The Study Of Dogs

The Study Of Dogs

The dog (Canis Familiaris when considered a separate species or Canis lupus familiaris when considered a subspecies of the wolf) is a domestic carnivore of the species Canidae. It is part of the wolf-like canids and is the most widely sufficient mundane carnivore. 

Dog (Canis lupus familiaris) at Gubbeen, Co. Cork, Republic of Ireland

The dog and the surviving gray wolf are sibling taxa as new wolves are not similarly related to the first domestic wolves, which signifies that the dog’s literal ancestor is extinct.

 The dog was the first species to be domesticated and has been selectively reproduced over utopias for various sensible capabilities and physical properties. Their long bond with humans has influenced dogs to be uniquely tuned to human behavior, and all can thrive on a starch-rich diet that would be inadequate for other canids. 

Dogs vary widely in shape, size, and colors. They fulfill many roles for humans, such as sporting, herding, dragging loads, security, assisting police and military, company, and, more recently, aiding disabled people, and remedial roles. This impact on human society has given them the moniker of “man’s best friend.”

A brief history of dogs by the National Geographic


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,” 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 ranked the wolf as Canis lupus. Linnaeus considered the dog to be a separate species from the wolf because its cauda recurvata – its upturning tail is not found in any other canid.

“Carl Linneaus”

 In 1999, a study of mitochondrial DNA indicated that the domestic dog might have originated from various grey wolf communities. The dingo and New Guinea singing dog “breeds” had developed when human neighborhoods were more segregated from another.

 In the third edition of Mammal Species of the World published in 2005, the mammalogist W. Christopher Wozencraft posted under the wolf Canis lupus its wild subspecies also offered 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 equivalent for the dingo. Wozencraft related to the mDNA study as one of the leads informing his decision.

 Other mammalogists have remarked the formation of familiaris and dingo under a “domestic dog” clade. That classification by Wozencraft is disputed between zoologists. In 2019, a workshop hosted by the IUCN/Species Survival Commission’s Canid Specialist Group recognized the New Guinea singing dog and the dingo to be feral dogs. 

Canis familiaris should not be assessed for the IUCN Red List.

Origin of dogs

The domestic dog’s ancestry includes its genetic difference from the wolf, its domestication, including its evolution into dog groups and dog classes.

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.

 Genetic studies comparing dogs with modern wolves show correlative monophyly (separate groups), signifying that dogs are not genetically close to any living wolf and that their wild ancestor is extinct. An extinct Late Pleistocene wolf may have been the dog’s ancestor, with the dog’s similarity to the extant grey wolf being the result of genetic admixture between the two. In 2020, a literature review of canid domestication stated that modern dogs were not descended from the same Canis lineage as modern wolves and propose that dogs be descended from a Pleistocene wolf closer in size a village dog. The genetic divergence between dogs and wolves occurred between 20,000 and 40,000 years ago, just before or during the Last Glacial Maximum (20,000–27,000 years ago). This period represents the upper time-limit for domestication commencement because it is the time of divergence and not domestication, which occurred later. One of the most critical 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. 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. By 11,000 years ago, there were five distinct dog lineages, all sharing a common ancestry different from present-day wolves.


Domestic dogs have been selectively bred for millennia for various functions, sensory capabilities, and physical attributes. Contemporary dog breeds exhibit more numerous differences in size, appearance, and behavior than any other domestic animal. 

Dogs are predators and scavengers; like many other predatory mammals, the dog has powerful muscles, large and sharp claws and teeth, 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, which stood only 6.3 centimeters (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 most massive 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. The tallest dog is a Great Dane that stands 106.7 cm (3 ft 6 in) at the shoulder.


The dog’s senses include vision, hearing, smell, taste, touch, and sensitivity to the earth’s magnetic field. 

Another study suggested that dogs can see the earth’s magnetic field.


The coats of domestic dogs are of two varieties: “double” being familiar with dogs (as well as wolves) arising from colder climates, made up of a coarse guard hair and a soft down hair, or “single,” with the topcoat only. 

Some breeds may have an occasional “blaze,” stripe, or “star” of white fur on their chest or underside. The Coat can be maintained or affected by multiple nutrients in the diet; view Coat (dog) for more information.

Premature graying can occur in dogs from as early as one year of age; this is shown to be associated with spontaneous behaviors, stress behaviors, fear of noise, and fear of unknown people or animals.


There are many different looking 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 crucial in getting along with others. 

In some hunting dogs, however, the tail is traditionally docked to avoid injuries. In some breeds, such as the Braque du Bourbonnais, puppies can be born with a short tail or no tail at all.

Differences of domesticated dogs from wolves

Despite their close genetic relationship and interbreeding, several distinguishing features identify the gray wolves from domestic dogs. Domesticated canines are distinct from wolves by polysaccharide gel electrophoresis of red blood cell acid phosphatase. The tympanic bullae are large, arched, and nearly spherical in gray wolves, while the bullae of canines are more modest, compressed, and somewhat crumpled. 

