I seem to recall a Sci-Am article from years ago where urban dogs were studied. It seems that even purebred in urban settings soon end up breeding after a couple generations, something that quickly resembled a very generic, feral dog.
The Russians did the opposite with wild foxes. After selective breeding, observation, and lots of human contact, after 10-15 generations of foxes, the resultant animals are as domesticated as your average poodle.
It does seem to me (if I remember the article—the fox one— it’s been quite awhile since I read it) that the coats ended up spotted or mismarked tho, and unsuitable for fur. What I remember from the breeding experiment was that the gist was that dogs (and the foxes) never get past the juvenile state. Is this the same article? It was fascinating.