Cats and Dogs [3]

? Cat Conservation status: Domesticated
other images of cats
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Family: Felidae Genus: Felis Species: F. silvestris Subspecies: F. s. catus
Trinomial name
Felis silvestris catus (Linnaeus, 1758)

This article is about the domestic cat. For alternative meanings see cat (disambiguation).

The cat, also called the domestic cat or house cat, is a small feline carnivorous mammal of the subspecies Felis silvestris catus. Its most immediate, pre-domestication ancestor is the African wild cat, Felis silvestris lybica. The cat has been living in close association with humans for at least 3,500 years; the Ancient Egyptians routinely used cats to keep mice and other rodents away from their grain (and also believed that cats were sacred). The history of the domestic cat may stretch back even further, as 8,000-year-old bones of humans and cats were found buried together on the island of Cyprus^[3].

A group of cats is referred to as a clowder, while a male cat is called a tom, and a female is called a queen or quean. An immature cat is called a kitten (which is also an alternate name for young rats, rabbits, hedgehogs, beavers, and squirrels). A cat whose ancestry is formally registered is called a purebred cat, a pedigree cat, or a show cat (although not all show cats are pedigree or purebred). In strict terms, a purebred cat is one whose ancestry contains only individuals of the same breed. A pedigree cat is one whose ancestry is recorded, but may have ancestors of different breeds.

Purebreds are less than one percent of the total feline population; cats of mixed ancestry are referred to as domestic longhairs and domestic shorthairs or commonly as random-bred, moggies, mongrels, mutt-cats or alley cats. The ratio of pedigree/purebred cats to random-bred cats varies from country to country.

There are dozens of breeds of domestic cats, some hairless or tailless, and they exist in a variety of different colors including multicolored. They are skilled predators and have been known to hunt over one thousand different species for food. They are also intelligent animals: some are able to manipulate simple mechanisms such as lever-handled doors and flush toilets. They communicate by calling ("meow"/"miaou"), purring, hissing, and gesturing. Because the domestication of the cat is relatively recent, cats may also still live effectively in the wild, often forming small colonies. The cat's association with humans leads it to figure prominently in the mythology and legends of several cultures, including the ancient Egyptians, Vikings, and Chinese.

Characteristics

Physical

Cats typically weigh between 2.5 and 7 kg (5.5–16 lb); however, some breeds, such as the Maine Coon can exceed 11.3 kg (25 pounds). Some have been known to reach up to 23 kg (50 lb), due to overfeeding. This is very unhealthy for the cat, and should be prevented through exercise (playing) and diet, especially for cats living exclusively indoors.

In captivity, indoor cats typically live 15 to 20 years, though the oldest-known cat lived to age 36.^[4] Domestic cats tend to live longer if they are not permitted to go outdoors (reducing the risk of injury from fights or accidents) and if they are spayed or neutered. Spaying and neutering a cat also decreases the risk of testicular and ovarian cancer, and female cats spayed before their first heat or litter benefit from reduced risk of mammary cancer.^[5] Feral cats living in modern urban environments often live only two years, or less. Feral cats in maintained colonies can live much longer; the British Cat Action Trust reported a 19-year-old feral female. The oldest feral cat was Mark who was maintained by the British charity Cats Protection and who reached 26 years of age.

Thirty-two individual muscles in the ear allow for a manner of directional hearing; ^[6] the cat can move each ear independently of the other. Thus a cat can move its body in one direction and point its ears in quite another direction (such as pointing backward toward its owner). Most cats have straight ears pointing upward. Unlike dogs, flap-eared breeds are extremely rare. (Scottish Folds are one such exceptional genetic mutation.) When angry or frightened, a cat will lay its ears back, to accompany the growling or hissing sounds it makes. Cats conserve energy by sleeping more than most animals, especially as they grow older. Daily durations of sleep are various, usually 12–16 hours, with 13–14 being the average. Some cats can sleep as much as 20 hours in a 24-hour period. The term cat nap refers to the cat's ability to fall asleep for a brief period; someone who nods off for a few minutes is said to be "taking a cat nap".

A cat's temperament can vary depending on the breed and socialization. Shorter haired cats tend to be skinnier and more active, while cats with longer hair tend to be heavier and less active.

The normal body temperature of a cat is between 38 and 39 °C (101 and 102.2 °F).^[7] A cat is considered febrile if it has a temperature of 39.5 °C (103 °F) or greater, or hypothermic if less than 37.5 °C (100 °F). Comparatively, humans have a normal temperature of approximately 37 °C (97 to 100 °F). A domestic cat's normal heart rate ranges from 140 to 220 beats per minute, and is largely dependent on how excited the cat is. For a cat at rest, the average heart rate should be between 150 and 180 bpm, depending upon level of activity.

A popular belief holds that cats always land on their feet. They do usually, but not always. During a fall, a cat can reflexively twist its body and right itself using its acute sense of balance and flexibility. ^[8] It always rights itself in the same way, provided it has the time to do so during a fall. Certain breeds that don't have a tail are a notable exception, since a cat moves its tail and relies on conservation of angular momentum to set up for landing.

Cats, like dogs, are digitigrades: they walk directly on their toes, the bones of their feet making up the lower part of the visible leg. They are capable of walking very precisely, placing each hind paw directly in the print of the corresponding forepaw, minimising noise and visible tracks.

Senses

A close-up of a cat's eye.

Many zoologists believe that the feline is the most sensual of all mammals. While its smell and hearing may not be as keen as, say, those of a mouse, its highly advanced eyesight and superior (by human standards) aural (sound) and olfactory (smell) senses combine with highly evolved taste and touch receptors to make the cat arguably the most sensitive of any mammal. Measuring the senses of any animal can be difficult, because there is usually no explicit communication (e.g., reading aloud the letters of a Snellen chart) between the subject and the tester. However, testing indicates that a cat's vision is superior at night in comparison to humans, and inferior in daylight. Cats, like dogs, have a tapetum lucidum that reflects extra light to the retina. While this enhances the ability to see in low light, it appears to reduce net visual acuity, thus detracting when light is abundant. In very bright light, the slit-like iris closes very narrowly over the eye, reducing the amount of light on the sensitive retina, and improving depth of field. The tapetum and other mechanisms give the cat a minimum light detection threshold up to 7 times lower than that of humans. Variation in color of cats' eyes in flash photographs is largely due to the interaction of the flash with the tapetum.

Average cats have a visual field of view estimated at 200°, versus 180° in humans, with a binocular field (overlap in the images from each eye) narrower than that of humans. As with most predators, their eyes face forward, affording depth perception at the expense of field of view. Field of view is largely dependent upon the placement of the eyes, but may also be related to the eye's construction. Instead of the fovea which gives humans sharp central vision, cats have a central band known as the visual streak. Cats can apparently differentiate among colors, especially at close range, but without appreciable subtlety.

Cats have a third eyelid, the nictitating membrane, which is a thin cover that closes from the side and appears when the cat's eyelid opens. This membrane partially closes if the cat is sick; although in a sleepy, content cat this membrane is often visible. If a cat chronically shows the third eyelid, it should be taken to a veterinarian.

Humans and cats have a similar range of hearing on the low end of the scale, but cats can hear much higher-pitched sounds, even better than dogs. Cats can hear 2 octaves higher than humans, and one-half octave higher than dogs. When listening for something, a cat's ears will swivel in that direction; a cat's ear flaps (pinnae) can independently point backwards as well as forwards and sideways to pinpoint the source of the sound. Cats can judge within three inches (7.5 cm) the location of a sound being made one yard (approximately one meter) away.

