How Good Is a Dog’s Sense of Smell?

Dogs are super smellers, but do we really know how super they are?

They’re so good that they are used to sniff out drugs, explosives, weapons, and illnesses like diabetes and cancer.

Learn about your dog’s nose and why they love to sniff everything. Find out which dog breeds have the best sense of smell and whether all this sniffing is beneficial to you and your dog.

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Dogs sense of smell

How Good is a Dog’s Sense of Smell?

Dogs have an exceptional sense of smell. It’s their primary sense for understanding and interacting with their environment.

A dog’s sense of smell is up to 100,000 times stronger than ours.

Smelling gives them more information about their surroundings than what they learn with looking, feeling, hearing, or tasting. 

For example, dogs will know more about who was in your place and what’s in their food when using their nose than when they use their eyes.

Another example is how dogs greet each other. They transmit information via noses, and secondary to this are their barks, and paw shakes. 

Their sense of smell is so dominant that a blind dog will have less trouble coping with blindness than a human does. 

It’s unimaginable. The way they acquire information through scent is much more powerful than we can think of because our human noses are simply not wired like that.

They have way more scent receptors than we do. Around 300 million to our mere 6 million.

This means they devote a lot of brainpower to interpreting smells. The part of their brain for their sense of smell is 40 times larger than the part in the human brain.

The Anatomy of a Dog’s Nose

Your dog has a part of their brain called the Olfactory Bulb. It’s neural tissue that processes the scents detected by cells in the nasal cavity. 

As mentioned, the portion of a dog’s brain for smelling is much bigger than the human’s. Ours is dominated by the visual cortex, while our furry friends’ are dominated by the olfactory cortex.

Scent information goes from the Olfactory Bulb to the limbic system, the oldest part of the brain that is responsible for emotions, memory, and behavior.

As for the nose itself, it functions differently than our own. When we inhale, we not only smell but also breathe through one airway.

Dogs get a tissue in the airway folded when they inhale to separate the two functions. This means there are two paths, one for olfaction and the other for respiration.

The air we smell usually just goes in and out when we breathe, unlike with dogs who have a recessed area in the back of their nose for smelling and gathering more information. 

The air they smell filters through bony structures called turbinates.

Dogs Have a Second Olfactory System

Aside from all of that, dogs also have a second olfactory system due to their vomeronasal organ, or the Jacobson’s organ. 

It picks up pheromones, the chemicals that each animal species uniquely have that give information on mating readiness and other sex-related details. 

Why Dogs Have Wet Noses

The canine nose is more efficient and effective when it is damp. The outer nose must be moist and covered in mucus to capture scent particles.

Some dogs even lick their noses when they become dry so they can work better. They do not want to miss any important information just because of a dry nose. 

Dogs’ Noses are Unique

Each dog’s nose is unique, just like snowflakes or human fingerprints. 

Before micro-chipping became a thing, nose prints in dogs were used to identify them. 

Some owners take their dog’s nose prints and decorate them as a way to celebrate and remember them.

Why Dogs Like to Sniff

Now that we know how powerful a dog’s sense of smell is, you might continue wondering why dogs keep on sniffing stuff.

Dogs Like to Smell to Communicate

As mentioned, dogs smell differently than humans. It’s a huge part of doggy communication.

They like sniffing even the pavement on the street because they want to learn the scent marks of another dog in the neighborhood. 

Their sense of smell is so powerful that they can tell if the dog is a male or female. It also allows them to know if the dog is someone they know and if it is currently nearby.

You will also notice your dog sniffing other dogs’ bums in the park when they first meet. It’s just how they greet and get to know the other dog’s distinct smell.

Sniffing is also a way for dogs to reduce tension to let other dogs know they are not a threat. It’s an appeasement behavior that allows them to relax.  

Sniffing Makes Your Dog Feel Better

When your dog is doing a high-energy level activity, they may become overstimulated but still not satisfied.

On the other hand, dogs harness their sniffing as a natural way to calm and mentally stimulate themselves. 

They don’t have to run, bark, or jump to be occupied and happy. Sniffing is a relaxing option.

A study published in the Applied Animal Behavior Science Journal recommends sniffing opportunities for dogs to feel more optimistic.

This is also why olfactory stimulation on dogs is being done in rescue shelters. Most dogs in shelters need serious environmental enrichment.

When they bark excessively odors like vanilla, coconut, valerian, and ginger can reduce their stress.

Some essential oils can be useful in calming your dogs, and they can also get rid of dog fleas in the house and diffuse pet odor.

Dogs Like Stinky Things

Dogs like sniffing, but they especially prefer the stinky stuff. In the perspective of evolution, going to something smelly is a way to mask their scent and be better hunters.

But modern dogs don’t see it this way anymore. For them, it’s sensory overload. 

They make themselves smell bad the same way we like bright-colored shirts. It makes them feel dominant to stand out from other dogs. 

