A pet door system is provided including a casing configured to attach the pet door system to a building and a flexible door attached to the casing. In some embodiments, the door is segmented and comprises a plurality of interlocking segments that are rotatable with respect to each other. In some embodiments, the pet door system further includes a rotating cylinder attached to the flexible door and rotatably connected to the casing and a motor comprising a gear head, where the gear head is attached to the rotating cylinder, such that when the motor is activated, the gear head is rotatable in a first direction to wind the flexible door around the rotating cylinder. In some embodiments, the pet door system may be operated by a pet-worn collar and/or may be remotely controlled via a mobile device.
