Dog/Citable Version

Domestic dog
Labrador Retriever a breed of domestic dog
Conservation status
Template:StatusDomesticated
Scientific classification
Domain: Eukaryota Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Mammalia Order: Carnivora Family: Canidae Genus: Canis Species: C. lupus Subspecies: C. l. familiaris
Trinomial name
Canis lupus familiaris

The dog is one of the first animals ever domesticated. Throughout most of the world, dogs can be found associated with humans, although certainly not always as part of the household. Their status in society ranges from a form of food to a cherished companion.

Dogs are like humans in being highly social animals. The loyalty and devotion that dogs demonstrate as part of their natural instincts as pack animals closely mimics the human idea of love and friendship. Many dog owners view their pets as full-fledged family members. That's probably because most dogs are able to act the part. As best as we can tell, that ability comes about from two basic sources: (1) the "hard-wiring" of the dog's behavior programmed by its canine genes, and (2) the individual dog's experience with people.

When puppies are raised with plenty of contact to people and to other dogs, they become socialized. Socialized pups seem to view their human companions as members of their pack, and make few, if any, distinctions between their owners and fellow dogs. As these puppies grow and mature, they generally learn to modify their behavior slightly towards their human companions - as opposed to their canine ones, following cues from dog and man at each session of contact.

Dogs fill a variety of roles in human society and are often trained as working dogs. For dogs that do not have traditional jobs, a wide range of dog sports provide the opportunity to exhibit their natural skills. In many countries, the most common and perhaps most important role of dogs is as companions. Dogs have lived with and worked with humans in so many roles that their loyalty has earned them the unique sobriquet "man's best friend" Conversely, some cultures consider dogs to be unclean. In some cultures, certain types of dogs are used as food.

Dog breeds

A Jack Russell Terrier playing with his toy.

The dog has developed into hundreds of breeds with a great degree of variation, such as this Miniature Pinscher and Boxer.

A Maltese enjoying the fall leaves.

There are numerous dog breeds, with at least over 800 different breeds being recognized by various kennel clubs worldwide. Each breed have been has been bred from mixed-breed dog populations, and so the term "purebred" has meaning only with respect to a certain number of generations. However, in some parts of the world the XXXX. Such ancient working breeds include the Greyhounds, the Mastiff and the Anatolian Shephard.

Perhaps more than any single species of mammal, dogs have an enormous range of normal height and weight. The smallest of the breeds is the Chihuahua, and the largest, the Great Dane. Despite the great differences in size between these two extremes, both the Chihuahua and the Great Dane are the same species and can interbreed successfully.

Pharaoh Hound

File:Staffordshire Bull Terrier - Labrador Cross.JPG

A 10-year-old Staffordshire Bull Terrier/Labrador cross enjoys the sunlight.

In February 2004, the Canine Studies Institute in Aurora, Ohio, arranged recognized breeds of dogs into ten categories.

Mixed-breed dogs or Mongrels are dogs that do not belong to specific breeds, being mixtures of two or more in variant percentages. Mixed breeds, or dogs with no purebred ancestry, are not inherently "better" or "worse" than purebred dogs as companions, pets, working dogs, or competitors in dog sports. Sometimes mixed-breed dogs are deliberately bred, for example, the Cockapoo, a mixture of Cocker Spaniel and Miniature Poodle. Such deliberate crosses may display hybrid vigor and other desirable traits, but can also lack one or more of the desired traits of their parents, such as temperament or a particular color or coat. However, without genetic testing of the parents, the crosses can sometimes end up inheriting genetic defects that occur in both parental breeds. Deliberately crossing two or more breeds is also a manner of establishing new breeds.

Breed popularity

Breed popularity varies widely over time and in different parts of the world and different segments of the population. Counting by AKC registration (not by licensing registration or by UKC registration, which could present different statistics), the Labrador Retriever has been the United States's most commonly registered breed of dog since 1991. However, even within parts of the United States, popularity varies; for example, in 2005 the most-registered breed in New York City was the Poodle; the Yorkshire Terrier was the second-most-registered breed in Houston but didn't even make the top ten in Honolulu. However, animal shelters in many parts of the United States report that the most-commonly available dog for adoption is the American Pit Bull Terrier or pit bull-type mixes, making up as much as 20% of dogs available for adoption, none of which would be registered with the AKC. Two decades ago, in 1983, the AKC's top two registered breeds were the American Cocker Spaniel and the Poodle.

