How dogs see the world trough their nose
Updated: Sep 2
When I come home from my daily outings, I always get profoundly investigated by my dog's schnoz. And I often wonder what information he gathers. After weeks of observation, I have noticed something very interesting. He can determine where I've been, who I've been with, and how frequently I see them. He can even identify a particular scent of the culprit's home indicated by his signature wiggle and small woof of recognition. Familiar odours don't hold his interest for long and he quickly turns away, but takes his time exploring any new ones.
Have you ever stopped to think about what you smell right now? Most of us don’t spend much time noticing smells around us. Our senses are overwhelmed by sights and sounds, and smell often takes a backseat. When we do notice odours, it’s usually because it is enticing or offensive, but rarely, because they provide useful information. Our comparatively modest olfactory abilities simply limit how much of that information we can perceive.
But for dogs, their noses are much more than a decorative feature on the muzzle. It is the leading moist headliner and sophisticated biological sampler that guides them through life, helps them explore, communicate, navigate, identify and generally understand the world of rich landscape of scents, dense with detail - much of it invisible and almost entirely inaccessible to us.
How humans experience smell
Humans rely heavily on vision. We take in vast amounts of visual information every day, often without consciously attending to it and frequently overlook our sense of smell.
Our noses are relatively simple and clumsy, compared to dogs. When we sniff, air enters and exits through the same nostril, and we often have to take deep, almost hyperventilating breaths to get a strong whiff of something. Our olfactory system also adapts quickly to many odours in environment, meaning, we stop noticing smells after a relatively short time, such as sitting in a room for several minutes, we may cease to notice its odour altogether. This adaptation helps us avoid sensory overload but limits our ability to gather ongoing information from odors.
We might detect a pleasant aroma of freshly brewed coffee or the sourness of spoiled food, but we typically don't consider what these smells reveal about our surroundings: who has been in the room, how recently were they there, what they touched, or whether their physical state has changed. As a result, smells seldom provide us with detailed information.
Dogs live in a world of smell
Since I started paying more attention to the vast amount of information dogs can gather from simple sniff, I see them with very different eyes now. Try to watch a dog investigating an intriguing patch of ground and the process becomes visible. The nostrils flare. The muzzle quivers. The head shifts by tiny increments. Sometimes the dog pauses, lifts its nose into the breeze and appears to read the air itself. That pause is not idleness. It is analysis.
Humans (and other beings) constantly shed microscopic fragments of skin, oils, bacteria and other organic compounds. Our clothing, shoes, hair and breath carry a changing chemical signature. We also acquire traces of odour from the places we visit and the people or animals we encounter. Dogs experience the world primarily through their noses and to a dog, a person is not identified solely by their face or voice. We have a very distinct odor. Yes. Let's say it. We do reek. Our armpits are a significant source of scent, our breath can be confusing (and very apealing) and our skin is covered in sweat, oils, and with bacteria. All that creates a unique signature "Eau De Parfum".
Their sense of smell is far more sensitive and complex than ours. While humans have about 5-6 million olfactory receptors, dogs have around 200 (as sheepdog) to 300 million (such as a beagle). This difference means dogs can detect scents at incredibly low concentrations and distinguish between many more odors. We might notice if our coffee has been sweetened with one teaspoon of sugar but trained dogs can detect that teaspoon of sugar in an olympic size pool of water.
The number of receptors is only part of the story. When a dog sniffs, it’s not just breathing in air. Sniffing is an active process involving quick, sharp inhalations that pull air deep into the nasal cavity. The muscles around their nostrils work to create a strong current of air, allowing odour molecules to reach specialised receptor cells. Because the external nostrils can move independently, it helps the dog to detect the direction from which an odour is arriving. At the same time, some of the air is pushed deeper in to the nose, or out through side slits at the side of the nose and backwards out of the way, clearing the way for new scent to be inhaled. This complex airflow system helps dogs continuously refresh the scent information they receive and sample the environment repeatedly without waiting for an entire breath cycle to finish.
