Mushroom coat
Mushroom (chestnut)
A chestnut mushroom pony has grayish beige, sepia or muted brown hair on its trunk and neck, often with a lighter mane and tail. The usual chestnut red becomes a softer shade that can approach taupe.
Mushroom (chestnut): how the color works and is inherited
Mushroom is an MFSD12 variant affecting red pigment. A pony must inherit two Mushroom variant copies to show the characteristic dilution on a chestnut base.
Each parent must pass on a Mushroom copy. Two ponies carrying one copy each have a one-in-four chance of producing a mushroom foal at each birth, even though neither parent shows the dilution.
Mushroom (chestnut): origins and the role of breeding
Shetland breeders knew sepia-colored ponies before they knew what caused the color. A study published in 2019 connected Mushroom to a variant of MFSD12. The researchers identified a variant already being passed through pony families; they did not create the coat color.
Mushroom can be inherited within the Shetland breed without crossing to another breed. Choosing variant-carrying parents increases the chance of bringing two copies together in a foal.
Mushroom (chestnut): photographs of horses
A pale mushroom Shetland with almost white mane and tail.
A darker mushroom Shetland with sepia-colored hair.
Marquise Unique, a mushroom filly with white patches.
Photograph credits
Photographs have been resized. Photographs within scientific figures have been separated by cropping. Colors are preserved.
- A pale mushroom Shetland with almost white mane and tail. — Maria and Joana Tammi · CC BY 4.0
- A darker mushroom Shetland with sepia-colored hair. — Maria and Joana Tammi · CC BY 4.0
- Marquise Unique, a mushroom filly with white patches. — Elsaraja · CC BY-SA 4.0
- A Shetland combining Mushroom, Cream and white patches. — David Hodge · CC BY 4.0
- A mushroom palomino pony with pale mane and tail. — Tanaka et al. (2019) · CC BY 4.0
- A mushroom palomino foal with white patches. — Tanaka et al. (2019) · CC BY 4.0
Mushroom (chestnut): telling similar coats apart
Silver black lightens black pigment, whereas Mushroom mainly changes reddish tones. Palomino can also look similar, and some ponies carry both Mushroom and Cream.