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Dog
Conservation status
Domesticated
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Canidae
Genus: Canis
Species: C. lupus
Subspecies: C. l. familiaris
Trinomial name
Canis lupus familiaris
The dog (Canis lupus familiaris) is a domestic subspecies of the wolf, a
mammal of the Canidae family of the order Carnivora. The term encompasses
both feral and pet variants. It is also sometimes used to describe wild
canids of other subspecies or species. The domestic dog has been and
continues to be one of the most widely-kept working and companion animals in
human history, as well as being a food source in some cultures.
Over time, the dog has developed into hundreds of breeds with a great degree
of variation. For example, heights at the withers range from just a few
inches (such as the Chihuahua) to roughly three feet (such as the Irish
Wolfhound); colors vary from white through grays (usually called blue) to
black, and browns from light (tan) to dark ("red" or "chocolate") in a
tremendous variation of patterns; and coats can be anything from very short
to several centimeters long, from coarse hair to something akin to wool,
straight or curly, or smooth.
Overview
Origins
Some research appears to show that dogs were domesticated from wolves as
recently as 15,000 years ago,[1] or perhaps as early as 100,000 years ago
based upon recent genetic, fossil and DNA evidence.[2] Other research
suggests that dogs have only been domesticated for a much shorter amount of
time and were domesticated from populations of wild dogs, which had
previously diverged from wolves.[3][4]
New evidence suggests that dogs were first domesticated in East Asia,
possibly China,[5] and the first peoples to enter North America took dogs
with them from Asia. Genetic research has identified 14 ancient dog breeds,
with the oldest being the Chow Chow, Shar Pei, Akita Inu, Shiba Inu and
Basenji. Because many of the 14 breeds are associated with China and Japan,
the theory that the dog originated in Asia seems to be likely.[5]
As humans migrated around the planet a variety of dog forms migrated with
them. The agricultural revolution and subsequent urban revolution led to an
increase in the dog population and a demand for specialization. These
circumstances would provide the opportunity for selective breeding to create
specialized working dogs and pets.
Human relationships
Dogs are highly social animals due to selective breeding. This can account
for their trainability, playfulness, and ability to fit into human
households and social situations. This similarity has earned dogs a unique
position in the realm of interspecies relationships.
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, leading many dog owners to view their pets as full-fledged
family members. Conversely, dogs seem to view their human companions as
members of their pack, and make few, if any, distinctions between their
owners and fellow dogs. 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 and worked with humans in so many roles that their loyalty
has earned them the unique sobriquet "man's best friend".[6] However, some
cultures consider dogs to be unclean. In some parts of the world, dogs are
raised as livestock to produce dog meat for human consumption. In many
places, consumption of dog meat is discouraged by social convention or
cultural taboo.
Terminology
The English word dog, in common usage, refers to the domestic pet dog, Canis
lupus familiaris. The species was originally classified as Canis familiaris
by Linnaeus in 1758. In 1993, dogs were reclassified as a subspecies of the
gray wolf, Canis lupus, by the Smithsonian Institution and the American
Society of Mammalogists. "Dog" is sometimes used to refer collectively to
any mammal belonging to the family Canidae (as in "the dog family"), such as
wolves, foxes, and coyotes. Some members of the family have "dog" in their
common names, such as the African Wild Dog. The constellations Canes
Venatici, Canis Major and Canis Minor are named from the Latin word for
"dog," for their perceived resemblance to dogs.
The English word dog might derive from the Old English docga, a "powerful
breed of canine". The French dogue and Spanish dogo as in dogo Argentino are
borrowings from English. The English word hound is a cognate of German Hund,
Dutch hond, common Scandinavian hund, Icelandic hundur which, though
referring to a specific breed in English, means "dog" in general in the
other Germanic languages. Hound itself derives from the Proto-Indo-European
*kwon-, which is the direct root of the Greek κυων (kuōn) and the indirect
root of the Latin canis through the variant form *kani-.[7]
In breeding circles, a male canine is referred to as a dog, while a female
canine is called a bitch. The father of a litter is called the sire, and the
mother of a litter is called the dam. 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.
Intelligence
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. Being highly adaptable
animals themselves, dogs have learned to do many jobs as required by humans
over the generations. Dogs are employed in various roles across the globe,
proving invaluable assets in areas such as search-and-rescue; law
enforcement (including attack dogs, sniffer dogs and tracking dogs); guards
for livestock, people or property; herding; Arctic exploration sled-pullers;
guiding the blind and acting as a pair of ears for the deaf; assisting with
hunting, and a great many other roles which they may be trained to assume.
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 impaired) are specially trained to
recognize and avoid dangerous situations.
