I use a dog choke chain on my highland who, when hes hungry, will drag you to the nearest blade of grass! I thread it through the two side rings, then pull both ends down through the bottom ring and attach the lead rein through both of the ends. He knows when its attached and is good as gold. I now use it for loading and unloading as well after being dragged across a lorry park a couple of weeks ago which was just plain dangerous. I load, tie up on the trailer tie, take the chain off to travel, then reverse the procedure to unload. It doesnt go over his nose or through his mouth, just under his chin, but he seems to respect it. As he weighs nye on 600kg and I dont, I think its a sensible precaution!