Do all dogs run away?  

No, not all dogs run away. I have a Godlen Retriever who can go outside without a leash and she stays right with you. She is a very good dog and I trust her not to run. The reason she isn't allowed outside alone with fences is because she could get hit by a car (people don't drive well around my neighborhoods) or she could get attacked by another dog (a lot of people around me let their dogs run loose) OR she could even get taken (she is a beautiful dog).
If it was a more trusting world I'm sure she could be let out alone.

We had a min pin that used to follow scents of rabbits and squirrels or other critters out in the country. We lived on a highway and didn't have a fenced yard. So one morning he followed a scent to the other side of the highway, when we called him, he turned around and got hit by a car and died. It was devastating. We now have two dogs, and they are the same as far as following scents. I don't think they pay attention to where it's leading them, they are so focused. We have a fenced yard now, but if we didn't, they would run off chasing other dogs and cats that neighbors let run wild in the neighborhood. I couldn't handle another death like the first one. The fence was a lot of work, but well worth it. Our neighbor has their dog chained up outside 24/7, but the chain is long enough that it attacked me awhile back and I think it's because it's chained up all the time and gets no love. Anyway, if that dog got loose, it would never go back home.

It depends on the dog. Some dogs just love to follow their nose or chase cars. Even dogs that run off will usually return home unless they get lost or hurt. Other dogs will wander the neighborhood in the day but go home when they know their owners are home. We had a terrier that would stay home and was careful about cars, so we were able to let her free all the time. Our new terrier is not as good about staying home, but we let him run free in the evenings or take him to a dog park in the day when we have time.

I have had dogs that run away and I have had dogs that would not. My dog now is a purebred (I think that most purebreds are inbreds). He runs away every chance he gets. I think it is because he is a little slow in the head and forgets where he lives because when he is out he is not coming back on his own. I have had dogs in the past that were escape artists. I had a privacy fence and yet everytime I came home they were gone. I think they talked each other into it. I have also had dogs that would not run away and were the best dogs (without formal training). While I think a dog that runs away will almost always do it again, happy or not, I know an awesome trainer that can get a dog to do anything. She is very strict on both owner and dog though.

i have to have my dog on lead at all time when outside the house, when i first got him, we took the lead off him a couple of time and he was alright, maybe becasue he was new to us and didn't know what to do.

now he's got a bit braver so we cant take it off, last time we did he ran to the tennis courts and stole a ball and ran home with it...

only once has my dog got out of the garden, but a rottwieler broke boards in the fence..and my dog ran away into the park behind us..

my mum noticed he was gone becasue it was only 7am..she called him..and there was no response...she was turning around to go back insdie and my dog came running back in and ran up the stairs..>,<

My dog is a traveler by nature of his breed. Before we got him, we saw a profile of the breed on TV and knew getting into it that he would claim a domain around the neighberhood. He's gotten out and taken off before, but he always comes back. He just likes to go check things out.

This is not true to all dogs. Sometimes dogs can get confused too, like humans. I think dogs have feelings like us and when he's feeling uncomfortable or something is on his mind, he would go out of the house. I don't think his intention was to run away, I just think that he wanted to get out for a while but then got lost somewhere else. This is only my view. Others may have more opinion on this.