My dog is a 3 year old female Maltese. When I leave the house and she feels left alone, she will retaliate by pooping on my couches or chairs. Aside from the obvious "gross" factor, I am at my wits end. When I will be out of the home for a couple of hours or so I will confine her to an area where there is no furniture. Sometimes, though, I want to just run down to the corner for something or even just next door for a moment and don’t want to go to the trouble of confining her. She goes out regularly for potty breaks so that is not an issue. I am a stay at home mom and so I am home a good majority of the time. I have actually caught her mid-squat on the couch after I have just left the house, having JUST taken her out for her potty break. She shares our home with another female Maltese and the other one does not behave like this. There is nothing medically wrong with her; I feel she is just doing it out of vengeance when we leave her home. It seems personal. Any help?