This article is about the domestic dog. For related species known as "dogs", see Canidae.
For other
uses, see Dog (disambiguation).
Domestic dogs
Temporal range: At least 14,200
years ago – present[1]
Selection of the different breeds of
dog
Conservation status
Domesticated
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Canidae
Subfamily: Caninae
Tribe: Canini
Subtribe: Canina
Genus: Canis
Species: C. lupus
Subspecies: C. l.
familiaris
Trinomial name
Canis lupus familiaris
Linnaeus, 1758
Synonyms
Canis familiaris Linnaeus, 1758 [2]
aegyptius Linnaeus, 1758, alco C. E. H.
[3]
Smith, 1839, americanus Gmelin,
1792, anglicus Gmelin,
1792, antarcticus Gmelin,
1792, aprinus Gmelin,
1792, aquaticus Linnaeus,
1758, aquatilis Gmelin,
1792, avicularis Gmelin, 1792, borealis C.
E. H. Smith, 1839, brevipilis Gmelin,
1792, cursorius Gmelin,
1792, domesticus Linnaeus,
1758, extrarius Gmelin, 1792, ferus C. E.
H. Smith, 1839, fricator Gmelin,
1792, fricatrix Linnaeus,
1758, fuillus Gmelin, 1792, gallicus Gmelin,
1792, glaucus C. E. H. Smith,
1839, graius Linnaeus,
1758, grajus Gmelin,
1792, hagenbecki Krumbiegel,
1950, haitensis C. E. H. Smith,
1839, hibernicus Gmelin,
1792, hirsutus Gmelin,
1792, hybridus Gmelin,
1792, islandicus Gmelin,
1792, italicus Gmelin,
1792, laniarius Gmelin,
1792, leoninus Gmelin, 1792, leporarius C.
E. H. Smith, 1839, major Gmelin,
1792, mastinus Linnaeus,
1758, melitacus Gmelin,
1792, melitaeus Linnaeus,
1758, minor Gmelin,
1792, molossus Gmelin,
1792, mustelinus Linnaeus,
1758, obesus Gmelin,
1792, orientalis Gmelin, 1792, pacificus C.
E. H. Smith, 1839, plancus Gmelin,
1792, pomeranus Gmelin,
1792, sagaces C. E. H. Smith,
1839, sanguinarius C. E. H. Smith,
1839, sagax Linnaeus,
1758, scoticus Gmelin,
1792, sibiricus Gmelin, 1792, suillus C. E.
H. Smith, 1839, terraenovae C. E. H.
Smith, 1839, terrarius C. E. H. Smith,
1839, turcicus Gmelin, 1792, urcani C. E.
H. Smith, 1839, variegatus Gmelin,
1792, venaticus Gmelin,
1792, vertegus Gmelin, 1792[4]
The dog (Canis familiaris when considered a distinct species or Canis lupus familiaris when
considered a subspecies of the wolf)[5] is a domesticated carnivore of the family Canidae. It is part of
the wolf-like canids,[6] and is the most widely abundant terrestrial carnivore.[7][8][9][10][11] The dog and
the extant gray wolf are sister taxa[12][13][14] as modern wolves are not closely related to the wolves that
were first domesticated,[13][14] which implies that the direct ancestor of the dog is extinct.[15] The dog
was the first species to be domesticated,[14][16] and has been selectively bred over millennia for various
behaviors, sensory capabilities, and physical attributes. [17]
Their long association with humans has led dogs to be uniquely attuned to human behavior [18] and
they are able to thrive on a starch-rich diet that would be inadequate for other canids. [19] Dogs vary
widely in shape, size and colors.[20] They perform many roles for humans, such
as hunting, herding, pulling loads, protection, assisting police and military, companionship and, more
recently, aiding disabled people and therapeutic roles. This influence on human society has given
them the sobriquet of "man's best friend".