A domestic cat's sense of smell is about 14 times stronger than a human's. Cats have twice as many smell-sensitive cells in their noses as people do, which means they can smell things we are not even aware of. Cats also have a scent organ in the roof of their mouths called the vomeronasal, or Jacobson's, organ. When a cat wrinkles its muzzle, lowers its chin, and lets its tongue hang a bit, it is opening the passage to the vomeronasal. This is called gaping. Gaping is the equivalent of the Flehmen response in other animals, such as dogs and horses.

Cats generally have about a dozen whiskers in four rows on each upper lip, a few on each cheek, tufts over the eyes and bristles on the chin. Whiskers may also be found on the cat's "elbows." The Sphynx (a nearly hairless breed) may have full length, short, or no whiskers at all.

Whiskers (technically called vibrissae) can aid with navigation and sensation. Whiskers may detect very small shifts in air currents, enabling a cat to know it is near obstructions without actually seeing them. The upper two rows of whiskers can move independently from the lower two rows for even more precise measuring.

It is thought that a cat may choose to rely on the whiskers in dim light where fully dilating the pupils would reduce its ability to focus on close objects. The whiskers also spread out roughly as wide as the cat's body making it able to judge if it can fit through an opening.

Whiskers are also an indication of the cat's attitude. Whiskers point forward when the cat is inquisitive and friendly, and lie flat on the face when the cat is being defensive or aggressive.

An oddity about cat's sense of taste is, according to National Geographic (December 8), cats can not taste sugary foods due to a faulty sweet receptor gene. Some scientists believe this is related to the cat's diet being naturally high in protein, though it is unclear whether it the cause or the result of it.

Communication

A cat vocalizing

The unique sound a small cat makes is written onomatopoeically as "meow" in American English; "meow" or "miaow" in British English; "miaou" or "miaw" in French; "miao" in Mandarin Chinese and Italian; "miau" in German, Spanish, Finnish, Lithuanian, Polish and Portuguese; "mjäu" in Estonian; "mowa'a" in Arabic; "nyaa" or "nyan" in Japanese; "meong" or "ngeong" in Bahasa Indonesia; "ngiau" in Malay; "yaong" or "nyaong" in Korean; and various ways in other languages. The sound of an increasingly annoyed cat is transcribed in James Joyce's Ulysses as "mkgnao", "mrkgnao" and "mrkrgnao" ^[9]. The cat's pronunciation of this call varies significantly depending on meaning. Usually cats call out to indicate pain, request human attention (to be fed or played with, for example), or as a greeting. Some cats are very vocal, and others rarely call out. Cats are capable of about 100 different vocalisations, compared to about 10 for dogs.

A kitten's call first starts out as a high-pitched squeak-like sound when very young, and then deepens over time. Some cats, however, do not exercise their voices a lot, so their call may remain similar to that of a kitten through adulthood.

Cats can also produce a purring noise that typically indicates that the cat is happy, but also can mean that it feels distressed. Cats purr among other cats—for example, when a mother meets her kittens. Until recently, there were many competing theories to explain how cats purr, including vibration of the cat's false vocal chords when inhaling and exhaling, the sound of blood hitting the aorta, vibration of the hyoid apparatus, or resonation directly in the lungs. Currently, though, it is believed that purring is a result of rhythmic impulses to the cat's larynx.

It is possible for a cat to call out and purr simultaneously, although this is typical only in very vocal cats. In addition to purring, happy cats may blink slowly or partially close their eyes to break any possible stares and communicate their ease in the situation. However, purring may also be a way for the cat to calm itself down. For example, cats have been known to purr when hurt.

Most cats growl or hiss when angered or in danger. Some may engage in nipping behavior or batting with their paws, either with claws extended or retracted. With cats who are improperly socialised and do not know their own strength, this can result in inadvertent damage to human skin. Cat scratches can easily become infected, and in extreme cases can result in cat scratch fever.

Cats are also known to make chirping noises when observing prey, or as a means of expressing interest in an object to nearby humans. When directed at out-of-reach prey, it is unknown whether this is a threatening sound, an expression of frustration, or an attempt to replicate a birdcall (or replicate the call of a bird's prey, for example a cicada). Since this feline expression often involves a mouth movement similar to the one they would use to kill their prey (their "killing bite"), they may be trying to practice this mouth movement in anticipation.

When passing solid waste, cats, like many types of predators, release from anal glands a small amount of liquid that scents their feces, to mark their territory. These scent-producing anal sacs are found in all predators; those of the skunk are used for self-defense, for example. During moments of excitement or other strong emotions, a cat's anal sac may discharge, releasing a foul-smelling brown liquid. Anal irritation, possibly shown by the cat rubbing its bottom on the floor and frequent licking of the area, can be a sign that the cat's anal sacs are not being emptied when waste passes ^[10]. Although this condition can be treated through the addition of a small amount of bran to each meal, it may require veterinary attention. Shorthair cats are more prone to this problem.

Cats will twitch the tips of their tails when hunting or angry, while larger twitching indicates displeasure. A tail held high is a sign of happiness, while half-raised shows less pleasure, and unhappiness is indicated with a tail held low. A scared cat may puff up its tail and the hair along its back to increase its apparent size. Touching noses is a friendly greeting for cats, while a lowered head is a sign of submission.

When cats are happy, they are known to paw their owners, or that on which they sit, with a kneading motion. Cats often use this action alongside purring to show contentment and affection for their owners. The action is often referred to as paddy-pawing, making muffins or treading paws. It is instinctive to cats, and they use it when they are young to stimulate the mother cat's nipple to release milk during nursing. Cats that are hand-raised by humans may lack this reflex.

Hunting and diet

Relative to size, domestic cats are very effective predators. They ambush and dispatch vertebrate prey using tactics similar to those of leopards and tigers by pouncing; they then deliver a lethal neck bite with their long canine teeth that severs the victim's spinal cord, or asphyxiate it by crushing the windpipe. They are one of the most graceful hunters on land with the blueprint to be lethal killers. From lions and leopards to cheetahs and jaguars, cats are very highly specialized with their own mode of attack.

The domestic cat can hunt and eat about one thousand species—many big cats will eat fewer than 100. Although, theoretically, big cats can kill most of these species as well, they often do not due to the relatively low nutritional content that smaller animals provide. An exception is the leopard, which commonly hunts rabbits and many other smaller animals.

A cat yawning, showing characteristic canine teeth.

Cats have highly specialized teeth and a digestive tract suitable to the digestion of meat. The premolar and first molar together compose the carnassial pair on each side of the mouth, which efficiently functions to shear meat like a pair of scissors. While this is present in canines, it is highly developed in felines. The cat's tongue has sharp spines, or papillae, designed to retain and rip flesh from a carcass. These papillae are small backward-facing hooks that contain keratin and assist in their grooming. Unlike most carnivores, cats eat almost no vegetable matter apart from that found in the digestive tracts of their prey. Whereas bears and dogs commonly supplement their diet of meat with fruits, berries, roots, and honey when they can get them, cats feed exclusively on meat, usually freshly killed. Cats, including the great cats, have a genetic anomaly that prevents them from tasting sweetness ^[11], which is probably related to their meat-only habits.