Evaluation of a dog's intelligence
The meaning of "intelligence" in general, not only in reference to dogs, is
hard to define. Some tests measure problem-solving abilities and others test
the ability to learn in comparison to others of the same age. Defining it
for dogs is just as difficult. It is likely that dogs do not have the
ability to premeditate an action to solve a problem. Some dogs may, however,
have more drive to keep trying various things until they accidentally reach
a solution and still others might have more ability to make the association
between the "accident" and the result.[citation needed]
For example, the ability to learn quickly could be a sign of intelligence.
Conversely it could be interpreted as a sign of blind subservience and a
desire to please. In contrast, some dogs who do not learn very quickly may
have other talents. An example is breeds that are not particularly
interested in pleasing their owners, such as Siberian Huskies. Huskies are
often fascinated with the myriad of possibilities for escaping from yards,
catching small animals, and often figuring out on their own numerous
inventive ways of doing both.
Assistance dogs are also required to be obedient at all times. This means
they must learn a tremendous number of commands, understand how to act in a
large variety of situations, and recognize threats to their human companion,
some of which they might never before have encountered.
Many owners of livestock guardian breeds believe that breeds like the Great
Pyrenees or the Kuvasz are not easily trained because their stubborn nature
prevents them from seeing the point of such commands as “sit” or “down”.
Hounds may also suffer from this type of ranking. In fact several rank in
the bottom tier of "The Intelligence of Dogs" list (such as Beagles,
Bloodhounds, and Basset Hounds).[citation needed] These dogs are bred to
have more of a "pack" mentality with other dogs and less reliance on a
master's direct commands. While they may not have the same kind of
intelligence as a Border Collie, they were not bred to learn and obey
commands quickly, but to think for themselves while trailing game.
Physical characteristics
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
Amazonian dogs, such as this one from Alto Amazonas, Peru are critical for
indigenous peoples' hunting strategies, particularly in the rain forest.
Amazonian dogs, such as this one from Alto Amazonas, Peru are critical for
indigenous peoples' hunting strategies, particularly in the rain forest.
Like most mammals, dogs are dichromats and have color vision equivalent to
red-green color blindness in humans.[8][9]
Different breeds of dogs have different eye shapes and dimensions, and they
also have different retina configurations.[10] Dogs with long noses have a
"visual streak" which runs across the width of the retina and gives them a
very wide field of excellent vision, while those with short noses have an
"area centralis" — a central patch with up to three times the density of
nerve endings as the visual streak — giving them detailed sight much more
like a human's.
Some breeds, particularly the best sighthounds, have a field of vision up to
270° (compared to 180° for humans), although broad-headed breeds with short
noses have a much narrower field of vision, as low as 180°.[8][9]
Hearing
Dogs detect sounds as low as the 16 to 20 Hz frequency range (compared to 20
to 70 Hz for humans) and above 45 kHz[11] (compared to 13 to 20 kHz for
humans),[9] 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.
Coat color
Domestic dogs often display the remnants of countershading, a common natural
camouflage pattern. The general theory of countershading is that an animal
that is lit from above will appear lighter on its upper half and darker on
its lower half where it will usually be in its own shade. This is a pattern
that predators can learn to watch for. A countershaded animal will have dark
coloring on its upper surfaces and light coloring below. This reduces the
general visibility of the animal. One reminder of this pattern is that many
breeds will have the occasional "blaze", stripe, or "star" of white fur on
their chest or undersides.
Sprint metabolism
Dogs can generate large amounts of energy for a short period of time. This
setup is useful for hunting and combat. An example of this is that almost
any dog, even one that is usually slow and lazy, can outsprint any human.
However, almost any human can catch up with any dog in a marathon run, or
other activity where endurance is needed.
A dog's heart and lungs are oversized relative to its body and its normal
everyday needs. A dog also has relatively more red blood cells than a human.
Most of the time the dog will keep the extra red blood cells stored in its
spleen. When the animal enters into a situation where its full metabolism is
required, such as play, catching game, or fighting other dogs, the extra
cells are released into the bloodstream. The "oversized" heart and lungs
will now be running at full capacity, and the animal will have an enhanced
ability to engage in aerobic activity. This activity will produce internal
heating. Dogs, being covered in fur, are limited in their ability to cool
down. After a short time the animal must either cease its athletic activity
or risk harming itself from overheating. One can easily observe this pattern
of intense activity followed by rest periods in puppies. During the rest
phase the spleen collects red blood cells and the animal may pant to cool
down.
Working, utility and assistance dogs
There are several types of working dogs:
* Assistance dogs which help the seeing and hearing-impaired. Others are
trained to help those with epilepsy and psychiatric disorders, by detecting
the onset of the condition so they can seek help. The typical assistance dog
is a sociable breed such as a Labrador Retriever.
