Puppies are born attached to the placenta that nourished them while they were developing in the uterus. The puppy's mother will, in the course of caring for them, chew away the umbilical cord that attaches them to their placentas, before consuming the placenta. Sometimes, however, the female dog is slow to chew apart the cord or is unable to do so. When this happens, it falls upon the owner or your veterinarian to remove the umbilical cords.
Removing the Umbilical Cord
It is usually best for the puppies if the mother removes the umbilical cords from the puppies. If it becomes necessary for you to remove them, allow the mother to clean the placenta from the puppy's face and start to wash them. Cut a short piece of white, unflavored dental floss or white thread and tie it around the umbilical cord around 2 inches from the puppy's body. Use a pair of blunt-tipped scissors to cut the cord above the dental floss, between the floss and the placenta. Dip the cut cord end into a small amount of styptic powder to prevent it from bleeding and iodine to prevent infection. If you are not comfortable doing this, consult your veterinarian.
Contrary to popular belief, umbilical hernias are congenital defects, present at birth. They rarely are caused by pulling on a puppy's umbilical cord. All care should be taken while removing the puppy's umbilical cord, but it is unlikely that manually removing the cord will cause an umbilical hernia.