Not sure on the answer to this either but I do know that when he was married to Pilar his house burnt to the ground when her was away making a movie, the dog he had at that time barked so much when the fire started that it woke Pilar and the children and thus they safely evacuated the house. When Duke heard this he seen to it that the dog receive an extra steak for his dinner.
Theres a great picture somewhere as well of Duke sleeping on a couch beside his brother and there is a small dog lying on him.
