home         gallery        genetics          darks          dilutes          white          tests


---  Gray  ---


Genetics 000
Dark Colors

 Previous Next

Gray : new hairs grow in with inhibited pigment, increasing in both number and lack of pigment as the horse ages.

G : the gene that causes graying; a dominant gene,
        abbreviated "G". 
g :  the gene that keeps pigment constant in each
       successive new hair (during shedding); non-gray, or "g".

Dominant and recessive genes are explained in "Genetics".

There is a test for gray.  DNA color test links are on THIS PAGE.

The gray gene causes depigmentation (loss of pigment) in hair.

The hair grows in with "inhibited" pigment: at first there may simply be less pigment than the original, unchanged hairs, or with "distorted" pigment, sometimes even making areas of a palomino look black. The final hairs are crystal-clear, and when they reflect ambient light, they appear white.

The skin underneath the previously-colored hairs stays dark except for in a few cases (see gray depigmentation, below.)

Graying often starts before birth, in which case a foal will be born with gray (white) hairs around its eyes, giving the appearance of "goggles" (seen here in a foal bred by Simone LaPlante).

Sometimes gray hairs don't start to appear until much later, as late as age 2, and then sometimes they start appearing first in the tail (see bottom picture).

In all cases, the horse has more pigment-impaired hairs every year, until, in advanced cases, they can appear snow white all over.  The number of years this takes to happen can vary greatly.  During the process, otherwise-unexpected changes can happen in other areas of pigmentation:  the legs of palominos turning gray have been known to turn "black" during the process!  (See the oddly-pigmented legs on the foal, above.  Usually red-based foals are born with legs more of a buff color.)

Most "white horses" seen in pictures and in movies, etc., are actually highly advanced cases of graying, or lack of pigment of the hair.

"Gray depigmentation"

Some gray horses also lose the pigment in parts of their skin, resulting in what is usually called "gray depigmentation", similar to vitiligo in humans.  It's usually found in areas where there is little or no hair.

Gray may also be spelled "grey", which is a more British spelling, whereas "gray" is a more American spelling.

This picture shows a horse that is going gray beginning with its tail hair.  This web master hopes to investigate whether the way horses turn gray is inherited separately, implying different genes/mutations causing it.

To follow the educational, logical progression of this web site, click "Next", below.

Back Gray Tobiano Sabino Frame Splash White Rabicano Roan Appaloosa Misc. White

Main HorseColors.online sections:

Home Back Genetics 000 Dark Colors Dilutions Camouflage

Previous Next

Web design, graphics and text Copyright 2018 
by Barbara A. Kostelnik /