Dogs are known as mans best friend because they were the first domesticated animals. The dogs have been kept by human beings for hunting, working and as a pet. They are a subspecies of the gray wolf and are related to jackals and foxes.
The characteristics of affection, loyalty, protectiveness and friendship have earned them an important position in the society. In hunter-gatherer societies they are used as bodyguards and hunting allies against predators. They can also serve as guardians of cattle, sheep and goats, they can also be used for companionship and social purposes. They can even be used for therapy in hospitals with the aim of encouraging patients toward recovery.
Dogs come in a large range of shapes and sizes, although they are all genetically identical having the same anatomic features. They have two sets of teeth with twenty-eight deciduous teeth and forty two adult teeth. Dogs do not chew their food, instead they gulp or swallow it once it is taken in the mouth. All dogs are running animals and can run over long distances except those that are bred specifically for different purposes.
Dogs have five senses although some senses are more highly developed, and others deficient. The sense of smell is the most acute and is better than that of human beings. This is the reason dogs are used to track missing persons, dig underground, and trace any type of toxic substances like gases. The sense of taste is not as developed but the sense of hearing is well developed and can detect noises that are well beyond the range of the human ear. They have a wide field of vision because their eyes are located toward the side of their heads. They are sensitive to touch and use it to communicate with one another as well as with human beings.
Dogs have growls, barks, and howls that are identified among themselves. Certain sounds made by dogs can enable the dog owner to determine if the dog is fearful, playful, warning of a stranger nearby, or hurt.
When determining the type of dog it is important to get a healthy dog, friendly, outgoing, the eyes should be shiny and bright, ears should smell clean, and the dog should have a good form and build.