In captivity, cats cannot be adapted to an unsupplemented vegetarian diet because they cannot synthesize all the amino acids they need from plant material. Specifically this applies to taurine, the absence of which causes the cat's retina to slowly degenerate, causing eye problems and (eventually) irreversible blindness. This condition is called central retinal degeneration (CRD). Cow's milk is a poor source of taurine and adult cats are generally lactose intolerant. Lactose-free milk is perfectly safe, but still not a substitute for meat. This contrasts with domesticated dogs, which commonly are fed a mixture of meat and vegetable products and have been adapted in some cases to a vegetarian diet. Despite this, however, the majority of brand-name cat foods are primarily grain based, often containing large amounts of corn or rice and supplemented with meats and essential vitamins. Some vegetarian owners feed their cats a vegetarian diet containing supplemental taurine.

Cats are also known to munch on grass, leaves, shrubs and houseplants. They do not eat a lot in one sitting, but prefer to have it as a snack. Eating vegetation in this way may aid the cat's digestive system and can prevent hairballs. ^[12].

Cats can be fussy eaters. This mostly happens when the vomeronasal, or Jacobson's, organ becomes sensitized to a specific food, at which point the cat will reject any food that doesn't fit the pattern it is expecting. Additionally, cats have been known to develop a fondness for "people food" such as barbecued chicken, bread, french fries, pepperoni pizza, ice cream, tomato soup, carrot juice, and carnitas burritos, as well as cat diet exotica such as corn kernels and diced cantaloupe. Many "people foods" are not good for cats; chocolate, for example, can be fatal due to the theobromine found in chocolate (see theobromine poisoning).

Domestic cats, especially young ones, are known for their love of string play. Many cannot resist a dangling piece of string, or a piece of rope drawn randomly and enticingly across the floor. This notorious love of string is often depicted in cartoons and photographs, which show kittens or cats playing with balls of yarn. This propensity is probably related to their hunting instinct. However, string is more often being replaced with a red dot laser pointer. This is because, if the string is ingested, it can be caught in the cat’s stomach or intestines causing illness or, in extreme cases, death. Some people discourage the use of laser pointers for play with pets, however, because of the risk of eye damage and the loss of satisfaction (especially for cats) associated with the successful capture of prey.

Because of their small size, domestic cats pose almost no danger to humans—the only hazard is the possibility of infection (or, rarely, rabies) from a cat bite or scratch.

Cats can be destructive to ecosystems in which they are not native and whose species did not have time to adapt to their introduction. In some cases, cats have contributed to or caused extinctions — for example, see the case of the Stephens Island Wren.

Hygiene

A cat using its litter box.

Cats are known for their cleanliness. They groom themselves by licking their fur. Their saliva is a powerful cleaning agent, but it can provoke allergic reactions in humans. Some people who are allergic to cats - typically manifested by hay fever, asthma or a skin rash - quickly acclimatise to a particular animal and live comfortably in the same house as it, while retaining an allergy to cats in general. Many cats also enjoy grooming humans or other cats. Some cats occasionally regurgitate hair balls of fur that have collected in their stomachs as a result of their grooming. Longhair cats are more prone to this than shorthairs. Hairballs can be prevented with certain cat foods and remedies that ease elimination of the hair. Cats expend nearly as much fluid grooming as they do urinating.

Indoor cats may be provided a litter box containing sand or similar commercial material (litter). This arrangement serves the same purpose as a toilet for humans. It should be cleaned daily and changed often (depending on the type of litter—clumping litter stays cleaner longer, but has been reported to cause health problems in some cats. ^[13]) A litterbox is recommended for indoor-outdoor cats as well. Litterboxes may pose a risk of toxoplasmosis transmission to susceptible pregnant women and immuno-compromised individuals. Transmission risk may be reduced by daily litterbox cleaning.

Toilet-trained cat

In addition, some cats may be toilet trained, eliminating the litterbox and its attending expense and odor. Training involves two or three weeks of incremental moves, such as moving and elevating the litterbox until it is near the toilet. For a short time, an adapter, such as a bowl or small box, may be used to suspend the litter above the toilet bowl. When training is complete, the cat uses the toilet by perching over the bowl. ^[14]

Indoor cats will also benefit from being provided with a scratching post so they are less likely to ruin furniture with their claws.^[15] Nails can be trimmed, but care should be taken to avoid cutting a vein in the quick of the claw.

Declawing

Main article: onychectomy

Some cat owners choose to have their cat declawed (onychectomy). This major surgery removes the tip of each digit (from the first knuckle out) of the cat's forepaws. Some people are opposed to declawing, claiming it is inhumane. Declawing is not a simple procedure; serious complications can arise, such as an increased risk of infections, or life-long discomfort in the cat's paws. This operation is rare outside of North America. In Germany and Switzerland, declawing cats is explicitly forbidden by the laws against cruelty to animals.^[16] In many other European countries, it is also forbidden under the terms of the European Convention for the Protection of Pet Animals, unless "a veterinarian considers [such] non-curative procedures necessary either for veterinary medical reasons or for the benefit of any particular animal". ^[17]

Where it is legal, some cat veterinarians refuse to do this type of surgery because it deprives the cat of its main defense ability, although cats usually learn to donkey kick or rake with their hind claws in defense. Other experts mention difficulties with the cat's typical stretching and exercise habits, which can lead to muscle atrophy. Declawing surgery requires anesthesia, which carries with it a small risk of death. Additionally, some experts believe that declawed cats are more inclined to bite. If a cat is not declawed at an early age, it becomes too dangerous to declaw them when they are older. However, many American cats are still declawed, often when the owner finds that it is the only option for keeping the cat (sometimes it is mandated by landlords). Some cats that are not declawed and cannot be retrained are either abandoned or turned in to animal shelters, where they may be euthanized. In Britain, where the prevailing style of ownership is indoor/outdoor, shelters find it difficult to rehome imported cats that had previously been declawed. One popular, relatively inexpensive alternative to declawing is the application of vinyl nail caps (marketed in the US as Soft Paws® or Soft Claws®) that are affixed to the claws with nontoxic glue, requiring periodic replacement when the cat sheds its claw sheaths (usually every four to six weeks).

Environment

The wild cat, ancestor of the domestic cat, is believed to have evolved in a desert climate, as evident in the behavior common to both the domestic and wild forms. Wild cats are native to all continents other than Australasia and Antarctica. Their feces are usually dry, and cats prefer to bury them in sandy places. They are able to remain motionless for long periods, especially when observing prey and preparing to pounce. In North Africa there are still small wildcats that are probably related closely to the ancestors of today's domesticated breeds.

Cats enjoy heat and solar exposure, often sleeping in a warm area during the heat of the day. Cats like to be a lot warmer than humans do. People start to feel uncomfortable when their skin's temperature gets higher than about 44.5 °C (112 °F), but cats don't start to show signs of discomfort until their skin reaches about 52 °C (126 °F).

Being closely related to desert animals, cats can withstand the heat and cold of a temperate climate, but not for long periods. Although certain breeds such as the Norwegian Forest Cat and Maine Coon have developed more protection than others, they have little resistance against fog, rain and snowand struggle to maintain their 39 °C (102 °F) body temperature when wet. Most cats dislike immersion in water, but one exception is the Turkish Van cat. If a cat is continually exposed to water from a very young age, often it will develop a fondness for it; however, this rarely if ever occurs naturally.

Reproduction and genetics

Four kittens being nursed.

