At this age, Chief requires less time and attention than he did when he was younger. Was your son the only one that gave Chief attention, love, affection? Just being in the same house as you and in your presence is enough to make Chief happy. That is unless he's an outside only dog. Are you not capable of giving Chief any attention? Maybe this link will help:

http://www.wonderpuppy.net/canwehelp/notime.htm