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Interesting articles about dogs
The dog is a canine omnivorous mammal that has been domesticated for somewhere between 14,000 and 150,000 years. In this time, the dog has developed into hundreds of breeds with a great degree of variation. For example, heights ranging from just a few inches (such as the Chihuahua) to nearly three feet (such as the Irish Wolfhound), and colours ranging from white to black with reds, greys, and browns also occurring in a tremendous variation of patterns. |
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The dog is known for its trainability, its playfulness, and for its ability to fit into human households and social situations. In some countries dogs are most often kept as pets, although a wide range of dog sports provides opportunities for dogs to exhibit their natural skills, and working dogs of all kinds still fill traditional dog roles such as herding sheep and cattle while moving into new jobs such as detecting contraband. They have lived with and worked with humans in so many roles that they have earned the sobriquet Man's best friend. 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. |
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Dog is also a term used by breeders to specifically denote a male domestic dog. The female is known as a bitch. A young dog is called a puppy. The words pooch and poochie are generic, generally affectionate terms for a dog. Many additional terms are used for dogs that are not purebred; see Terms for mixed-breed dogs.
Colour, Sound and Build
Modern dog breeds show more variation in size, appearance, and behaviour 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. |
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Their legs are designed to propel them forward rapidly, leaping as necessary, to chase and overcome prey. Consequently, they have small, tight feet, walking on their front toes; their rear legs are fairly rigid and sturdy; the front legs are loose and flexible, with only muscle attaching them to the torso.
Dogs have a form of colour-blindness that affects how they see red (same as yellow), green, and blue (both appear white). 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 sight hounds, 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°.
Dogs detect sounds in the 70-100,000 Hz frequency range (compared to 16-20,000 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. Dogs have about 220 million smell-sensitive cells (compared to 5 million for humans). Some breeds have been selectively bred for excellence in detecting scents, even compared to their canine brethren.
All dogs have a tremendous capacity to learn complex social behaviour and to interpret varied body language and sounds, and, like many predators, can react to and learn from novel situations.
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