By Pam Bonsper
Have you ever taken your dog on a walk and been upset that she doesn't walk? Does she stop at every bush, post, rock, or leaf and just smell? "Come on," you say, "this is your walk. Let's get on with it."
My husband once said (when my dog took twenty-five minutes to go twenty-five feet) that I shouldn’t micromanage her walk. “Let her do her walk her way. After all, what would you do if your nose was in charge?"
He had a point. Rather than spending time looking at paintings or watching a movie (we humans depend much more on our sense of sight), I would probably spend most of my time in a bakery or coffee shop.
A canine's incredible sense of smell is widely known, but there are a few interesting facts you may not know. Let's see how knowledgeable you are.
1) Compared to humans, how much more powerful is a dog's sense of smell?
Anywhere from 1,000 to 100,000 times stronger. This is due, in part, to the percentage of the brain that is used for identifying scents. That part of a dog's brain is 40 percent larger than a human's. The strength ratio also depends upon the breed (length and size of nose). For example, a Dachshund has 125 million scent receptors, while a Bloodhound has 300 million. Humans have 5 million. This difference is due to the pattern of ridges and dimples and the outline of the nostril openings.
2) In a dog's world, what is the equivalent of a human fingerprint?
Why a nose print, of course. The nose print is a picture of the nasal pattern mentioned above. Nose prints are becoming more popular as a way of identifying lost or stolen dogs. You can take your dog's nose print. Just wipe his nose so it's nice and dry, pour food coloring on a paper towel and coat your dog's nose with it. Then hold a pad of paper to the nose, curving the pad around to pick up impressions from the sides. Remember to use nontoxic food coloring, never ink or paint.
3) Does a dog breathe the same way we do?
No. When we inhale, we breathe and smell at the same time. When a dog inhales, the two functions are separate. Rather than going to the lungs, about 12 percent of the air goes to a special area in the nasal cavity, which chemically analyzes the odors and sends the information to the brain. Dogs also exhale differently—the smells swirl around in their noses, allowing them to sniff more or less continuously.
4) Can humans wiggle their nostrils independently?
No. (Try it!) But dogs can. Also, the space between their nostrils is smaller. Both of these physical attributes allow dogs to locate and track the source of a smell.
5) What else helps scent-tracking dogs?
Their ears. For instance, a Bloodhound's ears are large and flop to the ground, fanning the odors to its nose.
6) Why did dogs develop such a strong sense of smell?
Before dogs were domesticated, they needed a way to locate food and hide from predators. Their sense of smell could mean the difference between life and death.
7) How does a dog's sense of smell aid humans?
While most of us are familiar with search and rescue dogs who sniff their way to trapped or lost humans, dogs can also locate and recover drowned bodies. They help farmers identify cows who are ovulating, notify beekeepers of bacteria that infect hives, and sniff out the polycarbonates in DVDs to catch DVD thieves. In wartime, they find tunnels and weapons and booby traps of the enemy. For diabetics, they can predict onset of a seizure and detect a rise in blood sugar. They can detect cancer cells by sniffing a person’s breath. Dogs help biologists monitor the health of whales by smelling and locating whale poop from more than a mile away. They can also find bedbugs before they are visible to the human eye, and they can even sniff out minerals and ores in rocks.
So the next time your pooch pulls at the leash and spends his walk time in a very common-looking bush, just remember—there are sensory treasures in that bush that you will just never be able to appreciate. Be patient. This is his time to enjoy. Look at the pretty sky and let him smell.
Answers for questions 1 and 2 taken from Understanding Your Dog For Dummies, by Stanley Coren and Sarah Hodgson
Answers for 3–6, from “Dogs’ Dazzling Sense of Smell,” by Peter Tyson, posted October 4,2012, http://www.pbs.org/wgbh/nova/nature/dogs-sense-of-smell.html
Answers for 7, from Adam Wears on Listverse: http://listverse.com/2013/01/17/10-unexpected-things-that-dogs-can-smell/