A dog’s wet nose isn’t just cute. Their sniffing sense is one of their superpowers! Your dog’s nose helps them pick up all kinds of scents, turning them into expert detectives of the dog world.
Dogs have roughly 200–300 million smell receptor sites in their nasal cavity, compared to a human’s paltry six million receptor sites. The way a dog’s nasal cavity is constructed, along with the wet moisture on the outside, primes their nose to detect even very faint and distant scents.
Dogs can smell things from very far away. For instance, research has found that trained dogs can smell a wild tortoise from a distance of 60 metres, a rodent from 50 metres, spoiling meat from 200 metres, and whale faeces from just under two kilometers, says Dr Blake Gibson, a resident in behavioural medicine at Texas Veterinary Behavior Services.
Read on to learn more about a dog’s extraordinary sense of smell, along with the factors that affect their ability to sniff out everything, from garbage in a bush to those delicious treats you have hidden in your pocket.
Can Dogs Smell People From Far Away?
The exact detection range of a dog’s nose varies based on several different factors.
Dr Kenneth Martin, a board certified veterinary behaviourist, explains that the distance from which a dog can smell their person can depend on:
- the dog’s genetics (breed) and age
- the dog’s physical health
- any medications the dog is taking
- training
- environmental conditions, including the target odour, distractor odours, and the landscape or topography
- weather conditions, including humidity, rain, or the presence of snow or dew on the ground
Due to these factors, there isn’t necessarily a fixed range for how far a dog can smell a human.
Dr Martin also pointed out that some breeds, mainly hounds, have a much stronger sense of smell than others. The Bloodhound, for example, has large drooping ears and facial skin folds that appear to help aid scent collection. That’s one reason why this breed excels at tracking and trailing.
How dogs know when you’re coming home
A dog’s keen sense of smell can even help them predict when something will happen based on the strength of familiar odours.
For example, when you leave to go into the office in the morning, your scent in the house remains strong. But with every hour that passes, your smell diminishes—and your dog notices this.
This experience has taught your dog that when your odour inside your home has weakened to a certain point, you’ll come back—and that’s how they can ‘smell’ when you’re coming home.
Tip: Does your dog have a hard time staying home alone? Consider hiring a pet sitter or dog walker in your area. Having a companion stop by can help make the hours away from you pass more quickly, not to mention give your pup a new friend to sniff out!
Can Dogs Smell Health Conditions?
Increasing evidence suggests dogs can detect certain health conditions through their sense of smell.
According to Dr Gibson, there are many popular reports of untrained dogs detecting illness in their owners. This is likely because a dog’s sense of smell can pick up on subtle scent changes, such as those from someone with diabetes experiencing low blood sugar.
Some untrained dogs also seem to have the ability to detect a person’s stress level based on their scent!
Yet while untrained dogs may detect changes in a person’s scent, Dr Gibson says, reliable and accurate detection work requires training and validation. This training process helps make sure the dog picks up on the right scent and responds to that odour reliably.
Many service dogs are specifically bred and trained for this purpose. You may see a service dog sniffing their person when they sense a blood sugar drop to let them know to address it right away.
Experts are also exploring the possibility of training dogs to detect other human diseases, including cancer.
How far can a dog smell another dog in heat?
Dr Gibson says that while there’s not much research exploring how far a dog can smell another dog in heat, many sources report dogs can scent heat over about one to three miles. That said, many factors can affect this distance, including weather and a dog’s scenting abilities.
If your dog is in heat, it’s important to keep her secure inside your home or garden and on a lead for walks. Similarly, if you have an unneutered male dog, you can keep them from straying by walking them only on a lead!
Which Dogs Have The Best Sense Of Smell?
Certain dog breeds have been bred specifically for their sense of smell. These dogs, mostly hounds, have an increased surface area in their nasal cavity and an improved ability to breathe.
Dr Martin explains that dogs with long snouts (dolichocephalic breeds) and dogs with medium snouts (mesocephalic breeds) generally have a better sense of smell than dogs with short or flat snouts (brachycephalic breeds).
Hounds and other breeds known for their strong sense of smell include:
- Bloodhounds
- Beagles
- Basset Hounds
- Labrador Retrievers
- German Shepherds
Many of these breeds are popular as hunting dogs, since a keen sense of smell and the ability to find scent molecules are very important traits for this work!
Putting Your Dog’s Nose To Work
Regardless of your dog’s breed, engaging their amazing sense of smell is a great way to keep them entertained and mentally active.
Activities that give your pup a chance to use their sense of smell for enrichment are called nosework. These include scent-based games, snuffle mats, or scent detection in canine sports.
Many dogs also get professional training in detecting specific smells and following a scent trail. These types of trained dogs include:
- Sniffer dogs: trained to find explosives, narcotics, or chemicals.
- Search-and-rescue dogs: used to find living people.
- Cadaver dogs: these dogs are trained to find dead bodies.
Additionally, Dr Gibson adds that specially trained detection dogs can participate in many other fields, including:
- Conservation efforts: dogs can help find a particular animal, excrement, or remains.
- Medicine: trained dogs can detect seizures and raise an alert. They can also help detect pathogens, infections, diabetes, cancers, and more.
- Commercial and public health applications: dogs with specific training may help find risks like harmful mould in homes and other buildings.
- Agricultural purposes: farm workers can use dogs to detect animals in heat to optimise breeding.
Takeaway
Dogs have an incredible sense of smell that goes far beyond yours! Whether they’re tracking a familiar scent from miles away, detecting health conditions, or simply sniffing around on their daily walk, a dog’s nose is astonishingly impressive!
Getting your dog snuffle boards and other foraging toys can help them boost their natural scenting skills.
Scent reminders can also help keep dogs calm when you’re away—try giving them a worn T-shirt of yours or a blanket you sleep with. Your familiar scent can help ease any separation anxiety they feel when you leave. In short, you can use their own natural talents to help keep them feeling happy and loved!