* The detection dog, which is a dog trained to and works at using its senses
(almost always the sense of smell) to detect substances such as explosives
or illegal drugs.
* Guard dogs trained to protect property. These are commonly Doberman
Pinschers, German Shepherds and Rottweilers or mixes of these breeds.
* Herding dogs trained to protect livestock in the range against predators.
Sheepdogs are a common breed.
* Hunting dogs that search for and retrieve game. Pointers and retrievers
are typical hunting breeds.
* Police dogs, typically German Shepherds, are trained to assist law
enforcement officers.
* Rescue dogs that search for missing humans. The archetypal breeds are the
St. Bernard and the Bloodhound, although any dog with a good sense of smell
can be trained to perform this task.
* Therapy dogs, with friendly and gentle temperaments, trained to provide
comfort and affection to hospitalized and institutionalized patients.
* The war dog, used by the military to detect mines and enemy soldiers.
Show and sport (competition) dogs
Owners of dogs often enter them in competitions, whether show (breed
conformation shows) or sports, including dog racing & dog sledding. The
winners garner much prestige and prize money. These dogs are often bred
specifically for competition, which may not be entirely beneficial for the
breeds due to the magnification of hereditary defects.
* Dog agility is a sport in which dogs complete a timed obstacle course.
* Dogsled racing is a winter sport where a team of dogs, usually high
performance mixed breed dogs called Alaskan Huskies or Eurohounds, pull a
sled and driver (called a musher). The Iditarod Trail Sled Dog Race is
perhaps the most famous of these races. Dog sledding is an ancient form of
transportation and still a very effective way of moving freight across this
type of terrain.
* Dog racing, almost always Greyhounds, involves dogs racing at betting
tracks in a sport not unlike horseracing, reaching speeds of 40 miles per
hour. Elsewhere, Dachshunds are often raced, as a humorous sidelight in
charity events.
* Dog fighting and dog baiting are blood sports involving dogs. They are
illegal in most jurisdictions, but are still occasionally performed
underground.
* The show dog, purebreds entered in conformation dog shows and evaluated by
how closely they match the ideal characteristics of the breed. The
Westminster Kennel Club Dog Show is one of the most famous of this type of
competition.
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 dogs 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,[12] 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 Trail Sled Dog Race and by scientific studies of
similar conditions, that high-protein (approximately 40%) diets including
meat help prevent damage to muscle tissue. (This research is also true for
some other mammals.) 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 seem to confer no added benefit.
Dogs frequently eat grass, which is a harmless activity. Explanations
abound, but rationales such as that it neutralizes acid, or that eating
grass might make the dog vomit, so dogs eat grass to remove unwanted
substances from their stomachs, are at best educated guesses. Indeed, dogs
may eat grass when they have an upset stomach in order to cause vomiting.
The grass binds with the offending material. Then the grass acts as an
irritant and causes the dog to vomit, bringing up the poisonous material at
the same time..[13] 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.
Also, dogs eat grass, because it's a normal part of their diet. Wild canine
relatives of dogs — wolves and foxes — eat all of an animal when they catch
it. They end up, therefore, eating grasses and plants in the intestines of
these animals. Domestic dogs, eating prepared dog food, lack this part of
their diet and so they eat grass. Finally, dogs may appear to eat grass,
when they are just running the blades through their mouth to gather
information. Their sense of smell and taste may act together to detect if
other animals have walked through their area or urinated on the grass.[14]
Dangerous substances
Some foods commonly enjoyed by humans are dangerous to dogs, including
chocolate (Theobromine poisoning), onions, grapes and raisins,[15] some
types of gum, certain sweeteners[16] and Macadamia nuts. It is currently
believed that the only dangerous substance in chocolate is cocoa, meaning
that forms of chocolate without this ingredient, such as white chocolate may
become re-evaluated for their safety in future.
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.
Whatever the reason, since only small quantities are necessary to induce
acute renal failure, dogs should not be fed grapes or raisins, and sultanas
and currants should likely be withheld as well.
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, slug 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.[17]
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.
Zinc toxicity, mostly in the form of the ingestion of US pennies minted
after 1982, is commonly fatal in dogs where it causes a severe hemolytic
anemia.[18]
Dogs will occasionally eat their own feces or the feces of other species if
available, such as that of cats and horses. This is known as coprophagia,
and may be indicative of boredom or hunger, although there is no definitive
reason known. Owners of both cats and dogs may find that dogs treat the
catbox as a snack bar. Such behavior should be discouraged, as it could lead
to Toxoplasmosis. Dogs seem to have different preferences in relation to
eating feces. Some are attracted to the stools of deer, cows, or horses.
