Our Shitzu we bought when he was four months only, and now just turned five. We do not really have a yard, so must keep him in the house most of the time. At night, he stays in his crate, during the day time he gets to run around the ground floor.
We have bought those 'sheets' you put on the floor, where he is supposed to pee and poop. He does alright with the pooping, mostly going to the sheets. For the peeing, he does not seem to be learning . . . sometimes on the sheets, but sometimes not. Just now I've brought him up to our second floor, where we also keep some sheets on the floor, and in the space of an hour he managed to both pee and poop on a rug up here.
Different sources say different approaches about whether to praise only when he does a good job, or do/do-not punish if he does badly. And I've heard estimates of how long it takes to train him from a couple of weeks, to a few months!
Any suggestions from your good experiences??