So you think you know how well a dog can smell? Well keep reading and you may learn a thing or two. Nothing beats the talents of a dog's snout except maybe Dumbo's trunk, but I'll get to that later.
Even though there are different numbers for how many olfactory (smell) receptors dogs have, we can safely say they have between 100 and 300 million depending on the type of dog it is. How many do humans have? Around six million.
The more air that's circulating, the better they can smell -- And we wonder why they love to hang their heads out the car window. That they're smelling the world isn't much of an overstatement.
As they sniff us when we come home after petting another dog, they're sniffing what kind of dog it was, its gender, and many other details. If only I could use that on my husband. They use their nose to get information like we use our eyes. Fascinating.
When they sniff a tree before they urinate on it, they can tell if Fido from next door has paid a visit or if it was a strange canine. That's why they face-plant their noses into you when you get home -- They're getting information on where you've been.
They can tell what you've eaten, who you've been in contact with, if you're on medications, and the state of your health just by sniffing you.
The fact they can "smell the past" is remarkable:
"...dogs can understand much about the past because of the extreme sensitivity of their noses."
"...odors change over time...the smell of you in the house decreases with each hour of your absence, and your dog can detect the difference."
The Bark
Simply put…
"Dogs can smell the passage of time."
PetMD
That explains why they can sniff out odors of a person who was previously in an area when they're tracking someone.
They can smell chemicals and hormones in our bodies like adrenaline which increases, as well as sweat, when we're afraid. (Yep, they can smell it.) It's also why they can sniff out illnesses like cancer and COVID-19.
"...the smelling section of a dog brain is 40 times larger than ours. In fact, one-eighth of a dog’s brain is dedicated to interpreting odor. That’s even bigger than the section of our brain dedicated to interpreting sight."
The American Kennel Club
And some dogs have a leg up on others when it comes to interpreting smells.
"As it moves along the ground, the bloodhound's giant, flappy ears help fan up odors to its nose, one reason the breed is the superstar of scent-tracking."
PBS/NOVA
It's easy to know now how a dog knows when you're coming home before you even pull into the driveway. In fact, a dog can smell something from as far away as 12 miles. Twelve miles! But it does vary depending on the dog, air circulation/the weather, what or who they're trying or trained to detect, and other conditions like the density of things in their path.
Imagine having the ability to smell ½ a teaspoon of sugar in an Olympic-sized swimming pool. That's how well a dog can smell. If we could do this, we'd be taking a few more showers a week. And not eating garlic.
But before your dog gets a big head and wants to walk away with the "World's Best Sniffer" trophy, other animals with just as good if not better smellers are bears, cats, sharks, and the king-daddy of them all...the African elephant who has the best sense of smell in the animal kingdom and can make dogs walk off with their tails between their legs mutt-ering, "So he can smell a mouse from a mile away. What's the big deal."
How the Heck Can Dogs Smell So Well?
Here's how it works: Dogs have two air passages -- one to smell and one to breathe. That alone differentiates their abilities from ours, but they can also break down the air into small molecules. Humans have one tiny area in our nasal cavity that smells pass over which we then exhale. So dogs can virtually smell continuously whereas we only have the ability to detect something on a quick inhale.
My canines have often pressed their noses against my skin and not sniffed like we do with an audible sound but with silence and intensity. The smells are permeating their senses with no interruption.
Dogs also have something called the Jacobson's organ that allows them to smell pheromones or chemical signals other dogs emit. It's why they can zone in on a dog who is ready to mate. This organ works independently or isn't interfered with by any other smells. It has its own nerves leading to the brain. Watch out, Toodles.
The olfactory receptors in dogs are so sensitive that even exercise, diet, and stress can affect them. Although humans generally don't want to eat something that smells bad, that sensitivity is far less than in dogs. Plus, we don't go for a run, come back and say, "By golly, I can now smell far better than before!"
Because of this sensitive ability, most of us know how vitally important a dog's nose is to law enforcement and other agencies and how much they are entrusted with the very lives of these men and women. Why?
"The ability to find the source of the scent, even in the presence of competing odors, makes the detection dog a critical partner in many military, law enforcement, and search and rescue operations."
Government Report -- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5884888/
This heightened sense and complete focus on their intended target is exactly why these dogs must take breaks after a relatively short period of time and even be replaced by a different dog -- it's taxing on them physically and mentally.
All the facts about this super-dog power isn't just made up or exaggerated. There have been thousands of scientists who have studied and tested their abilities and have come up with these certainties. There is someone right now in some laboratory who is studying if there is even more we don't know about a dog's sense of smell.
Now don't get me started on their ability to sniff out obnoxious people.
P.S. If you need blogs that will grab your customers' attention, gimme a shout! Contact me at jenflattosborn@writeawaycreations.com or here. And my tail will be wagging.
References:
1. Smithsonian Magazine -- "In Some Ways, Your Sense of Smell is Actually Better Than a Dog's" by Brian Handwerk -- www.smithsonianmag.com -- May 22, 2017
2. American Kennel Club -- "Why Does My Dog Sniff Everything?" by Stephanie Gibeault, MSc CBDT -- Nov 7, 2019 https://www.akc.org/expert-advice/training/why-does-my-dog-sniff-everything/
3. The University of Adelaide -- Faculty of Sciences -- "How Far Away Can Dogs Smell and Hear? -- By Dr. Susan Hazel and Dr. Eduardo J. Fernandez -- Posted by Sam Le Gallou -- This article is republished from The Conversation -- June 9, 2020 https://sciences.adelaide.edu.au/news/list/2020/06/09/how-far-away-can-dogs-smell-and-hear
4. The Labrador Site -- "How Far Can a Dog Smell: Your Dog's Amazing Nose" by Kristin Hitchcock -- June 24, 2018 -- https://www.thelabradorsite.com/how-far-can-a-dog-smell/
5. NOVA Nature -- "Dogs’ Dazzling Sense of Smell" by Peter Tyson -- Oct 3, 2012 https://www.pbs.org/wgbh/nova/article/dogs-sense-of-smell/
6. NCBI - PMC -- "When the Nose Doesn’t Know: Canine Olfactory Function Associated With Health, Management, and Potential Links to Microbiota" -- Frontiers in Veterinary Science -- By Eileen K. Jenkins, Mallory T. DeChant, and Erin B. Perry -- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5884888/
7. The Bark -- "Dogs Smell Passage of Time: Their Noses Take Them to the Past" -- By Karen B. London, PhD -- Nov, 2016
https://thebark.com/content/dogs-smell-passage-time#:~:text=Horowitz%20writes%20in%20her%20new,extreme%20sensitivity%20of%20their%20noses
8. PetMD -- "8 Dog Nose Facts You Probably Didn't Know" -- Editorial -- Jan 21, 2021 https://www.petmd.com/dog/behavior/5-dog-nose-facts-you-probably-didnt-know