This is not a local/western/expat issue. This is simply a Hong Kong issue. The overwhelming majority of Hong Kong residents have no business owning a dog due to lack of space and lack of time to spend with dog. Dogs need open space, grass and time spent walking and running. The Hong Kong lifestyle just isn't very conducive to that. Too many people living on the 38th floor of a tiny flat owning a dog that seldom gets walked or played with.
Here's a clue.... if you can't even find grass for your dog to pee on, you probaly shouldn't own one. Using a water bottle to dilute the urine on the sidewalk is probaly a clue you live in an area that isn't very dog friendly.
I'm honestly surprised most block towers allow dogs, but they do. It just not a good environment for a dog in most cases.