It makes no difference which dog you have, all their nails grow at different lengths. Some dogs get their exercise from softer surfaces; sometimes these surfaces don’t allow a dog’s nails to get filed down much. Dogs that get their exercise on harder surfaces like concrete sidewalks, for instance, might have their nails worn down naturally. In the wild, wild animals keep their nails trimmed even on the softer ground but it’s because they are out there all the time, day and night – that’s what they’re made to do. But domesticated dogs – well, their nails need to be trimmed occasionally.