Some people believe that allowing a dog to lick broken nails could lead to infection, while others believe the licking will help promote healing. Ultimately, it is up to the dog's owner to decide what is best for their pet. Dogs have bacteria in their mouths that can cause infection if introduced to an open wound. However, licking can also help to clean the wound and remove debris. If the dog's owner is concerned about infection, they may want to consult with veterinary care before allowing their pet to lick the broken nails.