Overview of the Dog Sniffing Science

A dog’s sense of smell is up to 100,000 more acute than that of a human’s. Dogs can detect tiny amounts of odor -- around one part per trillion. This means dogs can detect a teaspoon of sugar in a million gallons of water; or two Olympic-sized pools. A dog can detect one rotten piece of apple in two million barrels. When making an analogy to human vision, what you can see at 1/3 mile away, a dog could see at more than 3,000 miles away, just as clearly. This means your dog could see the Statue of Liberty from anywhere in the United States.

Dogs can exhale and inhale air all at the same time. Try this! This is so the canine nose can engage in continuous non-stop sniffing. The dog’s nose has two functions, one for sniffing and one for respiration, and they work independently of each other. Pretty amazing.

Dogs smell in stereo. The dog's brain uses different odor profiles from each nostril to help determine where an odor is located in the environment.

A dog has 300 million scent receptors in the nose, while a human has only 5 million, and 40% of the dog’s brain is dedicated to analyzing odor.

A dog can isolate a specific odor from a scent. When you smell bread baking in the oven, you smell a combination of odors, or the scent of baking bread. The dog can easily detect whether the flour being used has been bleached by chlorination or not, because the dog can detect each of the ingredients being used, and even the ingredients within the ingredients.

The dog has a second scent-detecting organ that humans do not have. This organ is called the vomeronasal organ, and it helps dogs to detect and analyze pheromones, or the chemicals released by animals of the same species. This is likely what your dog is doing when they sniff out other interesting canine smells.