Dun Factors

The dun gene, besides usually diluting the body color, will create a number of 'primitive marks', or 'dun factors'. These are:

Dorsal Stripe: This is the essential dun factor, as every dun has it. If a horse lacks this, then it is not a dun. The dorsal stripe is a dark stripe running from the poll to the dock of the tail. It shows up along the horse's spine. Usually the center of the mane and tail will be darker, too, because of the stripe running through it.

Leg Barring/Zebra Stripes: These are stripes that appear on the legs, usually about the knees and hocks. They are the same color as the dorsal.

Face Mask: Duns will usually have a darker 'mask' on the front of their face. The size varies from horse to horse; some will have a small dark 'smudge', others may have such a large mask that it darkens the entire head.

Neck Shadow: Some dun horses will have a smudge of darker hair over the crest of the neck or in the hollow of the neck.

Shoulder Stripe & Shadow: A stripe coming off the dorsal and running across the withers is sometimes seen. Or, instead of a distinct stripe, some horses just have a shadow.

Frosting: The dorsal runs through the mane and will darken the center, and sometimes lighten the edges, creating 'frosting' or 'silvering'. Dun will also create "sandwich manes", where the middle is very dark and the outer hairs very light. This effect can be seen best in Fjords, where the mane is stiff and stands upright.

Cobwebbing: These are dark lines spreading across the horse's forehead. They resemble a spider's web. They are also sometimes called "chicken feet".

Ear Tips: The ear tips are usually dark. Sometimes the entire ear will be edged (called "ear frames"), or the top half will be dark.

Mottling: Some duns will show mottling on the shoulder, rump, or over the ribs. Sometimes the shoulder stripe and neck stripes will be very large and blend far down onto the body... it will kind of look like one large shadow over the horse's upper body. Rib barring is the term for heavy dun mottling appearing as bands across the ribs.

Dark Points: The legs will usually have dark points, where the fetlocks, knees, and front of the cannon bone are darker.

Guard Hairs: Some duns will have stiff white hairs at the base of the tail, called "guard" hairs.