I have no idea what happened. I know nails don't just rip off. I think he got it caught on something, pulled, and yanked his nail. It was hanging on the side for a bit then he ripped it off completely. No shed stuck to his toes, I make sure to check him every time he sheds to make sure. I checked the rest of his toes and there's nothing wrong with them. I have no idea what happened and that's probably what worries me the most...