Yorkies have a reputation for being difficult to house train, and it isn't entirely undeserved. The reason is mostly mechanical rather than stubbornness: a bladder the size of a walnut simply cannot hold on as long as a larger dog's, and a puddle from a four-pound dog is small enough to be missed, which lets a habit form in a spot you never cleaned.
The good news is that the method is straightforward. What it demands is frequency and consistency rather than cleverness.
