After seeing the Furry Art thread and the character designs one for many years now, I'll throw in that those breeds are all super easy to draw, since they all generally look the same at first glance (can throw wolves and foxes in there too). Just throw some 'unique' pattern and colors on and bam, you got yourself a very simple, easy to re-draw/commission character. All that needs changing is tail shape (huskies have curled tails, shepherds generally have straight ones) and ears (pointed or flopped). It probably also ties into why there are a lot of 'rarer' animal species to see, since once step away from the 'easy' territory that is basic canine/feline face structure, everything else is harder to pull off unless you do research, which these people rarely do.