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 dog breeds and types. Dogs are the only animal with such a wide
variation of breeds, it is unknown why their genetics differ so
dramatically compared to the majority of animals.
The following list uses a wide interpretation of
"breed". 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.
Please see individual articles for more information. For breeds
categorized by national origin, refer to the list of dog breeds
by country.
The dog (Canis lupus familiaris) is a domesticated
subspecies of the wolf, a mammal of the Canidae family of the order
Carnivora. The term encompasses both feral and pet varieties and
is also sometimes used to describe wild canids of other subspecies
or species. The domestic dog has been one of the most widely kept
working and companion animals in human history, as well as being
a food source in some cultures. There are estimated to be 400 million
dogs in the world.
The dog has developed into hundreds of varied breeds.
Height measured to the withers ranges from a few inches in the Chihuahua
to a few feet in the Irish Wolfhound; color varies from white through
grays (usually called blue) to black, and browns from light (tan)
to dark ("red" or "chocolate") in a wide variation
of patterns; and, coats can be very short to many centimeters long,
from coarse hair to something akin to wool, straight or curly, or
smooth.
Etymology and related terminology
The English word dog can be traced back to the Old English docga,
a "powerful breed of canine". The term may derive from
Proto-Germanic *dukkon, represented in Old English finger-docce
("finger-muscle"). Due to the linguistically archaic structure
of the word, the term dog may ultimately derive from the earliest
layer of Proto-Indo-European vocabulary, reflecting the role of
the dog as the earliest domesticated animal.
The English word hound is cognate to other Germanic
terms, including German Hund, Dutch hond, common Scandinavian hund,
Icelandic hundur which, though referring to a specific breed group
in English, means "dog" in general in the other Germanic
languages. Hound itself is derived from the Proto-Indo-European
*kwon-, which is also the direct root of the Greek (kuon) and the
indirect root of the Latin canis through the variant form *kani-.
In breeding circles, a male canine is referred
to as a dog, while a female canine is called a b-itch. The father
of a litter is called the sire, and the mother of a litter is called
the dam. Offspring are generally called pups or puppies until they
are about a year old. A group of offspring is a litter. The process
of birth is whelping. Many terms are used for dogs that are not
purebred.
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Taxonomy
The English word dog, in common usage, refers to the domestic pet
dog, Canis lupus familiaris. The species was originally classified
as Canis familiaris and Canis familiarus domesticus by Linnaeus
in 1758. In 1993, dogs were reclassified as a subspecies of the
gray wolf, Canis lupus, by the Smithsonian Institution and the American
Society of Mammalogists. "Dog" is sometimes used to refer
collectively to any mammal belonging to the family Canidae (as in
"the dog family"), such as wolves, foxes, and coyotes.
Some members of the family have "dog" in their common
names, such as the Raccoon Dog and the African Wild Dog. A few animals
have "dog" in their common names but are not canids, such
as the prairie dog.
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