Evidence suggests that dogs were first family in East Asia, possibly Dog ID China, and some of the peoples who entered North America took dogs with them from Asia.

Dogs have nigh 220 million smell-sensitive cells over an division about the capacity of a pocket handkerchief (compared to 5 million over an area the content of a postage stamp for humans). Some breeds have been selectively refined for excellence in detecting scents, even compared to their canine brethren.