In Britain, The Kennel Club reports that the most-registered breed from at least 1999 to 2005 was the Labrador Retriever. It rounds out the top three for 1999 to 2005 with the German Shepherd Dog, also popular in the States, and the English Cocker Spaniel, which is no longer even in the top ten in the States.

Intelligence and skills

Among dog lovers, dogs are generally valued for their intelligence, and both anecdotal evidence and scientific research suggest that dogs have a reasonably high intelligence. This intelligence is expressed differently with different breeds and individuals, however. For example, Border Collies are noted for their ability to learn commands, while other breeds may not be so motivated towards obedience, but instead show their cleverness in devising ways to steal food or escape from a yard. Dogs are descended from wolves, and are also pack animals, making them easier than other animals to train because dogs' instincts are to obey. But most dogs rarely have to deal with complex tasks and are unlikely to learn relatively complicated activities (such as opening doors) unaided. Some dogs (such as guide dogs for the visually impared) are specially trained to recognize and avoid dangerous situations.

Physical characteristics

File:DSC01405.JPG

Shiba Inus have a unique appearance that resembles foxes.

Some dogs, like this Weimaraner, have their predatory instincts suppressed in order to better assist human hunters.

Amazonian dogs, such as this one from Alto Amazonas, Peru are critical for indigenous peoples' hunting strategies, particularly in the rain forest.

This Australian Cattle Dog puppy, bred to herd livestock in the heat and harsh conditions of the bush, enjoys a bone.

See also: Dog health

Modern dog breeds show more variation in size, appearance, and behavior than any other domestic animal. Within the range of extremes, dogs generally share attributes with their wild ancestors, the wolves. Dogs are predators and scavengers, possessing sharp teeth and strong jaws for attacking, holding, and tearing their food. Although selective breeding has changed the appearance of many breeds, all dogs retain basic traits from their distant ancestors. Like many other predatory mammals, the dog has powerful muscles, fused wristbones, a cardiovascular system that supports both sprinting and endurance, and teeth for catching and tearing. Compared to the bone structure of the human foot, dogs technically walk on their toes.

Sight

Dogs were thought to be dichromats and thus, by human standards, color blind. New research is now being explored that suggests that dogs may actually see some color, but not to the extent that humans do; color may serve as a subliminal signal helping to distinguish overlapping objects from each other, rather than a distinct feature that the dog can directly determine. It has also been suggested that dogs see in varieties of purple/violet and yellow shades. Because the lenses of dogs' eyes are flatter than humans', they cannot see as much detail; on the other hand, their eyes are more sensitive to light and motion than humans' eyes. Some breeds, particularly the best sighthounds, have a field of vision up to 270° (compared to 180° for humans), although broad-headed breeds with their eyes set forward have a much narrower field of vision, as low as 180°.

Hearing

This Collie/Saluki angles her ears to find the source of a sound.

Dogs detect sounds as low as the 16 to 20Hz frequency range (compared to 20 to 70 Hz for humans) and as high as 70 kHz to 100 kHz (compared to 13 to 20 kHz for humans), and in addition have a degree of ear mobility that helps them to rapidly pinpoint the exact location of a sound. Eighteen or more muscles can tilt, rotate and raise or lower a dog's ear. Additionally, a dog can identify a sound's location much faster than a human can, as well as hear sounds up to four times the distance that humans are able to. Those with more natural ear shapes, like those of wild canids like the fox, generally hear better than those with the floppier ears of many domesticated species.

