17 Jul 2011

Dilution Genes

Creme Dilution Gene

Palomino Horse
The cream dilution gene affects base colors by lightening them, a single dilution of the gene produces colors like palomino and buckskin. While a double dilution creates the light skinned cremello and smokey cream colors often mistaken for greys.

Basic Creme Gene

  • Incomplete dominant gene
  • Does not noticeably affect black pigment
  • Dark red colors lighten to tan or yellow
  • Makes chestnut and bay base coats lighter
  • Bay becomes buckskin
  • Chestnut become palomino

Single Dilute Creme Shades

A single creme gene can affect black, chestnut and bay animals, however it requires a double dose to have much physical affect on black animals.
Palomino Horse
Image from Princes Milady
  • Caused by one dose of cream gene diluting chestnut base
  • Shades range from very light to very dark
Dark Palomino Horse
Images from Just Chaos & Reynaldo
  • Light shades can appear almost white
  • Darkest shades mistaken for silver dapple
  • Born light and grow darker with age
  • Eyes can be a light amber in color
Smokey Black
Smoky Black Horse
  • Created by a single dose of the creme gene on a black base
  • Has a slight affect on pigment
Buckskin Horse
Image from Rozpravka
  • Often incorrectly called with dun
  • Dun and Buckskin are different genetically
  • Caused by one dose of cream gene diluting a bay horse
Buckskin Horse
Images from Rozpravka & Derrick Coetzee
  • Range from very light to very dark
  • Purest form will have black points
  • Dark points fade with age

Double Dilute Creme Shades

A double dose of the cream gene affects colors much more dramatically and can even make black animals almost pure white. Double cream dilutions are the most often mistaken for albinos (which don’t exist in horse genetics).
Cremello Horse
Image from Steven_Walling
  • Caused by a double dose of cream gene on chestnut base
  • Always have pink skin and blue eyes
Cremello Horse
Image from HP Quarter Horses
Smokey Cream
Smoky Cream Horse
  • Created by a double dose of cream gene on black base
  • A double dose has a much stronger affect on a black animals
Perlino Horse
Image from Hidden Rock Ranch
  • Created by a double does of cream gene on a bay horse
  • Points are darker than body hair
  • Blue eyes and pink skin

Mixed Dilutions

Animals can carry more than one dilution gene, (or modifier for that matter) furthering the rainbow of colors & patterns that can be found. Here are some examples.
Dunskin Horse
Creme & dun dilution genes on a black base
Dunalino Horse
Dun & cream dilution genes on a chestnut base
Image of Major Heart’s Desire courtesy of Circle P Ranch

Silver Dilution Gene

Silver Dapple Horse
Image credit Arsdelicata
One of the rarer color dilutes, the silver gene does not affect hair with red pigment. This means that it has a much more dramatic effect on a blackbase than it does on a bay horse.
Silver dapple is often confused with flaxen liver chestnuts because they both display dapples and often have creamy colored mane and tail hair.

Basic Silver Gene

  • Generally called silver dapple
  • Still rare, but becoming more commonly found

Different Silver Shades

Because it only affects animals with black bases, (and especially black hair) the silver effect is rather dramatic.
Silver Dapple or Chocolate Silver
Silver Dapple Horse
Image credit Equine Now
  • Result of silver gene on black base coat
  • Shetland and miniature breeds call it silver dapple
  • Gaited and mountain breeds call it chocolate
  • Icelandic breeders call it blue silver
  • Vary from light to dark
  • Light silver / gray and dappled common in pony breeds
  • Also occurs in chocolate color ranging from light to dark
  • May have flaxen mane and tail
  • Darkest color is almost black
Silver Bay
Silver Bay Horse
Image from Philipendula
  • Result of silver gene on bay coat
  • Silver gene does not physically affect red pigment
  • Body color stays the same
  • Dark points can be diluted
  • Foals have light legs and as they age they become darker

Champagne Dilution Gene

Amber Champagne
Image from Kersti Nebelsiek
The champagne gene is a rather recent discovery in the world of horse color and it has a diluting effect on both chestnut and black base coats. This pigment alteration can exhibit in a showy display of colors which often have an almost metallic sheen.
Although it should be noted that not all horses with a metallic sheen are champagne.

