Cavaliers can be great playmates for kids who will enjoy throwing a ball for them, teaching them tricks, participating in dog sports, or simply having them on a lap while they read or watch television. Because of their small size, however, they should be supervised when playing with small children who might injure them accidentally.
As with every breed, you should always teach children how to approach and touch dogs, and always supervise any interactions between dogs and young children to prevent any biting or ear or tail pulling on the part of either party. Teach your child never to approach any dog while he's eating or sleeping or to try to take the dog's food away. No dog, no matter how friendly, should ever be left unsupervised with a child.
They get along well with other dogs and can learn to play nice with cats and other pets if introduced to them at an early age. It helps if the cat is willing to stand up for herself because a Cavalier enjoys a good game of chase. They even enjoy it if the cat chases back. Some Cavaliers live peaceably with pet birds while others try to eat them--or at the very least pull their tails. Always supervise your Cavalier's interactions with birds and other small animals; they can have a strong hunting instinct.