Canine Senses & Cognition: Understanding How Dogs Perceive & Think About The World

By Norma Jeanne Laurette

Introduction

​Imagine a world where scent paints a clearer picture than sight and every sound tells a story – this is everyday reality for our dogs. Their senses are very different from ours because a dog’s senses are shaped by evolution to suit their specific needs. Scent drives their choices, sound alerts them to environmental changes and movement plays a key role in triggering communication, exploration and hunting instincts.

In order to better understand our dogs and their behaviour as well as how they experience the world, we should adjust our perspective and appreciate the unique ways their senses work.

Vision

Dogs do not see the world the way we do. While it was once a common belief that they are colour-blind, research has shown that dogs do see colours, primarily in shades of yellow and blue, whereas greens and reds are perceived as varying tones of grey R7.

Their ability to see in the dark is much better than ours because they have more rod cells in their eyes than we do. They also have a special reflective layer behind their retinas called tapetum lucidum, which also helps them to see more effectively in dim lighting R8.

Evolution has shaped canine vision to prioritize the detection of movement over fine detail, an adaptation crucial for hunting and survival. Because wild dogs primarily hunted during low-light conditions at dusk and dawn, their eyes evolved to enhance sensitivity to subtle movements in dim environments.

During our radio/television show we were ask if dogs recognize what they see on TV. While dogs are capable of perceiving images on a screen, their interpretation differs significantly from ours. Dogs primarily rely on contrast and movement to make sense of visual stimuli, which enables them to identify familiar shapes such as other dogs, animals or people, especially when these visuals are accompanied by relevant sounds such as familiar voices, barking or learned cues R14 R15 R16.

Each dog is unique and their attention to television varies based on factors such as personality, breed and training. For instance, herding breeds like Border Collies, Australian Shepherds and German Shepherds tend to be more responsive to movement on screen. Rather than watching TV as humans do, dogs primarily react to familiar visual or auditory stimuli R14 R17.
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The differences in perception can account for many misunderstood behaviours such as barking at shadows or chasing and pouncing on things we don’t see moving. Due to their unique traits, dogs use movement, contrast and brightness instead of detail or shape to identify what they’re seeing. This also explains why a dog may ignore a stationary object yet become concerned if it starts to move.

Hearing

Dogs have a remarkable advantage over humans when it comes to hearing, with auditory sensitivity approximately four times greater and an ability to detect sounds from much farther away. While humans hear frequencies ranging from about 20 Hz to 20,000 Hz, dogs can perceive sounds between 40 Hz and 60,000 Hz, which enables them to detect high-frequency noises that we can’t hear such as dog whistles R5. 

As well as their sensitivity to ultrasonic frequencies, dogs are excellent at pinpointing the origin of sounds. This acute hearing allows them to detect distant thunder, the movement of small animals in bushes and even high-pitched electronic noises that we can’t detect. Because of this, dogs can hear people and vehicles approaching from great distances, as well as a wide array of sounds that remain unnoticed by humans.
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While a dog’s extraordinary sense of hearing is invaluable, it can also contribute to challenges and misunderstandings regarding their behaviour and motivations. Dogs with a fear of fireworks, thunderstorms or other loud noises are not deliberately being difficult, they are responding physiologically to stimuli that are far more intense and overwhelming for them than they are for us R6. Now that we’re aware of how intense sound is for our dogs, we can be more compassionate and realistic during these times

Sense of Smell

Even more exceptional than all the other dog’s senses is its sense of smell, which is the most acute of all their senses. In fact, their sense of smell is estimated to be between 10,000 and 100,000 times greater than ours. That’s huge and it has big implications on what they perceive. To put this in perspective, a dog can smell a teaspoon of salt in 1 million gallons of water or a body of water the size of two Olympic-sized swimming pools. Compared to our 5 to 6 million scent receptors, dogs have 200 to 300 million depending on breed R10. The part of their brain that processes scent is approximately 40 times larger than ours R11. 

Dogs use their highly developed sense of smell to gather detailed information about their surroundings, including the presence of other animals and people, emotional states, health conditions and even the passage of time. For example, a dog can sniff the ground and determine that a specific person, dog or animal was there hours earlier and they are also capable of air tracking someone from considerable distances.

