Have you seen the PlexiDor electronic pet door?

PlexiDor Electronic pet door in door with white frame The PlexiDor Electronic  pet door is a unique solution that works well for both dogs and cats. The door has a composite panel that slides up and down, and the panel is controlled by an RFID key attached to the pet’s collar. 

When the pet comes close to the door, the panel slides up. The door will only open for pets with the right key. When the door is closed the panel acts as a security door.

The collar key is waterproof and lacks moving parts, so it is very sturdy while being small enough not to disturb the pet.

See the PlexiDor Electronic dog door and cat door in action in this video:

//youtu.be/zxeAnyQhrrI