Human interaction with cats

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Girl with young cat

Hundreds of millions of cats are kept as pets around the world. Cats have either a mutualistic or commensal relationship with humans. Cats are also used in the fur trade, as food, and to control pests.

Cats and humans evolutionarily diverged from a common ancestor (boreoeutherian ancestor) approximately 80 million years ago, accumulating only 10–12 chromosomal translocations. The order of several genes in chromosomes X and Y in cats closely resembles that in humans.

Pet

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Cat and human resting in bed together.

Cats are common pets in all continents of the world, and their global population is difficult to ascertain, with estimates ranging from anywhere between 200 million to 600 million. In 1998 there were around 76 million cats in Europe, 7 million in Japan and 3 million in Australia. A 2007 report stated that about 37 million US households owned cats, with an average of 2.2 cats per household giving a total population of around 82 million; in contrast, there are about 72 million pet dogs in that country. Cats exceeded dogs in number as pets in the United States in 1985 for the first time, in part because the development of kitty litter in the mid-20th century eliminated the unpleasantly powerful smell of cat urine.

Although cat ownership has commonly been associated with women, a 2007 Gallup poll reported that men and women in the United States of America were equally likely to own a cat. The ratio of pedigree/purebred cats to random-bred cats varies from country to country. However, generally speaking, purebreds are less than 10% of the total population.

Fur

According to the Humane Society of the United States, as well as being kept as pets, cats are also used in the international fur trade. Cat fur is used in coats, gloves, hats, shoes, blankets and stuffed toys. About 24 cats are needed to make a cat fur coat. This use has now been outlawed in several countries, including the United States, Australia and the European Union. However, some cat furs are still made into blankets in Switzerland as folk remedies that are believed to help rheumatism.

Meat

Main article: Cat meat

It has long been common for cats to be eaten in some parts of China and in some other Asian countries and it is estimated that in southern China's Guangdong province people eat 10,000 cats per day. Animal People estimates that 4 million cats are killed and consumed in Asia every year. An animal rights group collected 16, 000 signatures in 2014 to outlaw the consumption of cat meat in Switzerland.

Pest control

Cats are also used as a form of pest control, particularly in the case of rat or mouse infestation.

Domesticated varieties

The current list of cat breeds is quite large: with the Cat Fanciers' Association recognizing 41 breeds, of which 16 are "natural breeds" that probably emerged before humans began breeding pedigree cats, while the others were developed over the latter half of the 20th century. Because of common crossbreeding, many cats are simply identified as belonging to the homogeneous breeds of domestic longhair and domestic shorthair, depending on their type of fur.

Cat coat patterns and colors

Cat coat genetics can produce a variety of colors and coat patterns. These are physical properties and should not be confused with a breed of cat. Furthermore, cats may show the color and/or pattern particular to a certain breed without actually being of that breed. For example, cats may have point coloration, but not be Siamese.

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Blue (grey) and white bicolor cat

Bicolor, Tuxedo and Van 

This pattern varies between the tuxedo cat which is mostly black with a white chest, and possibly markings on the face and paws/legs, all the way to the Van pattern (so named after the Lake Van area in Turkey, which gave rise to the Turkish Van breed), where the only colored parts of the cat are the tail (usually including the base of the tail proper), and the top of the head (often including the ears). There are several other terms for amounts of white between these two extremes, such as Harlequin. Bicolor cats can have as their primary (non-white) color black, red, any dilution thereof, and tortoiseshell (see below for definition).

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Mackerel tabby, showing the characteristic "M" on its forehead.

Tabby 

Striped, with a variety of patterns. The classic blotched tabby (or marbled) pattern is the most common and consists of butterflies and bullseyes. The mackerel or striped tabby is a series of vertical stripes down the cat's side (resembling the fish). This pattern broken into spots is referred to as a spotted tabby. Finally, the tabby markings may look like a series of ticks on the fur, thus the ticked tabby, which is almost exclusively associated with the Abyssinian breed of cats. 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.

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Female tortoiseshell-and-white cat

Tortoiseshell and calico

This cat is also known as a calimanco cat or clouded tiger cat, and by the abbreviation 'tortie'. In the cat fancy, a tortoiseshell cat is patched over with red (or its dilute form, cream) and black (or its dilute blue) mottled throughout the coat. Additionally, the cat may have white spots in its fur, which make it a 'tortoiseshell and white' cat; if there is a significant amount of white in the fur and the red and black colors form a patchwork rather than a mottled aspect, in North America the cat will be called a calico. All calicos are tortoiseshell (as they carry both black and red), but not all tortoiseshells are calicos (which requires a significant amount of white in the fur and patching rather than mottling of the colors). The calico is also sometimes called a tricolor cat. The Japanese refer to this pattern as mi-ke (meaning "triple fur"), while the Dutch call these cats lapjeskat (meaning "patches cat"). A true tricolor must consist of three colors: a reddish color, dark or light; white; and one other color, typically a brown, black, or blue. 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). Conversely, cats where the overall color is ginger (orange) are commonly male (roughly in a 3:1 ratio). In a litter sired by a ginger tom, the females will be tortoiseshell or ginger. Male tortoiseshells can occur as a result of chromosomal abnormalities (often linked to sterility) or by a phenomenon known as mosaicism, where two early stage embryos are merged into a single kitten.

