Dog/Citable Version

Domestic dog
Pair of very different dogs ex.Gr.Dane and Chiuaua two breeds of the domestic dog Pair of very different dogs ex.Gr.Dane and Chiuaua two breeds of the 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. Bred from selected wolves thousands of years ago, this species is commonly known as "man's best friend". In communities throughout the world, dogs can be found associated with humans, although certainly not always as an intimate part of the household! Their status ranges all the way from a form of food to that of a cherished companion. The reason people whose culture rejects dogs often still tolerate them may be the same as the reason for the affection given by people whose culture accepts them: dogs act in ways that humans relate to and sympathize with, even if the people are disinclined to be particularly friendly. reference: (Stephen Budiansky, The Truth about Dogs: An Inquiry into Ancestry Social Conventions Mental Habits Moral Fiber Canis familiaris. 2001 ref: ISBN: 014100228X). Dogs and humans can communicate. On a basic level, we correctly interpret the dog's instinctive body language, and the dog, in turn, has an inate ability to respond appropriately to human body language and voice. Beyond the basics, people can be educated to manage their dogs and dogs can be trained to be more responsive to people. (see Obedience Training section below).

The domestic life of dogs

Many dog owners view their pets as full-fledged family members, probably because most dogs are able to act the part. As best as we can tell, that ability stems 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 as it grows up from birth. Dogs are like humans in being highly social animals. Although the instincts to behave in ways that ease interactions in the pack are inborn in all normal dogs, the right early experiences are critical if puppies are to grow up into companiable dogs. Those "right" experiences have everything to do with contact to people and other dogs, and they must occur early in the dog's life - before the puppy reaches XXX weeks of age.

puppies are rarely born alone

In fact, that particular period of time in a puppy's life is actually called the "critical period". When puppies are raised with plenty of close 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 mature, they generally learn to modify their behavior towards people, and treat their human companions more gently than their canine ones. Evidence shows that puppies who are raised without human nurturing do not fully adjust to interactions with owners once they have passed the critical period, no matter how much gentle attention is given them.

Female dogs (called bitches) ordinarily give birth to more than one puppy at a time (sometimes to more than a dozen!). The group of puppies born together is called a litter. In other words, being born in a litter is the natural lot of the dog, and that means most pups are raised in a social group. However, in situations where puppies are isolated from other dogs, and are raised alone, without experiences in canine society, they can fail to learn the give and take of normal puppies and often can never be successfully integrated into a group of dogs, once grown.

Any dog lover sees this face as friendly

Dogs fill a variety of roles in human society and are often trained as working dogs. In many countries, the most common (and perhaps most important) role of dogs is as companions.

Dog breeds

More than wrinkles make a Shar pei!

Perhaps more than any single species of mammal, dogs have an enormous range of normal height and lean 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!

Purebred dogs are breeds that have been selected to "breed true". That means that a good example of a pure bred (pedigreed) dog looks like its kind in physical appearance, and acts like its kind in temperment and certain behaviors. Generally, two purebred parents of the same breed will produce a litter of pups that will grow up to be like them, and fit the breed standard. The two Shar pei youngsters pictured at left show the famously loose and wrinkled skin of their breed, but there are many more characteristics that typify that breed.

Presently, over over 800 dog breeds are recognized by kennel clubs worldwide. Additional breeds exist that are not formally recognized by these organizations but are defined by fanciers by their appearance and behavior. It is such breeds that usually represent the more recent additions to the list of breeds recognized by kennel clubs. Every single dog is descended 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 isolation of dogs by geography (islands, mountain passes) has produced so-called natural breeds. Sometimes these natural breeds have also undergone selective breeding by humans who desired a certain type of working dog. Such ancient working breeds include the Greyhounds, the Mastiff and the Anatolian Shepherd.

Dog breeders sometimes select for a certain "look" in the breed. And so the pomeranian -insert beed standard and show picture, where as the Afghan Hound- describe standard show picture. Describe conformational shows and championships. Describe Breed registries and pedigrees.

Other breeders concentrate on inherited behavioral traits. The phrase "that dog don't hunt" comes from the rural United States and refers to a hunting dog that lacks the finer instincts of its breed. Explain. The Border collie exceptional herding abilities explain.

