Dun Dilution Gene

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 a sooty / smutty modifier.

The quick and easy way to determine a dun gene is to look for a dorsal stripe down their back.

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.

• 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 stripe, lineback, backstripe

• Horizontal marks on legs
• Can go above hock / knee
• May be very dark or so light they are hard to see

• Shading or striping over withers and shoulder can be dark or so light it is hard to see

• Rings or stripes on the forehead & sometimes on the chest

Different Dun Shades

These are general color categories & each one can produce a wide variety of dun shades.

• 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

• 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’

• 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, furthering the rainbow of different horse colors.

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 or chestnut base. Also rare enough I couldn’t find images.