What do dogs have that’s lacking in humans? Harry Truman, the straight-talking former president of the United States, remarked that, “If you want a friend in Washington, get a dog.” But friendship is not the dog’s only virtue. A dog’s nose has 220 million cells that detect odours compared to a mere five million in humans. And although none have yet graduated from The Harvard Medical School, they can often outsmart doctors in recognizing serious disease.