Behavior and skills

xxx

Among dog lovers, dogs are generally valued for their intelligence, and both anecdotal evidence and scientific research suggest that dogs do have a reasonably high intelligence. This intelligence is expressed differently in different breeds and individuals, however, along with sets of specific behaviors and talents that appear to be inherited.

For example, Border Collies are noted for their ability to learn complex commands on dry land, while Newfoundlands are known as powerful swimmers who can be trained to rescue the drowning. There are many breeds of retrievers, all of them share the propensity to not only chase that ball (or rabbit) but to bring it back. In the days when retrievers were all working dogs, only those animals that were excellent fetchers were bred, the puppy who might be beautiful and loving, but who remained totally uninterested in delivering the goods even when fully grown, was not propogated. One criticism lodged at breed registries such as the American Kennel Club is that success in the showring is based on conformation rather than on working ability. The AKC does sponsor field trials, however, for working dogs. If a retrieving retriever is what's wanted, the person shopping for a puppy might be advised to look for field championships in the puppy's pedigree, and not just awards for body type. On the other hand, a puppy born of even the great retrievers may not be inclined to retrieve.

Health, Care, and Breeding of Dogs

See also: Dog anatomy

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 bothpredators 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

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). It is fair to say that all dogs have a rich sensory experience in olfaction, as compared to ours. Some breeds have been selectively bred for excellence in detecting scents, over and above their canine brethren. Blood hounds

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 thrive 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.

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 especially 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, and seems to be somewhat related to size. 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.

Obedience Training

For details, see Category:Dog training and behavior.

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.

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."

Choosing a Dog

When it comes to dogs, "the best" is a fit between the animal and the owner. Beyond that, most advice in choosing a dog comes down to opinion. No one would advise picking out a sick dog, for example, and yet there are those dogs who have been nursed back to health by dedicated owners who swear that the special bond they have with the animal came about for just that reason. Of course, the usual outcome of choosing a sick animal is expensive and time-consuming at best, and, at worst, dangerous to the new owner's physical and emotional health. This section aims to examine the pros and cons of each choice of companion dog in detail. Hunters and herders, and others who are interested in choosing a proper working dog are best off consulting their peers rather than following any of the guidelines for pet dogs.

Where do you best find a dog?

Shelters and Rescue Groups

There are animal shelters and rescue groups in many regions of the world that have dogs and puppies available for adoption. Many people who have taken in these animals have greatly benefited, and there may be some truth to the notion that the rescued dog appreciates its good fortune and makes the best of all pets. There are certain apects of adopting from a shelter, however, that must be acknowledged as risks. Some shelters house dogs together in groups without first insuring that parasites and infectious diseases are not present. This can lead to adopting a dog or puupy who is in the early stages of an infestation or infection and not becoming aware of it until there is an obvious problem. Other shelters are very careful to avoid this, and the wise adopter checks on the policies carefully.

Socialization is another issue. Shelters (and breeders) who take pains to see that puppies are handled sufficiently to be socialized are the best places to find pups.

Many of the dogs and puppies that are in a shelter are there because of deficiencies in their previous owner's commitment to pet care and through no fault of their own. However, some dogs abandoned by neglectful owners will pose challenges to the adoptor. For example, dogs who are adults but have not had boundries of proper behavior imposed as they grew up can be very difficult to live with, particularly if they are large and active or have not been housebroken successfully. These dogs can make wonderful companions, but are best adopted by a person who is very experienced with dogs, and both able and willing to provide training.

Rescue groups that care for giant breeds like Great Danes and large, potentially aggressive dogs like Rottweilers often insist that obedience training is mandatory after any adoption. Rescue groups and breeders who are sophisticated about the larger and more aggressive dogs know that an owner who can take over the dominant role with such a dog is likely to do well them, but that the owner who gets shy, nervous, or giddy around a bounding dog weighing more than a hundred pounds is not a good choice for the dog". Placing such a dog with the wrong owner, from the point of view of the dog's welfare, is a poor decision. This is also true of breeds known for mischeviousness, and high energy. Placing a dog like a Jack Russell terrier, or a Border collie that thrives on exersize and the physical work of herding or ratting in a home where it will be confined indoors and spend long periods alone, for example, is generally a recipe for disaster. The same dog, in a different enviroment, might do well with the same owners.

