From dictionary.com:
pig Pronunciation Key (pg)
n.
a. Any of several mammals of the family Suidae, having short legs, cloven hooves, bristly hair, and a cartilaginous snout used for digging, especially the domesticated hog, Sus scrofa domesticus, when young or of comparatively small size.
b. The edible parts of one of these mammals.
hog Pronunciation Key (hôg, hg)
n.
a. Any of various mammals of the family Suidae, which includes the domesticated pig as well as wild species, such as the boar and the wart hog.
b. A domesticated pig, especially one weighing over 54 kilograms (120 pounds).