Smell

Dogs have nearly 220 million smell-sensitive cells over an area about the size of a pocket handkerchief (compared to 5 million over an area the size of a postage stamp for humans). Some breeds have been selectively bred for excellence in detecting scents, even compared to their canine brethren. What information a dog actually detects when he is scenting is not perfectly understood; although once a matter of debate, it now seems to be well established that dogs can distinguish two different types of scents when trailing, an air scent from some person or thing that has recently passed by, as well as a ground scent that remains detectable for a much longer period. The characteristics and behavior of these two types of scent trail would seem, after some thought, to be quite different, the air scent being intermittent but perhaps less obscured by competing scents, whereas the ground scent would be relatively permanent with respect to careful and repetitive search by the dog, but would seem to be much more contaminated with other scents. In any event, it is established by those who train tracking dogs that it is impossible to teach the dog how to track any better than it does naturally; the object instead is to motivate it properly, and teach it to maintain focus on a single track and ignore any others that might otherwise seem of greater interest to an untrained dog. An intensive search for a scent, for instance searching a ship for contraband, can actually be very fatiguing for a dog, and the dog must be motivated to continue this hard work for a long period of time.

Dog Care

Diet

At present, there is some debate as to whether domestic dogs should be classified as omnivores or carnivores, by diet. The classification in the Order Carnivora does not necessarily mean that a dog's diet must be restricted to meat; unlike an obligate carnivore, such as the cat family with its shorter small intestine, a dog is dependent on neither meat-specific protein nor a very high level of protein in order to fulfill its basic dietary requirements. Dogs are able to healthily digest a variety of foods including vegetables and grains, and in fact can consume a large proportion of these in their diet. Wild canines not only eat available plants to obtain essential amino acids, but also obtain nutrients from vegetable matter from the stomach and intestinal contents of their herbivorous prey, which they usually consume. Domestic dogs can survive healthily on a reasonable and carefully designed vegetarian diet, particularly if eggs and milk products are included. Some sources suggest that a dog fed on a strict vegetarian diet may develop dilated cardiomyopathy since it lacks L-carnitine, however, maintaining a balanced diet is also a factor since L-carnitine is found naturally in many nuts, seeds, beans, vegetables, fruits and whole grains. In the wild, dogs can survive on a vegetarian diet when animal prey is not available. However it has been noted, both by observation of extremely stressful conditions such as the Iditarod race and by scientific studies of similar conditions, that high-protein (approximately 40%) diets including meat help prevent damage to muscle tissue. This level of protein corresponds to the percentage of protein found in the wild dog's diet when prey is abundant; higher levels of protein have not been proven to add a benefit.

Dogs often eat grass, sometimes avidly. This is a harmless activity, and although it may be important for health, the role of grass in the canine diet is unknown. Some people claim that grass might neutralize excess stomach acid, others suggest that eating grass prompts the dog to vomit, and so dogs eat grass to remove unwanted substances from their stomachs. Dogs do vomit more readily than humans, as part of their typical feeding behavior of gulping down food then regurgitating indigestible bones, fur, etc. This behavior is typical of pack feeding in the wild, where the most important thing is to get as much of the kill as possible before others consume it all. Individual domestic dogs, however, may be very "picky" eaters, in the absence of this evolutionary pressure.

Dangerous substances

Some foods commonly enjoyed by humans are dangerous to dogs, including chocolate (Theobromine poisoning), onions, grapes and raisins , some types of gum, and Macadamia nuts. Now that it is thought that the only dangerous substance in chocolate is the cocoa, this means that white chocolate can be used as a rare treat.

The acute danger from grapes and raisins has been uncovered only since about 2000, and made public slowly since then. At present the cause is not known, but one veterinarian believes it may be an acute auto-immune response to plant-borne viruses in the same manner as FIP in cats. Whatever the reason, since only small quantities are necessary to induce acute renal failure, dogs should not be fed grapes or raisins, and perhaps sultanas and currants should also be withheld.

Cooked bones should never be given to dogs, as the heat changes the chemical and physical properties so that they cannot be chewed properly, splintering into jagged shards, and resist digestion.

Human medications should not be given to a dog as a substitute for their regular medication as some can be especially toxic, especially paracetamol/acetaminophen (Tylenol). Alcoholic beverages pose much of the same hazards to dogs as they do to humans.

Dogs may also find some poisons attractive, including antifreeze, snail bait, insect bait, and rodent poisons. Antifreeze may be one of the most insidious of poisons to dogs because of its sweet taste and because a dog may walk upon or lie down upon a spill of it or its residue and then lick it off. Dogs must be kept strictly away from antifreeze and not allowed access to any place that has had a spill of it that has not been completely removed.

