The breeder from whom we got Chase trimmed his the day we picked him up, so that was about 9 weeks of age. They probably don't need major trimming at his age, but getting him accustomed to having his feet manipulated and clippers used, even to nip off the tiniest amount while he's young, may help in the long run. I use a drill to grind my dogs' nails now. Chase doesn't mind, Lark has never really warmed up to the drill or clippers and still acts a little freaked out by the whole thing. Some folks on here use a file and just run the file over the nails fairly often. I've never tried that.