The dogs have well, larger eyes, floppy ears, ect... The reason why they have also become like this, is because it creates a hormone in humans that make them want to care for them more, like what happens with babies. This creates a loving bond between them. Wolves also bark much less than dogs, because dogs use it to communicate their emotions to people. Dogs can also see emotions in people, that would make it easier for them to see if it was a good time to go to people. All in all, dogs seem to be parasites, they survive by being fed by people because they wouldn't survive well in the wild, but... I suppose everything is parasitic.
Edit: it also says some of that in that Neoteny page.