Other than making themselves stink, they enjoy smelling bad. Health, gender, location, and other information are more long-lasting when they have a strong smell.

Dogs Can Smell Ovulation in Humans

Dogs can pick up on human ovulation, which is why they sniff female human and animal crotches during certain times of the month.

Dairy farmers even help dogs capitalize on very short fertility widows for cows. They can also sense some types of cancer, diabetes, and some strains of infectious bacteria.

A dogs sense of smell

Why Does My Dog Sniff Me?

This is because your dog links your scent with pleasure. 

A study published in Behavioral Processes examined the areas of the dog brain that are similar to areas in our brains.

The researchers performed an fMRI on 12 dogs, including five service therapy dogs and the leader’s dog, Callie. 

They were presented with five scents on gauze pads, including a familiar human, an unfamiliar person, a dog in their household, an unfamiliar dog, and their own smell.

They found out that the scent of the familiar person activated the dogs’ caudate nucleus the most. This is a part of their brain that is associated with positive expectations.

What does this imply? Dogs recognize the scents of their human owners and associate them with positive expectations and feelings. It also means that our smells linger in their mind.

You don’t have to worry if your dog keeps sniffing you. They just really enjoy your smell.

Service Dogs Sniffing

This study is also beneficial for people with service dogs. 

More research through fMRI will be done by their team to focus on hand signals and if our furry friends’ reward responses depend on who gives the signals.

Dogs’ brains are so powerful. Pair that with their keen sense of smell.

Check out the story of Jackson, a service dog who can smell fluctuations in its owner’s blood sugar levels then alert them.

Benefits of Dog Sniffing

Sniffing has benefits for both of you and your dog.

Benefits of Sniffing for Dogs

We may never fully comprehend why we should let our dogs maximize their sense of smell. It’s because we can’t smell the same way dogs do, and we aren’t as interested as they are.

We understand the benefits of exercise and socialization, but sniffing is just as necessary. It is a part of mental stimulation for your dog that requires less effort and tools.

The scope of their ability is incomprehensible. Dogs can be trained to sniff bombs, bedbugs, and fugitives. They can even detect sickness and ovulation.

When we allow dogs to use their noses, they are less prone to destructive and aggressive behavior. 

It’s an outlet for them to use their energy instead of being anxious all the time, vigilant of threats, and barking at the air. 

This study shows that dogs spend 280% more time sniffing on a long leash than when they are on a short leash.

They also found that sniffing lowers dogs’ pulse even when they are walking—the more intense the smelling, the lower the pulse. 

The results imply that sniffing has the following benefits:

  • Sniffing calms dogs whether or not they are stressed.
  • Sniffing helps them manage and alleviate stress in dogs.
  • Sniffing is important to your dog’s physical and behavioral health.
  • Sniffing is crucial for dogs who are always anxious or have other behavioral issues.

Benefits of Dog Sniffing for Humans

Dogs get employed in hunting, police, military, and service jobs mostly because of their sniffing talents.

Dogs can find heroin, cocaine, marijuana, spices, and tobacco. You can even train them to find contraband like cell phones. 

With their strong sense of smell, k9 dogs can search an area four times faster than a human. They can also detect bombs and other threats, and track and find people by scent.

Service dogs, on the other hand, can smell threats like fluctuations in blood sugar levels. They can even detect warning signs of diseases like diabetes before they occur. 

They can also be trained to sniff different types of cancer, like skin cancer, breast cancer, and bladder cancer.

A study shows that dogs when trained, can detect breast cancer with 88 percent accuracy and lung cancer with 99 percent accuracy. 

However, dogs are not yet consistently used in labs to replace standardized testing because researchers do not know precisely what the dogs are noticing when detecting diseases.

Dogs have a good sense of smell

Dogs With the Best Sense of Smell

While all dogs have a great sense of smell, some have it stronger than others.

Here are the top dog breeds that have strong smelling abilities.

Belgian Malinois

The Belgian Malinois usually works with police and military forces to do Search and Rescue. They can also specialize in sniffing explosives, prostate cancer, and cheetah scat.

These dogs were originally bred to be herding dogs. Now they are also protection dogs, loving pets, and assistant dogs.

The Belgian Malinois is athletic, intelligent, and intense. Despite this, they are not suitable for first-time owners. 

They are obedient but they need a special type of attention. Otherwise, they can get stressed, bored, or reactive.

German Shepherd

german shepherd

German Shepherds are popular police and military dogs who work in Search and Rescue most of the time. 

These dogs also make their noses beneficial through narcotics detection. These devoted dogs are brave and versatile as well.

Aside from their keen sense of smell, German Shepherds do well at anything they are trained to do, whether it’s assisting disabled people, herding, or competitive obedience. 

Basset Hound

basset hound breed

The Basset Hound is a French dog that is known to follow scent trails. These stout and long dogs are called Basset Hounds as the French word “bas” means low. 

