Just my 2cents. I have 2 cats and they are very curious but nothing bad. In fact I had both Gable and Bogie out for lap time Saturday and the cats came up to both of them and sniffed them, gave them nosey kisses and then moseyed off. I was very proud of them.
And piggies didn't seem to mind. Bogie squeaked a little but Gable didn't seem to care. So it depends on the nature of the cats but I take precautions with mine and keep the door closed with the pigs when I'm gone and have the cover on at night. They seem to do quite well.