Toy dog traditionally refers to a very small dog or a grouping of small and very small breeds of dog. A toy dog may be of any of various dog types. Types of dogs referred to as toy dogs may include Spaniels, Pinschers and Terriers that have been bred down in size. Not all toy dogs are lapdogs, although that is an important and ancient type of toy dog. The very smallest toy dogs are sometimes called teacup size, although no major dog registry recognizes that term.
Dogs referred to as toy or teacup dogs, are dogs found in the Toy Group of breed registries, may be of the very ancient lapdog type, or they may be small versions of hunting dogs or working dogs, bred down in size for a particular kind of work or to create a pet of convenient size. In the past, very small dogs not used for hunting were kept as symbols of affluence, as watchdogs, and for the health function of attracting fleas away from their owners.
Most major dog clubs in the English-speaking world have a toy group, under one exact name or another, in which they place breeds of dog that the kennel club categorises as toy, based on size and tradition. The Kennel Club (UK), the Canadian Kennel Club, the American Kennel Club, the Australian National Kennel Council, and the New Zealand Kennel Club all have a group named "Toy", all though they may not all categorise the same breeds in this category. The United States has a second major kennel club, the United Kennel Club (UKC, originally formed for hunting and working breeds, though general today), and it does not recognize such a group; instead, small dogs are placed with larger dogs of their type, or into a UKC's "Companion Dog" group. As of September 2008,[update] the American Kennel Club began debating whether or not to change the name of their "Toy" group to "Companion", in order to emphasise that dogs are not playthings, but the name change was resisted by traditionalists.