Do Dogs Smell Fear? Understanding the Science Behind Canine Detection

Can Dogs Smell Fear? Understanding Canine Reactions

Has anyone ever told you, “Don’t show fear” when you encounter a strange dog? The belief that dogs can literally “smell fear” and might react aggressively is common. This advice is actually good — not because dogs sense fear directly, but because they react to the emotions they perceive from their humans. So if you’re afraid, they will likely sense that and become uneasy too.

• Dogs can detect chemical signals associated with fear.
• Their acute sense of smell allows them to pick up these subtle cues.
• Body language, along with these chemical signals, helps dogs understand human emotions.

But how exactly can dogs smell fear? The short answer is: Yes, dogs do smell fear through the chemical signals our bodies produce under emotional conditions like fear and stress. This ability, combined with their interpretation of body language, allows them to sense when we are afraid.

For more insights into reading your dog’s body language, check out this resource: Body language.

A Dog’s Nose Knows: The Power of Canine Scent Detection

Without question, the nose is the best source of information for the average dog. According to The Psychology of Dog Ownership authors Theresa Barlow, PhD, and Craig Roberts, “Some 200 million or so scent receptors make it much more sensitive than the human nose.” Some estimates suggest dogs have around 300 million scent receptors, compared to the roughly 6 million that humans possess.

• Dogs can detect a wide range of scents, such as the individual ingredients in a pizza or the various human and animal scents present in a person’s clothing.
• This heightened sense of smell enables dogs to perceive subtle cues that are invisible to humans, such as the presence of other animals or environmental changes.

With their highly developed sense of smell, dogs use their noses to gather information about the world around them. They can detect not only the scents of objects and people but also changes in chemical signals that might indicate fear or anxiety in humans. This ability underlies the belief that dogs can smell fear.

Dogs’ remarkable scent detection capabilities are utilized in various roles, including assisting in tracking missing people, detecting drugs and explosives, and identifying medical conditions like early-stage cancer, post-traumatic stress disorder, and seizures. Their role in detecting these conditions supports the idea that dogs can smell fear, as they can sense the chemical changes in our bodies associated with different emotions and physical states.

In recent developments, dogs are even being trained to detect the novel coronavirus that causes COVID-19. These COVID-19 detection dogs are expected to screen up to 250 people per hour with high accuracy, even in asymptomatic cases.

For further information on this topic, consider exploring the following references:

• The Psychology of Dog Ownership
• Human Scent Receptors
• Dogs Used as Assistants
• Tracking Missing People, Drugs, and Explosives Detection
• Detecting Early-Stage Cancer
• Post-Traumatic Stress Disorder
• Seizures Detection
• COVID-19 Detection Dogs

This revised content focuses more on the scientific aspects and less on anecdotes, while still highlighting the key points about how dogs smell fear and other scents.

How Do Dogs Smell Fear? Understanding Chemosignals in Canine Detection

The question of whether dogs can detect emotions has intrigued researchers. A study published in Animal Cognition in January 2018, led by neurobiologist Biagio D’Aniello, PhD, from the University of Naples Federico II, explored this phenomenon. The study investigated if dogs could detect chemicals related to human emotions, particularly fear, in sweat.

Researchers collected armpit sweat samples from male volunteers under different conditions:

• Happy Videos: Sweat from men watching happy videos.
• Scary Videos: Sweat from men watching scary videos.
• Control: No sweat, used as a control.

These samples were then presented to Labrador Retriever and Golden Retriever participants to sniff. The study showed that dogs can indeed “smell” fear, as dogs exposed to “fear sweat” had higher heart rates and demonstrated more stress compared to those exposed to “happy sweat.”

The findings suggest that interspecies emotional communication is facilitated by chemosignals, confirming that dogs can detect chemicals produced by the human body when we are afraid. For more details, you can read the Animal Cognition Study.

And Not Just Dogs: Horses Can Smell Fear Too

The intriguing research on animals detecting human emotions through chemosignals didn’t stop with dogs. Some of the same researchers conducted a similar experiment with horses, revealing surprising results. According to a study publicized in July 2018, horses can also smell your fear or happiness.

These findings pave the way for further studies on human-animal communication through emotional chemosignals. A November 2019 follow-up article in the journal Animal highlights that while these chemosignals can trigger an emotional response in animals, it’s still unclear if these reactions are automatic or learne

Why You Shouldn’t Show Fear: Managing Dog Interactions

Body language plays a critical role when interacting with dogs. Unfortunately, humans often engage in behaviors that can trigger dogs’ defensive instincts, such as:

• Staring directly at a dog: Direct eye contact can be seen as a challenge or threat, making dogs uncomfortable. As Kirk A. Janowiak explains, this behavior can establish or challenge dominance.
• Facing a dog straight on: This can be perceived as aggressive. Dr. Sophia Yin, DVM, an animal behavior expert, suggests standing slightly sideways to avoid seeming confrontational.
• Hitting or threatening a strike: This not only appears aggressive but also signals to the dog that they must defend themselves. Dr. Yin advises interacting in a calm, gentle manner.

As a professional pet sitter, I’ve learned that staying calm and avoiding these behaviors can help de-escalate a potentially aggressive situation. In cases where a dog approaches aggressively:

• Avoid direct eye contact.
• Turn your body slightly away.
• Speak calmly and avoid yelling or striking.

