These dogs are a constant worry. They are so enthusiastic, so adventurous, have no sense of risk, there are bound to be nasty accidents. Mine will jump a 4 ft river-bank.
One day I found he had climbed on a fallen tree and run along it until he was 20ft above ground. He could not turn round and come back.
I had to do the same unti I could grab his tail and drag him back. We were miles off the beaten track in a forest and I remember thinking that if I fell we could both perish.
Still I am reluctant to ground him by keeping on lead, but quite large open spaces are now too small.