A guide to your pup's sense of smell
The nose of your dog has a completely unique breathing system than humans do. When he takes a breath in, around 12 percent of the air travels into what's known as the "odor pocket" at the back of his nose, which is specifically designed for smelling. The remaining 88 percent of the air goes through his pharynx, and then it goes into his lungs. The air inside the pocket is passed via turbinates, which are bony structures arranged in a labyrinth and are responsible for separating scents into their component components depending on the chemical characteristics of those molecules.
The turbinates are lined with tissue that has olfactory receptors all over their surface. When molecules of an odor reach these receptors, the receptors identify the individual molecules based on their structure and then transmit electrical impulses to the brain of your dog so that it can process the information. The portion of your dog's brain that is devoted to processing scents is roughly speaking forty times bigger than the same portion of a human brain.
Consider that when you put a spoonful of sugar in your coffee, you can smell it, and that's how you should think of these statistics: as something that can be smelled. Your dog is able to detect a single grain of sugar even while submerged in a volume of water that is sufficient to fill two Olympic-sized swimming pools. Or think about the fact that you can smell cake. He is able to classify each and every component that is included in it.
Sense of scent
Your dog relies on its sense of smell more than its eyesight to see the world around it. His environment is rich with aromas that humans will never be able to comprehend fully. Because of this, dogs are quite excellent at detecting explosives and other potentially explosive devices, as well as concealed narcotics and other prohibited substances, as well as corpses that have been buried beneath snow, water, or debris. Because of this, they are also experts in search and rescue, as well as in following the footprints of missing children, hikers, and criminals who are on the run.