Arwen used to do this all the time espically when we entered the room. We just ignored her and she got used to us coming into the room and stop doing it. However when my mother in law arrived down to us a few weeks ago for dinner Arwen weed with excitement. My mother in law was so happy to see her that she got the dog excited. My OH does get her excited every now and again (espically when he has been away for a night) and she does have her accidents but apart from that she doesn't wee. So the best thing to do is ignore her when you come into the room, and try to let your dog calm down and your floor will appreciate it!!!!!!!!!!!
