You could do a variety of dog things... a bone, a pawprint, a food dish, a kong, a ball, a knotted rope... that's six different things around the edge, which might be good because your design has four elements. If you did four or eight things around the edge, it would seem misaligned unless it's centered, but with six, it will just look separate.
My other thought was a single leash or chain that goes all the way around the chip, but I'm not liking the idea.