Siamese cat, classical colorpoint pattern

Colorpoint

The colorpoint pattern is most commonly associated with Siamese cats, but may also appear in any domesticated cat. A colorpointed cat has dark colors on the face, ears, feet, and tail, with a lighter version of the same color on the rest of the body, and possibly some white. The exact name of the colorpoint pattern depends on the actual color, so there are seal points (dark brown), chocolate points (warm lighter brown), blue points (dark gray), lilac or frost points (silvery gray-pink), red or flame points (orange), and tortie (tortoiseshell mottling) points, among others. This pattern is the result of a temperature sensitive mutation in one of the enzymes in the metabolic pathway from tyrosine to pigment, such as melanin; thus, little or no pigment is produced except in the extremities or points where the skin is slightly cooler. For this reason, colorpointed cats tend to darken with age as bodily temperature drops; also, the fur over a significant injury may sometimes darken or lighten as a result of temperature change.

The tyrosine pathway also produces neurotransmitters, thus mutations in the early parts of that pathway may affect not only pigment, but also neurological development. This results in a higher frequency of cross-eyes among colorpointed cats, as well as the high frequency of cross-eyes in white tigers.

White cats

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White cat

True albinism (a mutation of the tyrosinase gene) is quite rare in cats. Much more common is the appearance of white coat color that is caused by a lack of melanocytes in the skin. A higher frequency of deafness in white cats is due to a reduction in the population and survival of melanoblast stem cells, which in addition to creating pigment-producing cells, develop into a variety of neurological cell types. White cats with one or two blue eyes have a particularly high likelihood of being deaf.

Smoke cats

The bottom eighth of each hair is white or creamy-white, with the rest of the hair being a solid color. Genetically this color is a non-agouti cat with the dominant inhibitor gene; a non-agouti version of the silver tabby. Smoke cats will look solid colored until they move, when the white undercoat becomes apparent. It is mostly found in pedigreed cats (especially longhair breeds) but also present in some domestic long-haired cats.

Body types

Cats can also come in several body types, ranging between two extremes:

Oriental

Not a specific breed, but any cat with an elongated slender build, almond-shaped eyes, long nose, large ears (the Siamese and Oriental Shorthair breeds are examples of this).

Foreign

Less slender than the oriental type, but nevertheless a cat with a slight build and generally athletic look. Typical example breeds would be the Abyssinian cat and the Turkish Angora.

Semi-Foreign

More or less the middle range of body conformation types, this type of cat is less slender without being stocky. Example breeds would be the Devon Rex and the Egyptian Mau.

Semi-Cobby

These cats look more rounded without looking too stocky. Example breeds would be the American Shorthair and British Shorthair.

Cobby

Any cat with a short, muscular, compact build, roundish eyes, short nose, and small ears. Persian cats and Exotic cats are two prime examples of such a body type.

Effects on human health

Because of their small size, domesticated house cats pose little physical danger to adult humans. However, in the USA cats inflict about 400,000 bites per year. This number represents about one in ten of all animal bites. Many cat bites will become infected, sometimes with serious consequences such as cat-scratch disease, or, more rarely, rabies. Cats may also pose a danger to pregnant women and immunosuppressed individuals, since their feces can transmit toxoplasmosis. A large percentage of cats are infected with this parasite, with infection rates ranging from around 40 to 60% in both domestic and stray cats worldwide. Research indicates a link between the parasite Toxoplasma gondii, which sexually reproduces exclusively in cats, and numerous human psychiatric conditions, including OCD. The compulsive hoarding of cats, a symptom of obsessive compulsive disorder (OCD), has long been associated with "crazy cat ladies".

Allergic reactions to cat dander and/or cat saliva are common. Some humans who are allergic to cats—typically manifested by hay fever, asthma, or a skin rash—quickly acclimate themselves to a particular animal and live comfortably in the same house with it, while retaining an allergy to cats in general. Whether the risk of developing allergic diseases such as asthma is increased or decreased by cat ownership is uncertain. Some owners cope with this problem by taking allergy medicine, along with bathing their cats frequently, since weekly bathing will reduce the amount of dander shed by a cat. There have also been attempts to breed hypoallergenic cats, which would be less likely to provoke an allergic reaction.

