even
silver, and the "new" meaning of dun, of a diluted body color with
darker striping, is becoming the norm.
An older meaning of "buckskin", a tan horse with dark zebra-like
markings, no longer applies. Perhaps this term was once used this was
because deer tend to have a darker area along their spines, slightly similar to
a dorsal stripe. "Buckskin" now describes "a bay horse diluted
with one cream gene", which would be a horse with a tan or golden body color with black points ...
The gene that causes the diluting and striping effect we now call "dun" can be added to any color base coat,
with any number of other color modifiers also present.
On this site, I hope:
To explore the general effect of the "dun" gene on bay, red
(chestnut/sorrel), black and seal brown base colors under "4 Basic Dun
To explore just how the specific effects can vary
To explore the results of additional color modifiers under "Combinations"
To explore some individual horses which have various usual or
unusual traits under "Puzzles".
To explore the dun patterns in specific Breeds
To provide a meeting place for dun fanciers to
Last but not least, to conduct and report on research that into those exotic, or primitive, "Dun
Sometimes a horse with one or more dun traits is
summarily declared a "false dun" without
exhausting the possibilities.
I hope this web site will discourage this
Dun is a "dilution gene"
Dilution genes lighten the base coat of what would have otherwise been a
darker color. In addition, it leaves some "markings" behind
(undiluted, or darker.)
Dun is a very intriguing and complex color modifier. It is sometimes called a "primitive" color manifestation, because it involves striping
and barring similar to that seen in zebras and in some indigenous, truly wild
horse breeds (like a deer or an antelope is wild), like the Spanish/Portugese
Sorraia, the Mongolian horse, Tarpan, or Przhevalski's horse. There is
some question as to whether there is more than one form of dun,
or whether it consists of more than one gene. This site tends toward the
commonly held theory that it is only one simple dominant gene, while continuing to investigate the alternatives.
Q: What is "a Dun"?
A: A horse with one or two dun genes.
All genes come in pairs. The dun gene has long been believed to be a SIMPLE DOMINANT gene, which means only
one is needed for full expression, so adding another has no effect on the
horse's color. The current DNA test reflects that (see link just below). If
further laboratory research determines that there is more than one
form of dun gene, or that it is a COMPLEX (several different genes expressing
themselves), the site will be updated to reflect that.
We detect whether the horse carries a dun gene (or two) by its APPEARANCE
and by its genealogy. If dun is a simple dominant gene, and a horse has NO dun parents, it CANNOT be a dun.
(This does not mean "if its parents don't LOOK dun". Sometimes dun can be
obscured by other variables.) If it produces duns when mated with non-duns, it MUST be a dun.
However, now the definition of "dun" has been narrowed somewhat by a new DNA
**** note: it may take some real detective work to find the dun parent or
Some people don't KNOW their horses are duns, and some don't
WANT to...especially those
that are also Palominos, since the PHBA rules exclude
IMPORTANT NOTE: Repeating: a dun is not a buckskin. A buckskin is a horse with
black, bay, and one cream, genes. Its body color is golden, with a black
mane, tail, and legs. If it is a "sooty" buckskin, it may also
have a black shaded area down the center of its back, across its shoulders and
hips, and on its upper face. The genetics of "sootiness", also
known as "smuttiness" or "countershading", are unknown at
A FEW DUN LINKS
Here are some relevant sites; pictures to see, information to read:
Sorraias: the dun, Iberian "wild horse"
Hardy Oelke's wonderful book for Sorraia, dun, wild, or other horse lovers:
current web address: