For Smudge I use a harness because he's so strong if he decided to he could pull my arm out of my socket and for Winter we're trying the harness but I would also like to be able to walk her with just a collar on because in agility the dogs run naked which means she can't train with a harness and you should only take a slip leash or something like that up to ring with you...only one problem with her. She has really sensitive wind pipe and I fear a repeat rush to the vet like last time when her tonsils popped out.