If there is one word to describe the Cavalier King Charles Spaniel, it might be "adaptable." Averaging 12 to 13 inches (30 to 33 centimeters) in height to the shoulder and around 13 to 18 pounds (5.8 to 8 kilograms) when fully grown, the Cav is an excellent option for families with children or other animals because of its easy-going demeanor. This small breed got its name from King Charles II of England, who had a penchant for the elegant pooch. Since its reign as royal pup, the Cav has been a top choice for many families, has excelled in the dog show ring and made its mark in popular culture as Charlotte York's dog on the cable television series "Sex and the City."
Although Cavs are alert and might bark at strangers approaching the door, they're more apt to lick an intruder than attempt to take a bite out of him. According to the Cavalier King Charles Spaniel Club of America, this breed enjoys being around family and playing with children, and tends to bond easily with new people [source: CKCSC]. Cavaliers also do well with other dogs and even cats. They are energetic, but will adapt to most households from small apartments to large farms. This breed does need some exercise -- at least one walk per day -- but the laid-back Cav will be happy curling up for a nap with you, too.