There are quite a few pot-bellied pig sites and books out 
there, but here are a few basic pig facts we've learned.

TOPICS:

LIFESPAN

Several sources I have read say that pot-bellied pigs can live for 10-15 years.  I don't have evidence to back this up, but I'd bet that the larger pigs tend to have shorter lifespans.  Of the few pigs I've known, only Arnold and Charlie made it past the age of ten years, which I hope is the exception rather than the rule.  Our pig vet told us she's met a couple of 18-year-old pigs, but that is exceedingly rare; fifteen years is considered to be extreme old age.

INTELLIGENCE

Rating the intelligence of animals is not easy to do since behavior varies so much from species to species and communication is limited.  It usually boils down to a matter of opinion.  So, here is my opinion: I would say pigs are at least as smart, if not smarter, than the average dog.  Pigs are generally not as active as dogs, nor are they as motivated to please their owners as dogs are, so they tend not to do as many of the tricks and such that humans associate with intelligence.  They can be trained with food rewards, though, and aside from performing tricks, they seem to do quite a good job of figuring things out and solving problems - especially when food is involved.

LIVING QUARTERS

(Note:  I can't provide any information on indoor pigs, as ours have always been outdoors.)
Pot-bellied pigs don't do well in very cold or very warm weather.  With this in mind, our pigs have pig houses (When all four pigs were alive, Charlotte and Chuckie slept in one pig house and Arnold and Charlie in the other).  The houses were constructed for us by a friend's husband, who is a carpenter, and they are something like oversized doghouses.

In the winter, we put plenty of hay in the houses so the pigs can burrow into it for warmth.  The hay had to be replaced regularly, since they ate a fair amount of it and eventually crushed the rest of it into dust.  Our pigs also loved to creep under blankets, and I have a suspicion that most pigs enjoy doing this.  When the weather was cold and windy, we draped a rug or a tarp over the doorway after the pigs settled in for the night.

In the summer, they preferred a natural dirt floor with a little hay for padding.  During warm months, we also provided them with a children's swimming pool that they could lie in to cool off and to moisten their skin.  In addition, we used the hose to make a couple of mud wallows.  Lying in cool mud is nice on a hot day, and the mud also acts as a moisturizer and helps to keep flies away.  They also had their own, personal evaporative cooler.

Year round, the pigs could roam freely about our fenced 2.8 acre property, and in their younger days, they moved around quite a bit.  Charlotte especially did a good deal of wandering about, and as a result, there are several "pig paths" through the undergrowth.

DIET

Pigs love food.  Most pigs will eat just about anything, anytime, and it is very rewarding to feed them, since it makes them so happy.  Not surprisingly, given these two factors, a lot of pigs end up being very overweight.  Excess weight isn't any better for pigs than it is for humans, so it pays to go easy on the treats.  In my experience, once pigs gain weight, they don't lose it easily.

We fed our pigs a commercial brand of pot-bellied pig chow twice a day as the major part of their diet.  They always had hay to eat as well, since it's a good low-calorie "filler" food, and we gave them greens, fruits, and vegetables on occasion.  Once a day, they each got a 200 IU vitamin E tablet, which helped keep their skin in good condition, and a children's chewable vitamin tablet.

Pigs are remarkably efficient at turning food into fat and are very clever about getting extra food whenever possible.  Charlotte once noticed a full bag of wild bird seed we had stored on top of an otherwise empty shelving unit in our workshop, and pushed the shelving unit vigorously until it fell over, sending the bag of birdseed to the ground.  She then ripped open the bag and had quite the little feast before we discovered her.  

MAINTENANCE

Once you have food and shelter taken care of, pig are fairly low maintenance animals, unless you are into training them and the like.  Our guys were pigs of leisure.

Daily tasks included scooping poop and refilling water dishes, which they loved to tip over.  In the warmer months, their swimming pool also needed to be cleaned and refilled on a daily basis. Brushing them regularly helped to keep their skin in good shape, though this may not be as much of an issue in places with higher humidity.  We live in a desert, and their skin tended to get quite dry here.  They really liked being brushed, though, so it was worth the effort just to make them happy.  Fly spray was a must during the warmer months to keep the bugs away.