Others will eat the stools of other dogs. And a great many dogs are
attracted to cat droppings, possibly because cat foods are very high in
protein and the dogs are going after undigested nutrients.[19]
Reproduction
General
In domestic dogs, sexual maturity (puberty) begins to happen around age 6 to
12 months for both males and females, although this can be delayed until up
to two years old for some large breeds. Adolescence for most domestic dogs
is around 12 to 15 months, beyond which they are for the most part more
adult than puppy. As with other domesticated species, domestication has
selectively bred for higher libido and earlier and more frequent breeding
cycles in dogs, than in their wild ancestors.
Females
Females have a twice-yearly fertile period (technically every 7 months in
most breeds), known as 'seasons', during which her body prepares for
pregnancy, and at the peak she will come "into heat", her fertile period,
during which time she will be mentally and physically receptive to
copulation. A female is able to become pregnant on her first heat; this is
not normally considered advisable as she is mentally and physically still
young in other ways.
As with most domesticated species, one of the first and strongest effects
seen from selective breeding is selection for cooperation with the breeding
process as directed by humans. In domestic dogs, one of the behaviors that
is noted is the abolition of the pair bond seen in wild canines. The ability
of female domestic dog to come into estrus at any time of the year and
usually twice a year is also valued. The amount of time between cycles
varies greatly among different dogs, but a particular dog's cycle tends to
be consistent through her life. This is also called in season or in heat.
Conversely, undomesticated canine species experience estrus once a year,
typically in late winter.
Most female dogs come into season for the first time between 6 and 12
months, although some larger breeds delay until as late as 2 years. Like
most mammals, the age that a bitch first comes into season is mostly a
function of her current body weight as a proportion of her body weight when
fully mature. The different rates of maturation are responsible for the
menarche, not the chronological age. They then experience fertile seasons
biannually until old age. Female dogs do not experience menopause, although
their cycles will become irregular and fertility becomes unpredictable as
they become older. Dogs over around 7 or 8 years are usually considered no
longer appropriate for breeding, but can still remain fertile.
Copulation
When copulating, a male canine initially mounts the female from behind, as
with most tetrapods, a position known informally as doggy style. The female
will hold her tail to the side and allow this if receptive. If unreceptive
she may sit or lie down, snap, move away, or otherwise be uncooperative or
not allow mating. The male will often move about as he tries to get a good
purchase upon her, and whilst attempting penetration of his penis to the
female's vulva. At the time of penetration, the penis is not truly erect.
Rather, it is held rigid by a small bone, known as the baculum.
When the male achieves penetration, he will often hold tighter and thrust
faster. At this point the male's penis expands. Canine reproduction is
different from human sexual intercourse, because human males acquire an
erection prior to penetration. Canine males enter first, then swell and
become erect.
The male dog has a bulbus glandis, a spherical area of erectile tissue at
the base of the penis, which traps the penis inside the female's vagina
during copulation as it becomes engorged with blood. [1]
Once the penis is locked into the vagina by the bulbus glandis, the male
will usually lift a leg and swing it over the female's back while turning
around. The two stand with their hind ends touching and the penis locked
inside the vagina while ejaculation occurs, decreasing leakage of semen from
the vagina. After some time, typically 5 - 20 minutes (but sometimes
longer), the bulbus glandis disengorges, allowing the mates to separate.
Virgin dogs can become quite distressed at finding themselves unable to
separate during their first copulation, and may try to pull away or run. Dog
breeders' often suggest it is appropriate to help calm and settle the mating
dogs once this stage is reached, if they show anxiety.
Note that similar canine mounting behavior (sometimes with pelvic thrusting)
is also used by dominant canines of both sexes. Dominance mounting, with or
without thrusting, should not be confused with copulatory mounting, in which
the thrusting is short term until a "tie" is achieved.
Gestation and litters
Dogs bear their litters roughly 9 weeks after fertilization, although the
length of gestation can vary from 56 to 72 days. A general rule of thumb is
that a mammal will produce half as many offspring as the number of teats on
the mother. This rule is altered in domesticated animals since larger
litters are often favored for economic reasons and in dogs, particularly,
the great range of sizes and shapes plays a role in how many healthy puppies
a female can carry. An average litter consists of about six puppies, though
this number may vary widely based on the breed of dog. Toy dogs generally
produce from one to four puppies in each litter, while much larger breeds
may average as many as 12 pups in each litter. The number of puppies also
varies with the mother's age and health, the father's sperm count, the
timing of the breeding, and many other factors.
Some breeds have been developed to emphasize certain physical traits beyond
the point at which they can safely bear litters on their own. For example,
the Bulldog often requires artificial insemination and almost always
requires cesarean section for giving birth. Since a mother can provide
nutrients and care to only a limited number of offspring, humans must assist
in the care and feeding when the litter exceeds approximately eight puppies.