Analyzed with equally sized wolves, dogs tend to have 20% smaller skulls and 30% smaller brains. The teeth of gray wolves are also proportionately more massive than those of dogs. Dogs have a more domed forehead and a distinctive “stop” between the forehead and nose. The temporalis muscle that closes the jaws is more robust in wolves. Wolves do not have dewclaws on their back legs unless there has been admixture with dogs that had them. Most dogs lack a functioning pre-caudal gland and enter estrus twice yearly, unlike gray wolves, which only do so once a year. So-called primitive dogs such as dingoes and Basenjis retain the yearly estrus cycle. Dogs generally have brown eyes, and wolves almost always have amber or light-colored eyes. Domestic dogs’ skin tends to be thicker than that of wolves, with some Inuit tribes favoring the former for use as clothing due to its more excellent resistance to wear and tear in harsh weather. The paws of a dog are half the size of a wolf, and their tails tend to curl upwards, another trait not found in wolves. 

The dog has developed into hundreds of varied breeds and shows more behavioral and morphological variation than any other land mammal.


Many household plants are poisonous to dogs and cats (and other mammals), including Begonia, Poinsettia, and Aloe vera. Some dogs are prone to particular genetic illnesses such as joint and hip dysplasia, blindness, deafness, pulmonic stenosis, cleft palate, and joke knees. 

Two severe medical conditions affecting dogs are pyometra, affecting unspayed females of all types and ages, and gastric dilatation-volvulus (bloat), which affects the larger breeds or deep-chested dogs. Both of these are acute situations and can kill rapidly.

Dogs are also susceptible to parasites such as fleas, ticks, mites, hookworms, tapeworms, roundworms, and heartworms (roundworm species that lives in the heart of dogs).

Several human foods and household human-grade digestible foods are toxic to dogs, including chocolate solids (theobromine poisoning), onion and garlic (thiosulphate, sulfoxide, or disulfide poisoning), grapes and raisins, macadamia nuts, xylitol, as well as various plants and other potentially ingested materials. The nicotine in tobacco can also be dangerous.

Dogs can be endangered to the material by scavenging opened trash bins or ashtrays and consuming cigars and cigarettes. Signs can be vomiting of large amounts (e.g., from eating cigar butts) or diarrhea. Some other symptoms are abdominal pain, loss of coordination, collapse, or death. 

Dogs are susceptible to theobromine poisoning, typically from the ingestion of chocolate. Theobromine is toxic to dogs because, although the dog’s metabolism can break down the chemical, the process is so slow that for some dogs, even small amounts of chocolate can be fatal, mostly dark chocolate.


In 2013, a study found that mixed breed dogs live on average 1.2 years longer than purebred dogs. Increasing body-weight was negatively correlated with longevity (i.e., the heavier the dog, the shorter its lifespan). 

The typical lifespan of dogs varies widely among breeds, but the median longevity, the age at which half the dogs in a population have died and half are still alive, ranges from 10 to 13 years. Individual dogs may live well beyond the median of their breed.

The breed with the shortest lifespan (among species for which there is a questionnaire survey with reasonable sample size) is the Dogue de Bordeaux, with a median longevity of about 5.2 years. Still, several breeds, including miniature bull terriers, bloodhounds, and Irish wolfhounds, are nearly as short-lived, with median longevities of 6 to 7 years.  

The longest-lived breeds, including toy poodles, Japanese spitz, Border terriers, Australian Cattle Dogs, and Tibetan Spaniels, have median longevities of 14 to 15 years. The median longevity of mixed-breed dogs, taken as an average of all sizes, is one or more years longer than that of purebred dogs when all breeds are averaged. 

The longest-lived dog was “Bluey,” an Australian Cattle Dog who died in 1939 at 29.5 years of age.


In domestic dogs, sexual development occurs around six to twelve months of age for both males and females, although this can be delayed until up to two years old for some large breeds, and is the time at which female dogs will have their first estrous cycle. They will experience subsequent estrous cycles semiannually, during which the body prepares for pregnancy.

How Dogs Tell Us What We Need To Know- Barbara Sherman TED talks

 At the peak of the cycle, females will become estrus, mentally and physically sensitive to mating. Because the ova survive and can be fertilized for a week after ovulation, more than one male can sire the same litter.

Fertilization typically happens 2–5 days after ovulation; 14–16 days after ovulation, the embryo attaches to the uterus, and after 7-8 more days, the heartbeat is detectable. Dogs bear their litters roughly 58 to 68 days after fertilization, with an average of 63 days, although the length of gestation can vary. 

An average litter consists of about six puppies, though this number may differ extensively based on canine breed. Overall, toy dogs produce from one to four puppies in each litter, while much larger breeds may average as many as twelve.

