I realize that this is the wrong manga to take the setting seriously or expect it to be well-thought-out, but it makes no sense that they're supposed to have evolved independently, yet our protagonist has well-bred domesticated dog instincts.
Like, I don't know how much time you need after the domestication of dogs to evolve into that, but there isn't enough. The only other option is they were domesticated post-anthropomorphization which I guess would work and fit the BDSM theme but that would be one hell of a crap-sack world.