Mixed breed dogs are in the majority at shelters, and offer all the same qualities as purebred dogs but one. In young mixed breed dogs and puppies (those that are still growing), the adult height and weight, and to some degree temperament, are not as predictable as in the pure bred dog. Often, this is of no concern, but for people who live in a small apartment who have other constraints, adopting an adult mixed breed dog or a pure bred puppy of a suitable breed is probably a better choice.

Pet Stores

Stores that sell puppies are usually a problematic source for a new dog. Unless the store has special arrangements with breeders, and is staffed by knowledgeable people who are trained in proper care, the other alternatives for finding a canine pet are considered more reliable.

What age is best?

Few of us can resist a puppy, but most of us are probably better off (on a practical level) with an older animal. Puppies require house breaking, and all go through a stage where chewing can be tremendously destructive. Managing puppies can be done by anyone with the time and inclination, and is certainly worth the effort but usually involves the sacrifice of more than one pair of shoes and assorted other household items. When a grown dog is available who is reliably housebroken, and who responds to the new owner, an equally strong bond can develop between them without that kind of loss and aggravation.

Male or Female?

Children and Dogs

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 include behavior.

Dog/Wolf Hybrids

In the wild, in areas where wolves still roam but the human population is also established, there is the occaisional inter-breeding of wolf and dog. Since a wolf pack is not likely to perceive a dog as anything but prey, and a domestic dog is unlikely to survive attack from even a lone wolf, this is not as common as the interbreeding of dogs and coyotes in similar circumstances. When dogs and coyotes do interbreed in the wild, the resulting hybrids often fail to thrive because they lack behavior features of the wild canine parent. For example, the domestic bitch ordinarily comes into heat twice or more times a year, where as the coyote female is fertile only once a year. The timing of the dog's estrus does not correspond to the local seasons in a way that is advantageous to a newborn litter, and so puppies born in the lean times of winter or drought are more likely to die. The instinct to only allow one mating pair of animals in the pack and the nurturing instincts of other pack members, including the males, is almost completely lost in the dog; and so hybids in the wild are less able to raise litters that survive.

In human society, there are people who selectively breed wolves and dogs as pets. Currently, in many areas, there are laws against keeping wolves in captivity, but there are regions where this is not the case. Often, the breeder of these hybrids works not from full wolves, but select a hybrid wolf/dog as one parent, and either another hybrid or a domestic dog as the other parent.

Molecular genetic research has shown that dogs appear to have been domesticated from wolves, but not from wolves in general - instead, selected individual ancient wolves were kept and interbred. There is speculation that among the wolves that harried these early human settlements or frequented ancient dumps, the particular individuals chosen for "adoption" by people were probably not only very young - but were exceptionally "nice". There is variation in behavioral characteristics in every large group of wolves, and it is not likely that the wild wolf pup who is at the extreme for aggressiveness, for example, would be tolerated in human society - once grown into an adult wolf, even if originally adopted in its infancy.

That has been the overall situation with wolf/dog hybrids. Breeders of these hybrids routinely remove the puppies from the mother by 2-3 weeks of age, and hand raise them, bottle feeding the puppies every few hours. Each puppy is allowed contact with at least one other puppy, but all puppies are kept isolated from adult dogs and wolves (including their own mother) because if they are allowed contact they usually will not bond to their human handlers. Even then, and even though these hybrid puppies are usually much less than 50% wolf, there is an extremely high rate of attacks on humans by adult hybrid wolf/dogs - including the members of the human family that raised them. Breeders of hybrid wolf/dogs counsel that these dogs must at all times be fenced off from any possible contact with strangers [2]. Fatal human attacks by hybrids are not rare, and often victimize children.

Notable Dogs

Many dogs have earned a level of fame

Barry: Buried in an island graveyard in the River Seine in Paris, lies this Newfoundland dog who patrolled the St. Bernard Pass in the Swiss Alps. The monument depicts him saving a child, and in fact he saved the lives of forty people, lost in snowstorms in those mountains.( ref <A Hero DogThe Watchman (1894-1906). Boston: Nov 8, 1900. Vol. 81, Iss. 45; p. 22 (1 page) >

Balto (1922 – March 14, 1933) was a lead sled dog in the 1925 serum run to Nome, in which diphtheria antitoxin was transported from Anchorage, Alaska to Nome by dog sled teams to combat an outbreak of the disease. Balto and his team became famous during coverage of the event, and went on to tour the country before being placed in a Cleveland Zoo.

1st seeing eye dog

See also

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

Further reading

• 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