I have 2 18 month-old Great Dane mixes. The female, Agness, has always been very good about not going potty in the house. But when we moved about a month ago, she pooped in the house for the first time ever and peed in the house for about 3 days. Then she quit, and has been golden ever since. But on Monday, my friend came to visit and brought her 2 dogs, one of which is a littermate of Agness. They only stayed one night, but we had somewhere around 5 accidents in the house. While my friend was here, I think her dog did most of them, but now Agness has peed in the house twice since they left yesterday. I am getting relatively frustrated, because this dog knows better. Any suggestions as to why this may be happening? Is it nerves? Fear? Anxiety? Any advice on how to avoid this in future would be great! Thanks!