As every morning when I wake up, it is time to walk my 8 month old, Chocolate Lab pup. A stout 55lbs. and capable of pulling my 07 Dodge Ram 1500. I've seen her try. She has on more than one occation tried to pull me down when she sees something of interest (cats, frogs, squirrels, leaves). Not wanting to risk another potential slipping of the shoulder socket, I install a shock cord between her collar and leash. Problem solved. Apparently they are effective on 35lb. Grouper and dogs. Now walks are 10x safer for her and I. Feel free to try!