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Canis lupus familiarisdog

By Tanya Dewey and Sheetal Bhagat

Ge­o­graphic Range

Do­mes­tic dogs are now found world­wide. Their wild an­ces­tors, gray wolves oc­curred in north­ern hemi­sphere con­ti­nen­tal areas, in­clud­ing North Amer­ica and the Palearc­tic.

Habi­tat

Do­mes­tic dogs are found in as­so­ci­a­tion with hu­mans world­wide and in a wide va­ri­ety of habi­tats.

Phys­i­cal De­scrip­tion

Do­mes­tic dogs come in a be­wil­der­ing va­ri­ety of shapes and sizes. They have been se­lec­tively bred for mil­lenia for var­i­ous be­hav­iors, sen­sory ca­pa­bil­i­ties, and phys­i­cal at­trib­utes, in­clud­ing dogs bred for herd­ing live­stock (col­lies, shep­erds, etc.), dif­fer­ent kinds of hunt­ing (point­ers, hounds, etc.), catch­ing rats (small ter­ri­ers), guard­ing (mas­tiffs, chows), help­ing fish­er­men with nets (New­found­lands, poo­dles), pulling loads (huskies, St. Bernard's), guard­ing car­riages and horse­men (dal­ma­tians), and as com­pan­ion dogs. Some kinds were even bred sim­ply as lap warm­ers (Pekingese). Their basic mor­phol­ogy though, no mat­ter how mod­i­fied, is that of their wild an­ces­tors, gray wolves.

  • Sexual Dimorphism
  • male larger
  • Range mass
    <1 to 70 kg
    to 154.19 lb

Re­pro­duc­tion

Re­pro­duc­tion in do­mes­tic dogs is gen­er­ally ma­nip­u­lated by hu­mans. Feral males tend to com­pete amongst them­selves for ac­cess to re­cep­tive fe­males. Some feral do­mes­tic dog pop­u­la­tions have re­verted to an­ces­tral habits where a sin­gle male and fe­male pair (the alpha an­i­mals) dom­i­nate mat­ing in a small, fam­ily group, or pack. Other pack mem­bers help to care for the off­spring of the dom­i­nant pair.

Do­mes­tic dogs have a ges­ta­tion pe­riod of 9 weeks, after which any­where from 1 to dozens of pup­pies can be born, de­pend­ing on the breed and nu­tri­tional sta­tus of the mother. Av­er­age lit­ter sizes are from 3 to 9 pup­pies. Male and fe­male dogs usu­ally reach pu­berty be­tween 6 and 12 months of age; how­ever, the time that a dog ac­tu­ally breeds de­pends on many so­cial fac­tors, rang­ing from size of breed (larger dogs need more time be­fore they are ready to breed) and level of con­fi­dence a dog must at­tain be­fore being ready to breed.

Most breeds are sea­son­ally mono­cyclic, show­ing signs of heat every 6 months or so. The re­pro­duc­tive cycle has four stages: anestrus, proestrus, es­trus, and diestrus. The anestrus pe­riod lasts about 2 to 4 months. Proestrus is the time when a bloody dis­charge first ap­pears in a fe­male. This is the be­gin­ning of "heat," a pe­riod that usu­ally last 9 days but that can last up to 28 days. The end of this pe­riod is marked by the fe­male's ac­cep­tance of a male part­ner. Es­trus is the pe­riod when the fe­male is sex­u­ally re­cep­tive and breed­ing can occur. Ovu­la­tion oc­curs about 24 hours after the ac­cep­tance of the male. Ova sur­vive and are ca­pa­ble of being fer­til­ized for about 4 days after ovu­la­tion; there­fore it is pos­si­ble for a fe­male to mate with more that one male. Diestrus fol­lows es­trus in the non­preg­nant cycle, char­ac­ter­ized by a state of "pseudo­preg­nancy", which is fol­lowed by a re­turn of the uterus and ovaries to the anestrus, rest­ing state.

  • Breeding interval
    Domestic dogs can reproduce at approximately six month intervals, though usually less frequently.
  • Breeding season
    Breeding can occur throughout the year.
  • Range number of offspring
    1 (low)
  • Average number of offspring
    3-9
  • Average gestation period
    63 days
  • Range age at sexual or reproductive maturity (female)
    6 to 12 months
  • Range age at sexual or reproductive maturity (male)
    6 to 12 months

Fe­males nurse and care for their pup­pies until they are weaned at about 8 to 10 weeks of age. In feral do­mes­tic dog packs, pup­pies are cared for by all mem­bers of the pack.

Lifes­pan/Longevity

Longevity in do­mes­tic dogs de­pends on the care they re­ceive, their breed, and body size. In gen­eral, larger breeds have shorter lifes­pans. Well-cared for an­i­mals can live for 12 years or more.

Be­hav­ior

Do­mes­tic dogs are sim­i­lar to their an­ces­tors, wolves, in that they are both pack an­i­mals with a com­plex set of be­hav­iors re­lated to de­ter­min­ing the dogs po­si­tion in the so­cial hi­er­ar­chy and their mood. There is only one leader in a pack, and often there is a strug­gle be­tween mem­bers of the pack to de­ter­mine who the leader is. The strug­gle ends with one an­i­mal on top of the other, with the sub­mis­sive an­i­mal lying on its back. The dom­i­nant an­i­mal places its paw on the chest of the sub­mis­sive one, and until the sub­mis­sive an­i­mal looks away from the eyes of the dom­i­nant an­i­mal, the strug­gle con­tin­ues. As soon as the sub­mis­sive an­i­mal averts his eyes, he has ad­mit­ted de­feat and the leader of the pack has been de­ter­mined. Dogs ex­hibit char­ac­ter­is­tic pos­tures that re­veal their states of mind. The neu­tral po­si­tion is when a dog is calmly ob­serv­ing things in the en­vi­ron­ment. The mouth of a dog in this po­si­tion may be open or closed. In the alert po­si­tion, the dog's mouth may be open or closed, de­pend­ing on the ex­cite­ment level and en­vi­ron­men­tal tem­per­a­ture. The hairs along the back and shoul­ders may raise with­out any in­tent of the dog to at­tack. The dog has sim­ply fo­cused his at­ten­tion on some ob­ject and is cu­ri­ous about it. Of­fen­sive threat pos­ture: hair raised, teeth show­ing, nose wrin­kled, and growl­ing may be heard. The tail is up­right, al­though it may be wag­ging. A dog in this stance is ready to at­tack. De­fen­sive threat: al­though the dog may be growl­ing and snarling, the ears are laid back, which is a sign of sub­mis­sion in nor­mal dogs, and the tail is hang­ing down. Greet­ings: re­laxed face, mouth slightly open, loosely pulled back ears, tail wag­ging. This is the pos­ture dogs as­sume when play­ing with fam­ily mem­bers or other dogs. Play in­vi­ta­tion: low­ered front part of body while keep­ing the rear end up. A dog may bark in this in­vi­ta­tion to play, but it does not growl ex­ces­sivly. Sub­mis­sion: body low to the ground, as com­pact as pos­si­ble. Ears are drawn back, tail is tucked tightly under body. Sub­mis­sive dogs pull the cor­ners of their mouths back but do not show their teeth (sub­mis­sive grin). Some sub­mis­sive dogs as­sume the most vul­ner­a­ble po­si­tion known to dogs, lying on the backs, ex­pos­ing their un­der­sides. This po­si­tion ad­mits ul­ti­mate de­feat in the strug­gle of dom­i­nance be­tween dogs.

Do­mes­tic dogs can be ac­tive at any time of the day or night. Feral do­mes­tic dogs main­tain home ranges that they de­fend against oth­ers and may move around through­out the year.

Com­mu­ni­ca­tion and Per­cep­tion

Do­mes­tic dogs use a com­plex set of com­mu­ni­ca­tion modes to nav­i­gate their so­cial en­vi­ron­ment. Chem­i­cal cues, such as pheromones, com­mu­ni­cate in­for­ma­tion on re­pro­duc­tive sta­tus, so­cial sta­tus, and mood. Body lan­guage is heav­ily used and var­i­ous vo­cal­iza­tions are used as well. So­cial bond­ing and com­mu­ni­ca­tion also oc­curs through touch.

Food Habits

Pup­pies have dif­fer­ent feed­ing habits than older dogs. A puppy needs twice as much pro­tein and 50% more calo­ries per pound of body weight daily in order to meet its growth re­quire­ments. A rapid change in a puppy's diet may cause gas­troin­testi­nal up­sets. Pup­pies must feed 4 times daily until the age of 3 months, 3 times daily until 6 months and twice daily for the rest of its life. Older dogs' feed­ing habits are dif­fer­ent in a cou­ple of ways. The av­er­age size dog re­quires about 30 calo­ries per pound of body weight per day. In­ter­est­ingly, larger breeds need only 20 calo­ries per pound of weight, while smaller breeds need about 40 calo­ries per pound of body weight. A dog's diet should con­sist of bal­anced por­por­tions of pro­teins, car­bo­hy­drates, fats and, of course, water. A dog can go days with­out food and lose 30% to 40% of it's body weight with­out dying, but a 10% to 15% water loss could be fatal. All-meat diets are not rec­om­mended for dogs due to the lack of cal­cium and iron found in meat. Diet sup­ple­ments should be avoided. Human foods that can be fatal to dogs in­clude moldy cheese, onions, and choco­late. Feral do­mes­tic dogs will eat a va­ri­ety of foods in­clud­ing an­i­mals and fruits.