Some dog breeds have acquired characteristics through judicious breeding that conflict with breeding. Male French Bulldogs, for example, are unsuited to mounting the female. For many dogs of this breed, the female must be artificially inseminated to reproduce. Additionally, the female will most likely need a C-section due to the breed’s characteristically admired large heads.


Neutering refers to the sterilization of animals, usually by removing the male’s testicles or the female’s ovaries and uterus, to eliminate the ability to procreate and reduce sex drive.

Because of dogs’ overpopulation in some nations, many animal control agencies, such as the American Society for the Prevention of Cruelty to Animals (ASPCA), recommend that dogs not intended for further breeding should be neutered. This way, they do not have undesired puppies that may later be euthanized.

According to the Humane Society of the United States, 3–4 million dogs and cats are euthanized each year. Many more are confined to cages in shelters because there are many more animals than there are homes. Spaying or castrating dogs helps keep overpopulation down. Local humane societies, SPCAs, and other animal protection organizations urge people to neuter their pets and adopt animals from shelters instead of purchasing them.

Neutering reduces problems caused by hypersexuality, especially in male dogs. Spayed female dogs are less likely to develop cancer, affecting mammary glands, ovaries, and other reproductive organs. 

However, neutering increases the risk of urinary incontinence in female dogs, prostate cancer in males, osteosarcoma, hemangiosarcoma, cruciate ligament rupture, obesity, and diabetes mellitus in either sex.

Inbreeding depression

A common breeding practice for pet dogs is mating between close relatives (e.g., between half-and full siblings). Inbreeding crisis is considered to be due mainly to the creation of homozygous unhealthy dormant deviations. Outcrossing in separate canines, including dogs of different breeds, results in the beneficial masking of harmful recessive mutations in offspring.

A study of seven breeds of dogs (Bernese mountain dog, basset hound, Cairn terrier, Epagneul Breton, German Shepherd dog, Leonberger, and West Highland white terrier) found that inbreeding decreases litter size and survival. 

New Age Bully Breed Unable To Reproduce Naturally

Another analysis of data on 42,855 dachshund litters found that as the inbreeding coefficient rose, litter quantity decreased, and the portion of stillborn pups raised, thus revealing inbreeding depression.

 In a study of boxer litters, 22% of puppies died before seven weeks old. Stillbirth was the most common reason for death, attended by disease. 

Mortality due to infection increased significantly with raises in inbreeding.


Dog intelligence is the dog’s capacity to understand information and maintain it as information to solve problems. 

Studies of two dogs propose that dogs can think by understanding and have excellent memory skills. A study with Rico, a border collie, showed that he comprehended the labels of over 200 various things. He understood the names of new items by exclusion learning, including accurately recovering those new items quickly and four weeks after the initial exposure. 

A study of another border collie, “Chaser,” documented his learning and memory capabilities. He had learned the names and could associate by verbal command over 1,000 words. Dogs can read and react appropriately to human body language, such as gesturing and pointing and human voice commands.

A 2018 study on canine cognitive skills found that dogs’ aptitudes remain no more exceptional than those of other creatures, such as horses, chimpanzees, or cats. Various animals, including pigs, pigeons, and chimpanzees, can identify the “what, where, and when” of an affair, which dogs cannot do.  

Dogs show a method of cognizance by meshing in betrayal. An exploratory study displayed compelling proof that Australian dingos can defeat domesticated dogs in non-social problem-solving, symbolizing that domestic dogs may have lost much of their primary problem-solving capabilities once they met humans. 

Another study showed that following support practice to solve a simple administration duty, dogs confronted with an unsolvable version of the same predicament look at the human, while socialized wolves do not.


Dog behavior is the inside regulated responses (actions or inactions) of the domestic dog (individuals or groups) to inner and outer stimuli.

Bane and Athena at the Chicago Dog Beach

 As the oldest domesticated species, with estimations varying from 9,000–30,000 years BCE, dogs’ brains inescapably have transpired fashioned by utopias of contact with people.

 As a result of this environmental and cultural evolution, dogs have earned the ability to recognize and interact with humans more than any other species. They are uniquely attuned to human behaviors. 

Behavioral scientists have revealed a unique set of social-cognitive skills in the family dog. These abilities are not maintained by the dog’s closest canine relatives or other highly sensible mammals such as great apes but relatively alike to children’s social-cognitive skills.

Unlike other domestic species selected for production-related traits, dogs were chosen initially for their behaviors. In 2016, a study found that only 11 fixed genes presented a variety of wolves and dogs. These gene variations were unlikely to have been the outcome of fundamental metamorphosis and show a pick on both morphology and behavior while dogs learned domestication. 

