Many pig breeds can have spotted markings, including:
* American Spotted Pig
* Meishan
* Mangalitsa (often has a "spotted" appearance due to the curly hair pattern)
* Pot-bellied Pig (some varieties can have spots)
So, to be more specific, you could say "a spotted American Spotted Pig," or "a spotted Mangalitsa pig," depending on the breed.