ARTHRITIS (ARNOLD AND CHARLIE)
Both Arnold and Charlie had some joint stiffness for a while, but starting in early 1999, their joints appeared to actually be causing them some pain.  Joint problems are quite common in pigs and when you look at the way they're built, with those little stubby legs supporting a large, heavy body, it's no wonder.
We started giving both pigs glucosamine to see if that would help.  Glucosamine, which is often found combined with chondroitin, is a dietary supplement commonly used to treat arthritis in people.  After some experimenting, I found chewable Cosequin brand tablets, which both pigs ate quite willingly.   
Giving pills to pigs can be something of a challenge.  There is no way you're going to force a pig's mouth open and stuff the pill down its throat like you would with a cat or a dog.  Before we found the chewable tablets, we tried hiding pills in bits of bread, grapes, and other tidbits.  Charlie fell for it and we fooled Arnold for a little while, but eventually, he'd take the tidbit into his mouth, move his tongue around a bit, then swallow the food and neatly spit out the pill.  Pigs are pretty darn smart...
The glucosamine helped for a while, but eventually, we had to put both pigs on Rimadyl (aka Carprofen 100 mg), which is a prescription medication used to treat arthritis in dogs.  Eventually, Charlie was unable to get up by herself even on Rimadyl and we had to euthanize her.  Unfortunately, this is a very common occurrence with older pigs.

PROBABLE HEART FAILURE (ARNOLD)

In mid-April of 2007, we noticed that Arnold seemed a bit more sluggish than usual and wasn't as interested in food.  We made an appointment for him, but the day after doing so, noticed that his breathing was becoming labored.  Fortunately, his vet was able to come out and see him that day.  She found fluid in his lungs and agreed that this was the end and euthanasia was the best choice.

Given his age and his symptoms, we believe his heart was failing.