Dun (D)
Dun is a dominant dilution that affects both red and black pigment, meaning it can visibly dilute all three base coat colors. The resulting effect depends on the horse's underlying base color.
Dun horses typically have lighter body colors while retaining darker pigmentation on their mane, tail, and lower legs.
They also commonly display primitive markings, including a dorsal stripe (back stripe), leg barring (leg stripes), and shoulder stripes. Note that other genetics and markings can cover these up, so even if a horse visually has no primitive markings it does not mean they do not carry the dilution. Likewise, the extent and location of these markings can vary, some horses may have extreme primitive markings that extend up the legs or along the back, whereas some horses may have less noticeable markings.
Dun Coat Colors
The resulting color depends on the horse's base color:
- Chestnut + Dun (D) - Red Dun
- Bay + Dun (D) - Bay Dun (Classic Dun)
- Black + Dun (D) - Grullo (Blue Dun)
Dun Inheritance
Because Dun is dominant, only one copy is needed for the dilution to be visibly expressed.
- D/D - The horse has two copies of Dun and will always pass Dun to its offspring.
- D/nd2 - The horse has one copy of Dun and has a 50% chance of passing Dun to its offspring.
- nd2/nd2 - The horse does not have the Dun gene and will not visibly display it or be able to pass it to its offspring.
Non-Dun Alleles (nd1 & nd2)
In real horses, there are two non-Dun alleles: nd1 and nd2.
- nd1 - Can produce primitive markings without diluting the coat. This means a horse may display leg stripes and a dorsal stripe while retaining its original base color.
- nd2 - Does not produce Dun dilution or its associated primitive markings.
Our genetics system currently includes nd2, but not nd1 as of yet - we do plan to release this eventually however!