The Golden Retriever is a large-sized breed of dog. They were bred as gun dogs to retrieve shot waterfowl such as ducks and upland game birds during hunting and shooting parties, and were named retriever because of their ability to retrieve shot game undamaged. Golden Retrievers have an instinctive love of water, and are easy to train to basic or advanced obedience standards. They are a long-coated breed, with a dense inner coat that provides them with adequate warmth in the outdoors, and an outer coat that lies flat against their bodies and repels water. Golden Retrievers are well suited to residency in suburban or country environments. Although they need substantial outdoor exercise, they should be housed in a fenced area because of their instinctual tendency to roam. The dog sheds copiously, particularly at the change of seasons, and requires fairly regular grooming.
The breed is a prominent participant in conformation shows for purebred dogs. The Golden Retrievers' intelligence makes it a versatile breed and allows it to fill a variety of roles – common ones being guide dog for the blind, hearing dog for the deaf, hunting dog, detection dog, and search and rescue participant. The breed's friendly, gentle temperament means it is unsuited to being a professional guard dog, but its temperament has also made it the third most popular family dog breed (by registration) in the United States, the fifth most popular in Australia, and the eighth most popular in the United Kingdom. Golden Retrievers are rarely choosy eaters, but require ample exercise (of two or more hours a day). The breed is fond of play but also highly trainable; Augie, a Golden Retriever from Texas, holds the world record for the most tennis balls held in the mouth by a dog.
Dogs have been selectively bred for thousands of years, sometimes by inbreeding dogs from the same ancestral lines, sometimes by mixing dogs from very different lines. The process continues today, resulting in a wide variety of breeds, hybrids, and types of dog. Centuries of selective breeding by humans has resulted in dogs being more genetically diverse than most other mammals by a considerable margin. As such, dogs are the only animal with such a wide variation in appearance without speciation, "from the Chihuahua to the Great Dane".
The following list uses a wide interpretation of "breed". Breeds are usually categorized by the functional type from which the breed was developed. The basic types are companion dogs, guard dogs, hunting dogs, herding dogs, and working dogs, although there are many other types and subtypes. Breeds listed here may be traditional breeds with long histories as registered breeds, rare breeds with their own registries, or new breeds that may still be under development.
In some cases, a breed's origin overlaps the boundaries of two or more countries; the dog is normally listed only in the country with which it is most commonly associated (for example, by its designated country according to the Fédération Cynologique Internationale (FCI)). Some dogs, such as the Löwchen, have an uncertain origin and are listed under several countries.