Cats are seasonally polyestrous, which means they may have many heat periods over the course of a year. A heat period lasts about 4 to 7 days if the female is bred; if she is not, the heat period lasts longer and recurs at regular intervals.

The male cat's penis has spines which point backwards. Upon withdrawal of the penis, the spines rake the walls of the female's vagina. The female needs this stimulation for ovulation to begin. Because of this, females are rarely impregnated by the first male with which they mate. Furthermore, cats are superfecund; that is, a female may mate with more than one male when she is in heat, meaning different kittens in a litter may have different fathers.

The gestation period for cats is approximately 60 days. The size of a litter averages three to five kittens. Kittens are weaned at between six and seven weeks, and cats normally reach sexual maturity at six months (females) to seven months (males).

Blue-eyed cats with white fur have a higher genetic incidence of deafness.

Completely white cats (not due to albinism, but white because of the dominant epistatic white (W) gene) with two blue eyes have a forty percent probability of being born deaf.

The deafness is an effect of the W gene. This gene produces a white coat because it completely masks any other color or pattern the cat has. Blue irises can result, and they are linked to deafness. ^[18] Any cat that receives even one W from one parent may exhibit this. Blue eyes can also result from the form of albinism characteristic of the siamese breed; white cats from this genetic background, sometimes called Foreign whites or Oriental Shorthairs may not have a problem with deafness, but it can happen if the cat inherits the W gene. This also occurs with dogs if they have white coat and blue eyes, and in the case of dogs, it can be equally common for them to be born blind. ^[19] However, blindness in cats has not found to be associated with the W gene. ^[20] Often, blue eyes will lack a tapetum lucidum and thus will not reflect like colored cat eyes. This may diminish the cats' visual acuity, but the extent is not known. Humans with common albinism, white skin and blue eyes generally suffer from visual problems, but in Tietz syndrome they suffer from deafness.

Around 5% of all cats are completely white, of which 10%–20% are deaf. Very few survive in the wild because of all the hazards that they cannot avoid as easily as other cats would in the same situation. Many people believe that deaf white cats should not be used for breeding as it is not ethical to propagate such a disability, and instead deaf cats should be spayed or neutered to avoid passing the trait to their offspring. ^[21] Some breeds however, such as the Turkish Angora are based on all white cats and produce a higher percentage of deaf cats as a results. It was not until recently that colored Turkish Angoras were allowed to be shown, making deafness an issue in that breed.

Domestication

Like some other domesticated animals, cats live in a mutualistic arrangement with humans. Cats, however, have done so for a much shorter time than almost all other domesticated animals, and the degree of domestication of cats is somewhat disputed. Since the benefit of removing rats and mice from humans' food stores outweighed the cost of allowing a formerly wild animal to enjoy the relative safety of a human settlement, the relationship between cat and human flourished. Unlike the dog, which also kills rodents, the cat did not eat grains, fruits, or vegetables. A cat that is good at hunting rodents is referred to as a mouser.

The venerable simile, "like herding cats" refers to the seeming intractability of the ordinary house cat to be trained in the manner of the dog. Despite occasional cohabitation in colonies, cats are lone hunters. It is no coincidence that cats are also "clean" animals, the chemistry of their saliva, expended in frequent grooming, acting as a natural deodorant. The "purpose" of this cleanliness is to help hide the cat's presence while stalking prey. A dog's odor, on the other hand, is an advantage, for a dog is a pack hunter; part of the pack stations itself upwind, and its odor drives prey towards the rest of the pack stationed downwind. This requires a cooperative effort, which in turn requires communications skills. No such communications skills are required of the lone hunter. Thus, communicating with such an animal is problematic, and cats in particular are labelled as opaque or inscrutable, if not obtuse, as well as aloof and self-sufficient. However, cats can be very affectionate towards their humans, especially if they imprint on them at a very young age and are treated with consistent affection.

European cat catching a pigeon.

Human attitudes toward cats vary widely. Some humans keep cats for companionship as pets. Some people (known as cat lovers) go to great lengths to pamper their cats, sometimes treating them almost as if they were children. When a cat bonds with its human owner, at times, the cat may display behaviors similar to that of the human. Such behavior may include a trip to the litter box before bedtime and snuggling up close to its companion in bed or on the sofa. Other behaviors could include mimicking sounds of the owner or using certain sounds the cat picks up from the human; sounds representing specific needs of the cat, which the owner would recognize. The cat may also be capable of learning to communicate with the human using non-spoken language or body language such as rubbing for affection (confirmation), facial expressions and making eye-contact with the owner if something needs to be addressed (e.g. finding a bug crawling on the floor for the owner to get rid of). Some owners like to train their cat to perform "tricks" commonly exhibited by dogs such as jumping.

Allergies to cat dander are one of the most common reasons people cite for disliking cats. However, in some instances, humans find the rewards of cat companionship outweigh the discomfort and problems associated with allergies. Many chose to cope with cat allergies by taking prescription allergy medicine and bathing their cats frequently, since weekly bathing will eliminate about 90% of the cat dander present in the environment. Recent studies have indicated the humans who are exposed to cats or dogs within the first year of their lives develop few animal allergies, while most adults who are allergic to animals did not have a cat or a dog as a pet in childhood.

In urban areas, some people find feral and free roaming pet cats annoying and intrusive. Unaltered animals can engage in persistent nighttime calling (caterwauling) and defecation or "marking" on private property. Indoor confinement of pets and TNR (Trap, Neuter, Return) programs for feral cats can help in this situation.

In rural areas, farms often have dozens of semi-feral cats. Hunting in the barns and the fields, they kill and eat rodents that would otherwise spoil large parts of the grain crop. Many pet cats successfully hunt and kill rabbits, rodents, birds, lizards, frogs, fish, and large insects by instinct, but might not eat their prey. They may even present such victims, dead or maimed, to a beloved owner, perhaps expecting their owner to praise or reward them, or possibly even complete the kill and eat the mouse.

Despite its reputation as a solitary animal, the domestic cat is social enough to form colonies, but does not attack in groups as do lions. Some breeds like bengal, ocicat and manx are very social, but these breeds are exceptions. While each cat holds a distinct territory (sexually active males having the largest territories, and neutered cats having the smallest), there are "neutral" areas where cats watch and greet one another without territorial conflict or aggression. Outside of these neutral areas, territory holders usually vigorously chase away strangers, at first by staring, hissing, and growling, and if that does not work by short but noisy and violent attacks. Fighting cats make themselves look larger by raising their fur and arching their backs. Attacks usually comprise powerful slaps to the face and body with the forepaws as well as bites, but serious damage is rarely done, and usually the loser runs away with little more than a few scratches to the face. Sexually active males may be engaged in many fights over their lives and often have decidedly weathered faces with obvious scars and cuts to the ears and nose. Not only males will fight; females will also fight over territory or to defend their kittens and even neutered cats will defend their small territories vigorously.

