Puppies are born blind and deaf. Dogs' eyes and ears remain closed for about 14 days after birth, but Paul Waggoner says, "pups come out smelling; that's how they interact and get around the world."
No one knows what makes a dog's sense of smell so sensitive, but Waggoner, co-director of Auburn University's Canine Performance Sciences Program, says olfaction may be "the most 'preserved' sense -- it's probably the most ancient one."
By most estimates, dogs have 40 times as many olfactory receptors as humans do -- 220 million versus 5 million. Studies using rats, another animal with superior sniffers, suggest that even when 95 percent to 98 percent of the receptors are degraded, a sharp sense of smell remains intact.
Yet what might be most striking is not that dogs can detect odors at parts per trillion ("like a splash of Kool-Aid in a swimming pool," Craig Angle, a co-director of the program, said) but that they can discriminate among so many scents. Arson investigators have witnessed this for years, as dogs sift through smoldering ruins to find accelerants. "Think of it like picking out someone's voice in a crowded conversation," Waggoner said. "Dogs can detect a very small sample amidst a lot of odor noise."
ActiveStyle on 08/03/2015