Think You Know Dog Noses?

Think You Know Dog Noses?


Your dog’s nose may seem like a scary alien from outer space, but understanding how it works may be the key to unlocking some of your dog’s most confusing behavior.

For instance, did you know that there’s actually a reason your dog’s nose is always so cold and wet? Or that it makes just as much sense for him to smell another dog’s urine during your daily walks as you checking social media when you’re bored at work?

It may not surprise you that dog noses are much more complex than ours, and far superior for gathering information. But maybe these other 15 facts about dog noses will:


1. Dog Noses are Different from Human Noses

Human and dog noses both have two nostrils divided by cartilage and a bony septum.

While humans have one passageway for breathing, the nostrils in dog noses operate independently. So when a dog finds a smell and breathes in, that air can take two different paths. Air going the first path helps the dog identify which scents he’s come in contact with, while air traveling the second path is used solely for breathing purposes

2. Dogs are Not Waiting to Exhale

To make sure sniffing takes priority, dogs don’t exhale through their nostrils like we do. If you take a look at your dog’s nose, you’ll notice slits on the outside of each nostril. This is where your dog’s exhaled air is released. New smells are inhaled directly into the nostril, without the distraction of exhaling air getting in the way.

3. Wet Noses Mean Secret Powers

The rhinarium, or the tip of the dog’s nose, is usually cool and moist. Dogs have glands inside their noses that produce moisture and lubrication for their nostrils. When dogs sniff new smells, this mucus allows the odor molecules to dissolve and travel in the breathed-in air until the scent receptors identify the specific odor molecules.

“Once the odour is recognised, a pathway of tiny nerves relay signals to the brain area dedicated to olfaction — the olfactory lobe — which then interprets the odours in combination with other specialised areas of the brain.”

Without this wet mucus, it would be harder for dogs to identify the smells of their world.

4. Dog Sniffing is an Art

During sniffing, your dog will flare his nostrils to open a direct passageway to his scent receptors in the olfactory area of his brain. Sniffing is defined as a series of rapid inhalations and exhalations used to identify an odor quickly and effectively. Sniffing can happen as many as three to 30 times and may disrupt normal breathing if done over and over again.

Each nostril is capable of smelling from separate areas, so the smells go into a dog’s nose like sounds come in stereo for us.

5. A Dog’s Sense of Smell is His Super Power, CC-BY-SA-3.0 ( or CC BY-SA 2.5-2.0-1.0 (], via Wikimedia Commons

Called “a nose with a dog attached,” the bloodhound’s scent-tracking ability is so keen his results are admissible evidence in court.
(Photo by Pleple2000)

Dogs have the ability to smell 10,000 to 100,000 times better than humans because their noses are 1,000 to 10 million times more sensitive than ours.

To give you an idea of what that means, humans have five million scent receptors, but dogs can have 125–300 million scent receptors depending on their breed. Case in point: bloodhounds, a breed “unrivaled for its scenting powers,” have a staggering 300 million scent receptors.

The part of a dog’s brain responsible for assessing olfactory messages is 40 times larger than a human’s. Your dog doesn’t have a sniffing problem: 33% of his brainpower is devoted entirely to odor detection. Our human odor computer only takes up about 5% of our brainpower.

6. Dogs Make Great Undercover Agents

Dogs are able to detect smells we could never be able to find on our own. This is a big help for officers searching for missing persons, hidden drugs, or thoroughly sweeping crime scenes.

While we can’t see the microscopic skin cells we shed every day (around 50 million per minute!), dogs are able to smell all of them. When people go missing, dogs will help by tracking their skin cells left behind, which is something humans cannot do.

Police dogs can tell the difference between identical twins. While this may fool the eyes of a human, dogs are trained to use their noses.”

Additionally, dogs have very specific and picky senses. They can isolate and identify a single scent even when it’s masked by several others. This is how they’re able to smell illegal drugs packed in layers of concealment, landmines, bombs, volatile organic compounds (VOCs), and even cancer.


Dogs really can sense our emotions with help from their noses.

