2 year old pig accident while sleeping

Question
Hi. I have an almost 2 year old pig that we have had since he was 8 weeks old. He has never had an accident since we have had him and has always gone outside or in his litterbox if he couldn't hold it when we aren't home. Almost a year ago he had surgery for a congenital intestinal issue and has since mainly slept with my husband or I at night. He always wakes me up around 4-5 AM to go to his room for food and to use the restroom and generally remains there until I begin work at 8 AM (I work from home so he is out with me all day). This evening, my husband and I took him to the park where he grazed and exercised for a few hours before coming home. He went pee and poop outside as normal as soon as we got home. Almost as soon as we got inside (around 9 PM), he hopped on the couch and fell asleep like he was really worn out. He woke up a few hours later and immediately went to his room to eat. He is acting completely normal, eating and drinking without an issue. But when I came downstairs and sat on the couch I was met with a surprise of pee all over the couch where he was sleeping. He has never done this before and I was worried it could mean he may have a UTI or something else going on. Sorry for all the info, I figured more info was best. Any advise would be much appreciated. Thanks.

Answer
I am not a veterinarian and can not make a medical diagnosis over the internet.

It is possible that piggy has a UTI. Another possibility is that piggy expelled the contents of his preputial diverticulum. This is a pouch shaped gland located in the middle of the belly. It's job is to collect and secrete all sorts of body fluids to make "Boar Odor". Female pigs adore Boar Odor, most people do not like it at all.

When a pig is neutered, the pd stops growing and slowly begins to shrink. It continues to collect fluid. If piggy is frightened or really stressed he may empty the pd. Sometimes pigs will empty the pd while they sleep. It can seem as if they are peeing the bed, but it isn't pee, it's fluids from the pd.

Sometimes this can happened because the pd has a mild infection. Wash his belly with a warm, damp soapy cloth twice a day. He will enjoy the belly rub! Usually a few days of belly washing is enough to clear up any pd problems.

As piggy grows older, the pd will gradually begin to shrink. By the time piggy is about five years old the pd will be very small, and hold very little fluid.