These genes have been shown to affect the catecholamine synthesis pathway, with most of the genes affecting the fight-or-flight response (i.e., selection for tameness) and emotional processing. Dogs generally showed reduced fear and aggression compared with wolves. The genes associated with aggression in some dog breeds indicate their importance in both the initial domestication and next in breed development. 

Traits of high sociability dogs and lack of fear in dogs may include genetic adjustments related to Williams-Beuren syndrome in humans, which cause hyper sociability at the cost of problem-solving intelligence.


Dog communication is how dogs convey information to other dogs, understand messages from humans, and translate the information dogs are transmitting. Communication behaviors of dogs include eye gaze, facial expression, vocalization, body posture (including movements of bodies and limbs), and gustatory communication (scents, pheromones, and taste). Humans communicate with dogs by using vocalization, hand signals, and body posture.

Athena smiling and sleeping


In 2013, an estimated global dog population was between 700 million and 987 million. However, it is known as “dog man’s best friend,” which refers to the >20% of dogs that live in advanced countries.

 In the developing world, dogs are more commonly wild or communally owned, with pet dogs uncommon. Most of these dogs live their lives as scavengers and have never been owned by humans, with one study showing their most common response when approached by strangers is to run away (52%) or react aggressively (11%). 

Little is known about these dogs or the strays in advanced countries that are wild, stray, or live in shelters because most modern research on dog cognition has centered on pet dogs living in human houses.

Competitors and predators

Although dogs are the most sufficient and broadly distributed terrestrial carnivores, feral, and free-ranging dogs’ potential to compete with other noble carnivores is limited by their powerful connection with humans. For example, a review of the studies in dogs’ competitive effects on sympatric carnivores did not discuss any examination on competition in dogs and wolves. 

Although wolves are known to kill dogs, they favor living in pairs or in small packs in spheres where they are numerous, supplying them with a weakness standing large dog groups. Wolves kill dogs wherever they are found together. 

One study reported that in Wisconsin, in 1999, more pay had been compensated for losses due to wolves hunting dogs than for wolves taking livestock. In Wisconsin, wolves will frequently kill tracking dogs, perhaps because they are in the wolf’s region. 

A strategy reported in Russia noted one wolf luring a dog into a large hedge where another, different wolf, waits in ambush. In some instances, wolves have displayed an uncharacteristic fearlessness of people and homes when attacking dogs, to the degree that they must to be beaten off or destroyed.

Although the quantities of dogs killed each year are moderately low, it provokes a concern of wolves invading settlements and farms to take canines, and eradicating dogs to wolves has driven to demands for more liberal wolf hunting laws.

Coyotes and big felines have similarly been known to strike dogs. In particular, leopards have been known to have a liking for dogs and have come known to kill and devour them no matter their size. 


Reports of Tigers in Manchuria, Indochina, Indonesia, and Malaysia have shown many tiger’s likeliness to kill dogs.

Tiger in Manchuria

Striped hyenas are known to kill canines in Turkmenistan, India, and the Caucasus.



Dogs are carnivores or omnivores. Contrasted to wolves, canines from farming communities possess extra copies of amylase and other genetic factors such as those involved in starch digestion that contributes to an increased ability to prosper on a starch-rich regime.

 Also, like humans, some dog breeds produce amylase in their saliva. Based on metabolism and diet, many view the dog to be an omnivore.  

However, the dog is not only an omnivore. Likewise, like the cat and less like other omnivores, the dog can only manufacture bile acid with taurine, and it cannot generate vitamin D, which it receives from animal fat. Also, more like the cat, the dog demands arginine to support its nitrogen balance. These nutritional claims set the dog part-way amidst carnivores and omnivores.


As a domesticated or semi-domesticated animal, the dog is nearly widespread among human societies.

 Notable exceptions once included:

  • Aboriginal Tasmanians, who were separated from Australia before the arrival of dingos on that continent.  
  • The Andamanese, who were isolated when rising sea levels, covered the land bridge to Myanmar.
  • The Fuegians, who instead domesticated the Fuegian dog, a different canid species
  • Individual Pacific islands whose maritime settlers did not bring dogs, or where dogs died out after original settlement, notably: the Mariana Islands, Palau, Marshall Islands, Gilbert Islands, New Caledonia, Vanuatu, Tonga, Marquesas, Mangaia in the Cook Islands, Rapa Iti in French Polynesia, Easter Island, Chatham Islands, and Pitcairn Island (settled by the Bounty mutineers, who killed off their dogs to escape discovery by passing ships).
  • Dogs were introduced to Antarctica as sled dogs but were later outlawed by international agreement due to the possible risk of spreading infections.


