We have an 8 month old Shih Tzu who ever since we got him from the breeder at 9 weeks has been going like clockwork... sleep 8 hrs. during the night and then we let him go potty. This past week however he's been waking us in the middle of the night (5.5-6 hrs.) and we have no idea why the sudden change? We've went as far now to take his water bowl away three hours prior to bedtime yet this makes little difference. We're first time pet owners so kinda learning as we go. Any help would be appreciated. FYI We were told by the vet he's a little overweight for his age if that possibly could have something to do with it.