Why not have the parent or responsible person use a child tether? I understand that people sometimes worry about a child thinking the adult is treating them like a critter, but if I had three or four toddlers and had to get them from point A to point B on foot, and that area included a busy roadway, tethering may be a safety thing. If you have a child with special needs, that can be like having a handful.
At the end of the day kids who are alive and well do a whole lot better than kids that were smooshed in the road or lost somehow.
But tethering a child to a dog. I guess I always worry about a dog being a dog no matter how much training and how solid they are. Will they still stand still if a bear or moose wanders up? How about a deer -- more common. Can a dog be rock solid with cats, but still chase a deer or a rabbit? I do not tether my dogs to me. I hold the leash in my hand but do not wrap it around and affix it to me. It is not very dangerous I suppose, not like tying yourself to a horse. But I don't know that I would want a kid tethered to a dog, because if that dog gets attacked by another dog, well, that kid is likely to get dragged and injured.
Bear Cub, Hepsi-Pepsi
Cujo2, Karma Chameleon
Ramona the Pest, Kojak -- who loves you baby?
Tiny Tinnie, Susie's Uzzi, Kaiah -- The Baby Monster.