I wouldn't use one for a dog you don't want outside unobserved. A Yorkie is usually at risk outside from predators of all kinds - animal and human. People will take them right out of the yard and so well birds of prey and other large animals. They can find ways to escape the yard, etc., get into all kinds of mischief when you aren't watching.
Also, with most of the non-coded doors that you dog activates with a device on his collar, anything small enough can crawl through that door - field rats, possum, cats, stray dogs, lizards and other critters. I'm too afraid of the uninvited to use one and afraid to have my Yorkie outside whenever he chooses. If I wasn't home and there were a rabid cat out in the back yard, he'd be right out that doggie door!
__________________  Jeanie and Tibbe One must do the best one can. You may get some marks for a very imperfect answer: you will certainly get none for leaving the question alone. C. S. Lewis |