My Bogie is bowlegged in the front, more severely on one side than the other. On the worse side, his normal walk involves dragging the paw against the pavement, so his nails scrape the ground. His nails are extremely short on that foot (i've never had to cut anything but the duclaw). When I first adopted him when he was very young, once or twice they bled. My vet said there wasn't really much to do about it other than to stop the bleeding. The more Bogie filed his nails on the sidewalk, the shorter the quick got, and he hasn't bled for at least 2 years.