We have an 11 year old parsons jack Russell, we kennel him still because if we leave him out even for an hour when we are away he pees in the house. Never when we are home does he do this. This has been something he has always done so now we don't test it, just curious as to why he may be like this. Also thinking of getting another one from the same breeder but worried Lenny has been alone with us for so long it wouldn't go well. Any thoughts on how to introduce him to a new puppy?