Mushroom (Mu)

The mushroom gene is currently only found naturally in the Shetland Pony. The gene must be homozygous (MuMu) on a red-based coat, chestnuts or bays, to show the dilution. Any horses that show mushroom dilution will show as a mushroom base.

Mushroom can be graded into other breeds as seen below. Click here to learn more about grading horses.