My main family's dog is Adventurous, but only after a cas.fulleditmode change. He used to be Smart, but I changed the trait to Adventurous so he could learn to go to potty on his own. (Known bug with Smart trait.) Saying that immediately 'cause it's perfectly possible the cas-editing affected something.
That said, he never leaves the lot on his own. He is also Loyal, so I am wondering if that counters the desire to semi-runaway.
I have also noticed that when my sim goes on an adventure with the dog, when they return, he's sort of... slightly bugged. He'll respond and react to other sims and dogs, aka comes when called, eats when instructed, plays with other dogs if they initiate it, but if no one initiates anything with him, he just stands and stares, like... sort of frozen in spot where he was last left. This is always fixed by traveling with him, something about the traveling resets the adventure-aftereffects and he becomes normal active curious dog again, who can eat when he's hungry and go out to potty when he feels the need.
In comparison, lately started playing a sim with two free spirit cats and they run out the house all the time and are greyed out who knows where. They come home when called, no problem, and are loved and taken care of, very different from the actual running away.
I haven't yet played a household that has an Adventurous dog that would actually go out on his/her own, but will keep an eye on it more.
