As long as there are no obstacles to hang himself on, leads are fine. We use one for Humphrey since he likes to go runabout a couple times a week. If we try to use one on Lily, she pouts and acts like we've beaten her. She wont go. I suggest getting the lightest lead you can find, polyester rope is good. The cabled ones can be very painful if the wrap them around your ankles (and they will).
My neighbor has a larger dog that has nearly hung himself 4 times with his lead. Twice over the fence and twice off the steps to her deck. Just keep a close eye on him.