It’s All in the Nose, Just Ask a Dog
You don’t have to be a dog lover to know that dogs are famous for their sense of smell. There’s a good chance you have been given the “nose scan” by any number of dogs, most you may not have known. A dog is constantly monitoring its environment for food (particularly your food), companionship, a lover, danger, fear, for example in human sweat, and the weather.
It has been estimated that dogs have an acuity of scent ~10,000 times great that humans. It is well established that dogs can detect human diseases such as cancer and more recently, Covid-19. It is believed that when a dog inhales a breath that about 12% of the intake goes to the olfactory and the remainder down the windpipe to the lungs. The two hemispheres of the brain are wired to one of the two nostrils, depending upon the signal.
Which Breeds have the Best Sense of Smell?
You might guess that whenever a “best” list is published it leaves room for an argument. Regardless, here is one list that has been posted on-line.
- Bloodhound
- Basset Hound
- Beagle
- German Shepard
- Labrador Retriever
- Belgian Malinois
- Bluetick Coonhound
- Black and Tan Coonhound
- Golden Retriever
- Dachshund
What are the Built-in-Detectors?
A dog’s olfactory system is, depending upon the breed, connected to millions of smell receptors.
“Dogs have roughly forty times more smell-sensitive receptors than humans, ranging from about 125 million to nearly 300 million in some dog breeds, such as bloodhounds.[1] This is thought to make its sense of smell up to 40 times more sensitive than human’s.”
Did Early Humans have Keener Senses of Smell?
Recent research out of Duke University (USA) would suggest that possibly not so much fine-tuned but likely tuned into a different repertoire of odours.
“So then they tested the responses of 30 lab-grown olfactory receptors from each hominin against a battery of smells to measure how sensitive each kind of receptor was to a particular fragrance.
The laboratory tests showed the modern and ancient human receptors were essentially detecting the same odors, but their sensitivities differed.
The Denisovans, who lived 30,000 to 50,000 years ago, were shown to be less sensitive to the odors that present-day humans perceive as floral, but four times better at sensing sulfur and three times better at balsamic. And they were very attuned to honey.”
This note is dedicated to Bj. The kindest and most loving being we have ever been fortunate enough to have loved and with whom we shared our home. We were blessed in the truest sense of the word.
I hope that you have enjoyed reading this. Comments are welcome. Stay safe and keep well.
Zack Florence, May 28, 2023
