Meet the Ruff-Weather Pet Door with Alarm Alert Slide: a double flap dog door with an alarmed lock out slide that lets you know when the slide is removed. It is designed for dogs up to 120lbs depending on the size you pick. It comes with an optional wall installation kit to save you time.
This pet door can be installed in walls from 4 to 7 inches in thickness. You will need 2 x AAA batteries to power this.