Aww. I'm sure a harness would help a lot, just make sure he can't slip out of it.

My aunt owns my shepherds brother, he has a 50 foot tie out (on one of those trolley lines) across their yard. I watched him one time..he got tangled around a tree and himself. He stopped, looked at himself, stepped out of the line, studied the tree, and walked around until he was completely tangle free.

That's one smart dog.