The domestic dog is the first species and the only large carnivore known to have been domesticated. Especially over the past 200 years, dogs have undergone rapid phenotypic change and were formed into today’s modern dog breeds due to humans’ artificial selection. These breeds can vary in size and weight from a 0.46 kg (1 lb) teacup poodle to a 90 kg (200 lb) giant mastiff. Phenotypic variation can include height measured to the withers ranging from 15.2 cm (6 in) in the Chihuahua to 76 cm (30 in) 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 variety of patterns; coats can be short or long, coarse-haired to wool-like, straight, curly, or smooth. The skull, body, and limb proportions vary significantly between breeds, with dogs displaying more phenotypic diversity than can be found within carnivores’ entire order. Some species demonstrate outstanding skills in herding, retrieving, scent detection, and guarding, presenting dogs’ functional and behavioral diversity. The first dogs were domesticated from shared ancestors of modern wolves; however, the phenotypic changes that coincided with the dog-wolf genetic divergence are unknown.

Roles with humans

Domestic dogs inherited problematic behaviors, such as bite inhibition, from their wolf ancestors, which would have been pack hunters with complex body language. These sophisticated forms of social cognition and communication may account for their trainability, playfulness, and ability to fit into human households and social situations. These attributes have given dogs a relationship with humans, enabling them to become one of the most successful species today. The dogs’ value to early human hunter-gatherers led to them quickly becoming ubiquitous across world cultures. Dogs perform many roles for people, such as hunting, herding, pulling loads, protection, assisting police and military, companionship, and, more recently, aiding disabled individuals. This influence on human society has given them the nickname “man’s best friend” in the Western world. In some cultures, however, dogs are also a source of meat.

Early roles

Wolves, and their dog descendants, likely derived significant benefits from living in human camps – more safety, more reliable food, lesser caloric needs, and more chance to breed. They would have benefited from humans’ upright gait that gives them a more extensive range over which to see potential predators and prey, and better color vision that, at least by day, gives humans better visual discrimination. Camp dogs would also have benefited from human tool use, bringing down larger prey, and controlling fire for various purposes. Humans would also have derived enormous benefit from the dogs associated with their camps. For instance, dogs would have improved sanitation by cleaning up food scraps. Dogs may have provided warmth, as referred to in the Australian Aboriginal expression “three dog night” (a frigidly cold night). They would have alerted the camp to predators or strangers, using their acute hearing to provide an early warning. It has been suggested that the most significant benefit would have been the use of dogs’ robust sense of smell to assist with the hunt. The relationship between a dog’s presence and success in the pursuit is often mentioned as a primary reason for the domestication of the wolf, and a 2004 study of hunter groups with and without a dog gives quantitative support to the hypothesis that the benefits of cooperative hunting were an essential factor in wolf domestication.

 The cohabitation of dogs and humans likely improved the chances of survival for early human groups. The domestication of dogs may have been one of the fundamental forces that led to social success. 

Human emigrants from Siberia that came across the Bering land bridge into North America likely had dogs in their company. Although one writer even suggests that sled dogs’ use may have been critical to the success of the waves that entered North America roughly 12,000 years ago, the earliest archaeological evidence of dog-like canids in North America dates from about 9,400 years ago. Dogs were an essential part of life for the Athabascan population in North America and were their only domesticated animal. Dogs as pack animals may have contributed to the Apache and Navajo tribes’ migration 1,400 years ago. This use of dogs in these cultures often persisted after the introduction of the horse to North America.

As pets

It is estimated that three-quarters of the world’s dog population lives in the developing world as feral, village, or community dogs, with pet dogs uncommon.” The most widespread form of interspecies bonding occurs between humans and dogs” and the keeping of dogs as companions, particularly by elites, has a long history (see the Bonn–Oberkassel dog). Pet-dog populations grew significantly after World War II as suburbanization increased. In the 1950s and 1960s, dogs were kept outside more often than they tend to be today (the expression “in the doghouse” – recorded since 1932 – to describe exclusion from the group implies a distance between the doghouse and the home) and were still primarily functional, acting as a guard, children’s playmate, or walking companion. 

From the 1980s, there have been changes in the pet dog’s role, such as dogs’ increased role in their human guardians’ emotional support. People and their dogs have become increasingly integrated and implicated in each other’s lives, to the point where pet dogs actively shape how a family and home are experienced.

There have been two significant trends occurring within the second half of the 20th century in pet dogs’ changing status. The first has been the “commodification,” shaping it to conform to social expectations of personality and behavior. The second has been the broadening of the family’s concept and the home to include dogs-as-dogs within everyday routines and practices. A vast range of commodity forms aims to transform a pet dog into an ideal companion. The list of goods, services, and places available are enormous: from dog perfumes, couture, furniture, and housing, to dog groomers, therapists, trainers and caretakers, dog cafes, spas, parks and beaches, and dog hotels, airlines, and cemeteries. While dog training as an organized activity has operated since the 18th century, it became a high-profile issue in the last decades of the 20th century. Many normal dog behaviors such as barking, jumping up, digging, rolling in dung, fighting, and urine marking (which dogs do to establish territory through scent) became increasingly incompatible with a pet dog’s new role. Dog training books, classes, and television programs proliferated as the process of commodifying the pet dog continued.

