Bill Ormiston of Normal Square walks "Pumba", his 1-year old pot-bellied pig, and "Peppy", his Chihuahua. Normally smaller than the standard American or European farm pig, the majority of adult pot-bellied pigs are about the size of medium to large sized dog. This breed of pig, originating from Vietnam, can be easily discerned from a variety of other pig breeds by their size, upright ears and straight tail.