Chestnut dun

Appearance

Foals		Chestnut dun foals have a paler orange-red coat color and primitive markings. Leg primitives may be harder to see. Foals that also have grey often have intense primitive markings.

Foals

Chestnut dun foals have a paler orange-red

coat color and primitive markings. Leg

primitives may be harder to see. Foals that

also have grey often have intense primitive

markings.

Dun on a chestnut base dilutes the coat to a dull light apricot to orange-red color. It also causes primitive markings. Points and primitive markings have a darker shade of red.		Adults

Dun on a chestnut base dilutes the coat

to a dull light apricot to orange-red color.

It also causes primitive markings. Points and

primitive markings have a darker shade of red.

Adults

Mimics

Since there is less contrast between the coat and the primitive markings (compared to black dun or bay dun), chestnut duns may be confused with regular chestnuts or chestnut horses with nd1.

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The dun dorsal stripe goes through the tail, while nd1 dorsal stripes don’t.
Dun is more likely to cause striping at the back of the ears than nd1.
Foals with dun tend to have a darker lower face mask, while nd1 foals have a darker forehead.

Genetics

Chestnut dun is the result of a chestnut base diluted by one of two copies of dun. The dun (D) dilution is an allele of the TBX3 gene.

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Chestnut dun:
Chestnut (e/e) + D/_

Dun is dominant, so horses could carry nd1 or nd2 (located on the same gene) without it being noticeable, but still pass it on. D/nd1 horses possibly tend to be lighter than D/nd2 horses.

Read more:
Chestnut | Black dun | Bay dun

Back to Dun

Articles

An, T.; Dugarjaviin, M.; Han, H. Expression and Analysis of TBX3 Gene in the Skin from Three Locations on Dun Mongolian Bider Horse; Genes (2024); dOI: 0.3390/genes15121589
Cieslak J, Brooks SA, Wodas L, Mantaj W, Borowska A, Sliwowska JH, Ziarniak K, Mackowski M.; Genetic Background of the Polish Primitive Horse (Konik) Coat Color Variation-New Insight into Dun Dilution Phenotypic Effect; Journal of Heredity Hered. (2021); Doi: 10.1093/jhered/esab034
Imsland, F., McGowan, K., Rubin, C. J., Henegar, C., Sundstrom, E., Berglund, J., Schwochow, D., Gustafson, U., Imsland, P., Lindblad-Toh, K., Lindgren, G., Mikko, S., Millon, L., Wade, C., Schubert, M., Orlando, L., Penedo, M. C., Barsh, G. S., & Andersson, L.; Regulatory mutations in TBX3 disrupt asymmetric hair pigmentation that underlies Dun camouflage color in horses; Nature Genetics (2015); Doi: 10.1038/ng.3475
Masuda M. Tsunoda J., Nomura H., Kimura N., Altangerel G., Namkhai B., Dolj U., Yokohama Y.; New Primitive Marking (Bider) in Mongolian Native Horse and Equus przewalskii; Journal of Equine Science (2007); Doi: 10.1294/jes.18.145