 Most contemporary dog owners describe their pet as part of the family, although some ambivalence about the relationship is evident in the dog-human family’s popular reconceptualization as a pack. Some dog-trainers, such as on the television program Dog Whisperer, have promoted a dominance-model of dog-human relationships. However, it has been disputed that “trying to achieve status” is characteristic of dog-human interactions. Pet dogs play an active role in family life; for example, a study of conversations in dog-human families showed how family members use the dog as a resource, talking to the dog or talking through the dog; to mediate their interactions with each other.

dogs at dinner

Increasingly, human family-members engage in activities centered on the dog’s perceived needs and interests. The dog is an integral partner, such as dog dancing and dog yoga.

 According to statistics published by the American Pet Products Manufacturers Association in the National Pet Owner Survey in 2009–2010, an estimated 77.5 million people in the United States have pet dogs. The same source shows that nearly 40% of American households own at least one dog, of which 67% own just one dog, 25% two dogs, and almost 9% more than two dogs. 

There does not seem to be any gender preference among dogs as pets, as the statistical data reveal an equal number of female and male dog pets. Although several programs promote pet adoption, less than a fifth of the owned dogs come from shelters.

Some research suggests that a pet dog produces a considerable carbon footprint. A study using magnetic resonance imaging (MRI) to compare humans and dogs showed that dogs have the same response to voices and use the same brain parts as humans do. This gives dogs the ability to recognize human emotional sounds, making them friendly social pets to humans.


Dogs have lived and worked with humans in many roles. In addition to dogs’ role as companion animals, dogs have been bred for herding livestock (collies, sheepdogs), hunting (hounds, pointers), and rodent control (terriers). Other types of working dogs include search and rescue dogs, detection dogs trained to detect illicit drugs or chemical weapons; guard dogs; dogs who assist fishers with the use of nets; and dogs that pull loads. In 1957, the dog Laika became the first animal to be launched into Earth orbit, aboard the Soviets’ Sputnik 2; she died during the flight. 

Various kinds of service dogs and assistance dogs, including guide dogs, hearing dogs, mobility assistance dogs, and psychiatric service dogs, assist individuals with disabilities. Some dogs owned by people with epilepsy have shown to alert their handler when the handler shows predictions of an impending seizure, sometimes considerably in advance of the attack, providing the guardian to seek safety, medication, or medical care.

Sports and shows

People often enter their dogs in competitions, such as breed-conformation shows or sports, including racing, sledding, and agility competitions.

In conformation shows, also referred to as breed shows, a judge familiar with the specific dog breed evaluates individual purebred dogs for conformity with their established breed type as described in the breed standard. As the breed standard only deals with the dog’s externally observable qualities (such as appearance, movement, and temperament), separately tested qualities (such as ability or health) are not part of the judging in conformation shows.

As food

Canine meat is eaten in some East Asian nations, including Korea, China, and Vietnam, which records back to Athens. It is estimated that 13–16 million dogs are killed and consumed in Asia every year

In China, disputes have happened over forbidding the eating of dog meat. Following the Sui and Tang dynasties of the first millennium, people inhabiting northerly China’s fields started to shun consuming dogs, which is possible due to Buddhism and Islam’s spread, two religions that prohibited the eating of specific creatures, including canine. 

As constituents of the uppermost classes evaded dog meat, it increasingly grew a cultural no-no to eat it, even though the general populace resumed to eat it for hundreds of years afterward.

Different cultures, such as Polynesia and pre-Columbian Mexico, also consumed dog meat in their archives. However, Western, South Asian, African, and Middle Eastern cultures, in common, view dog meat-eating as taboo. 

In some communities, though, such as Poland’s in-country areas, dog fat is acknowledged to have healing characteristics – being good for the lungs, for instance. 

Dog meat is also consumed in some sections of Switzerland. Proponents of eating dog meat have argued that placing a distinction between livestock and dogs is western hypocrisy and that there is no difference in eating different animals’ hearts.

In Korea, the primary reason for breeding the fundamental canine variety raised is for meat, the nureongi (누렁이), which differs from those breeds bred for pets that Koreans may have in their homes. The most popular Korean dog dish is gaejang-guk (also named bosintang), a savory soup intended to replace the body’s heat during summer. Followers of the system claim this is done to ensure good health by balancing their gi or the body’s vital energy. A 19th-century version of gaejang-guk tells that the meal is brewed by boiling dog meat with scallions and chili powder. Varieties of the dish contain chicken and bamboo shoots. While the recipes are yet every day in Korea with a state division, the dog is not as broadly utilized as beef, chicken, and pork.

Health risks to humans

In 2005, the WHO reported that 55,000 people died in Asia and Africa from rabies, a disease for which dogs are the most critical vector. 