Feral cats

Feral cats are thought to be a major predator of Hawaiian coastal and forest habitats, and are one species among many responsible for the decline of endemic forest bird species as well as seabirds like the Wedge-tailed Shearwater. [1] In one study of 56 cat scats, the remains of 44 birds were found, 40 of which were endemic species. [2]

Feral cats may live alone, but most are found in large groups called feral colonies with communal nurseries, depending on resource availability. Many lost or abandoned pet cats join these colonies out of desperation. The average lifespan of these feral cats is much shorter than a domestic housecat, which can live an average of sixteen years or more. Urban areas are not native environments to the cat; most domestic cats were artificially selected from cats in desert climates and were distributed throughout the world by humans, but some feral cat colonies are found in large cities, for example, around the Colosseum and Forum Romanum in Rome. Although cats are adaptable, feral felines are unable to thrive in extreme cold and heat, and with a protein requirement of about 90%, few find adequate nutrition on their own in cities. In addition, they have little defense or understanding of the dangers from dogs, coyotes, and even automobiles. However, there are thousands of volunteers and organizations that trap these unadoptable feral felines, spay or neuter them, immunize the cats against rabies and feline leukemia, and treat them with long-lasting flea products. Before release back into their feral colonies, the attending veterinarian nips the tip off one ear to mark the feral as spayed/neutered and inoculated, as these cats will more than likely find themselves trapped again. Volunteers continue to feed and give care to these cats throughout their lives, and not only is their lifespan greatly increased, but behavior and nuisance problems, due to competition for food, are also greatly reduced. In time, if an entire colony is successfully spayed and neutered, no additional kittens are born and the feral colony disappears. Many hope to see an end to urban feral cat colonies through these efforts.

Environmental impact

The environmental impact of feral cat programs and of indoor/outdoor cats is a subject of debate. Part of this stems from humane concern for the cats themselves and part arises from concerns about cat predation on endangered species. Nearly all studies agree that abandoned animals lead hard lives. Owners who can no longer keep their cats would do best to give them to friends, rescue organizations, or shelters.

The amount of ecological damage done by indoor/outdoor cats depends on local conditions. The most severe impact occurs with island ecologies. Serious concerns also exist in places such as Florida where housecats are not native, where several small sized endangered species live near human populations, and where the climate allows cats to breed throughout the year. Environmental concerns may be minimal in most of England where cats are an established species and few to none of the local prey species are endangered.

Pet owners can contact veterinarians, ecological organizations, and universities for opinions about whether local conditions are suitable for outdoor cats. Additional concerns include potential dangers from larger predators and infectious diseases. Coyotes kill large numbers of housecats in the Southwestern United States, even in urban zones. FELV (feline leukemia), FIV (feline immunodeficiency virus), or rabies may be present in the area. If faced with conflicting evidence, the safe choice is to keep a cat indoors. Experts recommend a gradual transition to indoor life for cats who are accustomed to going outside.

Scientific classification

The domestic cat was named Felis catus by Carolus Linnaeus in his Systema Naturae of 1758. Johann Christian Daniel von Schreber named the wild cat Felis silvestris in 1775. The domestic cat is now considered a subspecies of the wild cat: by the strict rule of priority of the International Code of Zoological Nomenclature the name for the species thus ought to be F. catus since Linnaeus published first. However, in practice almost all biologists use F. silvestris for the wild species, using F. catus only for the domesticated form.

In opinion 2027 (published in Volume 60, Part 1 of the Bulletin of Zoological Nomenclature, 31 March 2003 ^[22]) the International Commission on Zoological Nomenclature "conserved the usage of 17 specific names based on wild species, which are predated by or contemporary with those based on domestic forms", thus confirming F. silvestris for the wild cat and F. silvestris catus for its domesticated subspecies. (F. catus is still valid if the domestic form is considered a separate species.)

Johann Christian Polycarp Erxleben named the domestic cat Felis domesticus in his Anfangsgründe der Naturlehre and Systema regni animalis of 1777. This name, and its variants Felis catus domesticus and Felis silvestris domesticus, are often seen, but they are not valid scientific names under the rules of the International Code of Zoological Nomenclature.

Varieties of domestic cat

The list of cat breeds is quite large. Each breed has distinct features and heritage. The owners and breeders of show cats compete to see whose animal bears the closest resemblance to the "ideal" definition of the breed (see selective breeding). Due to common crossbreeding in populated areas, many cats are simply identified as belonging to the homogeneous breeds of domestic longhair and domestic shorthair, depending on their type of fur. In the United Kingdom and Australia, non-purebred cats are referred in slang as moggies (also an archaic slang word for a prostitute, probably referring to a female cat's promiscuous habits). In the United States, a non-purebred cat is sometimes referred to in slang as an alley cat, even if it is not a stray.

Cats come in a variety of colors and patterns. These are physical properties and should not be confused with a breed of cat.

This Greek cat has light fur and green eyes.

Household cats are divided into:

• Domestic longhaired
• Domestic shorthaired

Cat coat genetics can produce a variety of coat patterns; some of the most common are

Bicolor cat 

Also known as 'Tuxedo cat' or 'Jellicle cat' (tuxedos are mostly black with white paws/legs, bellies, chests, and possible markings on face).

Maltese cat 

The former name for a blue (grey) cat.

Oriental cat 

(not a specific breed, but any cat with an elongated slender build, almond-shaped eyes, large ears and very short sleek fur).

Tabby cat 

Striped, with a variety of patterns. The classic "blotched tabby" pattern is the most common and consists of butterflies and bull's-eyes. The mackerel tabby is a series of vertical stripes down the cat's side (resembling the fish). This pattern broken into spots is referred to as spotted tabby. The worldwide evolution of the cat means that certain types of tabby are associated with certain countries; for instance, blotched tabbies are quite rare outside NW Europe, where they are the most common type.

Tortoiseshell and Calico 

Featuring three colors mottled throughout the coat, this cat is also known as a Calimanco cat or Clouded Tiger cat, and by the nickname "tortie". A true tortoiseshell must consist of three kinds of color: a reddish color, dark or light; white; and one other color, typically a brown, black or blue, as described by American breeder Barbara French, writing for the Cat Fanciers community ^[23]. Calico cats are white with distinct black and red (or blue and cream in the dilute variant) spots. The Japanese refer to this pattern as mi-ke (meaning "triple fur"). Both tortoiseshell and calico cats are typically female because the coat pattern is the result of differential X chromosome inactivation in females (which, as with all normal female mammals, have two X chromosomes). Those male tortoiseshells that are created are usually sterile; conversely, cats where the overall color is ginger (orange) are virtually always male, and a litter sired by a ginger tom usually contains tortoiseshell females. See "Tortoiseshell and Tricolour Cats" for an extensive genetic explanation for tricolor cats, and detailing the possible combinations of coloring.^[24]

History and mythology

Main article History of cats

Cats have been kept with humans since the days of Ancient Egypt through various cultures.

