"Dog" is sometimes used to refer collectively to any mammal belonging to the clan Canidae (as in "the dog family"), such as wolves, foxes, and coyotes. Some members of the family have "dog" in their conventional names, such as the Raccoon Dog and the African Wild Dog. A few meat Dog Arthritis Treatment have "dog" in their colloquial names but are not canids, such as the prairie dog.

In the United Kingdom, The Kennel Club compilations that the most-registered breed from at least 1999 to 2005 was the Labrador Retriever. It rounds out the excellent three for 1999 to 2005 with the German Shepherd Dog, also leading in the US, and the English Cocker Spaniel , which is no longer in the fine ten in the US. In the UK, a national dog adoption and rescue service indicates that the most habitual breed appearing in shelters is the Greyhound followed by the Staffordshire Bull Terrier.