Citing a 2008 study, the U.S. Centers for Disease Control estimated in 2015 that 4.5 million people in the USA are bitten by dogs each year. A 2015 study estimated that 1.8% of the U.S. population is bitten each year.

 In the 1980s and 1990s, the U.S. averaged 17 fatalities per year, while since 2007, this has increased to an average of 31. 77% of dog bites are from the pet of family or friends, and 50% of attacks occur on the dog’s legal owner’s property. 

A Colorado study found bites in children were less severe than bites in adults. The incidence of dog bites in the U.S. is 12.9 per 10,000 inhabitants, but for boys aged 5 to 9, the incidence rate is 60.7 per 10,000. Moreover, children have a much higher chance of being bitten in the face or neck. Sharp claws with powerful muscles behind them can lacerate flesh in a scratch that can lead to severe infections.

 In the U.K., between 2003 and 2004, there were 5,868 dog attacks on humans, resulting in 5,770 working days lost in sick leave. 

In the United States, cats and dogs are a factor in more than 86,000 falls each year. It has been estimated that around 2% of dog-related injuries treated in U.K. hospitals are domestic accidents. The same study found that while dog involvement in road traffic accidents was difficult to quantify, dog-associated road accidents involving injury more commonly involved two-wheeled vehicles. 

Toxocara Canis (dog roundworm) eggs in dog feces can cause toxocariasis. In the United States, about 10,000 cases of Toxocara infection are reported in humans each year, and almost 14% of the U.S. population is infected. In Great Britain, 24% of soil samples taken from public parks contained T. canis eggs. Untreated toxocariasis can cause retinal damage and decreased vision. Dog feces can also contain hookworms that cause cutaneous larva in humans.


Canines, or dogs, suffer from common illnesses as people; these cover cancer, diabetes, heart disease, and neurologic dysfunctions. This pathogeny is comparable to humans, as is their acknowledgment of medicine and their outcomes. Researchers are now identifying the genes associated with dog diseases similar to human disorders but lack rodent prototypes to obtain canines and humans.

 The genes affected in canine obsessive-compulsive sicknesses led to discovering four genes in humans’ relevant pathways. The scientific data is jumbled about whether a dog’s company can improve human physical health and cerebral well-being. 

Studies implying that there are advantages to physical health and psychological well-being have been scrutinized for being poorly regulated. It discovered that “the health of elderly people is related to their health habits and social supports but not to their ownership of, or attachment to, a companion animal.” More advanced studies have shown that people that own pet dogs or cats display more excellent subconscious and physical health than those who do not, causing fewer visits to the doctor and implying less likely to be on prescription medication than non-pet owners.

A 2005 paper states, “recent research has failed to support earlier findings that pet ownership is associated with a reduced risk of cardiovascular disease, reduced use of general practitioner services, or any medications.

 However, research has pointed to significantly less absenteeism from school through sickness among children who live with pets.” In one study, new guardians reported a significant reduction in minor health difficulties throughout the first month following pet possession. This effect was supported in those with dogs through to the end of the study. 

People with pet dogs took considerably more physical exercise than those with cats and those without pets. The results provide evidence that keeping pets may have positive effects on human health and behavior and that for guardians of dogs, these effects are relatively long-term. Pet guardianship has also been associated with increased coronary artery disease survival. Human guardians are significantly less likely to die within one year of an acute myocardial infarction than those who did not own dogs. 

The health benefits of dogs can result from contact with dogs in general, not solely from having dogs as pets. For example, people show reductions in cardiovascular, behavioral, and psychological indicators of anxiety in a pet dog’s presence.

 According to the hygiene hypothesis, other health benefits are gained from exposure to immune-stimulating microorganisms, protecting against allergies and autoimmune diseases.

 The benefits of contact with a dog also include social support, as dogs can provide companionship and social support themselves and act as facilitators of social interactions between humans. One study indicated that wheelchair users experience more positive social interactions with strangers when accompanied by a dog than when they are not. In 2015, a study found that pet owners were significantly more likely to get to know people in their neighborhood than non-pet owners. 

Using dogs and other animals as a part of therapy dates back to the late 18th century when animals were introduced into mental institutions to help socialize patients with mental disorders. Animal-assisted intervention research has shown that animal-assisted therapy with a dog can increase social behaviors, such as smiling and laughing, among people with Alzheimer’s disease. One study demonstrated that children with ADHD and conduct disorders who participated in an education program with dogs and other animals showed increased attendance, increased knowledge and skill objectives, and decreased antisocial and violent behavior compared with those not in an animal-assisted program.


