You do need to retrain him. If you can't get him an X pen then attach a leash to him and keep it attached to you all the time. Take him out more often than before and don't let him out of your sight. We are responsible for how our dogs act. If he is doing something he is not supposed to it is up to you to communicate to him what the right thing to do is. Being consistent is the key. He will go back to being consistently right but it's up to you to train him diligently. |