Dogs do not adapt to smells the same way as we do. They may ignore the general smell of a home while immediately noticing that a new person has entered it. A familiar human odour may hold little interest, whereas the scent of an unfamiliar animal can provoke an extended investigation.
This distinction between detection and attention is important. Dogs may be able to perceive an odour without considering it relevant and their behaviour reflects not only what they smell, but also what they have learned to notice. They are capable of detecting scents that have become imperceptible to us, but it would be inaccurate to say they never adapt to odours. Like other animals, they can habituate to familiar smells. The difference is that their olfactory system is vastly more sensitive, and they can often redirect their attention or detect subtle changes that escape human notice. They continuously analyse odours without losing sensitivity. This capability enables them to track scents over long distances and notice subtle changes in the odour and their surroundings. This is incredibly useful not only for search and rescue dogs but also for our family members. For them tracking someone or something is wonderful game of going through clouds of molecules we leave behind.
The dog's exceptional sense of smell and their ability of detecting certain chemical signals, including pheromone-like compounds involved in social and reproductive communication is largely due to an additional organ called the "Vomeronasal Organ." This small bone in the nose is situated above the roof of the mouth along the floor of the nose, where sensory cells process pheromones (chemical information) released by other animals or specific odour information. Keeping the nose moist also helps capture tiny odour molecules and dissolve them more readily, allowing them to travel easily inside.
We leave traces everywhere
Our skin, breath, hair, clothing and footwear collect environmental odours. Porous objects that we spend a lot of time in such as slippers, shoes, socks, clothes or bedding they become extension of ourselves. We don't even need to touch a specific object for the dog to smell us. We leave an olfactory trail of skin cell, dehumidifying sweat and organs chemicals. A person’s scent is a composite of genetics, diet, hygiene, health, environment and daily activity. It is not static. it changes over time.
Dogs can often differentiate between people who appear identical to us, including identical twins. Their visual appearance may be nearly indistinguishable, but their individual chemical signatures differ. Their olfactory recognition is similar to our visual recognition of someone. The cocktail of odours is responsible for how we look to our dogs including how we feel that day, not to mention that you failed to share that bacon sandwich this morning.
But odours are subject to decay and dispersal. A smell of nearby object may not reach the nose immediately if the breeze carries it in the opposite direction and the strength of odour diminishes over time so the odour image of a person or object may be concealed to a dog momentarily.
Most dogs can tell from novel, new or old odour, but trained dogs can notice even very small changes in odour over time. The concentration of an odour from, for example, a footprint, diminishes and changes with every second that passes. A trained dog can tell the direction that the person has came from and where they moved next, based on the differences in the odour of each footprint. So if you are planning escape, unless you are wrapped in a scent prof body bag, the hound will find you.
Bloodhounds are the super-smellers among dogs. Their extra body features like more nose tissue, long ears to fan more scent up toward the nose or the stream of drool to gather extra liquid up to the nose, enables them to have this “ increased superpower”. Short legs of basset hound have extra advantage to have the whole head closer to the scent level.
Although, dogs can smell changes in mood and health of other animals, some changes might be very gradual. It also takes a litle bit of training for the dog to pay attention to a specific smell and for humans to pay attention to the dog’s behaviour indicating that they have found the smell you are after or teach them specific indications. Otherwise most odours, apart perhaps your afternoon snack or nearby bitch in heat, are not much of an interest to your dog.
In the human world, we leave our scent behind inadvertently, but in the dog’s world, leaving scent for others to find has a great social use. Urine marking is one of those methods of note making - and leaving. Those notes contain all sorts of information, such as who the marker is, how often they walk there, their recent victories, health, sexual status and interests. This one invisible pile of scent becomes a community centre bulletin board where old deteriorating announcements get replaced by recent posts of activities.
