"Here's that disgusting tainted water you enjoy drinking, human."

Approximately 160 million years ago, the modern dog's earliest mammalian ancestor walked the earth as a frightened little vole-like creature called a synapsid. After about 120 million years, their lineage broke away from other mammals to form the Carnivora order with their sharp meat-eating teeth and fierce flesh-tearing claws. 

Around 8 million years ago, the first wolves emerged from the crowd of Canidae relatives and established themselves as truly intelligent and fearsome hunters, and it was only about 32,000 years ago that a strain of those wolves broke off, allowed themselves to become domesticated by humans and turn into dogs as we know them.

Sources: Josh Ace | h/t Laughing Squid