A dog’s extraordinarily sensitive sense of smell can explain behaviours we don’t understand. Many clients have reported their dogs barking or becoming anxious for no reason, yet these reactions can often be traced to odours we are unaware of. These behaviours could be triggered by lingering scents of other people or animals or even subtle changes in their guardian’s scent caused by stress, hormonal fluctuations or illness R12. Dogs have also been trained for medical detection, using their olfactory abilities to identify changes in human breath, sweat and saliva associated with conditions such as blood sugar imbalances and even cancer R13. Behaviours that seem unexplainable can often be linked to a dog’s remarkable sense of smell, which works hand in hand with their keen sense of hearing.

Studies show that dogs can gauge how long someone has been gone by the fading intensity of their scent, which can trigger emotional longing for the person or animal they have bonded with. Dogs can retain scent memories for years, as seen in cases where those reunited with their guardians after long separations often initially hesitate upon seeing them, but immediately respond with recognition and excitement once they catch their scent.

Memory

A dog’s memory is far more sophisticated than many people realize, though it functions differently from human memory in key ways. Rather than recalling specific events in detail, dogs rely heavily on associative memory. They remember people, places and other animals based on the emotions or experiences linked to them. For instance, a dog may remember where it chased a rabbit the day before, not because it recalls the details of the event itself but because it associates that location with excitement and fun R10.

Science has shown that dogs are capable of long-term memory. They can remember people, routines and training experiences for years, particularly when those experiences are emotionally charged, whether positive or negative R11. We’ve worked with many dogs showing signs of PTSD long after a traumatic event, reinforcing the depth and persistence of emotional memory in dogs.

Dogs do not have episodic memory in the same way humans do, meaning they are unlikely to mentally replay specific events with vivid detail. However, this does not imply limited cognition in fact, their lack of preoccupation with the past points to an efficient, evolutionarily adapted memory system designed for survival and present-moment awareness R12.

Canine memory evolved to support social bonding and survival. Dogs remember where to find essential resources like food and water, who can be trusted or should be feared and which behaviours lead to pleasant or unpleasant outcomes. These memory-driven associations form the foundation of effective training, especially when the trainer is consistent and uses positive methods. On the other hand, negative, frightening or painful experiences can damage the dog’s emotional wellbeing and human-canine trust bond. Ultimately, a dog’s memory is key to nurturing or destroying trust, and it’s memory that deepens their extraordinary connection with those who treat them with kindness, compassion and respect R13.

Just as certain smells can trigger vivid memories in humans, familiar scents can evoke emotional responses and memories in dogs as well. A particular person’s scent, a favourite blanket, or even the aroma of a familiar place can instantly transport a dog back to previous experiences, bringing comfort, excitement, or even anxiety or fear depending on the association. Scent is not just informative for dogs – it’s deeply emotional and tightly linked to their memory R18.

Social Cues

Understanding how dogs perceive and respond to social cues is essential for effective communication. Unlike humans who rely heavily on spoken language and facial expressions, dogs interpret communication through body language, posture, vocal tone and scent R9. For example, a person may believe they are being calm while correcting their dog, yet if they are hovering over the dog with an angry tone and emitting stress-related scents, the dog is likely to perceive the interaction as a threat. This emphasizes the importance of viewing interactions from the dog’s perspective. It’s not our intention that matters most – it’s how the dog interprets our behaviour. Miscommunication can lead to stress, anxiety, fear, reduced responsiveness and even aggression.

Research has shown that dogs tend to focus more on the right side of a human’s face when trying to interpret our emotions. This phenomenon, known as the “left gaze bias,” means dogs instinctively look to the left side of our visual field, our right side to gather emotional information. Interestingly, this mirrors the way humans interpret facial expressions, suggesting a deep evolutionary bond and advanced social sensitivity in dogs. By reading our facial cues, particularly around the eyes and mouth, dogs can detect subtle changes in mood such as joy, anger, or sadness, which helps them respond appropriately and strengthen their connection with us R19.

Dogs do not generalize learning in the same way humans do. A dog that responds reliably to a cue such as “sit” in your home may not respond the same way in a park or unfamiliar setting. It isn’t disobedience – instead it demonstrates their context-dependent learning. To help a dog generalize a cue, it must be practiced and reinforced in a numerous environments with a variety of distractions. Because dogs experience the world differently than we do, training must account for their unique sensory and cognitive perceptions. Doing so reduces frustration and increases the likelihood of success.

