Happy lovely dog

The dog has been selectively bred over millennia for various behaviors, sensory capabilities, and physical attributes. Dogs are subclassified into breeds, which vary widely in shape, size and color.They perform many roles for humans, such as hunting, herding, pulling loads, protection, assisting police and the military, companionship, therapy, and aiding disabled people. This influence on human society has given them the sobriquet of "man's best friend."