In the white dock, there is a fall of white hair starting at the tail base. This is usually referred to as skunk tail or rabicano , and is believed to be a type of sabino gene. These spots are ancient in origin and can be of any size. They are present at birth and are permanent. This sabino mutation occurs when the binding effect of certain enzymes is lacking.
Beauty marks are dark red or black spots that occur most commonly in the chestnut coat.
They can be one or many in number, either large or small. The genetic control of these spots is unknown. Or, after the Thoroughbred horse most noted for them. Birdcatcher spots are very rare and are associated with certain families. These random white spots occurring on any area of the body can appear at any time in life and just as mysteriously disappear.