May have several different causes. An unknown gene and certain illnesses can both cause vitiligo
Speckles of white fur that start on the face and feet and continue to spread with age.
Only affects Black. If a creature has no black markings, and the base coat is ee (no Black gene), Vitiligo will not appear.
On a mixed base, like Wolf, Vitiligo will only affect black/brown areas where Eumelanin is affecting color. It would not affect exclusively red areas or markings. Black areas would become white, brown areas would become red or pale cream in hue because the red pigment would still be produced.
Vitiligo will also affect Melanism. It can reveal the original coat beneath melanism. If there is red fur underneath the melanism, it will be revealed by vitiligo. If there is black underneath the melanism, it will become white. If the fur had mixed red and black pigment, only the red will become visible and the black will disappear.
Not to be confused with Smoked, a white spotting gene that affects black in specific areas and does not spread.
This is the same cat, before and after vitiligo began to remove pigment!