Plants such as caladium, dieffenbachia and philodendron will cause throat irritations that will burn the throat going down as well as coming up. Hops are particularly dangerous and even small quantities can lead to malignant hyperthermia.

Amaryllis, daffodil, english ivy, iris, and tulip (especially the bulbs) cause gastric irritation and sometimes central nervous system excitement followed by coma, and, in severe cases, even death.

Ingesting foxglove, lily of the valley, larkspur and oleander can be life threatening because the cardiovascular system is affected. Equally life threatening is the yew which affects the nervous system. If any of these plants are ingested, get the dog to a veterinarian immediately.

Many household cleaners such as ammonia, bleach, disinfectants, drain cleaner, soaps, detergents, and other cleaners, mothballs and matches are dangerous to dogs, as are cosmetics such as deodorants, hair coloring, nail polish and remover, home permanent lotion, and suntan lotion.

Reproduction (Dog Breeding)

In breeding and show circles, a male canine is referred to as a dog, while a female canine is called a bitch. 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.

Overpopulation

According to the Humane Society of the United States, 3-4 million dogs and cats are euthanized each year in the United States and many more are confined to cages in shelters because there are many more animals than there are homes. Spaying or neutering dogs helps keep overpopulation down.[1] Local humane societies, SPCA's and other animal protection organizations urge people to spay or neuter their pets and to adopt animals from shelters instead of purchasing them. Several notable public figures have spoken out against animal over population, including Bob Barker. On his game show, The Price is Right, Barker stressed the issue every episode by stating: "Help control the pet population. Have your pets spayed or neutered."

Dog health

Further information: Category:Dog health

Dogs are susceptible to various diseases, ailments, and poisons, some of which affect humans in the same way, others of which are unique to dogs. Dogs, like all mammals, are also susceptible to heat exhaustion when dealing with high levels of humidity and/or extreme temperatures.

Diseases

Infectious diseases commonly associated with dogs include rabies (hydrophobia), canine parvovirus, and canine distemper. Congenital diseases of dogs can include a wide range from hip dysplasia and medial patellar luxation to epilepsy and pulmonic stenosis. Canines can get just about anything a human can get (excluding many infections which are species specific) like hypothyroidism, cancer, dental disease, heart disease, etc.

Parasites: Treatment and Prevention

Common external parasites are various species of fleas, ticks, and mites. Internal parasites include hookworms, tapeworms, roundworms, and heartworms.

Common Breed-related disorders

Some breeds of dogs are also prone to certain genetic ailments, such as hip dysplasia, luxating patellas, cleft palate, blindness, or deafness. Dogs are also susceptible to the same ailments that humans are, including diabetes, epilepsy, cancer, and arthritis. Gastric torsion and bloat is a dangerous problem in some large-chested breeds.

Lifespan

The typical lifespan of dogs varies considerably by breed. For example, many giant dog breeds average only 7 or 8 years, while some small terrier breeds might live as long as 20 years.The average lifespan for mixed-breed and midsize dogs is about 13 to 14 years. The longest-lived dog with reliable documentation died at 29 in 1939. Although the lifespans of all living species are mostly uncontrollable, one can significantly extend a dog's life by feeding it the right kinds of foods, giving it exercise, visiting the vet frequently, caring for its special needs, and loving it.

Behavior: Obediance training and work

For details, see Category:Dog training and behavior.

Dogs are very social animals, but this varies on how a dog is treated by its owners and other people it may be around (examples: kindness and nonaggression, physical abuse, starvation, etc.) It is not uncommon for dogs to attack humans and other animals.

Ancestry and history of domestication

This ancient mosaic, likely Roman, shows a large dog with a collar hunting a lion.

Molecular systematics indicate that the domestic dog (Canis lupus familiaris) descends from one or more populations of wild wolves (Canis lupus). As reflected in the nomenclature, dogs are descended from the wolf and are able to interbreed with wolves.

The earliest dog fossils, two crania from Russia and a mandible from Germany, date from 13,000 to 17,000 years ago. Their likely ancestor is the large northern Holarctic wolf, Canis lupus lupus. Remains of smaller dogs from Mesolithic (Natufian) cave deposits in the Middle East, dated to around 12,000 years ago, have been interpreted as descendants of a lighter Southwest Asian wolf, Canis lupus arabs. Rock art and skeletal remains indicate that by 14,000 years ago, dogs were present from North Africa across Eurasia to North America. Dog burials at the Mesolithic cemetery of Svaerdborg in Denmark suggest that in ancient Europe dogs were valued companions.

