Odie and Scout both have choker collars (without spikes, of course). I didn't want to do it, but they kept breaking collars. The final straw was at the park one night when Odie took of for a run and the collar broke. He just ran and ran and ran. I don't know what got into him -- he never has that kind of energy! He was doing huge circles around us, and there was NO WAY we could get him to come back. We were so close to a highway, and I was terrified that he would get hit. Dalmatians are quick too. He finally came back to us, that naughty boy. But he gave us quite a scare.