  • Every year, between 6 and 8 million dogs and cats enter U.S. animal shelters. The Humane Society of the United States (HSUS) estimates that approximately 3 to 4 million of those dogs and cats are euthanized yearly in the United States. The percentage of dogs in U.S. animal shelters eventually adopted and removed from holes by their new legal owners has increased since the mid-1990s from around 25% to a 2012 average of 40% among reporting shelters (with many shelters reporting 60–75%).
  • Terminology
  • The term dog typically is applied to the species (or subspecies) as a whole and any adult male member.
  • 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.
  • An immature male or female (that is, an animal not yet capable of reproduction) is a puppy.
  • A group of puppies from the same gestation period is a litter.
  • The father of a litter is a sire.
  • The mother of a litter is a dam.
  • A group of three or more adults is a pack.
  • A pack leader is an alpha. Typically a pack will have either an individual alpha or a male-female alpha pair.
  • Pack members subservient to alphas are betas.
  • Pack members subsidiary to all other members are omegas.

Cultural depictions

  • In China, Korea, and Japan, dogs are viewed as suitable protectors.

Mythicism and spirituality

  • In ancient Mesopotamia, of the Old Babylonian era to the Neo-Babylonian, canines were the representation of Ninisina, the goddess of healing and medicine, and her worshippers constantly sanctified miniature figures of seated hounds to her. In the Neo-Assyrian and Neo-Babylonian days, dogs were used as symbols of charm protection. 
  •  In mythology, canines often serve as pets or as watchdogs. Legends of dogs tending the gates of the netherworld recur throughout Indo-European mythologies and may originate from Proto-Indo-European religion. In Greek mythology, Cerberus is a three-headed watchdog who guards the gates of Hades. In Norse mythology, a bloody, four-eyed dog named Garmr guards Helheim. 
  • In Persian mythology, two four-eyed canines patrol the Chinvat Bridge. 
  • In Welsh mythology, Annwn is shielded by Cŵn Annwn. 
  • In Hindu mythology, Yama, the god of death, holds two watchdogs who have four eyes. They are narrated to guard the gates of Naraka.
  • The hunter god, Muthappan, from the North Malabar area of Kerala, possesses a hunting dog as his mount. Hounds are observed in and out of the Muthappan Temple, and sacrifices at the shrine use the design of bronze dog figurines. 
  • In Philippine mythology, Kimat, the pet of Tadaklan, the god of thunder, is bound for lightning.
  • The dog’s role in Chinese mythology includes a spot as one of the twelve creatures that cyclically describe ages (the zodiacal dog).

Three of the 88 constellations in western astronomy also represent dogs:

  • Canis Major (the Great Dog, whose brightest star, Sirius, is also called the Dog Star)
  • Canis Minor (the Little Dog)
  • Canes Venatici (the Hunting Dogs)
  • In Christianity, dogs represent loyalty.
  •  Within the Roman Catholic church individually, the iconography of Saint Dominic includes a dog, followed by the “hallow’s mother dream,” where a dog is springing from her womb and symbolizes pregnancy shortly after. As such, the Dominican Order (Ecclesiastical Latin: Dominicanus’ means “dogs of the lord” or “hounds of the Lord.” (Ecclesiastical Latin: Domini Canis)
  •  In Christian folklore, a church grim often takes the form of a black dog to guard Christian churches and their churchyards from sacrilege.
  • Jewish law does not prohibit keeping dogs and other pets. Jewish law commands Jews to maintain dogs (and different animals that people own) before themselves also perform arrangements for maintaining them before purchasing them.
  • The view on dogs in Islam is diverse, with some schools of knowledge seeing it as dirty. However, Khaled Abou El Fadl states that this aspect is based upon “pre-Islamic Arab mythology” and “a tradition to be falsely attributed to the Prophet.” Therefore, Sunni Malaki and Hanafi jurists permit the trade of and keeping of canines as pets.


  • In Homer’s epic poem, the Odyssey, when the disguised Odysseus returns home after 20 years, he is recognized only by his faithful dog, Argos, who has been waiting for his arrival.


  • Artistic depictions of canines in art stretch back thousands of years to when dogs were depicted on caves’ walls. Illustrations of dogs grew more detailed as particular classes developed, and the relationships between individual and canine evolved. Hunting scenes were famous in the Middle Ages and the Renaissance. Canines were portrayed to signify guidance, protection, loyalty, fidelity, faithfulness, watchfulness, and love.

Education and appreciation

  • The American Kennel Club reopened a museum called “Museum of the Dog” in Manhattan after transferring the attraction from outside of St. Louis. The museum includes old artifacts, exceptional art, and enlightening opportunities for guests.

See also

  • Lists of dogs
  • List of individual dogs

Further reading

  • Alexandra Horowitz (2016). Being a Dog: Following the Dog Into a World of Smell. Scribner. ISBN 978-1476795997.

External links

  • Biodiversity Heritage Library bibliography for Canis lupus familiaris
  • Fédération Cynologique Internationale (FCI) – World Canine Organisation
  • Dogs in the Ancient World, an article on the history of dogs
  • View the dog genome on Ensemble



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