Spaying and neutering
Spaying (females only) and neutering (both genders but more usually males)
refers to the sterilization of animals, usually by removal of the male's
testicles or the female's ovaries and uterus, in order to eliminate the
ability to procreate, and reduce sex drive. Neutering has also been known to
reduce aggression in male dogs, but can occasionally increase aggression in
female dogs.[20]
Animal control agencies in the United States and the ASPCA advise that dogs
not intended for further breeding should be spayed or neutered so that they
do not have undesired puppies.[21] In some countries of Europe, spaying or
neutering of dogs is less common, and owners are usually instead advised to
keep their dogs on leash and under supervision to avoid unwanted matings;
drugs are used to prevent pregnancy and abort unwanted litters.[citation
needed]
Because of the overpopulation of dogs in some countries, puppies born to
strays or as the result of accidental breedings often end up being killed in
animal shelters. Spaying and neutering can also decrease the risk of
hormone-driven diseases such as mammary cancer, as well as undesired
hormone-driven behaviors. However, certain medical problems are more likely
after neutering, such as urinary incontinence in females[22] and prostate
cancer in males.[23] The hormonal changes involved with sterilization are
likely to somewhat change the animal's personality, however, and some object
to spaying and neutering as the sterilization could be carried out without
the excision of organs.
It is not essential for a female dog to either experience a heat cycle or
have puppies before spaying, and likewise, a male dog does not need the
experience of mating before neutering.
Female cats and dogs are seven times more likely to develop mammary tumors
if they are not spayed before their first heat cycle. [24] The high dietary
estrogen content of the average commercial pet food as well as the
estrogenic activity of topical pesticides[citation needed] may be
contributing factors in the development of mammary cancer, especially when
these exogenous sources are added to those normal estrogens produced by the
body. Dog food containing soybeans or soybean fractions have been found to
contain phytoestrogens in levels that could have biological effects when
ingested longterm.[25]
A female dog can become pregnant on her first heat cycle (which can take
place as early as six months), and should be kept away from intact male
dogs, including littermates, over the age of 4 months[citation needed].
Gender-preservative surgeries such as vasectomy and tubal ligation are
possible, but do not appear to be popular due to the continuation of
gender-specific behaviors and disease risks.
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.[26]
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 stresses the issue at the end of every episode,
saying: "Help control the pet population. Have your pets spayed or
neutered."
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.[27]
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.
Two serious medical conditions affecting dogs are pyometra, affecting
unspayed females of all types and ages, and bloat, which affects the larger
breeds or deep chested dogs. Both of these are acute conditions, and can
kill rapidly; owners of dogs which may be at risk should learn about such
conditions as part of good animal care.
Parasites
Common external parasites are various species of fleas, ticks, and mites.
Internal parasites include hookworms, tapeworms, roundworms, and heartworms.
See also CVBD (Canine Vector-Borne Diseases).
Common physical 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 and old age
The typical lifespan of dogs varies considerably by breed. For example, many
giant dog breeds (such as Great Danes) average only 7 or 8 years, while some
small terrier breeds, or toy breeds might live as long as 20 or above. The
average lifespan for mixed-breed and midsize dogs is about 13 to 14 years.
The longest-lived dog with reliable documentation was an Australian cattle
dog in Virginia, USA, which died in 1939 at the age of 29 years and 27 days.
The oldest currently living dog is from Canberra, Australia and is now 27
years old. 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 regular exercise, treating its diseases,
caring for its special needs and giving it love and comfort.
Behavior
Dogs are very social animals, but their personality and behavior vary with
breed as well as how they are treated by their owners and others who come in
contact with them. Physical abuse and starvation can produce very neurotic,
dangerous dogs, and even simply failing to socialize them properly may
entail maladaptive behaviors.[citation needed] It is not uncommon for dogs
to attack humans and other animals; however, this is usually because of lack
of care or improper upbringing by its owner.
Laughter in dogs
Laughter might not be confined or unique to humans, despite Aristotle's
observation that "only the human animal laughs". The differences between
chimpanzee and human laughter may be the result of adaptations that have
evolved to enable human speech. However, some behavioral psychologists argue
that self-awareness of one's situation, or the ability to identify with
somebody else's predicament, are prerequisites for laughter, so animals are
not really laughing in the same way that humans do.
The dog-laugh sounds similar to a normal pant. However by analyzing the pant
using a spectrograph, this pant varies with bursts of frequencies, resulting
in a laugh. When this recorded dog-laugh vocalization is played to dogs in a
shelter setting, it can initiate play, promote pro-social behavior, and
decrease stress levels. In a study by Simonet, Versteeg, and Storie, one
hundred and twenty subject dogs residing in a mid-size county animal shelter
were observed. Dogs ranging from 4 months to 10 years of age were compared
with and without exposure to a dog-laugh recording. The stress behaviors
measured included panting, growling, salivating, pacing, barking, cowering,
lunging, play-bows, sitting, orienting and lying down. The study resulted in
positive findings. Exposure to the dog laughing recording resulted in the
following: significantly reduced stress behaviors, increased tail wagging
and the display of a play-face when playing was initiated, and more frequent
pro-social behavior such as approaching and lip licking. This research
suggests exposure to dog-laugh vocalizations can calm and possibly increase
shelter adoptions. (Simonet, Versteeg, & Storie 2005) A dog laughter sample:
Simonet 2005.