  • Animal Foods
  • birds
  • mammals
  • amphibians
  • reptiles
  • fish
  • eggs
  • carrion
  • insects
  • terrestrial non-insect arthropods
  • Plant Foods
  • seeds, grains, and nuts
  • fruit

Pre­da­tion

Be­cause of their as­so­ci­a­tion with hu­mans, do­mes­tic dogs are not preyed upon by wild preda­tors. How­ever, feral do­mes­tic dogs may be preyed upon by any large preda­tor. Often they are killed by other canids, such as wolves and jack­als.

Ecosys­tem Roles

Feral do­mes­tic dogs im­pact ecosys­tems pri­mar­ily through pre­da­tion on na­tive wildlife, often re­sult­ing in se­vere pop­u­la­tion de­clines, es­pe­cially of is­land en­demic species.

There are many species of par­a­sites and dis­ease or­gan­isms that in­fect dogs. Some of which can also in­fect hu­mans.

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

If trained prop­erly and treated well, dogs are loyal and pro­tec­tive an­i­mals. Do­mes­tic dogs have been bred to many pur­poses through­out the mil­lenia, in­clud­ing as draft an­i­mals, guards, hunt­ing, herd­ing, and fish­ing aids, and as lap an­i­mals. More re­cently dogs are em­ployed as guide dogs for the blind, deaf, and dis­abled, using their keen sense of smell to de­tect bombs or drugs, and as ther­apy an­i­mals.

  • Positive Impacts
  • pet trade
  • research and education

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Do­mes­tic dogs carry and trans­mit human dis­eases, in­clud­ing viral, bac­te­r­ial, and par­a­sitic dis­eases. Dogs are still one of the pri­mary vec­tors for trans­mit­ting ra­bies to hu­mans in un­de­vel­oped parts of the world. In ad­di­tion, do­mes­tic dogs are re­spon­si­ble for at­tacks on adults and chil­dren, some­times re­sult­ing in death.

  • Negative Impacts
  • injures humans
    • bites or stings
    • carries human disease

Con­ser­va­tion Sta­tus

Do­mes­tic dogs are not threat­ened, though some agen­cies try to pro­tect rare breeds from dis­ap­pear­ing.

Con­trib­u­tors

Tanya Dewey (au­thor), An­i­mal Di­ver­sity Web.

Shee­tal Bha­gat (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

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Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

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Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

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Neotropical

living in the southern part of the New World. In other words, Central and South America.

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Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

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acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carrion

flesh of dead animals.

chaparral

Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.

chemical

uses smells or other chemicals to communicate

cooperative breeder

helpers provide assistance in raising young that are not their own

cosmopolitan

having a worldwide distribution. Found on all continents (except maybe Antarctica) and in all biogeographic provinces; or in all the major oceans (Atlantic, Indian, and Pacific.

crepuscular

active at dawn and dusk

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

diurnal
  1. active during the day, 2. lasting for one day.
dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

male parental care

parental care is carried out by males

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

nomadic

generally wanders from place to place, usually within a well-defined range.

oceanic islands

islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

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pet trade

the business of buying and selling animals for people to keep in their homes as pets.

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

polar

the regions of the earth that surround the north and south poles, from the north pole to 60 degrees north and from the south pole to 60 degrees south.

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

polymorphic

"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scrub forest

scrub forests develop in areas that experience dry seasons.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

suburban

living in residential areas on the outskirts of large cities or towns.

tactile

uses touch to communicate

taiga

Coniferous or boreal forest, located in a band across northern North America, Europe, and Asia. This terrestrial biome also occurs at high elevations. Long, cold winters and short, wet summers. Few species of trees are present; these are primarily conifers that grow in dense stands with little undergrowth. Some deciduous trees also may be present.

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

tundra

A terrestrial biome with low, shrubby or mat-like vegetation found at extremely high latitudes or elevations, near the limit of plant growth. Soils usually subject to permafrost. Plant diversity is typically low and the growing season is short.

urban

living in cities and large towns, landscapes dominated by human structures and activity.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

Ref­er­ences

Amer­i­can Ken­nel Club. 1992. The Com­plete Dog Book. Howeel Book House, New York, N.Y.

McGin­nis, Terri. 1974. The Well Dog Book. Ran­dom House, New York

The Mar­shall Cavendish In­ter­na­tional Wildlife En­cy­clo­pe­dia.1989. V. 7. Mar­shall Cavendish Cor­po­ra­tion. Freeport, Long Is­land. New York.

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Classification

Classification

  • Kingdom Animalia animals
  • Phylum Chordata chordates
  • Subphylum Vertebrata vertebrates
  • Class Mammalia mammals
  • Order Carnivora carnivores
  • Family Canidae coyotes, dogs, foxes, jackals, and wolves
  • Genus Canis dogs, jackals, and wolves
  • Species Canis lupus gray wolf
  • Subspecies Canis lupus familiaris dog