dog

dog

The dog (Canis lupus familiaris), Brazil also called dog is a canine mammal, wolf subspecies, and perhaps the oldest domesticated animal by humans. postulate theories that emerged from the gray wolf in Asia for over 100,000 years. Over the centuries, through domestication, humans made an artificial selection of dogs for their skills, physical characteristics or types of behavior. The result was a wide range of dog breeds, which vary in size and coat within their own races, currently classified in different groups or categories. The designations mutt (in Brazil) or mutt (in Portugal) are given to crossbred dogs or mongrels descendants.

With life expectancy ranging between ten and twenty years, the dog is a social animal, most often accepts its owner as "head of the pack" and has several features that make it highly useful to man. It has an excellent sense of smell and hearing, it is good hunter and strong runner, relatively docile and loyal, intelligent and with good learning ability. Thus, the dog can be trained to perform a number of useful tasks, like a hunting dog, guard or herder, for example. As human beings, is also a victim of diseases like the common cold, depression and Alzheimer's disease, as well as the aging characteristics, such as vision and hearing problems, arthritis, and mood swings.

The affection and company of this animal are some of the famous phrase reasons: "The dog is man's best friend", since there is no record of friendship so strong and lasting between distinct species as the human and dog. This relationship appears in films, books and magazines, mentioning even different real stories from different times and in various nations. Among the most famous dogs that lived and societies are marked Balto, Laika and Hachiko. In mythology, Cerberus is said one of the scariest beings. In film, Lassie is one of the most widespread names and, in animation, Pluto, Snoopy and Scooby-Doo for decades are part of childhood for generations.