When my brother and I were kids, we lived in a rented farm house in SW Missouri. The landlord raised pigs; one cold winter evening he came to the house with two baby pigs...one was a Chester White, the other a Duroc Jersey. The Duroc had its tail frozen off. He said they were runts, and figured they would probably die and so he gave them to my brother and me. We put them in a box and fed them milk with baby bottles...and they grew like weeds. One evening we went to town, left them in the kitchen. They got into our trash and found a can of pork and beans that had 3 or 4 beans in the bottom of the can; they got them out somehow and chased them all over the kitchen linoleum, leaving snout tracks everywhere. Of course Mom hit the ceiling; they were banished to the screened in back porch.
They are very, very smart; they grew up running with the landlord's pigs and eating his feed, but they were still pets...we would try to ride them, but about 5 or 6 seconds was about all we could last. Finally Dad traded them to the landlord for one butchered and in-the-freezer pig, and the experiment was over. Pigs are actually a lot more tidy and sanitary that one would guess, if they are given the chance. But they are not very cuddly and some breeds will eventually grow to weigh several hundred pounds; in fact some breeds will get to be 1000 pounds or more. My Granddad claimed to have raised a Poland China that weighed over 1000 pounds, and I have personally seen a Duroc that weighed probably 700 pounds. It was an old boar, and you could smell him before you could see him. Bottom line; I wouldn't think of raising one as a pet unless you have the room he will need, and don't forget; sending ol' "Porky" to the butcher shop can be too traumatic for some family members to handle. Good luck.