German Shorthaired Pointer Q&A
Have you tried crate trainig him? I have used this method with my Lab, Pom and my YP. My Pom starting marking at 7 years old, We went back to the create training and it broke him of it!
I totally agree with the other writer about crate training; it should be mandatory info for all new dog owners. To help explain, understand what is going on. No animal wants to mess where it sleeps, and puppies of any breed aren't any different. So with a crate sized to accommodate it at full size (partition it off if it is a smaller puppy and will grow much larger...not so much an issue with Yorkie Poos...LOL) you are limiting it's sleeping space. As the dog grows and learns bladder control it will not want to mess in it's sleeping area. The idea is as soon as the dog awakes you take it outside for it to do it's business. Praise it well when it does, and tell it "NO" if it messes in the house on the way out. Then just make sure when you are not actively playing with the dog that it goes into it's crate. Repeat the process; it is a learned response for the dog, just as it is for infants. It may take a week or so, or longer if you didn't start this right away, but the dog will soon associate praise with going outside and will avoid messing it's own environment. The other thing to consider is what to do once you think it's crate-trained. Often people will just give the dog run of the house. That's usually a mistake, and you will find accidents when you return home. Keep the dog in a relatively confined area...for smaller dogs keep it even smaller, as this is what they begin to associate as being their "space" and thus won't want to mess it up; larger areas may be viewed as the equivalent of outdoors for them. Gradually give the dog more and more space as it earns your trust.
Very difficult to train these dogs even when they are very young. Suggest you try doggie pads.