References

1. ^  Speaking_of_Animals. URL accessed on August 15, 2005.
2. ^  Feline Statistics. URL accessed on August 15, 2005.
3. ^  Spay and Neuter Your Pet Cats. URL accessed on August 8, 2005.
4. ^  At Home : Care / Health : Understanding Cats. URL accessed on August 15, 2005.
5. ^  Normal Values For Dog and Cat Temperature, Blood Tests, Urine and other information in ThePetCenter.com. URL accessed on August 8, 2005.
6. ^  Falling Cats. URL accessed on October 24, 2005.
7. ^  Calypso (Ulysses ch4). URL accessed on October 24, 2005.
8. ^  Anal Sac Disease. URL accessed on October 24, 2005.
9. ^  PLoS Genetics: Pseudogenization of a Sweet-Receptor Gene Accounts for Cats' Indifference toward Sugar. URL accessed on August 8, 2005.
10. ^  Felidae World - Catnip and Grasses for Cats. URL accessed on August 8, 2005.
11. ^  Suspected bentonite toxicosis in a cat from ingestion of clay cat litter. URL accessed on September 10, 2005.
12. ^  Cat toilet-training. URL accessed on August 8, 2005.
13. ^  Scratching or clawing in the house. URL accessed on August 14, 2005.
14. ^  Swiss Federal Act on Animal Protection, 1978, Section 8: Prohibited Practices, §22(g). URL accessed on August 22, 2005.
15. ^  European Convention for the Protection of Pet Animals, Chapter II - Principles for the keeping of pet animals, Article 10(1). URL accessed on August 22, 2005.
16. ^  LMF: Roy Robinson on White Cats. URL accessed on August 8, 2005.
17. ^  Deafness in Dogs & Cats - Genetics: Dogs. URL accessed on August 8, 2005.
18. ^  Deafness in Dogs & Cats - Genetics: Cats. URL accessed on August 8, 2005.
19. ^  White Cats, Eye Colours and Deafness. URL accessed on August 8, 2005.
20. ^  Bulletin of Zoological Nomenclature 60(1) March 2003. URL accessed on August 8, 2005.
21. ^  Torties, Calicos and Tricolor Cats. URL accessed on October 24, 2005.
22. ^  Tortoiseshell and Tricolour Cats. URL accessed on November 27, 2005.
23. ^  AAAS - AAAS News Release. URL accessed on August 8, 2005.
24. ^  CBC News:Ancient tomb may hold oldest pet cat. URL accessed on August 8, 2005.
25. ^  Snopes - Murderous Moggies. URL accessed on August 15, 2005.
26. ^  Cat Breeds, Types and Variants. URL accessed on November 29, 2005.

See also

Look up cat in Wiktionary, the free dictionary.

Look up kitty in Wiktionary, the free dictionary

Look up meow in Wiktionary, the free dictionary

• Felidae
• Big cat
• Cat body language
• catnip
• Cat flap
• Cat Fanciers' Association
• Cats in Ancient Egypt
• Catfight
• List of historical cats
• List of fictional cats
• Polydactyl cat (extra toes)
• Cat types
• Cat breeds

External links

Wikispecies has information on:

Cat

Wikiquote has a collection of quotations related to:

Cat

Wikimedia Commons has media related to:

Cat

Wikibooks has more about this subject:

How to choose your pet and take care of it

• Introducing a new cat or kitten to your resident cat
• Cat-Guide.org
• Max's House Feline Medical & Behaviour Database (large number of short articles
• Australian Threat Abatement Plan for Predation by Feral Cats
• Feral cats (The Wildlife Society)
• Feral cats (University of Florida)
• American Bird Conservancy (domestic cat predation)
• American Veterinary Medical Association (large article on cat colonies)
• Feral cats (BBC)
• Animals Australia: Feral Cat bibliography

? Domestic Dog Conservation status: Domesticated
Labrador Retriever a breed of domestic dog
Scientific classification
Kingdom: Animalia Phylum: Chordata Subphylum: Vertabrata Class: Mammalia Order: Carnivora Family: Canidae Genus: Canis Species: C. lupus Subspecies: C. l. familiaris
Trinomial name
Canis lupus familiaris (Linnaeus, 1758)

The dog is a canine mammal of the Order Carnivora. It has been argued the dog has been domesticated for 12,000 years, but perhaps for as long as 150,000 years based on recent genetic evidence. In this time, the dog has developed into hundreds of breeds with a great degree of variation. For example, heights range from just a few inches (such as the Chihuahua) to nearly three feet (such as the Irish Wolfhound), and colors range from white to black, with reds, grays (usually called blue), and browns occurring in a tremendous variation of patterns. Dogs, like humans, are highly social animals and pack hunters; this similarity in their overall behavioral design accounts for their trainability, playfulness, and ability to fit into human households and social situations. Dogs fill a variety of roles in human society and are often trained as working dogs. For dogs that do not have traditional jobs, a wide range of dog sports provide the opportunity to exhibit their natural skills. In many countries, the most common and perhaps most important role of dogs is as companions. Dogs have lived with and worked with humans in so many roles that their loyalty has earned them the sobriquet "man's best friend." Conversely, some cultures consider dogs to be unclean. In other cultures, some dogs are used as food.

Terminology

Puppies engage in teething on almost anything.

Dog, in common usage, refers to the domestic dog, Canis lupus familiaris (originally classified as Canis familiaris by Linnaeus in 1758, but reclassified as a subspecies of the wolf, Canis lupus, by the Smithsonian Institution and the American Society of Mammalogists in 1993). The word 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.

• Dog is also a term used by breeders to specifically denote a male domestic dog.
• Bitch is a female dog who is capable of breeding or has bred.
• Pack is used to denote a group of dogs.
• Puppy is a juvenile dog.
• Pooch, Poochie, Dogay, Pup, Pupsie, Doggy or Doggie are all informal and affectionate terms for a dog often used by children.

Many additional terms are used for dogs that are not purebred; see Terms for mixed-breed dogs.

Physical characteristics

Although selective breeding has changed the appearance of many breeds, all dogs retain the basic ingredients from their distant ancestors. Like most predatory mammals, the dog has powerful muscles, a cardiovascular system that supports both sprinting and endurance, and teeth for catching, holding, and tearing. Its skeleton provides the ability to run and leap. They have small, tight feet, walking on their toes.

For details about dog appearance and physical attributes, see dog anatomy.

Intelligence

Among dog lovers, dogs are generally valued for their intelligence. Anecdotal evidence suggests that dogs have a reasonably high intelligence. For a detailed discussion on what dog intelligence is, see dog intelligence.

Diet

This English Springer Spaniel is enjoying a bone.

Presently, there is academic discussion as to whether domestic dogs are omnivores or carnivores. 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 a cat, a dog is not dependent on meat protein in order to fulfill its 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 its diet. Wild canines not only eat available plants to obtain key amino acids, but may also obtain nutrients from vegetable matter from the stomach contents of their herbivorous prey. Domestic dogs can survive healthily on a reasonable and carefully designed vegetarian diet, particularly if eggs and milk products are included. In the wild these diets are typically pursued in the absence of available meat. It has also been noted that extremely stressful conditions, such as the Iditarod race and scientific studies of similar conditions, suggest that high-protein diets including meat help prevent damage to muscle tissue. This research is also true of other mammals.

Dangerous substances

Some foods commonly enjoyed by humans are dangerous to dogs, including chocolate (Theobromine poisoning), onions, grapes and raisins, Macadamia nuts, and hops. Also, human medications, such as acetaminophen/paracetamol (Tylenol), can be highly toxic.

Dogs also may find some poisons attractive, including antifreeze and snail bait.

Reproduction

Among professional breeders, dogs are only allowed to mate for a specific purpose. Sometimes dogs are bred to create puppies to sell, or sometimes to carry on an award-winning purebred line. Breeders who do this are usually experienced in this process. Dog breeders have access to records which allow them to accurately guess which characteristics will "breed true" in a particular dog. Dog breeders also have accurate information on the complexities of the reproductive process for the breed of dog that they are accustomed to handling. Dog owners may accidently allow their pets to breed without regard to bloodlines.

Fertility

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 behaviours 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 also called in season or in heat. Conversely, undomesticated canine species experience estrus once a year, typically in late winter.

Menarche

Most bitches 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.

