my 3yr old potbelly pig goes potty in her bed

Question
Hi, i have a 3yr.old potbelly  pig  and she has been pottying in her  bed. She is overweight and has arthritis so she hasn't  been  getting  around  to well. She lives out in a little building with her sister have a potty area not far from her sleeping  area but she keeps  continuing to use her bedding. Is she doing  this  because  of lazyness or could she really be sore? Also they are both blind but her sister  has never  had  an accident. Please  help

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

A pig should not pee in bed, unless they are trapped in the bed. The girl that is peeing herself may have a urinary or uterine infection, or she may have severe arthritis and have trouble getting up. Another possibility is a very slippery floor  that makes it hard for her to get up. She might be getting up to go, then falling and peeing on herself.

I think she should see a vet to rule out any infection. A vet can prescribe arthritis medicine that will reduce pain and inflammation. If she is obese, loosing weight will help, too.