7. Dogs Can Smell Fear

You know how your friend who’s scared of dogs always seems to be surrounded by a circle of them? When people are afraid, their heart rate and blood pressure become elevated, which pushes certain hormones and chemicals to the surface of their skin. Dogs can smell these hormones and chemicals, so they are fully capable of understanding fear and stress.

Dogs use this ability to smell adrenaline to track down fleeing suspects, lost animals, or children who’ve accidentally fallen down wells.

8. There’s a Secret Language in Dogs Smelling Each Other

Your dog’s behind has a unique and informative smell. Since dogs don’t have Facebook, they need to learn about other dogs in the neighborhood by smelling each other’s bums.

Dogs can tell if they’re smelling a male or female, if the other dog is friendly or scared, how old they are, and even what they may have eaten for breakfast! Your dog will remember these smells and associate them with the other dog the next time they meet.

Cohabitating dogs sniff each other’s behinds to assess their emotional states after stressful times, or after playing in a new park. Some dog trainers even believe this act of smelling has a calming effect on dogs and helps them feel secure in their environment and around others they have already vetted.

9. Dog Love to Smell Another Dog’s Urine

Don’t get frustrated when your dog spends an inordinate amount of time smelling other dogs’ urine. Dogs have to store new smells in a designated olfactory chamber in their nose until they can completely identify it— which takes more than a few whiffs.

Dog urine contains a slew of information about the dogs in the neighborhood, such as how old they are, if they’re in heat, and their emotional states, but it may take awhile for your dog to completely bookmark all those smells. When he understands everything, he’ll then leave his own mark as a response to the others.

10. Some People Think Dog Noses are Used for Video Game Controllers!

Check out outlandish ideas like this on Snopes.

Check out outlandish ideas like this on Snopes.

The soft, squishy feeling of certain video game joysticks may be eerily reminiscent of your dog’s nose. But despite the rumors and myths, thumbsticks are made of the same mostly-plastic material as the rest of the controller— not canine noses.

11. A Warm, Dry Nose Does NOT Equal Sickness

Since a cold, wet nose seems to be the norm in dogs, many pet owners worry when their dog’s nose feels warm or dry. But dog noses fluctuate in temperature and between wet and dry all the time.

When their noses are dry, dogs will typically start licking them to reactivate their scent smelling power.

Here are six reasons your dog’s nose may be dry, according to Petful:

  • Your dog just woke up from a long time of not licking his nose
  • Sitting too close to an inside heat source in the winter
  • Allergies
  • Negative reaction to plastic
  • Sunburn
  • Dehydration

Moreover, you can’t measure a dog’s temperature by feeling his nose. You’ll still need a thermometer to make sure his temperature is within the normal 99.5–102.5 degree range.

This myth may have started due to the prevalence of distemper before modern day vaccines. During advanced stages of canine distemper, dogs will develop a thickening of the nose and footpads, causing them to become harder and drier. Therefore, a wet nose was seen as a welcome sign of good health.

However, canine distemper is much less common now, so dry noses are normally not an issue. If you start to notice discoloration, cracks, flakiness, or non-clear discharge, speak with your vet about your concerns.

12. A Really Wet Nose Means Something Else

We all know that dogs pant to cool themselves off, but dogs also sweat and release heat through their paws and nose. A super wet nose may mean your dog is extra hot from all the playing around outside.

Clear discharge is fine, as long as it doesn’t occur with other unusual symptoms. On the other hand, a runny nose with discharge that’s “cloudy, yellow, green, or smelly” may trigger the need to speak with your vet.

PetMD says these are the most common causes for your dog’s runny nose:


Allergies are by far the most prevalent reason for clear nasal discharge. Your dog may be allergic to a certain food, drug, pollen, and even human dander (shedded skin cells), among other triggers.

If your dog has an allergy, you may notice other symptoms appearing such as:

  • Itchiness
  • Breathing problems
  • Sneezing
  • Coughing
  • Nosebleeds

Speak with your vet about an allergy test, an elimination diet, and possible antihistamine treatment.


If you notice discharge from one particular nostril and not the other, your dog may have something obstructing his breathing path. Your dog may sneeze to try and remove the object or paw at his nose. Nosebleeds sometimes occur with just mild trauma.

