When we moved to the farm we went to the local Adopt-A-Pet and brought home a fixed puppy "chocolate lab."  Lab he is not.  Hound mix he is.  He's 90-100lbs of lean muscle and can run for miles at a time.  For the first 5 years he was our only outside dog and we never had a fence to contain him.  He'd stay home as long as people didn't run or ride bike past our place.  Most people learned after the first time that if they came by that way they would have a companion for the rest of their trip.  He followed a young lady 9 miles home on her run one day.  A buddy finally quit calling me when he followed him home after the third time and simply brought him back.  About three years ago we brought home female black lab puppy.  The two didn't get along well at first but eventually learned how to have fun. I put in an underground fence right away, turned the setting to mid-high correction level, and let them go.  They were trained in about 5 minutes.  Now, as long as they have collars on they stay home.  If the collar comes off the lab she gets adventurous.  The old hound just lays around until I call him.  He's healthy for an 8 year old 100 lb dog but someday he'll be gone. I'll cry.  If the lab disappeared tonight I might have a party.....but she really is a good dog.