Browse gun dog doors for small, medium, and large breeds below! Our premium dog doors are designed to be weather proof and built to last. Contact us with any questions about our dog flap doors. Contact us with any questions about our dog flap doors. Premium pet doors come in many sizes and materials to suit a range of needs. Our small dog doors are just as easy to use as our dog doors for big dogs. For information on how to install our doggie doors for large dogs, medium dogs and small dogs, check out our installation instructions page.