Ancestry and history of domestication
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 relationship between human and canine has deep roots. Wolf remains have
been found in association with hominid remains dating from 400,000 years
ago. Converging archaeological and genetic evidence indicate a time of
domestication in the late Upper Paleolithic close to the
Pleistocene/Holocene boundary, between 17,000 and 14,000 years ago. Fossil
bone morphologies and genetic analysis of current and ancient dog and wolf
populations have not yet been able to conclusively determine whether all
dogs descend from a single domestication event, or whether dogs were
domesticated independently in more than one location. Domesticated dogs may
have interbred with local populations of wild wolves on several occasions
(so-called introgression).
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 origin of the dog is so ancient and so worldwide that many
varieties of wolf played a part in it. It is wrong to say that dogs
descended from modern wolves. They descended from ancestral wolves, and this
difference must always be kept in mind. Ancestral wolves of many varieties
existed all over the world. Humans are of a tropical origin, and it was
there that the domestication of dogs from wolves first took place[citation
needed]. It follows then, that the first wolves to be domesticated were the
warm-climate, short-haired varieties that gave rise to many of our dog
breeds, with the long-haired, northern wolves giving rise to our northern
breeds when humans reached these latitudes.[citation needed]
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.
Rate of domestication
Current research indicates that domestication, or the attributes of a
domesticated animal, can occur much more quickly,[28] [not in citation
given] 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.
A 2007 Animal Planet documentary discussed a 1900-1920 domestication
experiment in Russia that led to rapid unusual changes in the coats of
foxes.
Dog meat for human consumption
In some countries, certain dog breeds, apart from being kept as pets, are
raised on farms and slaughtered for consumption. In countries where dogs are
particularly popular as household pets, consumption of dogs is generally
taboo and considered an abhorrent cultural practice, but there are
exceptions, such as Vietnam, where dogs are popular as both pets and
meat.[29]
Although the Chinese were the first to domesticate the dog and keep them as
pets, dog meat has been a source of food in China from at least the time of
Confucius, and possibly even before. Ancient writings from the Zhou Dynasty
referred to the 'three beasts' (which were bred for food), including pig,
goat, and dog. Mencius, the philosopher, recommended dog as the tastiest of
all meats.
Dog abuse
Cruelty to dogs refers to treatment that causes unacceptable suffering or
harm. What qualifies as unacceptable suffering varies among countries and
cultures. Cruelty can be passive, typified by simple neglect, or active,
with malicious intent.[30]
Signs of dog abuse
Signs of dog abuse include:
* Unusually frightened, fearful or subdued
* Fractures
* Bruising
* Eye injuries
* Scalds and burns
* Signs of malnutrition
* Significant matting or other poor grooming indicators
* Ignored health problems
* Injury history incompatible with injury or owner refusing to comment on
how injury occurred
* Owner showing lack of concern for animal’s injuries
* Owner exhibiting Munchausen’s Syndrome by Proxy (MSP)
Famous dogs & dog sayings
In the long shared history of dogs and humans, there have been many famous,
and notorious, dogs, and many fictional dogs have been featured in
literature, cinema, and other media.
"I've seen a look in dogs' eyes, a quickly vanishing look of amazed
contempt, and I am convinced that basically dogs think humans are nuts." -
John Steinbeck[31]
"When a dog wags her tail and barks at the same time, how do you know which
end to believe?" - Robin Williams in "Man of the Year"
Dog breeds
There are numerous dog breeds, with over 800 being recognized by various
kennel clubs worldwide. As all dog breeds have been derived from mixed-breed
dog populations, the term "purebred" has meaning only with respect to a
certain number of generations. Many dogs, especially outside the United
States of America and Western Europe, belong to no recognized breed.
A few basic breed types have evolved gradually during the domesticated dog's
relationship with humans over the last 10,000 or more years, but most modern
breeds are of relatively recent derivation. Many of these are the product of
a deliberate process of artificial selection. Because of this, some breeds
are highly specialized, and there is extraordinary morphological diversity
across different breeds. Despite these differences, dogs are able to
distinguish dogs from other kinds of animal.
