You can also ask for "kay-go-gi", which is dog meat. Finding places selling dog is much harder than in the past. In 1988, the Olympics committee forced such restaurants into side street and alleyways to avoid a bad reputation of the country. You might find a friendly Korean (maybe older man) who would know where to go.

As for Shanghai, in the years I lived there, I never once saw dog meat, but, of course, I wasn't really looking too hard.