why is my pot bellied pig started bitting?

Question
I adopted Kady in May, she is now 1 year old.  The previous owner had to get rid of her because she didnt like his daughter and her new baby, which had moved back home. When she came to live with use she moved into the barn with chickens and rabbits.  We all got along great, but she ran my youngest son out of the pen and tried to bite his ankle, her teeth scratched him.  I told him that she may have been in a bad mood, just leave her be.  But for the rest of the week when he was anywhere near the fence she would run at him...this was about 3 weeks age  now she is running me out of the barn and tries to bite my feet and hands when im patting her..I just dont understand and we are all very upset, the kids wont even go do chore now they are scared of her.  I dont know what to do, but something has to be done..Please help me.   ps  this is not the first pot bellied pig that i have owned, my first pig lived in the house and outside in the summer.  We had a dog and rabbits that she socialized with and I never seen this aggression in her??  Kady was also spayed just before I adopted her.. thanks Lisa and Kady

Answer
I am assuming that Kady is not in pain, and that she really was spade. More than one dumped "spade" pig has surprised the new owner with piglets!

Aggression is not uncommon in pigs that were taken from their parents at an early age. Also, a pig that is given away because it's aggressive is very likely to display aggression towards the new owners when the pig feels that the new place is "home". It's a natural pig instinct to try to be "top hog". Pampered and "spoiled" pigs are more likely to be aggressive than pigs that were raised with loving, but consistent, firmly enforced, rules.

Kady has finally realized that your home is now her home, and she is establishing dominance over "her" territory, which is her pen. Because she displayed aggression towards her former owners, and because she successfully ran your son out of "her" territory, the aggression was reinforced. She can be retrained, but it will take a bit of work.

Take a sorting board, something like a large garbage can lid, when you go into her territory. When she behaves aggressively, use the board to push her back. Expect her to be very angry at first! She's used to getting her own way and will not like letting you be in charge. If you are not frightened of her, push her back at her shoulders or the top of her head. You might even try "flicking" your finger at her snout. The idea is to teach her that bad things happen when she behaves badly.

Harness and trick training will go a long way towards teaching her that she is not in charge. No treats unless she "earns" them by performing simple tricks like "sit".

Kady has learned a lot of bad habits and it won't be easy to teach her new ones and it will take time. This is a difficult problem with many aspects to it.

Yahoo groups has a couple of groups devoted to pot-bellied pigs. I recommend PigInfoAndChat and PotSpot. Both groups have people who have dealt with the same problems you are having now with Kady.

I totally recommend Priscilla Valentines book Pot-Bellied Pig Behavior and Training. She has a couple of chapters devoted entirely to aggression in pigs and how to handle it. Her book is available from her website www.valentinesperformingpigs.com  or from Amazon.com