Pot Bellied Pigs/pig peeing in random spots
So my pig is about 4 1/2 months old and he is peeing around the house in random spots but normally within 3 feet of his litterbox. We know that he is young but just a month ago he was doing great every 2-3 hrs as he needed he would get up and go over and use his litter box. Then he started not to go there without us reminding him and now he is peeing anywhere. So every two hours we take him and put him in his area and make sure he uses the litter box and that has been helping but he has also been peeing while drinking his water. And his water bowl is only 1-2 ft away from the litter box. He didn't use to pee there until recently and we completely changed out the rug from there so that it wouldn't carry the scent. Sometimes he runs under a chair that is on the outside of his area next to the litter box and try to pee there but we normally catch him and redirect him. Is there anything we can do to prevent this. We are very confused since he didn't use to do this.
Two separate things are happening here. First, if he was waiting up to 3 hours to pee, chances are, he was actually taking a quick "sneak pee" here and there. Young pigs have tiny bladders, and they often do not realize they have to go until it's too late to run to a box. So they step quickly and quietly to one side, and are finished before the people around them realize what has happened.
And the pig gets in the habit of the quick pee to one side. But as the pig grows, so does the amount of pee and the time it takes. So he's finally caught. The pig doesn't understand why this is suddenly not Ok. The people don't understand why the pig has started doing this. That's probably why he likes the chair outside his area, he's "got away" with a sneak pee or two there before.
The other factor is the change in his environment. You mentioned a rug, and also that he's peeing while he drinks. The pee-while-drinking behavior often pops up in water-deprived pigs. It doesn't always happen when pigs are dehydrated, and sometimes it happens when the pig has always had plenty of water. Sometimes it's a symptom of a medical problem, like crystals or a urinary infection.
The best approach is to start potty training again from the beginning. Evaluate the box, it should be big enough for him to turn around in, with one low side so he doesn't have to step up to get in, and a non-slip floor so he can go comfortably. Use what ever litter works for you, some people even use washable old towels, others use no litter at all just a rubber mat.
Take him to the box every 90 minutes when he is awake. Make him potty in the box before letting him out of his area. Make him potty as soon as he wakes up from a nap and first thing in the morning. The idea is to keep him so empty he doesn't have the urge to potty elsewhere.
Keep him confined to his area unless you can keep a close eye on him. Keeping him on a harness and lead helps to alert you when he is preparing to go.