Pregnancy and litters

Catahoula Leopard Dog nursing litter of puppies

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 favoured for economic reasons. Dogs bear their litters roughly 9 weeks after fertilization. An average litter consists of about six puppies, though this number may vary wildly based on the breed of dog. Since a mother can only provide nutrients and care to a limited number of offspring, humans must assist in the care and feeding when the litter exceeds approximately eight puppies. 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.

Spaying and neutering

Dog experts advise that dogs not intended for further breeding should be spayed or neutered so that they do not have undesired puppies. Unwanted puppies are abandoned, eaten, or sometimes disposed of in an inhumane fashion. It is also common for adult stray dogs who are placed in animal shelters to be euthanized due to lack of space and resources. Spaying and neutering can also help prevent hormone-driven diseases such as breast cancer and prostate cancer, as well as undesired hormone-driven behaviors.

Contrary to myth, it is not required 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; these myths are responsible for numerous unnecessary health problems and unwanted puppies. It should also be noted that a female dog may become pregnant prior to her first cycle and should be kept away from other male dogs, including littermates over the age of 4 months. Many veterinarians recommend that owners neuter/spay their pets around the age of 5 months.

Attributes

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.

Sight

Dogs were thought to be dichromats and thus, by human standards, color blind.^{1, 2} New research is now being explored that suggests that dogs may actually see some colour, but not to the extent that humans do. 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 100° to 120° for humans), although broad-headed breeds with their eyes set forward have a much narrower field of vision, as low as 180°.^{1, 2}

Hearing

Dogs detect sounds as low as the 16 to 20 Hz frequency range (compared to 20 to 70 Hz for humans) and as high as 70,000 to 100,000 Hz (compared to 20,000 Hz for humans)², and in addition have a degree of ear mobility that helps them to rapidly pinpoint the exact location of a sound. They can identify a sound's location much faster than a human can, and they can hear sounds up to four times the distance that humans can.

Scenting

Dogs are predators suited to chasing after, leaping at, and killing prey. (pictured: Weimaraner)

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. Other than the oversimplified obvious, i.e. chemical compounds that affect chemical sensors in the nose, what a dog actually detects when he is scenting is not really 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.

Direction and spatial sense

It has been observed that a lost dog can often find its way home, sometimes traveling over long distances.

Weather detection

Dogs also have the ability to sense inclement weather (mainly thunderstorms) many miles away. This is due to their keen ability to detect fluctuations in barometric pressure and can explain a dog's anxiety before and during a storm. The evolutionary ability of sensing weather can be traced back to when wolves used it to move the pack into proper shelter before a dangerous storm.

Diseases and ailments

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.

For additional information on these and other related topics, see dog health and Category:Dog health.

Diseases

Diseases commonly associated with dogs include rabies (hydrophobia), canine parvovirus, and canine distemper, although there are many others.

Parasites

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

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.

Behaviour

Some dogs can be trained to retrieve

All dogs have a tremendous capacity to learn complex social behavior and to interpret varied body language and sounds, and, like many predators, can react to and learn from novel situations. The requirements of coordinating complex social behavior requires that canines have the ability to sense and deliver a wide variety of cues via body language, more so than for even humans, who can use language for the same purpose. Physiologically, this correlates with such features as a large number of nerves innervating the facial muscles of dogs, allowing subtle control of a wide variety of facial expressions; in contrast to cats, for instance, who have many fewer nerves governing their facial muscles, resulting in a smaller repertoire or "vocabulary" of expressions. This ability to read and deliver nonverbal cues makes dogs expert at reading human beings, as well, often even more so than other humans are, who rely on language. Most dog owners have a large collection of stories about their dogs recognizing individuals by their footsteps outside the door, and so on.

Interactions between Dogs and Humans

Main article: Dog society

The relationship between dogs and humans is rooted in history and dogs coexist with humans in a variety of ways. Dogs thrive in small social groups or packs which, from their viewpoint, can include humans. Dog society can be thought of as dog packs characterized by a companionate hierarchy, in which each individual has a rank, and in which there is intense loyalty within the group. Dogs thrive in human society because their relationships with humans mimic their natural social patterns. The dog is always aware of its rank relative to other individuals in the group. An assertive dog may consider itself the alpha animal, considering its human master to be subordinate.

Treats

Many dogs consider anything given to them directly by hand to be a treat, even the food they are accustomed to at meal time. Special dog treats are not necessary for such animals. Care should also be taken to avoid dropping small but inedible objects (such as marbles, coins, rings, etc.) around such dogs. Some food considered as treats for humans, such as chocolate and raisins, are poisonous to dogs.

If a dog has something valuable (rings, money, irreplaceable items), a treat should be used to "barter" with the dog to retrieve the stolen item. Chasing a dog will encourage play behavior, which may cause the item to be swallowed or destroyed.

Dogs as working partners

Many breeds of dogs, but not least German Shepherd, Labrador Retriever, and Border Collie are commonly used as working dogs. There are service dogs, guard dogs, hunting dogs, and herding dogs. Dogs have served as guides for the blind, as commandos, and have flown into outer space (see Laika and other Russian space dogs). Most modern working dogs are put in positions which capitalize on their sensory or strength and endurance advantages over normal humans. Dogs are also used for searching for or rescuing people and animals, such as in avalanches, at disaster sites, and for missing people or pets.

Dogs as hunting and sporting partners

Many people compete with their dogs in a variety of dog sports, including agility, flyball, and many others. This often strengthens the bond between human and dog, since they must trust one another in a variety of environments and must learn how the other works and thinks.

Setters in particular have a long history as upland gun dogs. They have a native ability to discover and "hold" upland game birds; to freeze them momentarily on the ground with their silent, elongated pointing stance. Once the hunter approaches, at his command they will flush the birds to fly and for the hunter to shoot at.

As water dogs, the retrievers are unsurpassed. They can spend long hours in a duck blind and, after the hunter has fired at multiple ducks or geese, they can visually spot and remember the location of downed birds. At command, they dive into the icy water, swim out and retrieve the birds one by one. They can follow hand, verbal, and whistle commands at great distance as the hunter directs them to the downed bird. They typically have large, gentle muzzles to mitigate any potential damage to the game.

When trained, beagles are particularly adept at chasing through thick briars and brush after rabbits. Many hound breeds are excellent at treeing raccoons during hunting season.

Hunters with dogs report the satisfaction that the dogs seem to exhibit. Excitement is evident as they see the hunters load weapons, take to the field, and begin the hunt.

Dogs as pets

A 9 year old English Collie cross. Some say mongrels make the best pets

Relationships between humans and dogs are often characterized by strong emotional bonds. Consequently, dogs are popular as pets and companions, independent of any utilitarian considerations. Many dog owners consider having unconditional acceptance from a friend who is always happy to see them to be quite utilitarian, particularly if the dog also leads them to regular exercise. Empirically, dogs are quite dependent on human companionship and may suffer poor health in its absence. Many dogs are reported to have separation anxiety if its owner is away for an extended period of time.

Some research demonstrates that dogs are able to convey a depth of emotion not seen to the same extent in any other animal; this is purportedly due to their closely-knit development with modern man, and the survival-benefits of such communication as dogs became more dependent on humans for sustenance.

Nevertheless, it is often unwise to anthropomorphize the responses of dogs. Despite understandably positive interpretations by dog owners, it is questionable whether these animals are truly capable of feeling emotions on a human level. More research is needed to determine the intelligence level of dogs, and the motivations behind their responses to their masters.

