Your right. You first need to have a good handle on your dog. But I know with my friends field trial dogs, they wear harness and a long rope style lead is used and attatched to the saddle. But before you do this you need to make sure that you practice in a round pen or arena.. But I know with our dog, we started him our as a puppy and he went everywhere with us and was always around the horses, so he just naturally stayed with us when we are on the trails. You could always speak with a dog trainer and see what they recommend.

Good Luck