A Dog is a member of genus Canis (canines) that forms part of the wolf-like canids, and is the most widely abundant carnivore. The dog and the extant gray wolf are sister taxa, with modern wolves not closely related to the wolves that were first domesticated. The dog was the first domesticated species and has been selectively bred over millennia for various behaviors, sensory capabilities, and physical attributes.
Their long association with humans has led dogs to be uniquely attuned to human behavior and they are able to thrive on a starch-rich diet that would be inadequate for other canid species. Dogs vary widely in shape, size and colours. Dogs perform many roles for people, such as hunting, herding, pulling loads, protection, assisting police and military, companionship and, more recently, aiding handicapped individuals. This influence on human society has given them the sobriquet "man's best friend".
Domestic dogs have been selectively bred for millennia for various behaviors, sensory capabilities, and physical attributes. Modern dog breeds show more variation in size, appearance, and behavior than any other domestic animal. Dogs are predators and scavengers, and like many other predatory mammals, the dog has powerful muscles, fused wrist bones, a cardiovascular system that supports both sprinting and endurance, and teeth for catching and tearing.
The dog's senses include vision, hearing, sense of smell, sense of taste, touch and sensitivity to the earth's magnetic field. Another study suggested that dogs can see the earth's magnetic field.
Here you can download free PNG dog and puppy pictures
In this gallery "Dogs" we have 86 free PNG images with transparent background.