Contents
1Terminology
2Taxonomy
3Origin
4Biology
o 4.1Anatomy
4.1.1Size and weight
4.1.2Senses
4.1.3Coat
4.1.4Tail
4.1.5Differences from wolves
o 4.2Health
4.2.1Lifespan
o 4.3Reproduction
4.3.1Neutering
o 4.4Inbreeding depression
5Intelligence, behavior, and communication
o 5.1Intelligence
o 5.2Behavior
o 5.3Communication
6Ecology
o 6.1Population
o 6.2Competitors and predators
o 6.3Diet
o 6.4Range
7Breeds
8Roles with humans
o 8.1Early roles
o 8.2As pets
o 8.3Work
o 8.4Sports and shows
o 8.5As food
o 8.6Health risks to humans
o 8.7Health benefits for humans
o 8.8Shelters
9Cultural depictions
o 9.1Mythology and religion
o 9.2Literature
o 9.3Art
o 9.4Education and appreciation
10See also
o 10.1Lists
11References
12Bibliography
13Further reading
14External links
Terminology
The term dog typically is applied both to the species (or subspecies) as a whole, and any
adult male member of the same.
An adult female is a bitch.
An adult male capable of reproduction is a stud.
An adult female capable of reproduction is a brood bitch, or brood mother.
Immature males or females (that is, animals that are incapable of reproduction)
are pups or puppies.
A group of pups from the same gestation period is called a litter.
The father of a litter is a sire. It is possible for one litter to have multiple sires.
The mother of a litter is a dam.
A group of any three or more adults is a pack.
Taxonomy
Further information: Canis lupus dingo § Taxonomic debate – dog, dingo, and New Guinea singing
dog
In 1758, the Swedish botanist and zoologist Carl Linnaeus published in his Systema
Naturae the binomial nomenclature – or the two-word naming – of species. Canis is the Latin word
meaning "dog",[21] and under this genus he listed the dog-like carnivores including domestic dogs,
wolves, and jackals. He classified the domestic dog as Canis familiaris, and on the next page he
classified the wolf as Canis lupus.[2] Linnaeus considered the dog to be a separate species from the
wolf because of its cauda recurvata - its upturning tail which is not found in any other canid.[22]
In 1999, a study of mitochondrial DNA indicated that the domestic dog may have originated from
multiple grey wolf populations, with the dingo and New Guinea singing dog "breeds" having
developed at a time when human populations were more isolated from each other. [23] In the third
edition of Mammal Species of the World published in 2005, the mammalogist W. Christopher
Wozencraft listed under the wolf Canis lupus its wild subspecies, and proposed two additional
subspecies: "familiaris Linneaus, 1758 [domestic dog]" and "dingo Meyer, 1793 [domestic dog]".
Wozencraft included hallstromi – the New Guinea singing dog – as a taxonomic synonym for the
dingo. Wozencraft referred to the mDNA study as one of the guides in forming his decision. [4] The
inclusion of familiaris and dingo under a "domestic dog" clade has been noted by other
mammalogists.[24] This classification by Wozencraft is debated among zoologists. [25]
In 2019, a workshop hosted by the IUCN/Species Survival Commission's Canid Specialist Group
considered the New Guinea singing dog and the dingo to be feral dogs Canis familiaris, and
therefore should not be assessed for the IUCN Red List.[26]
Origin
Main article: Origin of the domestic dog
The origin of the domestic dog includes the dog's genetic divergence from the wolf,
its domestication, and its development into dog types and dog breeds. The dog is a member of
the genus Canis, which forms part of the wolf-like canids, and was the first species and the only
large carnivore to have been domesticated.[14][27] Genetic studies comparing dogs with
modern wolves show reciprocal monophyly (separate groups), which implies that dogs are not
genetically close to any living wolf and that their wild ancestor is extinct. [28][14] An extinct Late
Pleistocene wolf may have been the ancestor of the dog,[27][1] with the dog's similarity to the extant
grey wolf being the result of genetic admixture between the two.[1] In 2020, a literature review of
canid domestication stated that modern dogs were not descended from the same Canis lineage as
modern wolves, and proposes that dogs may be descended from a Pleistocene wolf closer in size to
a village dog.[29]
The genetic divergence between dogs and wolves occurred between 20,000–40,000 years ago, just
before or during the Last Glacial Maximum[30][1] (20,000-27,000 years ago). This timespan represents
the upper time-limit for the commencement of domestication because it is the time of divergence and
not the time of domestication, which occurred later.[30][31] One of the most important transitions in
human history was the domestication of animals, which began with the long-term association
between wolves and hunter–gatherers more than 15,000 years ago.[28] The archaeological record
and genetic analysis show the remains of the Bonn–Oberkassel dog buried beside humans 14,200
years ago to be the first undisputed dog, with disputed remains occurring 36,000 years ago. [1]
Biology
Lateral view of skeleton
Anatomy
Main article: Dog anatomy
Skull of a dog
Domestic dogs have been selectively bred for millennia for various behaviors, sensory capabilities,
and physical attributes.[17] Modern dog breeds show more variation in size, appearance, and behavior
than any other domestic animal.[17] Dogs are predators and scavengers; like many other predatory
mammals, the dog has powerful muscles, fused wrist bones, a cardiovascular system that supports
both sprinting and endurance, and teeth for catching and tearing.
