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Cats |
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All cats, from large jungle
cats to small house cats, belong to the CAT FAMILY, Felidae, order Carnivora.
This article discusses the domestic cat, Felis catus catus, a species indigenous
to the Old World that includes such related forms as the European wildcat,
F. catus sylvestris, the African wildcat, F. catus lybica, and perhaps
some other distinct groups. The domestic cat is apparently not a
separate species: there is evidence of hybridization and interfertility
between it and the wild races.
The domestic form is most
clearly related to the African wild race, which also ranges into areas
of the Middle East. Domestic cats acquired wild-type genes wherever domestic
populations were established near wild regions. Domestic populations
may therefore differ from one another because of such regional contacts.
Today, however, such genetic exchanges are limited to those few refuge
areas where wild cats have not been exterminated. |
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Cats
in history |
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The domestic cat has evolved
as an urban scavenger and may have originated about 8000 BC, when nomadic
humans settled into village life. From archaeological and anatomical
evidence, however, it is impossible to distinguish wild from domestic types
until New Kingdom times (1570-c.1085 BC) in Egypt.
The cat was then bred by
a religious cult and worshiped as a sacred animal. This episode of
cultism in Egypt has perhaps been exaggerated and, in any event, distorted
in terms of its implications for the domestication process. The cultism
was undoubtedly the culmination of a long-standing familiarity between
humans and cats but was not critical in bringing about the domestication
of the species. Although the cat cult was spectacular, the Egyptians
domesticated many species, from snakes to gazelles, and the cat may simply
have been bred to protect granaries from rodents.
The spread of domestic cats
appears to have followed the pattern of progressive urbanization.
The appearance of local domestic cat populations therefore correlates with
the spread of civilization from the Middle East, and domestic cats now
inhabit every continent except Antarctica and most of the world's oceanic
islands. Cats have reverted to a wild state in many habitats where
they were not originally found, and in some places they persist even though
humans have abandoned the area. |
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Distribution
of cats |
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Recent studies indicate
that cat populations range from sparse to more than 2,000 per square mile,
depending on several factors. The largest populations exist in urban
areas, especially in so-called Mediterranean climates, where opportunities
abound for year-round food and shelter. Only in certain regions such
as Western Europe and North America are cats kept as pets in numbers sufficient
to support such large, subsidiary industries as veterinary services, pet
foods and novelty products, welfare societies, and publications. Elsewhere,
cats are tolerated but not regarded as pets. Their impact on urban
ecology is difficult to judge, and basic studies to assess their role in
vermin control and as disease vectors are needed. |
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The
cat as scavenger |
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Apart from a decrease in
body size, the most notable anatomical contrast between domesticated and
wild cats is the increased intestinal length in the former. This
may correlate with the cat's turning from chiefly predatory to chiefly
scavenging habits, and the resulting reliance on a low-protein diet. Theoretically,
increased small-intestinal length would maximize absorption of amino acids
from a minimum protein diet.
Domestic cats, like their
ancestors and contemporary relatives, are twilight hunter-scavengers.
The urban domestic cat has largely shifted toward scavenging behavior.
One study of the stomach contents of stray city cats revealed that only
3 percent of their diet comprised rodents; the balance was garbage.
Many studies have been devoted
to the question of the depredations of cats on birds. Cats would
seem to have only a modest effect, and generalizations are risky. |
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Breeding
habits |
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Domestic cats, like their
wild relatives, are seasonally polyestrous; they breed more than
once a year, depending on conditions. The breeding cycle is controlled
by sensitivity to light. At equatorial latitudes, where there are
longer periods of daylight, cats may breed throughout the year and have
three or four litters. In temperate latitudes, they normally have
two litters a year, one in the early spring and another in late summer.
Domestic cats living under
artificial light may breed at any time. Reproductive life begins
at 7.5 months and continues until an advanced age--15 years or more.
The gestation period is usually 63 days, and the average litter is four
kittens, except for the usually smaller first litter, and litters born
to older females (8 years of age or over). |
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Health |
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A cat's normal body temperature
is 38.6 deg C (101.5 deg F), with variations of 0.5 deg C (1 deg F) above
or below. The critical environmental temperature for the cat is about
36 deg C (97 deg F), at which point its body temperature rises and the
cat begins to pant to cool itself. Cats have sweat glands both in
the pads of their feet (eccrine glands) and scattered over their bodies
(apocrine glands), but sweating is not a temperature-regulating mechanism
in cats.
