I remember the dogs we had when I was a kid. What we thought was fun, was not what the dog had in mind. Jumping out of the hayloft onto some hay was a bit more than he planned. He made it through the first jump, but refused to let me take him back up. I reached down to carry him back up the ladder, and he latched on to my hand to the point that he could have lead me back to the house bent over. I had purple teeth marks for a while.
He soon learned that he better bite first before he found out what we (three of us) had in mind. I deserved every (many) bite he gave me. He was a Dashound and he lived to be 17 years old. Children can turn a gentle dog into a psychotic dog. I would get them a dog that could run faster and one that was too heavy to pick up. Just from experience that is!