Before urine tests and blood tests existed doctors were trained to smell the breath of their patients to determine blood glucose levels. However some researchers believe that dogs are possibly 100,000 times more able to smell than humans.
According to James Walker, director of the Sensory Research Institute at Florida State University in Tallahassee, canines' sense of smell is generally 10,000 to 100,000 times superior to that of humans.
It is unclear what exactly makes dogs such good smellers, though much more of the dog brain is devoted to smell than it is in humans. Canines also have a greater convergence of neurons from the nose to the brain than humans do.
"The dog's brain and nose hardware is currently the most sophisticated odor detection device on the planet," McCulloch, the study leader, said. "Technology now has to rise to meet that challenge."