One of the most common and
destructive cat diseases is feline viral rhinotracheitis, commonly called
FVR or cat flu. It is not contagious to humans or other animals.
An infected cat develops a fever in two to five days, begins sneezing and
drooling, and becomes lethargic. This is followed by a heavy discharge
from the eyes and nose, which tends to clog the nostrils and paste the
eyelids shut. Treatment consists of antibiotics to counter secondary
bacterial infections, cleansing the eyes and nose, and administering fluids
to offset dehydration. Feline distemper, also called panleukopenia,
feline enteritis or gastroenteritis, or cat fever or plague, is a common,
highly contagious viral disease characterized by its explosive course:
death may occur as soon as eight hours after the first signs of illness
appear. The virus is transmitted by even brief contact with contaminated
material. Dogs are not affected.
Fleas are tiny, dark red,
blood-sucking insects that may be seen moving quickly through the cat's
hair. Their droppings resemble particles of black sand, and the presence
of this gritty substance indicates an infestation of fleas, even if the
fleas themselves are not seen.
Fleas can be removed by
special shampoos, by powdering with rotenone insecticide, or by the wearing
of flea collars (if the cat is not allergic).
Roundworms are slender,
whitish worms, 2.5 to 10 cm long (1 to 4 in), with tapered ends. Heavy
infestation, especially in kittens, causes coughing, vomiting, potbelly,
bad breath, and stunted growth. Roundworms can be transmitted to
humans. Treatment consists of administering piperazine tablets.
As with other pets, cats
that roam outside the house can bring in parasites and transfer them and
the diseases they may carry to humans. Although studies of cats as
disease vectors are needed, few of the diseases appear serious; a
few cases of BRUCELLOSIS and, extremely rarely, of plague have been reported.
Pregnant women are cautioned about handling cats and their litter boxes
because of the possibility of transmitting TOXOPLASMOSIS to their fetuses;
the eventual effects of the disease when contracted before birth can be
quite serious. Cats may also transmit such infestations as ringworm and
roundworm, and some people exhibit a severe allergic reaction to the animals--most
likely, it has been suggested, to dried spittle on their fur. Cat-scratch
disease, a benign but sometimes painful disease of short duration, has
recently been found to be caused by a bacillus; despite its name,
the disease may be transmitted by many kinds of scratches besides those
of cats. |
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Senses
& Intelligence |
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Like all felids, domestic
cats have senses evolved to facilitate twilight predation. Thus,
they are especially well equipped to detect slight movements in semidarkness.
The field of visual overlap approximates that found in primates and gives
cats full depth perception.Cats are also extremely sensitive to sounds,
including frequencies beyond the range of human hearing. Sense of
smell is not greatly elaborated in felids, although there is some evidence
that olfactory cues are used in courtship behavior.
Domestic cats are apparently
no more or less intelligent than wild cats. They may be more versatile
than their wild relatives because of adaptations to urban life, but, originating
from basically solitary ancestors, they are not as tractable or malleable
as other domesticated species. Many of the apparent differences between
cat and dog behavior, for example, stem from motivation rather than innate
ability. Under controlled behavioral experiments, cats readily perform
highly complex tasks. |
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Breeds
of cats |
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The cat differs strikingly
from other domesticated animals, in that it has not, until recently, been
bred selectively. Hence, most of the observed genetic changes and
variations in cats probably result from inherent adaptations to domesticity
or to the perpetuation of novel anomalies. Most of the better-understood
genetic variations in cats relate to differences in color, pattern, and
texture of the coat, and to such minor skeletal peculiarities as taillessness
or supernumerary digits. Cats are remarkably similar in shape and
size.
The so-called breeds of
cats are normal variants in free-ranging populations that do not transmit
their traits generation after generation like pure strains. The Manx
cat did indeed originate from the Isle of Man as the result of a local
17th-century mutation, but it does not breed true. There is no evidence
that ABYSSINIAN cats are of Ethiopian origin, and PERSIAN cats are actually
more common in the Soviet Union than in Iran. The origin of most
of the older so-called breeds appears to be late 19th-century and early
20th-century England, despite the fanciful histories that are frequently
proffered. |
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