The definition of a dog breed is a matter of some controversy. Depending on
the size of the original founding population, closed gene pool breeds can
have problems with inbreeding, specifically due to founder effect. Dog
breeders are increasingly aware of the importance of population genetics and
of maintaining diverse gene pools. Health testing and new DNA tests can help
avoid problems, by providing a replacement for natural selection. Without
selection, inbreeding and closed gene pools can increase the risk of severe
health or behavioral problems. Some organizations define a breed more
loosely, such that an individual may be considered of one breed as long as
75% of its parentage is of that breed. These considerations affect both pets
and the show dogs entered in dog shows. Even prize-winning purebred dogs
sometimes possess crippling genetic defects due to founder effect or
inbreeding.[32] These problems are not limited to purebred dogs and can
affect mixed-breed populations.[33] The behavior and appearance of a dog of
a particular breed can be predicted fairly accurately, while mixed-breed
dogs show a broader range of innovative appearance and behavior.
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.
Neoteny in the rapid evolution of diverse dog breeds
It has been suggested that this article or section be merged into Origin of
the domestic dog. (Discuss)
This rapid evolution of dogs from wolves is an example of neoteny or
paedomorphism. As with many species, the young wolves are more social and
less dominant than adults; therefore, the selection for these
characteristics, whether deliberate or inadvertent, is more likely to result
in a simple retention of juvenile characteristics into adulthood than to
generate a complex of independent new changes in behavior. (This is true of
many domesticated animals, including humans themselves, who have many
characteristics similar to young bonobos.) This paedomorphic selection
naturally results in a retention of juvenile physical characteristics as
well. Compared to wolves, many adult dog breeds retain such juvenile
characteristics as soft fuzzy fur, round torsos, large heads and eyes, ears
that hang down rather than stand erect, etc.; characteristics which are
shared by most juvenile mammals, and therefore generally elicit some degree
of protective and nurturing behavior cross-species from most adult mammals,
including humans, who term such characteristics "cute" or "appealing".
The example of canine neoteny goes even further, in that the various breeds
are differently neotenized according to the type of behavior that was
selected.Stephen Jay Gould; Eight Little Piggies: Reflections in Natural
History; W. W. Norton & Company, 1993; pp. 394
* Livestock guardian dogs exhibit the controlled characteristics of hunting
dogs. Members of this group, such as Border Collies, Belgian Malinois and
German Shepherds use tactics of hunter and prey to intimidate and keep
control of herds and flocks. Their natural instinct to bring down an animal
under their charge is muted by training. Other members of the group,
including Welsh Corgis, Canaan dogs, and Cattle dogs herd with a more
aggressive demeanor and make use of body design to elude the defences of
their charges.
* Gun dog breeds used in hunting—that is, pointers, setters, spaniels, and
retrievers—have an intermediate degree of paedomorphism; they are at the
point where they share in the pack's hunting behavior, but are still in a
junior role, not participating in the actual attack. They identify potential
prey and freeze into immobility, for instance, but refrain from then
stalking the prey as an adult predator would do next; this results in the
"pointing" behavior for which such dogs are bred. Similarly, they seize dead
or wounded prey and bring it back to the "pack", even though they did not
attack it themselves, that is, "retrieving" behavior. Their physical
characteristics are closer to that of the mature wild canine than the
sheepdog breeds, but they typically do not have erect ears, etc.
* Scenthounds maintain an intermediate body type and behavior pattern that
causes them to actually pursue prey by tracking their scent, but tend to
refrain from actual individual attacks in favor of vocally summoning the
pack leaders (in this case, humans) to do the job. They often have a
characteristic vocalization called a bay. Some examples are the Beagle,
Bloodhound, Basset Hound, Coonhound, Dachshund, Fox Hound, Otter Hound, and
Harrier.
* Sighthounds, who pursue and attack perceived prey on sight, maintain the
mature canine size and some features, such as narrow chest and lean bodies,
but have largely lost the erect ears of the wolf and thick double layered
coats. Some examples are the Afghan, Borzoi, Saluki, Sloughi, Pharaoh Hound,
Azawakh, Whippet, and Greyhound.
* Mastiff-types are large dogs, both tall and massive with barrel-like
chests, large bones, and thick skulls. They have traditionally been bred for
war, protection, and guardian work.
* Bulldog-types are medium sized dogs bred for combat against both wild and
domesticated animals. These dogs have a massive, square skull and large
bones with an extremely muscular build and broad shoulders.
* Terriers similarly have adult aggressive behavior, famously coupled with a
lack of juvenile submission, and display correspondingly adult physical
features such as erect ears, although many breeds have also been selected
for size and sometimes dwarfed legs to enable them to pursue prey in their
burrows.