Dogs as food

Main article: Taboo food and drink

In some countries, certain breeds of dogs are raised for their meat. Often times, this causes friction with societies that want a complete ban on consumption of dog meat. In times of great stress, such as when the Vikings of Greenland starved to death at the start of the Little Ice Age (14th century - 19th century), humans have been known to eat their pets.

In some small Chinese provincial towns, there is a special breed of dog (called "Black Dogs" in Chinese language) mainly used for cuisine. Almost any breed of dog is eaten in some parts of China however in major cities like Beijing, Shanghai and Hong Kong, consumption of dog meat is prohibited by law and perpetrators will face heavy fines if caught. While some Western dog lovers may claim that dog is regarded as a "lower source of food," many Asians, in actuality, regard it as a luxury food, costing much more than other types of meat. However if dog meat is served to house guests that can be seen as an insult towards the guest, since dog meat is preferable to be eaten privately or at restaurants.

The people of Korea have been known to eat certain breeds of dogs as well. This led to issues during the 2002 Football World Cup when South Korea was hosting the game with the local government keen to obscure this practice from visiting countries.

Attacks on humans and livestock

Humans have a tendency to anthropomorphize animals, particularly pets such as dogs, which are generally portrayed as being "man's best friend". Animals are often given attributes such as "loyal", "cute", and "guardian", but these all have the potential to lure people into a false sense of security.

After thousands of years of domestication and selective breeding for dogs whose aggression towards humans goes no further than a ferocious bark that strongly indicates dislike of a human behavior, most dogs are unlikely to attack people. However, their sharp teeth and claws can inflict injury in an attack; a large dog can knock a human down. Provocation can range from something as seemingly innocuous as a toddler pulling a dog's tail, in which case the dog might nip to discourage the behavior, to something completely transparent to humans, such as an odor or a movement that sets a dog off, to blatant human aggression or violence towards a dog, causing it to defend itself. There are hundreds of shades of provocation that may or may not lead to an attack upon a human. Canine aggression upon humans is ordinarily not tolerated, but any human aggression against an animal having formidable means of self-defense is foolhardy in the extreme.

With formidable skills and weapons as hunters as well as large and unfussy appetites, dogs often menace livestock and wildlife. In most jurisdictions, dogs are destroyed for killing other creatures, so dogs should be prevented from any encounter with livestock or wildlife that might lead to a predatory response. The same creatures that wolves, coyotes, and foxes, attack as prey, especially sheep and poultry, are similarly attractive prey to dogs.

For more information about attack provocations and attack behavior, see dog attacks.

Abandoned Dogs

Wild dogs are shot by farmers in an effort to protect livestock. Bodies are sometimes tied to fences as warning to other dogs, especially in rural United States and Canada. Abandoned domestic dogs who become feral are particularly dangerous; they lack the survival skills of wild canines, as well as the genetic and learned fear of the humans' world. Feral dogs often form predatory packs that attack livestock and occasionally also prove dangerous to humans.

Ancestry and history of domestication

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

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

The relationship between man 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 appear to 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 indicate 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 results must be reevaluated in light of recent findings showing that molecular clocks must be recalibrated to date geologically recent events, such as 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 posses different distinctive colouration, 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, the dhole and 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 characteristic that distinguish a wolf from a dog are tenuous. Wolves typically have a "brush tail" and erect ears. While some dog breeds possess one of these characteristics, they rarely possess both.

Speed of domestication

Current research indicates that domestication, or the attributes of a domesticated animal, can occur much more quickly than previously believed. Domestication of a wild dog may occur within one or two human generations with deliberate selective breeding. It is also now generally believed that initial domestication was not attained solely by human desire intervention but 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. The relationship is theorized to have developed in this way.

Dog breeds

There are numerous dog breeds, 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 and Western Europe, belong to no recognized breed.

A few basic breed types have evolved gradually during the domesticated dog's relationship with man 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. Some groups use a definition that ultimately requires extreme inbreeding to qualify due to the low gene pool. Dogs that are bred in this manner often end up with severe health or behavioural problems. Other 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 come into play among breeders who enter their dogs in dog shows. Even prize-winning purebred dogs sometimes possess crippling genetic defects due to inbreeding. These problems are not limited to purebred dogs and can affect mixed-breed populations. 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

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 human beings themselves, who have many characteristics similar to young bonobo. 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.

• Breeds that guard flocks, such as the various sheepdog breeds, retain the most juvenile characteristics: they stay close to home with their foster "litter" (which might include a flock of sheep), rather than going out hunting, they have almost no predatory behavior (which would be disastrous in the vicinity of such a natural prey stimulus as sheep), they respond to perceived threats with a lot of vocalization and attempts to alert and engage the dominant individuals in their "pack" (i.e. humans) whenever possible, engaging in actual combat only as a last resort. In addition, they retain very juvenile physical characteristics such as round bodies and heads, soft coats, ears that hang down, and so on, which do not elicit fear responses from the sheep in the way that an appearance similar to that of an adult wolf would. (Compare to the physical appearance of the border collie, a sheep herding dog, whose physical configuration is closer to that of an adult wild canine and who therefore has a greater capacity to frighten sheep into a desired pattern of movement, along with the more adult aggressive temperament to do so).
• Breeds that are hunting dogs—that is, pointers, setters, spaniels, retrievers, etc.—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. This contrasts with sighthounds, who pursue and attack perceived prey on sight, and who maintain the mature canine body type with erect ears, lean bodies, and adult coats.
• 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.

See also

• Dog communication
• bark (dog)
• List of dog breeds

References and further reading

References

• Kennel Club Books Website 400 titles on dogs.
• Abrantes, Roger (1999). Dogs Home Alone. Wakan Tanka, 46 pages. ISBN 0966048423 (paperback).
• ¹A&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).
• ²Alderton, 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 0856687049
• Donaldson, Jean (1997). The Culture Clash. James & Kenneth Publishers. ISBN 1888047054 (paperback).
• Fogle, Bruce DVM The New Encyclopedia of the Dog, 2000
• 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 0688128416 (trade paperback).
• Pfaffenberger, Clare (1971). New Knowledge of Dog Behavior. Wiley, ISBN 0876057040 (hardcover); Dogwise Publications, 2001, 208 pages, ISBN 1929242042 (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 0345384393 (mass market paperback); Globe Pequot, 1992, ISBN 1558211403 (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 0345384393 (mass market paperback); Globe Pequot, 1992, ISBN 1558211403 (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 0395669588.
• 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.

External links

General info

• National Geographic News Many articles and photos about dogs

Genetics and origins

• Lindblad-Toh, K., et. al. "Genome sequence, comparative analysis, and haplotype structure of the domestic dog" Nature 438:803-819, December 2005.
• "Multiple and Ancient Origins of the Domestic Dog"
• Canid Genetics
• "Dog Genome Sequencing" - NHGRI
• "World's dogs are descended from Asian wolves"
• "From Wolf to Woof - The Evolution of Dogs"

Training and behavior

• Noncommercial site sponsored by the University of Wisconsin-Stevens Point

Breed listings from major kennel clubs

• American Kennel Club
• Canadian Kennel Club
• United Kennel Club Breed lists for many breeds and types not recognized by the AKC--and for many that are (U.S.)
• FCI Fédération Cynologique Internationale - FCI
• FCI International breed standards
• Australian National Kennel Club
• The Kennel Club (UK)
• New Zealand Kennel Club