A group of dogs, particularly wild dogs or dogs that are roaming around together, is referred to as a pack. Another name that is sometimes used for a group of dogs is a kennel.
According to About.com, dogs by nature are pack animals rather than lone creatures. Wolves are part of the Canidae family just as dogs are, and groups of wolves are also called packs. A kennel can also refer to a place where dogs and other animals are kept and cared for when their owner is not available to do so. Many kennels also offer services, such as grooming and training.