Should dewclaws be removed? For attached dewclaws, they do not need to be removed -- dewclaws do not usually cause any problem. Some breeders will remove dog dewclaws at birth to prevent future possible problems, such as catching on something, but elective removal of dewclaws on adult dogs is not usually necessary. Traumatic injury will necessitate trimming of the broken nail or possibly surgical removal, however.
If your dog has "unattached" dewclaws or hind dew claws and is a purebred dog, please check with the breeder or a breed standard guide to see if that is a desired trait. Ultimately, the decision to remove dewclaws (attached or not) is based on the health of the animal and the potential for future problems (ripping or tearing of the claw). Dewclaws, like extra toes, do not usually wear down naturally like the other toes. Careful monitoring and trimming is necessary to prevent the nail from growing into the pad.