Answer: First of all, we never remove our dogs' dewclaws and it has never caused us - or the dogs - any problems. 

The first digit in dogs  is the most medial — or "inside" — of the five toes on each foot. In many dog breeds, this first toe is only a vestige of a full digit and may not have a bony attachment to the rest of the foot. 

A practical reason to remove dewclaws, particularly in the hind feet, is to prevent trauma and tearing of the dangling digit. Dogs can snag the dangling dewclaw toenail and rip the skin open while running and playing. The bleeding could result in a trip to the emergency room. For show dogs, dewclaws should be removed in certain breeds if leaving them would be considered a show fault. There are no uniform rules. You should consult your organization. 

 Dewclaw removal is usually a minor procedure in newborn puppies. The procedure can be performed later during routine neutering or any other procedure requiring anesthesia. Emergency dewclaw removal is usually a more costly endeavor. 

If there is a choice, it is preferable to remove dewclaws in a litter of puppies when they are less than a few days old, as the procedure is more involved in an older dog. General anesthesia, routine surgical preparation for sterile surgery, surgical suturing, and often bandaging is required in older dogs.