What dogs learn from smelling
Have you noticed when you greet your or a friend's dog, they often come closer and nuzzle you first, they are most likely gathering your unique scent and news story of the day.
At some point, we've all had the pleasure of being welcomed by the excited and curious canine host, that heads directly for the "private parts". For them, these odour-producing areas provide very valuable information. Human social customs make such greetings sometimes a little awkward. Dogs naturally have no such inhibition. To them a close olfactory inspection is not rude - it is informative, and discouraging such greetings is like blindfolding yourself when opening a door to a stranger. The same principle explains why dogs sniff one another’s hindquarters as scent glands in that region produce individual chemical signals and interrupting every sniff can deprive a dog of valuable social information. Of course, safety and consent still matter, but ordinary, relaxed sniffing is a normal part of canine communication.
For dogs, sniffing is a way to investigate and understand their surroundings. When a dog stops to sniff something, it is gathering detailed information about that object or area. This could include:
Identifying other animals or people who have been there
Detecting food or potential dangers
Learning about the emotional state of other dogs through scent markers
Mapping out their territory or following a trail
Dogs can even detect changes in the environment that humans cannot perceive, such as the presence of certain chemicals or the health status of a person or animal.
The importance of smell in dog's behaviour
Smell shapes much of a dog’s behavior. It influences how they interact with other dogs, find food, navigate their environment and to communicate. By marking territory and creating landmarks with urine or gland secretions that carry messages to other dogs and having the ability to detect and interpret these chemical signals helps them understand social hierarchies, reproductive status, or emotional states. It is a rich olfactory communication and a key part of how dogs live and interact.
Understanding dogs' sense of smell can enhance our care and training methods. Next time you take your dog out, consider their perspective and allow them to sit and sniff the air, enjoy a scent-filled walk, and pause at landmarks they find intriguing. Being outdoors is the most aromatic and delightful part of their day.
Allow time for sniffing during walks. Dogs gather important information through sniffing.
Use scent-based games. Hide treats, toys or family members for your dog to find using their nose. This stimulates their natural instincts and provides mental exercise.
Be aware of environmental scents. Dogs may react to smells we don’t notice. Try to pay attention to their behavior and surroundings.
Respect their sniffing space. When dogs are investigating scents, let them. This is how they learn about their world.
Scent helps anxious and fearful dogs to gather information safely. The fear of unfamiliar and unpredictable things in environment is one of the most common cause of overreaction or shutting down.
The richness of the olfactory world
In a book " Another day another collar" by Steve Mann, he describes his small christmas tradition with his dog Alfa. On the morning of Christmas Day, Steve gathers turkey giblets and a few other items that are landmarks evidence and goes out tracking with Alfa. A christmas treasure hunt. Leving Alfa in the car at first, Steve would go and lay the track with items (evidence) and taking several turns along the way. The treasure (giblets for Alfa) are then placed at the end of the track. The scent that Alfa is tracking is composed not only from Steve's footsteps and body odour, but also the disturbed soil and vegetation.
I love watching my dog when we go tracking - searching for people. How excited he is the moment he gets out of the car and is so keen to get going because he knows what we are bout to do. The moment he sniffs the starting point scented evidence of a person we are going to search for, he changes. His mind is in working but ecstatic mode. Working the ground and navigating the dificult ever changing swirls of air. For him the price at the end is the satisfaction of finding the person with matching odour, and of course a big piece of cheese or favourite meat. And then proudly with head held high trotting back to the car.
Now gather your treasures and go hunting together - live their world for a minute!
While humans live in a world dominated by sight, dogs live in a world dominated by smell. Their noses open a door to a complex and detailed environment that we can only imagine. By appreciating this difference, we can better understand our canine companions and the unique ways they experience life. Next time you watch a dog sniff, remember that they are exploring a rich, invisible world that surrounds us all.
How dogs see the world trough scent handout free download
Comments