I'd like to warn everyone about putting in doggy doors. One of my friends just emailed me telling of her own house burglary. While she was away, someone put a small child through her doggy door and robbed her house, then stuck everything in HER car that was locked in the garage, stole the car too. I think they opened the garage door manually.
If you have a pack of Dobermans or wolves, okay, but do lock the doggy doors or not put any in if possible. Most folks seem to forget them when they go on vacation or even just out to the store.