Among members of the animal kingdom, dogs have one of the best senses of smell. Their sense of smell, in fact, far surpasses our own.
They can pick up on scents at concentrations as low as one part per trillion, which gives their sense of smell about 10,000 times the accuracy of yours! It may come as no surprise, then, many dogs have jobs that require an exceptional sense of smell, from detecting drugs and explosives to cancer.
Dogs use smell as their main sense, says Dr Meaghan Thomas, DVM, veterinarian at East Ridge Animal Hospital in the USA. “This sense allows them to process real-time data of their current environment, in addition to past events.” For example, they can tell through smell whether a predator or prey has visited an area or if food is available.
Dr Thomas adds that this evolutionary trait has allowed them to survive and adapt. “We have utilised dogs’ trainability as well as their sense of smell for years,” she says.
Read on to get the details on which dogs ‘nose’ best, along with a closer exploration of the factors that make dogs so adept at detecting scents.
Which Dog Breeds Have The Best Sense of Smell?
When it comes to ranking dog breeds based on their sense of smell, many lists only consider the number of olfactory receptors a dog has. However, research is inconclusive about whether a single breed is a powerhouse for scent work. For example, you may get a German Shepherd but if they are stubborn and hard to train, you may not be able to utilise their nose’s powers.
- German Shepherds, like Belgian Shepherds and Malinois, can enhance their olfactory abilities, making them particularly well-suited to scent detection work
- Belgian Malinois
- Bloodhounds are another breed often cited for their exceptional sense of smell, thanks to their long ears and wrinkles, both of which help trap and retain scents
- Dachshunds
- Beagles
- Basset Hounds
- Pointers
- Retrievers, particularly Labrador Retrievers
- Harriers
- Coonhound
- Greyhounds
Only limited research has explored the reasons why some dogs do better at detecting scents than others. According to the general consensus, it’s possible to alter some dogs’ genes for scent receptors and fine-tune them, in a manner of speaking. “Couple that with breeding specific animals for their scent of smell, and we do see some noticeable differences in breeds,” Dr Thomas says.
Other factors, including behavioural traits and instincts, may come into play in certain sniffing scenarios. For instance, dogs trained to recognise disease in living organisms may need different scenting skills than those trained to identify landmines.
Are There Any Concerns With Breeding Dogs For Their Extreme Sense of Smell?
“A highly driven scent dog is a great tool in all lines of work, from biosecurity to police work. These dogs are saving lives daily,” Dr Thomas says. She adds, however, that the stronger drive a working dog has to do their job, the more they require to stay enriched.
High performance dogs need pet parents who have experience with reducing any negative or destructive behaviours that manifest due to under-stimulation or boredom, she says.
In a nutshell, your scent dog will need lots of enrichment activities and mentally stimulating dog toys to keep them happy and healthy, along with regular opportunities to exercise their unique talents.
How A Dog’s Sense Of Smell Works
The size and shape of a dog’s nose and snout can also play a role in how—and how well—they smell.
Dogs like Greyhounds and Whippets have long, narrow snouts that work well for tracking prey over long distances. Dogs like Pugs and Bulldogs, on the other hand, have shorter, broader snouts that are better suited to sniffing out scents in small, confined spaces.
Certain breeds do have more olfactory receptors than others, but a dog’s trainability can make them an even better scent detector. German Shepherds and Labradors, for instance, are known for their trainability and willingness to work, so they’re well-suited to scent detection jobs even though they have fewer olfactory receptors than some other breeds.
How Do Experts Measure A Dog’s Sense of Smell?
Experts can measure a dog’s sense of smell in a few different ways.
Specificity, for example, refers to a dog’s ability to detect a particular scent among other smells. Distance refers to a given range over which a dog can detect a scent.
But researchers can also determine how well a dog can pair a scent with a particular object, person, or behaviour.
Even so, measuring a dog’s sense of smell can pose some challenges. These tests don’t always give a complete picture of a dog’s sense of smell, since factors like their experience, trainability, and intelligence all come into play.
In other words, a dog trained to detect a particular scent may perform better in a scent detection task than a dog who’s equally capable of smelling but hasn’t received the same training.
All the Things Dogs Can Sniff Out
Dogs sniff everything from each other’s butts to critter trails. Your dog’s cold nose houses such an incredible sense of smell, they can even tell when you’re ready to leave the house!
A trained dog can detect a single blade of grass in multiple football field, not to mention sniff out all kinds of explosives, cancer, malaria, and even COVID-19, Dr Thomas says.
“Dogs are even used in conservation efforts to track invasive species—such as the python in the Florida Everglades. The possibilities of dog scent work are endless!”