It’s common for broken blades of grass, small bugs, or stray debris to get accidentally stuck in your dog’s nostril. If you can easily see the problem, you can remove it very carefully with tweezers (if your dog can stay still). Call your vet if you don’t feel comfortable dislodging the item. You’ll want to use antibiotics to prevent an infection after the object is removed.


Seeing pus or discolored mucus from your dog’s nose could be a sign of a bacterial, viral, or fungal infection. Smelly odors, coughing or choking, and nosebleeds may also happen as a result of postnasal drip.

Bacterial infections will need antibiotic treatment, while a fungal infection may require topical anti-fungal medication.

13. Your Dog Can Have Nosebleeds

Most sudden and minor nosebleeds are caused by upper respiratory tract infections or everyday trauma (such as bumping into a wall during playtime).

To stop your dog’s nose from bleeding during an episode, follow these steps:

  1. Keep your dog as relaxed as possible; excitement will raise his blood pressure and increase bleeding.
  2. Find an ice pack or a small bag of frozen vegetables to place on top of your dog’s muzzle, or bridge of his nose, to constrict the blood vessels and decrease blood loss. Make sure your dog can breathe.
  3. Your dog’s nose should stop bleeding, but if it continues or hampers your dog’s normal breathing, contact your vet as soon as possible.

Dogs may swallow blood during their nosebleed, which may give you cause for alarm when you see black stools or even vomiting later that day. Rest assured, this is normal due to all the iron in blood.

More serious nosebleeds demand immediate medical attention. Your vet may want to run tests and evaluate your dog’s medical history if the nosebleed occurred suddenly and without a cause, or will not stop.

14. Reverse Sneezing Happens

Sneezing is when air is rapidly expressed out of the nasal cavity.

Reverse sneezing, also known as the pharyngeal gag reflex, occurs when it sounds like a dog is quickly pulling air into his nose. Dogs may make rapid, extended inhales while standing still and extending their head back. You may also hear a loud, snorting noise.

Reverse sneezing, as explained in this video by Dr. Karen Becker, can last for a few seconds to as long as a minute.

The most common trigger for reverse sneezing is a soft palate irritation. This causes spasms that narrow the airways, making it hard for dogs to breathe in air. Your dog may be using forced air as a reflex to remove irritants from his larynx or the upper area behind the nostrils.

Irritations can be the result of:

  • Eating or drinking
  • Excitement
  • Allergies
  • Foreign chemicals (cleaners, perfumes, sprays)
  • Nasal passage obstruction
  • Viral infections
  • Pneumonia
  • Respiratory tract mites
  • Post-nasal drip
  • A cleft palate
  • Nasal tumors
  • Dental diseases
  • Tugging on a leash or collar

Dogs that are unvaccinated or under vaccinated are at a much higher risk of developing infections, which may cause excessive sneezing.

Reverse sneezing may be strange to witness, but it’s harmless for dogs to experience. No treatment is needed and there are no long-lasting health effects.

Keep in mind that certain breeds make reverse sneezing noises that sound similar to serious respiratory conditions. If your dog has chronic reverse sneezes, speak with your veterinarian for more information.

15. Dog Nose Prints are as Unique as Fingerprints

The equivalent of fingerprints in humans is not paw prints in dogs— it’s actually nose prints.

Dog Nose Prints are as Unique as Our Fingerprints.

Dog Nose Prints are as Unique as Our Fingerprints.

Every single dog has a unique nose print that’s used as a way to identify them. Insurance companies now ask for nose prints if a dog is to be bonded. All dog breeders and trainers now have to keep nose prints of their dogs for their permanent records and insurance purposes.

Keeping your dog’s nose print on file could help identify him if he’s ever lost or stolen.

There’s more than meets the eye when it comes to dog noses. From their powerful scent-tracking abilities to their penchant for neighborhood dog gossip, dogs devote significant brainpower to using their noses.

Take care of your dog’s nose and look out for unusual signs such as discolored discharge, crusty or bloody edges, and abnormal breathing patterns. The more you know about your dog’s nose, the easier it will be to spot when something’s wrong.


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