I love pet rats. I use to breed some. They were the cuttest things. Before I sold them I had accumulated somewhere near one hundred. So I know lots about them. Such as the fact that MOST don't carry disease. I have to admit, a good few of mine died from sickness, but that was only the ones I didn't have a chance to get shots for. By the time they reach stores pet rats are clean and disease free. So they just get a bad rap for their cousins who live in sewers.