Dog Coat Color Piebald, Parti or Random White Spotting
White patterns in dogs does not have a uniform genetic basis. Some white patterns, are symmetrical with white markings on the undersides, collar and muzzle. Patterns of less symmetrical white spotting are often called piebald, parti, or random white.
The genetic determination of white spotting in dogs is complex. In some breeds, piebald is dosage dependent. A dog with one copy of the variant has some white pattern expression, while a dog with 2 copies of the variant display more extreme white with color only on the head and perhaps a body spot. In dogs with 2 copies of the MITF variant, some are completely white. Additional mutations in MITF or other white genes may be present that affect the amount of white being expressed. In others, piebald behaves as a recessive trait requiring 2 copies of piebald needed to produce white spotting.
N/N Dog has no copies of piebald
N/S Dog has 1 copy of piebald
S/S Dog has 2 copies of piebald