Pig problem

Question
I have two pot b. pigs.  They are bro/sis, spayed & neutered, never been apart. One year old. Live outside in huge fenced pen. Boy is the dominant one, but never aggressive to her. The boy got pneumonia and had to stay at the animal hospital for 1 night. They kept him in his own pen but in the dog section. His health improved dramatically overnight. Upon his return, they squealed with delight when they heard each other, until we put him in their yard.  She attacked him, vigorously trying to bite him.  There are bite scratches and torn ears. He defended himself, we separated them after it didn't get better, dividing their yard in half with fence.  That was 3 days ago and it's not much better.  We took the divider down, hoping they will work it out. She will allow him to be in the yard, but only if he cowers in the corner. If he leaves the corner she goes after him. Anyone know what's happening and what to do?

Answer
Yes, this is typical pig behavior. Upsetting to us humans, but very natural to them. Put Polysporin or Neosporin or something similar on the injured ears.

Pigs have an innate desire to be "Top Hog". For your pigs, it was the boy. When the Top Hog is ill or injured or grows old and can no longer maintain top status, the lower-ranking pigs will bump him (or her) down the social ladder, and the result is a lot of fighting and scuffling and an occasional injury.

Pigs are sexually mature at just a few weeks of age, but they don't reach mental adulthood until they are about age 2. This is when the drive to move up the social ladder really kicks in. Pigs this age pick fights with the pigs just above them, to get the higher spots.

A pig who is insecure in their position on the pig ladder will actively attack the pigs ranked below him, this is how he reinforces his position above them.

So what has happened here is that the boy is no longer physically capable of maintaining his position as "boss". The girl is now in charge! But, she doesn't feel secure in this position, and she wants to make sure the boy stays in spot #2. So, she bullies him to "teach him his place" so to speak.

I'm afraid the best thing to do is also the hardest, and that is to just put them together and let them work it out between themselves. Unfortunately, when people interfere in pig fights, the fighting just gets worse.

If you keep them apart until the boy heals, they might fight when reintroduced, to decide who will be in charge. As the boy gets stronger, he might want to regain his spot, causing more fights. And finally, when they reach age 2, there could be more fights, because very often the Top Pig is a female.

The sooner these two pigs get back together, the sooner they can reestablish their peaceful relationship.