As well as posing health risks, interactions with cats may improve health and reduce physical responses to stress: for example the presence of cats may moderate increased blood pressure. Cat ownership may also improve psychological health by providing emotional support and dispelling feelings of depression, anxiety and loneliness. Their ability to provide companionship and friendship are common reasons given for owning a cat.

From another point of view, cats are thought to be able to improve the general mood of their owners by alleviating negative attitudes. According to a Swiss study carried out in 2003, cats may change the overall psychological state of their owner as their company's effect appears to be comparable to that of a human partner. The researchers concluded that, while cats were not shown to promote positive moods, they do alleviate negative ones.

One study found that cat ownership is associated with a reduced risk of heart attacks and strokes at the 95% confidence interval.

Several studies have shown that cats develop affection towards their owners. However, the effect of these pets on human health is closely related to the time and effort the cat owner is able to invest in it, in terms of bonding and playing.

Indoor scratching

A natural behavior in cats is to hook their front claws periodically into suitable surfaces and pull backwards. Cats, like humans, keep their muscles trim and their body flexible by stretching. Additionally, such periodic scratching serves to clean and sharpen their claws. Indoor cats may benefit from being provided with a scratching post so that they are less likely to use carpet or furniture, which they can easily ruin. However, some cats may simply ignore such a device. Commercial scratching posts typically are covered in carpeting or upholstery. Using a plain wooden surface, or reversing the carpeting on the posts so that the rougher texture of the carpet backing, may be a more attractive alternative to the cat than the floor covering. Scratching posts made of sisal rope or corrugated cardboard are also common.

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Close-up of a cat's claw.

Although scratching can serve cats to keep their claws from growing excessively long, their nails can be trimmed if necessary. Another response to indoor scratching is onychectomy, commonly known as declawing. This is a surgical procedure to remove the claw and first bone of each digit of a cat's paws. Declawing is most commonly only performed on the front feet. A related procedure is tendonectomy, which involves cutting a tendon needed for cats to extend their claws. Declawing is a major surgical procedure and can produce pain, and infections.

Since this surgery is almost always performed for the benefit of owners, it is controversial and remains uncommon outside of North America. In many countries, declawing is prohibited by animal welfare laws and it is ethically controversial within the veterinary community. While both the Humane Society of the United States and the American Society for the Prevention of Cruelty to Animals strongly discourage or condemn the procedure, the American Veterinary Medical Association supports the procedure under certain guidelines and finds "no scientific evidence that declawing leads to behavioral abnormalities when the behavior of declawed cats is compared with that of cats in control groups." They further argue that many cats would be given up and euthanized were declawing not performed.

Waste

Being fastidious self-cleaners, cats detest their own waste and instinctually bury their urine and feces. Indoor cats are usually provided with a box containing litter, generally consisting of bentonite, but sometimes other absorbent material such as shredded paper or wood chips, or sometimes sand or similar material can be used. It should be cleaned daily and changed often, depending on the number of cats in a household and the type of litter; if it is not kept clean, a cat may be fastidious enough to find other locations in the house for urination or defecation. This may also happen for other reasons; for instance, if a cat becomes constipated and defecation is uncomfortable, it may associate the discomfort with the litter box and avoid it in favor of another location.

Daily attention to the litter box also serves as a monitor of the cat's health. Bentonite or clumping litter is a variation which absorbs urine into clumps which can be sifted out along with feces, and thus stays cleaner longer with regular sifting, but has sometimes been reported to cause health problems in some cats.

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A toilet-trained house cat

Some cats can be trained to use the human toilet, eliminating the litter box and its attendant expense, unpleasant odor, and the need to use landfill space for disposal. An exhibit at the San Diego Natural History Museum states that cat feces from urban runoff carry Toxoplasma gondii parasites to the ocean and kill sea otters.

Genetic similarities with humans

The order of eight genes on the cats' Y chromosome closely resembles that in humans. Genes on X chromosomes of cats and humans are arranged in similar way.

Domestic cats are affected by over 250 naturally occurring hereditary disorders, many of which are similar to those in humans, such as diabetes, hemophilia and Tay–Sachs disease. For example, Abyssinian cat's pedigree contains a genetic mutation that causes retinitis pigmentosa, which also affects humans. The domestic cat is also an excellent model for human infectious diseases, including HIV/AIDS. Feline immunodeficiency virus (FIV) is a genetic relative of HIV.

See also

• Animal domestication
• Cat behavior
• Puppy cat