The least paedomorphic behavior pattern may be that of the basenji, bred in
Africa to hunt alongside humans almost on a peer basis; this breed is often
described as highly independent, neither needing nor appreciating a great
deal of human attention or nurturing, often described as "catlike" in its
behavior. It too has the body plan of an adult canine predator. Of course,
dogs in general possess a significant ability to modify their behavior
according to experience, including adapting to the behavior of their "pack
leaders"—again, humans. This allows them to be trained to behave in a way
that is not specifically the most natural to their breed; nevertheless, the
accumulated experience of thousands of years shows that some combinations of
nature and nurture are quite daunting, for instance, training whippets to
guard flocks of sheep.
Breed popularity
Breed popularity varies widely over time[34] and in different parts of the
world and different segments of the population. Counting by American Kennel
Club (AKC) registration (not by licensing registration or by United Kennel
Club (UKC) registration, which could present different statistics), the
Labrador Retriever has been the United States's most commonly registered
breed of dog since 1991. [35] 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 while the Yorkshire Terrier was the
second-most-registered breed in Houston. [36] 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.[37] Two decades ago, in 1983, the AKC's top two
registered breeds were the American Cocker Spaniel and the Poodle.[38]
In 2006 a British dog journal published an exhaustive research paper which
pooled together quantifiable dog breed facts such as average lifespan, cost
of maintenance, insurance claims made, known behavioural faults and various
other criteria in order to arrive at the conclusion that the Staffordshire
Bull Terrier is the 'highest scoring' dog breed in terms of desirable and
established pedigree dog breed traits. [39]
In the United Kingdom, 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[40] , which is no longer even in
the top ten in the States. In the United Kindom a national dog adoption and
rescue service indicates that the most common breed appearing in shelters is
the Greyhound followed by the Staffordshire Bull Terrier. [41]
In religion
Islam
Muhammad, the prophet of Islam expressed that the company of dogs voids a
portion of a Muslim's good deeds.[42]
Islamic law considers dogs to be unclean, but this is not derived from the
Qur'an.[43] Muhammad is said to have given an order to kill all the dogs in
Medina because the archangel Gabriel does not enter a house in which there
is a dog. This hadith is however the "occasion for revelation" of verse 5:4
which indicates the importance of the hunting dog.[43] David Gordon White
states that Islam, like Judaism and Christianity, usually cast the dog in a
negative light by emphasizing its impurity and often identify dogs as demons
or minions of the Devil. The story of the Seven Sleepers of Ephesus in the
Qur'an (and also role of the dog in early Christianity) are the striking
exceptions.[44]. Muhammad didn't like dogs (and most Muslims do not have
dogs as pets). According to one tradition attributed to Muhammad, black dogs
are evil, or even devils, in animal form.[45]
Muhammad commanded Muslims not trade or deal in dogs.[46]
Muhammad said that dogs and donkeys, if they pass in front of men in prayer,
void or nullify that prayer.[47]
Khaled Abou El Fadl, a professor of law at the UCLA School of Law where he
teaches Islamic law, has written on the subject.[48][49]
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42. ^ Malik Ibn Anas, al-Muwatta’ (Egypt: al-Babi al-Halabi, n.d.), 2:969.
Reported in El Fadl
43. ^ a b Bruce Fudge, Encyclopedia of the Quran, Dog
44. ^ David Gordon White, Encyclopedia of religion, Dog, p.2393
45. ^ Dr. Khaled Abou El Fadl (2004). Dogs in the Islamic Tradition and
Nature. Dogs in the Islamic Tradition and Nature, quoting Encyclopedia of
Religion and Nature. Retrieved on 2007-05-11.
46. ^ Ahmad Ibn Shu‘ayb al-Nisa’i, Sunan al-Nisa’i (Beirut: Dar al-Kitab
al-‘Arabi, n.d.), 7: 309 (The commentaries by al-Suyuti and al-Sanadi are in
the margins). Ibn Hajar al-‘Asqalani, Fath al-Bari, 4:426. All reported in
El Fadl.
47. ^ Al-Nawawi, Sahih Muslim, 3-4:450-1; Ahmad Ibn Hanbal, Musnad, 5:194,
197, 202, 208; Abu Bakr Ibn al-‘Arabi, ‘Aridat al-Ahwadhi bi Sharh Sahih al-Tirmidhi
(Beirut: Dar al-Kutub al-‘Ilmiyya, n.d.), 1:133. All reported in El-Fadl.
48. ^ Dr. Khaled Abou El Fadl. Chapter 80 of The Search for Beauty in Islam
The Lord of the Essence: A Fatwa on Dogs. www.scholarofthehouse.org.
Retrieved on 2007-05-14.
49. ^ Dr. Khaled Abou El Fadl. Dogs in the Islamic Tradition and Nature.
www.scholarofthehouse.org. Retrieved on 2007-05-14.
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.
* Small animal internal medicine, RW Nelson, Couto page 107
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