Why I'm not a fan of pet doors
This one incident made me think they weren't so great! I had a wonderful pet sitting client with six cats and two dogs. She lived in the country (sort of) and had a lot of land. Her cats were indoor/outdoor cats. Sometimes she'd be gone for a few days or more with the dogs and would leave the cats in my care. Because she wanted the cats to go outside at their will she installed a nice cat door on the side of the house. With the door, the cats could come in and out of the base