The African elephant has 2,000 active olfactory receptor genes, the genes responsible for smell, making it the animal with the best sense of smell. Elephants beat out humans and dogs for a keen sense of smell, but that doesn't entail an elephant being trained to sniff out drugs or other scents like a canine.
An elephant's truck acts much like a hand. The elephant uses it to grab food, touch its surroundings and communicate with different elephant tribes. Every time the elephant touches something, it smells it. An elephant´s trunk gives them the ability to separate odor molecules and distinguish between them, a trait that humans and dogs cannot do.