Their ears have a lot to do with their smelling ability. Their huge ears touch the ground and pick up scents to their nose so they can smell more effectively.

They also have loose skin beneath to trap the smell. This is called the dewlap and it locks in a scent to make it more accessible as the Basset Hound works.


The Bloodhound is bred to hunt using their sense of smell because of their 300 million scent receptors. 

As one of the oldest dogs, they work with law enforcement so accurately that the trial evidence they provide is accepted in the courts of law. 

Bloodhounds are highly intelligent and active. They also make great pets because they are affectionate, gentle, and good-natured.

Unleash Your Dog’s Sense of Smell

Unleashing your dog’s sense of smell is essential for mental stimulation. It also helps with scent training so they can maximize their sense of smell.

There is no need to sign your dog up for the police academy for them to learn basic scenting skills. 

What You Need for Dog Scent Training

There are two things you need for scent training, treats, and toys.

Choose a treat that your dog will love, not one that is sticky. It will be hard to train your dog if the residue from greasy treats ends up on your hands.

Try Wild Buffalo Wilderness Trail Treats

This yummy and crunchy treat is made of real meat, which will motivate your dog to obey you.

This dog treat also contains omega 3 and 6 fatty acids and antioxidants to keep them healthy. Wild Buffalo is available in the following flavors:

  • Bison
  • Salmon
  • Denali Biscuits with Salmon and Venison
  • Red Meat
  • Duck
  • Turkey
  • Duck, Salmon, and Turkey.

Scent training is also as simple as giving your dog toys. Try one that is small enough to hide somewhere, like this dog toy set from Yotachi

It contains six different toys for your puppy that are made of high-quality materials that are non-toxic and safe.

You can hide one in your palm or somewhere else for them to smell and track down.

Play Fetch Before Scent Training

A game of fetch with your dog can engage their mind and body to make them excited for the next important activity, which is scent training.

A game of fetch also mimics scent training in a way. The reward system sets the tone for them to learn.

But don’t tire your dog out during a game of fetch to keep them engaged later.

Play Shell Game

Prepare three large and opaque cups four feet apart and hide a treat under one. Then, point to every cup while saying, “find it.”.

You can tap each cup to let your dog know. 

When your dog finds the right cup, lift it up, give verbal praises, then give them a treat.

If they don’t, lift the cup and try again.

See it in action here:

Test Their Scent Outdoors

Once your dog has understood the basics of scent training from the shell game, it’s time to train them in an outdoor environment.

You can train your dog to ignore other smells in the park or the backyard and just focus on one scent, starting with a toy.

This training method will also allow them to phase out distractions like noises and other animals. 

All you have to do is place treats randomly outside in hopes that they will locate them by scent. 

Start with a close distance between the treats and place them in obvious spots. Then, gradually increase the distance and difficulty. 

Once your dog finds the first treat, they will quickly figure out that they can find more. 

FAQ Dog Nose

Can My Dog Smell If I’m Sick?


Dogs can sense if you are sick, but it’s not just through smell. Dogs follow us around everywhere and snuggle up at us at every opportunity.

They may notice something odd with your routine, feel that you are hot, or see that you are in pain.

But dogs can also smell sicknesses, such as lung cancer, on your breath if they are well-trained. They can also show information on blood sugar changes and ketone presence.

Dogs can also smell if we’re sad through the rise and fall in our hormones, including oxytocin, dopamine, and serotonin. 

Find out how else dogs sense that you’re sick and why they act weird when we’re sick.

Why is My Dog’s Nose Dry?

Dogs usually have wet noses, which is why we worry when they look dry. 

Most of the time, it’s not something to be concerned about. Some dogs naturally have drier noses too.

It also usually means that your dog woke up from a nap in the heat, whether near a heater or in the sun.

If your dog has a dry nose, maybe they just need a bowl of water. 

Keep them dehydrated all the time to avoid sickness. 

Your dog can only survive a short time without water.

Why Does My Dog Smell My Face?

If you feel your dog’s face near you, it’s either because they are smelling you or licking you.

When dogs smell your face, they are simply interested in your scent. There might be leftover food on your mouth, or your moisturizer smells pleasant.

It is also possible for dogs to sniff our faces to gather information and interpret the scented molecules of your sweat.

When your dog licks your face, then you taste good. They might like the taste of our flesh, or they are simply showing affection.

Find out why your dog licks your face, so you know how to attend to their needs.

The Canine Nose Knows

Your dog’s sense of smell is a lot more powerful than yours, that’s for sure. But to explain just how powerful is incomprehensible.

This is why you need to consider sniffing activities for dogs. When they don’t put their sense of smell to good use, they might not be mentally stimulated enough.

They may also use it for misbehavior, such as following you everywhere to gather information about you. 

If your dog does this, you need to know why they always follow you so you can respond to what they are trying to communicate.