Basic Champagne Gene

  • Sometimes born with blue eyes
  • Born dark and coat lightens with age
  • Sometimes born with pink skin which darkens with age
  • Freckling around mucus membranes common
  • Mistaken for appaloosa, sabinos and sometimes grays
  • Can have reverse dappling

Different Champagne Shades

The champagne gene affects black, chestnut & bay animals to varying degrees, here are some examples.
Classic Champagne
Classic Champagne Horse
Image from Kersti_Nebelsiek
  • Black horses diluted by champagne gene
  • Sometimes called grullo even though they are not a true dun dilution
Gold Champagne
Gold Champagne Horse
  • Chestnut horse with champagne gene
  • Often confused with palominos
  • Mane and tail can be flaxen
Amber Champagne
Amber Champagne
Image from Kersti Nebelsiek
  • Bay horses with the champagne gene
  • Commonly confused with buckskins or silver buckskins

Mixed Dilutions

Animals can carry more than one dilution gene, (or modifier for that matter) which multiplies the color rainbow even further.
Silver Champagne
Silver Champagne Horse
Image from Equine Now
  • Black horse displaying both champagne and silver dilution genes
  • Also called sweet champagne

Want to Learn More

Be sure to check out a guest post with a more complex look at the champagne gene: Equine Champagne Gene

Dun Dilution Gene

Grulla Horse
Image from Amazona
The dun dilution gene is generally quite obvious due to the specific (almost primitive) markings that indicate its presence. Some animals will display darker striping of the legs, withers and face and can be mistaken for asooty / smutty modifier.
The quick and easy way to determine a dun gene is to look for a dorsal stripe from mane to tail.

Basic Dun Gene

  • Dilution gene that affects black and chestnut pigments
  • Changes the physical color of black, bay and chestnut horses
  • Arabian and thoroughbred don’t present dun characteristics
  • Mistaken for buckskin when present on a bay base

Dun Terminology

The dun gene causes primative markings on the horse which occur in different combinations and vary from animal to animal. The images below are rather extreme examples.
Dorsal Stripe
Dorsal Stripe
  • A dark line from the base of the mane to the base of the tail
  • Sometimes goes through the tail giving it a dark stripe
  • Also called eel stripelinebackbackstripe
Zebra Striping
Zebra Stripes
Image from Arsdelicata
  • Horizontal marks on legs
  • Can go above hock / knee
  • May be very dark or so light they are hard to see
Shoulder Stripe
Shoulder Stripes
Image from Kersti_Nebelsiek
  • Shading or striping over withers and shoulder can be dark or so light it is hard to see
Cobwebbing / Spiderwebbing
Cobwebbing / Spiderwebbing
  • Rings or stripes on the forehead & sometimes on the chest

Different Dun Shades

The dun dilution affects blackchestnut and bay animals and within each color a variety of shades can be displayed. Here is a little about each one.
Bay / Zebra Dun
Bay Dun Horse
Image from Podargus
  • Created by dun gene on bay coat
  • Most common type of dun
  • Come in many shades ranging from light to dark
  • Gene dilutes body hair more so points stay darker
  • Heads / face darker than rest of body
  • Dilution with a combination of other genes cause a variety of colors and combinations
Red Dun
Red Dun Horse
  • Created by a dun gene on a red base coat
  • Often confused with chestnut
  • Do not have black points
  • Primitive markings are distinguishing and a darker shade of red
  • Shades range from light to dark
  • Head darker color than body
  • Light shades called ‘Claybank Dun’
Grullo or Grulla (male – female)
Grulla Horse
Image from LD Acres
  • Created by a dun gene on a black base coat
  • Grullo is Spanish word so females are referred to as Grulla
  • Smoky blue color ranging from light to dark
  • Black points
  • Darker heads
  • Primitive markings are distinguishing and black

Mixed Dilutions

Animals can carry more than one dilution gene, (and modifier for that matter) furthering the rainbow of different horse colors.
Dunskin Horse
Dun & cream dilution genes on a bay horse
Perlino Dun
Perlino Dun Horse
Double dose of the creme gene on a bay dun.
Image from Perlino Morgan
Dunalino Horse
Dun & cream dilution genes on a chestnut base
Image of Major Heart’s Desire courtesy of Circle P Ranch

Rare Dilution Mixes

The stranger the genetic mix the stranger the color, but that also means that the resulting colors become very rare indeed.
Silver Dapple Dun - A combination of silver and dun genes on a black base. Even more rare than the silver dapple color. So rare, in fact, that I couldn’t find a suitable picture to show.
Champagne Dun - A combination of champagne and dun genes on a black orchestnut base. Also rare enough I couldn’t find images.

1 comment:

  1. Anonymous10/10/2013

    Hi! Nice work!
    Do you know what breed is the silver bay draft horse? And the chocolate silver above it?