Researchers identify why a dog's nose knows

You know that most pooches can sniff out a kibble even before the food bag has been opened. A new study sought to understand the science behind these smelling abilities. Their findings may spark more research into lifesaving machines for people.

Researchers at Penn State University in State College, Pa., created a computer model of a canine nose in hopes of understanding how air and odors reach a dog's olfactory recess. They first scanned the nasal airway of a mixed-breed dog with high-resolution magnetic resonance imaging. Then, the researchers fitted various breeds with a special muzzle that measured the dogs' rate of sniffing. Finally, they mapped the flow of air into the dogs' noses to calculate the nostrils' aerodynamic reach.

The researchers found that dogs typically sniff about five times per second, regardless of breed. They also found that when dogs sniff, each nostril pulls in a separate odor sample. Through the olfactory recess, dogs can determine which nostril is pulling in a particular scent, which tells them the correct direction to go when tracking. In addition, a dog's nose has an airflow pattern that transports odor molecules through a single airway to the olfactory recess. Here, the odor is retained in the dog's scent receptors, even after the dog exhales.

Why all this sniffing into the science of, well, sniffing? The findings could be useful in developing artificial nose machines that help people find narcotics, explosives, or even people trapped in disaster sites. In the meantime, you can continue your amazement with the next canine patient's ability to smell the cat in the exam room next door.