Genetic analyses have so far yielded divergent results. Vilà, Savolainen, and colleagues (1997) concluded that dogs split off from wolves between 75,000 and 135,000 years ago, while a subsequent analysis by Savolainen et al. (2002) indicated a "common origin from a single gene pool for all dog populations" between 40,000 and 15,000 years ago in East Asia. Verginelli et al. (2005), however, suggest both sets of dates must be reevaluated in light of recent findings showing that poorly calibrated molecular clocks have systematically overestimated the age of geologically recent events. On balance, and in agreement with the archaeological evidence, 15,000 years ago is the most likely time for the wolf-dog divergence.

Verginelli examined ancient DNA evidence from five prehistoric Italian canids carbon-dated to between 15,000 and 3,000 years old, 341 wolves from several populations worldwide, and 547 purebred dogs. Their results indicate multiple independent origins of dogs and/or of frequent interbreeding between early proto-dogs and wolves throughout a vast geographic range. The detailed history remains unexplored and until further evidence is available, the following section on wolf ancestors must be considered purely speculative.

Wolf ancestors

Although all wolves belong to the species Canis lupus, there are (or were) many subspecies that had developed a distinctive appearance, social structure, and other traits. For example, the Japanese Wolf and the Eastern Timber Wolf possess different distinctive coloration, hunting and social structures. The Indian Wolf is thought to have contributed to the development of more breeds of dogs than other subspecies. Many of today's wild dogs, such as the dingo and the pariah dogs, are descended from this wolf.

The Indian Wolf is also thought to have bred with descendants of the European wolf to create the Mastiffs and eventually leading to the development of such diverse breeds as the Pug, the Saint Bernard, and the Bloodhound. The Tibetan Mastiff is an example of an ancient breed.

The European wolf, in turn, may have contributed many of its attributes to the Spitz dog types, most terriers, and many of today's sheepdogs. The Chinese wolf is probably ancestor to the Pekingese and toy spaniels, although it is also probable that descendants of the Chinese and European wolves encountered each other over the millennia, contributing to many of the oriental toy breeds.

The Eastern Timber Wolf is a direct ancestor to most, if not all, of the North American northern sled dog types. This interbreeding still occurs with dogs living in the Arctic region, where the attributes of the wolf that enable survival in a hostile environment are valued by humans. Additionally, unintentional crossbreeding occurs simply because dogs and wolves live in the same environment. The general reproductive isolation which is required to define dogs and wolves as separate species is purely a result of lack of opportunity, stemming from a general mutual unfamiliarity, suspicion, mistrust, and fear.

The phenotypic characteristics that distinguish a wolf from a dog are tenuous. Wolves typically have a "brush tail" and erect ears. While some dog breeds possess one of these characteristics, they rarely possess both.

Speed of domestication

Current research indicates that domestication, or the attributes of a domesticated animal, can occur much more quickly than previously believed. Domestication of a wild dog may occur within one or two human generations with deliberate selective breeding. It is also now generally believed that initial domestication was through mutual desire. Wild canines who scavenged around human habitations received more food than their more skittish or fearful counterparts. Canines who attacked people or their children were likely killed or driven away, while those more friendly animals survived. Canines would have been beneficial by chasing away other vermin or scavengers. With their sharp senses, they would also be valuable as an alarm against marauding predators. The relationship is theorized to have developed in this way.

Dog meat for human consumption

Main article: Dog meat

In a number of countries around the world, apart from being kept as pets, certain breeds of dogs are slaughtered as a source of meat and specifically raised on farms for that purpose. In countries where dogs are particularly popular as household pets, the use of dogs as a source of food is often considered a taboo and abhorrent cultural practice, although there are exceptions such as Vietnam where dogs are popular as pets and as meat.Template:Fact

Dog Abuse

Cruelty to dogs refers to treatment which causes unacceptable suffering or harm. What qualifies as unacceptable suffering varies depending on the country and its culture.

