Guinea pigs are native to several countries in South America, including Bolivia, Ecuador, and Peru, their primary country of origin. Their habitat is in the Andes mountain range, which runs down through western South America.
A dwarf guinea pig is actually not a natural subset of the guinea pig species (cavia porcellus). A dwarf guinea pig is often the result of malnutrition, a medical problem, or the efforts of a breeder, who can create a genetic line of animals that are smaller, but not small enough to be considered a separate group.
While very popular pets in western countries, people often use guinea pigs food in the animals' native countries.