I've been walking my 5 1/2 mo old Jesse now for about 2 months with a normal nylon buckle collar. She's doing really well but does get gagged when she stops suddenly or exhibits the persistent basset behavior. I tried a harness but she pulls when she wants to go sniff or is interested in something. I've read about the martingale collar and am keen on trying it out as a middle ground between the chokers and the harnesses.