We had the pig vet out once a year to give their annual vaccinations, do a physical exam, trim hooves and, in Arnold's case, trim tusks.  Male pigs do grow tusks, and if they get long enough, they can curve around into the pig's face and cause some discomfort.  It's not a bad idea to wear earplugs and alert the neighbors when the vet comes, as the squealing is incredible...

SUITABILITY AS PETS

I think the three most important things to think about when deciding whether a pig might make a suitable pet are: the law, the pig's size, personality (yours and the pig's), and the availability of veterinary care.

The Law:  
In the U.S. at least, it is not legal to keep pigs in quite a few urban areas.  Before acquiring a pig, it's a good idea to contact the authorities in your area to make sure it is legal.

Pig Size:  
When pot-bellied pigs first became fad pets in the U.S., much was made of them being "miniature" pigs.  Compared to a farm pig, which can weigh over 1,000 pounds (454 kg), they are miniature pigs; however, pot-bellied pigs can weigh anywhere from 50-300 pounds (22.6-90.7 kg) and many weigh even more.  You've got to have sufficient space to comfortably house an animal that may end up weighing more than you do.

Many people in the U.S. acquired pot-bellied piglets, only to abandon them when they wound up getting larger than expected.  Some breeders are now producing miniature pot-bellied pigs, which weigh under 50 pounds (22.6 kg).  I have no idea whether the reduction in size has an adverse effect on the pigs' health.

Personality:  
If what you're after is a loyal, obedient companion, you should probably think about getting a dog.  In my experience, pigs tend to be a lot more obstinate than dogs and view you as a friend rather than a master.  Some pigs really don't like to be handled all that much and some even get nippy and aggressive with their owners.  On the other hand, many pigs can be sweet-natured and sociable.  I think pig owners have to not be insulted when their pet doesn't worship them and must be willing to accept an independent animal with a mind of its own.

Availability of Veterinary Care:
Encountering health problems has been by far the most frustrating, depressing part of our pig-owning experience.  Most vets won't treat pigs, and even when you find one who does, treatment and diagnostic options are rather limited, especially for larger pigs.  Pigs are a challenge to handle, and it's very tough hitting veins on them, so giving them fluids and taking blood can be difficult or impossible.  Transporting the larger pigs is generally a major undertaking, also, so x-rays, ultrasound, and surgery can be iffy.

We were lucky enough to find a practice with two great vets who were happy to treat pigs, but they were also located quite a distance from our place, so there were still logistical issues to overcome.

I've never felt as helpless and frustrated in my life as when Chuckie and Charlotte developed serious health problems.  In Chuckie's case, there was no way the vet could reach him in time to help (and we aren't sure she could have helped even if she'd made it in time) and in Charlotte's case, the vet was out of town and no one else was willing to treat her.  There was just not a whole lot anyone could do, and it was a terrible feeling.  It's something you may have to be prepared for as a pig owner.

INTERACTIONS WITH OTHER ANIMALS

Dogs and pigs can be a bad combination.  If you have a dog that has shown any aggression toward other animals, it's probably best not to get a pig - and certainly not a piglet - unless you can keep the two entirely separate.  Our dogs are not aggressive toward pigs, but we still kept them well apart during feeding time, as arguments are likely to break out over food.  

Pot-bellied pigs have few defenses and dogs can severely injure or kill them.  Not long after we moved into our house and before we got our dogs, a couple of neighborhood dogs dug under our fence, came into the yard, and attacked Charlie.  Arnold tried to defend her, but there was little either of them could do.  It was lucky I happened to be home and ran the dogs off, but as it was, Charlie looked like someone had sliced her all over with a razor.  She made a full recovery, and our dogs now keep stray dogs off the property.

Introducing a new pig to a resident pig can also be problematic.  Our pigs' previous owner said that Charlotte immediately attacked Arnold and Charlie when she first came to live here, and Charlotte and Arnold gave Chuckie a hard time when he arrived.  None of the altercations produced any significant injuries, however, and the pigs sorted out their differences in a few weeks.

