This injury can be a reel pain in the arse mate if the nail has totaly gone! it happened to me at the beginng of this season . I left my dog of for 4 weeks before i took him out and it just ripped out again . you need to keep it real clean mate and dont let him run anythin for a good while, in total i bet my dog was of for a good 2 and a half months. at least its happened at the end of the season mate