To truly understand our dogs and their behaviour, we must first understand how they perceive the world. What are their sensory strengths and limitations? How does their experience differ from ours? Dogs notice sights, sounds and scents that often go undetected by humans. By stepping into their world and adjusting our approach accordingly, we can better understand their emotions, motivations and needs. Unexplained behaviours usually have logical causes if we take the time to interpret their actions through their senses. Gaining insight into their perception is the key to improving communication and building stronger, more respectful relationships. Only by meeting dogs where they are can we become the guardians they truly deserve.

References

R1: Horowitz, A. (2016). Being a dog: Following the dog into a world of smell. Scribner. A deep dive into the dog’s olfactory capabilities and how it shapes their experience.
R2: Jones, B. M., & Joseph, R. J. (2020). Understanding canine olfaction: From detection to diagnosis. Veterinary Sciences, 7(4), 135. https://doi.org/10.3390/vetsci7040135
R3: Gazzano, A., Mariti, C., & Notari, L. (2021). The science behind dog anxiety: Causes, consequences, and management. Animals, 11(6), 1615. https://doi.org/10.3390/ani11061615
R4: Guest, C., Pinder, M., Doggett, M., Squires, C., Affara, M., Kallinikos, D. V., & Cobb, M. (2019). Trained dogs identify people with malaria parasites by their odour. Scientific Reports, 9, 9282. https://doi.org/10.1038/s41598-019-47838-6
R5: Heffner, H. E. (1983). Hearing in large and small dogs: Absolute thresholds and size of the tympanic membrane. Behavioural Neuroscience, 97(2), 310–318.
R6: American Kennel Club. (2022). How well can dogs hear? Retrieved from https://www.akc.org/expert-advice/lifestyle/how-well-can-dogs-hear/
R7: Miller, P. E., & Murphy, C. J. (1995). Vision in dogs. Journal of the American Veterinary Medical Association, 207(12), 1623–1634.
R8: Tanaka, Y., & Ueda, M. (2020). Visual motion detection and response in domestic dogs. Animal Cognition, 23(2), 315–326. https://doi.org/10.1007/s10071-019-01334-y
R9: Miklósi, Á. (2015). Dog behaviour, evolution, and cognition (2nd ed.). Oxford University Press. Comprehensive overview of canine cognition and social understanding.
R10: Fugazza, C., Pogány, Á., & Miklósi, Á. (2016). Recall of others’ actions after incidental encoding reveals episodic-like memory in dogs. Current Biology, 26(23), 3209–3213. https://doi.org/10.1016/j.cub.2016.09.057
R11: American Kennel Club. (2022). How long is a dog’s memory? Retrieved from https://www.akc.org/expert-advice/lifestyle/how-long-is-a-dogs-memory/
R12: Müller, C. A., Mayer, C., Dörrenberg, S., Huber, L., & Range, F. (2015). Female dogs remember more about an interactive game than male dogs. Animal Cognition, 18(4), 747–755. https://doi.org/10.1007/s10071-015-0849-y
R13: Horowitz, A. (2009). Inside of a Dog: What Dogs See, Smell, and Know. Scribner.
R14: Pongrácz, P., Miklósi, Á., & Csányi, V. (2001). Dogs’ (Canis familiaris) attention to human perception of visual stimuli. Animal Cognition, 4(2), 83-90.
R15: Williams, F. J., Mills, D. S., & Guo, K. (2014). Dogs’ attention towards visual stimuli on a screen: A pilot study. Journal of Veterinary Behavior, 9(6), e12.
R16: Neitz, J., Geist, T., & Jacobs, G. H. (1989). Color vision in the dog. Visual Neuroscience, 3(2), 119-125.
R17: Coren, S. (2004). How Dogs Think: Understanding the Canine Mind. Free Press.
R18: Horowitz, A. (2016). Being a Dog: Following the Dog Into a World of Smell. Scribner.
R19: Racca, A., Amadei, E., Ligout, S., Guo, K., Meints, K., & Mills, D. S. (2012). Animal Cognition, 15(5), 1023–1032. https://doi.org/10.1007/s10071-012-0539-6

Photo By Norma Jeanne Laurette