The only other animal our pigs have had contact with is Bobby, a cat who belonged to the man who shares our property.  On more than one occasion, I saw Bobby and the pigs curled up together in the sunshine, taking naps.  Bobby obviously knew the pigs were not a threat and the pigs didn't seem to mind him, either.

COMMON HEALTH ISSUES

Spaying/neutering:  
Be sure to have your piglet spayed or neutered when it is still young and small.  It's healthier for the pig and makes them better pets, plus I have heard that intact, adult male pigs smell awful!  Three of our pigs were neutered when they were young, but Charlotte was already an unspayed adult when her previous owner adopted her, and once a pig is full-grown, the surgery is difficult and risky.  Unfortunately, because she was not spayed, Charlotte developed a uterine tumor that killed her.

Arthritis/Joint pain:  
Pigs seem particularly prone to joint problems, and it's no wonder, considering that their stubby little legs have so much weight to support.  If a pig is overweight, it is more likely to develop joint problems since the additional weight puts extra stress on the joints.  Watching your pig's weight is probably the most important thing you can do to help ensure healthy joints.

If your pig does have joint problems, consult your vet.  The vet may recommend glucosamine, buffered aspirin, and/or Rimadyl or another prescription anti-arthritis drug, depending on the severity of the problem. 

Arthritis is a common cause of death in older pigs.  It doesn't kill them directly, but it gets so bad that they're unable to get up anymore and have to be euthanized.  That is what happened to Charlie.

Upper respiratory infections:  
So far, we have not encountered this problem in our pigs, but I hear these infections are reasonably common.  Watch for thick, yellow or greenish discharge from the nose and frequent sneezing or coughing.  Keep in mind that pigs have a clear nasal discharge most of the time, and this is normal.  Many pigs also salivate heavily and even foam at the mouth, especially at feeding time.  This is also normal.

Internal parasites:  
Like just about any other animal, pigs can get worms and other intestinal parasites.  Our pigs had a bout of diarrhea one year, and a fecal test showed coccidia, which was easily cleared up with medication.  It can't hurt to have a fecal test done when you first acquire a pig, just to make sure it doesn't have parasites, and it's also a good idea to have one done if you see diarrhea or other evidence of intestinal problems.

Other intestinal maladies:  
The pig's digestive system is very similar to ours and they tend to get the same kinds of intestinal problems we do, including upset stomach, ulcers, irritable bowel syndrome, intestinal blockages and strictures, etc.  Keeping the pig on a regular feeding schedule, not allowing it to overeat or become overweight, and keeping rich treats to a minimum will help prevent some of these problems.   

We have had experience with intestinal blockages (see Charlotte's medical page) and were fortunate the problem was not fatal.  We have also dealt with irritable bowel syndrome and intestinal stricture (see Chuckie's medical page) and unfortunately, the stricture was fatal.

EUTHANASIA

It's not something that's pleasant to think about, but most pigs don't die on their own, so euthanasia is necessary.  Our experience is probably outside the norm, as two of our pigs developed sudden medical problems and died at home.  Charlie and Arnold, however, had to be euthanized.

I added this section to the page because of a conversation we had with our pig vet when Charlie was euthanized.  She mentioned that pig euthanasia can be very stressful for everyone involved because it is difficult to hit veins on pigs and because most of them don't like being restrained and tend to struggle and squeal.  She told us that after some trial and error, she came up with a method that is humane and as low-stress as possible for everyone.

She pours some isofluorane, an inhaled anesthetic, onto cotton, then puts the cotton into a mask, which goes over the pigs mouth and nose.  Though some pigs may struggle a bit, it is due to their dislike of being restrained.  It is not painful in any way.  When the pig is completely anesthetized and unable to feel anything, she injects the euthanasia solution directly into the heart.

She used this method with Charlie and Arnold.  She did warn us that they might struggle and that it could take some time for the isofluorane to have an effect, but Charlie just lay there quietly and was under in just a few minutes.  Arnold protested briefly, but also went under very quickly.