Famous dogs

The long shared history of dogs and humans has resulted in many individual dogs achieving fame or notoriety, and many fictional dogs have been created for literature, cinema, and elsewhere.

See also

• Puppy
• Dog communication
• Dog licence
• Bark (dog)
• List of dog breeds
• Dog attack

Further reading

• Abrantes, Roger (1999). Dogs Home Alone. Wakan Tanka, 46 pages. ISBN 0-9660484-2-3 (paperback).
• A&E Television Networks (1998). Big Dogs, Little Dogs: The companion volume to the A&E special presentation, A Lookout Book, GT Publishing. ISBN 1-57719-353-9 (hardcover).
• Alderton, David (1984). The Dog, Chartwell Books. ISBN 0-89009-786-0.
• Brewer, Douglas J. (2002) Dogs in Antiquity: Anubis to Cerberus: The Origins of the Domestic Dog, Aris & Phillips ISBN 0-85668-704-9
• Coppinger, Raymond and Lorna Coppinger (2002). Dogs: A New Understanding of Canine Origin, Behavior and Evolution, University of Chicago Press ISBN 0-226-11563-1
• Cunliffe, Juliette (2004). The Encyclopedia of Dog Breeds. Parragon Publishing. ISBN 0-7525-8276-3.
• Derr, Mark (2004). Dog's Best Friend: Annals of the Dog-Human Relationship. University of Chicago Press. ISBN 0-226-14280-9
• Donaldson, Jean (1997). The Culture Clash. James & Kenneth Publishers. ISBN 1-888047-05-4 (paperback).
• Fogle, Bruce, DVM (2000). The New Encyclopedia of the Dog. Doring Kindersley (DK). ISBN 0-7894-6130-7.
• Grenier, Roger (2000). The Difficulty of Being a Dog. University of Chicago Press. ISBN 0-226-30828-6
• Milani, Myrna M. (1986). The Body Language and Emotion of Dogs: A practical guide to the Physical and Behavioral Displays Owners and Dogs Exchange and How to Use Them to Create a Lasting Bond, William Morrow, 283 pages. ISBN 0-688-12841-6 (trade paperback).
• Pfaffenberger, Clare (1971). New Knowledge of Dog Behavior. Wiley, ISBN 0-87605-704-0 (hardcover); Dogwise Publications, 2001, 208 pages, ISBN 1-929242-04-2 (paperback).
• Savolainen, P. et al. (2002). Genetic Evidence for an East Asian Origin of Domestic Dogs. Science 298. 5598: 1610–1613.
• Shook, Larry (1995). "Breeders Can Hazardous to Health", The Puppy Report: How to Select a Healthy, Happy Dog, Chapter Two, pp. 13–34. Ballantine, 130 pages, ISBN 0-345-38439-3 (mass market paperback); Globe Pequot, 1992, ISBN 1-55821-140-3 (hardcover; this is much cheaper should you buy).
• Shook, Larry (1995). The Puppy Report: How to Select a Healthy, Happy Dog, Chapter Four, "Hereditary Problems in Purebred Dogs", pp. 57–72. Ballantine, 130 pages, ISBN 0-345-38439-3 (mass market paperback); Globe Pequot, 1992, ISBN 1-55821-140-3 (hardcover; this is much cheaper should you buy).
• Thomas, Elizabeth Marshall (1993). The Hidden Life of Dogs (hardcover), A Peter Davison Book, Houghton Mifflin. ISBN 0-395-66958-8.
• Verginelli, F. et al. (2005). Mitochondrial DNA from Prehistoric Canids Highlights Relationships Between Dogs and South-East European Wolves. Mol. Biol. Evol. 22: 2541–2551.
• Vilà, C. et al. (1997). Multiple and ancient origins of the domestic dog. Science 276:1687–1689. (Also "Multiple and Ancient Origins of the Domestic Dog")
• Small animal internal medicine, RW Nelson, Couto page 107

External links

• American Kennel Club
• Australian National Kennel Club
• Canadian Kennel Club
• Fédération Cynologique Internationale (FCI) - World Canine Organisation
• FCI International breed standards
• The Kennel Club (UK)
• New Zealand Kennel Club