Size and weight
Dogs are highly variable in height and weight. The smallest known adult dog was a Yorkshire
Terrier, that stood only 6.3 centimetres (2 1⁄2 inches) at the shoulder, 9.5 cm (3 3⁄4 in) in length along
the head-and-body, and weighed only 113 grams (4 ounces). The largest known dog was a Saint
Bernard which weighed 167.6 kg (369 1⁄2 lb) and was 250 cm (8 ft 2 in) from the snout to the tail.
[32]
The tallest dog is a Great Dane that stands 106.7 cm (3 ft 6 in) at the shoulder.[33]
Senses
Further information: Dog anatomy § Senses
The dog's senses include vision, hearing, sense of smell, sense of taste, touch and sensitivity to the
earth's magnetic field. Another study suggested that dogs can see the earth's magnetic field. [34][35][36]
Coat
Main article: Coat (dog)
Dogs display a wide variation on coat type, density, length, color, and composition
The coats of domestic dogs are of two varieties: "double" being common with dogs (as well as
wolves) originating from colder climates, made up of a coarse guard hair and a soft down hair, or
"single", with the topcoat only. Breeds may have an occasional "blaze", stripe, or "star" of white fur
on their chest or underside.[37]
Regarding coat appearance or health, the coat can be maintained or affected by multiple nutrients
present in the diet, see Coat (dog) for more information.
Premature graying can occur in dogs from as early as one year of age. This has been shown to be
associated with impulsive behaviors, anxiety behaviors, fear of noise, and fear of unfamiliar people
or animals.[38]
Tail
See also: Docking
There are many different shapes for dog tails: straight, straight up, sickle, curled, or cork-screw. As
with many canids, one of the primary functions of a dog's tail is to communicate their emotional
state, which can be important in getting along with others. In some hunting dogs, however, the tail is
traditionally docked to avoid injuries.[39] In some breeds, such as the Braque du Bourbonnais, puppies
can be born with a short tail or no tail at all.[40]
Differences from wolves
The Saarloos wolfdog carries more gray wolf DNA than any other dog breed[41]
Despite their close genetic relationship and the ability to inter-breed, there are a number of
diagnostic features to distinguish the gray wolves from domestic dogs. Domesticated dogs are
clearly distinguishable from wolves by starch gel electrophoresis of red blood cell acid phosphatase.
[42]
The tympanic bullae are large, convex and almost spherical in gray wolves, while the bullae of
dogs are smaller, compressed and slightly crumpled.[43] Compared with equally sized wolves, dogs
tend to have 20% smaller skulls and 30% smaller brains. [44]:35 The teeth of gray wolves are also
proportionately larger than those of dogs.[45] Dogs have a more domed forehead and a distinctive
"stop" between forehead and nose.[46] The temporalis muscle that closes the jaws is more robust in
wolves.[5]:158 Wolves do not have dewclaws on their back legs, unless there has been admixture with
dogs that had them.[47] Most dogs lack a functioning pre-caudal gland and enter estrus twice yearly,
unlike gray wolves which only do so once a year.[48] So-called primitive dogs such
as dingoes and Basenjis retain the yearly estrus cycle.[49]
Dogs generally have brown eyes and wolves almost always have amber or light colored eyes. [50] The
skin of domestic dogs tends to be thicker than that of wolves, with some Inuit tribes favoring the
former for use as clothing due to its greater resistance to wear and tear in harsh weather. [51] The
paws of a dog are half the size of those of a wolf, and their tails tend to curl upwa
