Duncan is one of the ones who had a single back dewclaw removed during his neuter. He still has the other. There was zero bone-attachment and it just flopped there. Since I plan on doing dog sports with him, we were advised to have the flappy one removed. He didn't even mess with it much afterward, and I think he was relieved not to be pestering with it so much since it had bothered him some. I wish my breeder had removed both at 3 days.