[Britster]

First of all, smacking does nothing but make her fear you. She's not learning. Dogs don't learn that way.

Second, when she was a pup, did you just expect her to let her self out the doggy door or did you physically take her outside yourself? The doggy door may just be... another extension of your house, if that makes sense. It sounds to me like she doesn't understand the boundary of where to pee/where not to pee. It's just all free game for her.

You're going to have to start from step one like she is a baby if you want her to be successful since it does get harder the longer they have been "allowed" to do this.

In the mean time, you can use a doggy diaper to save your rugs and furniture. Tether her to you with a leash at all times when you are home. Take her outside every 30 minutes. Then as she proves she is getting better, take her out every hour. Keep increasing the amount of time over a period of a month. LOTS of praise and lots of treats RIGHT when she goes outside. Do not wait -- treat her immediately when she goes in the right spot, otherwise she won't know WHY you are rewarding her. With her being tethered to you (you can buy the kind that attach around your waist or belt), you can keep an eye at all times. If she is about to squat, you firmly but kindly say no and bring her outside to where she is supposed to go.

Where do you keep her when you leave the house?