While your fear may emit certain chemical signals, your body language can signal to the dog that you are not a threat. This can buy you time until the dog’s owner intervenes or help arrives.

If you find yourself in an area with potentially aggressive dogs, consider carrying a citronella-based deterrent spray or an air horn. In an incident this past May, three dogs escaped and attacked a FedEx driver, underscoring the importance of being prepared. As dog trainer Stephanie Colman advises, staying calm can help prevent escalation.

Everyone experiences fear, and dogs can detect it. However, by controlling your behavior, you can better manage the situation and minimize risk. For more tips on handling aggressive dogs, refer to our comprehensive guides.

For more on how dogs smell fear, check out this quick video:

Do Dogs Smell Fear? Final Thoughts

A dog’s nose is an extraordinary organ, providing them with a heightened sense of smell that reveals a rich tapestry of the world around them. This ability allows dogs to detect subtle scents and chemical signals that humans can hardly imagine. Whether it’s the smell of other animals, food, or even the emotions we emit, dogs’ noses are constantly gathering information.

It’s no wonder dogs spend so much time sniffing around. Even objects we find unpleasant, like feces or dead animals, can be fascinating to dogs because of the complex and detailed information they perceive through their scent receptors.

While humans don’t possess this super-advanced scent network, it does give us a glimpse into the intricate and sensory-rich experience of a dog’s daily life. It certainly makes one wonder what a day in the life of a dog truly feels like, doesn’t it?

Frequently Asked Questions (FAQ)

References

• Barlow, Theresa, PhD, and Craig Roberts. The Psychology of Dog Ownership. Taylor & Francis. 2019. 26. https://www.google.com/books/edition/The_Psychology_of_Dog_Ownership/6VKWDwAAQBAJ?hl=en&gbpv=1&pg=PA26.
• Tyson, Peter. “Dogs’ Dazzling Sense of Smell.” PBS. Oct. 4, 2012. https://www.pbs.org/wgbh/nova/article/dogs-sense-of-smell/.
• Fox, Kate. “The Smell Report.” Social Issues Research Centre. http://www.sirc.org/publik/smell.pdf.
• Buzhardt, Lynn, DVM. “How Dogs Use Smell to Perceive the World.” VCA Hospitals. https://vcahospitals.com/know-your-pet/how-dogs-use-smell-to-perceive-the-world.
• D’Aniello, Biagio, Phd, et al. “Interspecies Transmission of Emotional Information Via Chemosignals: From Humans to Dogs (Canis Lupus Familiaris).” Animal Cognition 21, no. 1 (January 2018): 67–78. https://pubmed.ncbi.nlm.nih.gov/28988316/.
• Lesté-Lasserre, Christa. “Study: Horses Can Smell Human Fear, Happiness.” The Horse: Your Guide to Equine Health Care. Jan. 17, 2019. https://thehorse.com/164973/study-horses-can-smell-human-fear-happiness/.
• Lanatà, Antonio, PhD, et al. “A Case for the Interspecies Transfer of Emotions: A Preliminary Investigation on How Humans Odors Modify Reactions of the Autonomic Nervous System in Horses.” Conference Proceedings of the IEEE Engineering in Medicine and Biology Society (July 2018): 522–525. https://pubmed.ncbi.nlm.nih.gov/30440449/.
• Semin, Gün R., PhD, et al. “Inter- and Intra-Species Communication of Emotion: Chemosignals as the Neglected Medium.” Animals (Basel) 9, no. 11 (November 2019): 887. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6912305/.
• Janowiak, Kirk A. “How Do Animals Perceive Eye Contact From Other Species?” Forbes. Sept. 20, 2016. https://www.forbes.com/sites/quora/2016/09/20/how-do-animals-perceive-eye-contact-from-other-species/.
• Yin, Sophia, DVM. “Preventing Dog Bites by Learning to Greet Dogs Properly.” May 17, 2011. CattleDog Publishing. https://drsophiayin.com/blog/entry/preventing-dog-bites-by-learning-to-greet-dogs-properly/.
• Treffeisen, Beth. “Dennis Dogs Quarantined After Attack on Delivery Driver.” Cape Cod Times. May 14, 2020. https://www.capecodtimes.com/news/20200514/dennis-dogs-quarantined-after-attack-on-delivery-driver.
• Colman, Stephanie. “Tips on Stopping a Loose Dog from Approaching You.” Whole Dog Journal. Oct. 12, 2017. https://www.whole-dog-journal.com/behavior/leash-barrier-reactivity/tips-on-stopping-a-loose-dog-from-approaching-you/.
• Ghose, Tia. “Humans Smell Fear, and It’s Contagious.” Live Science. Nov. 6, 2012. https://www.livescience.com/24578-humans-smell-fear.html.
• Hinwood, John, DC. “The Smell of Stress.” Stress to Strength. Sept. 15, 2014. https://www.stresstostrength.com/smell-stress/.
• Horwitz, Debra, DVM, DACVB, and Gary Landsberg, DVM, DACVB, DECAWBM. “Dog Behavior Problems: Aggression to Family Members — Introduction and Safety.” VCA Hospitals. https://vcahospitals.com/know-your-pet/dog-behavior-problems-aggression-to-family-members-introduction-and-safety.
• Coren, Stanley, PhD, DSc, FRSC. “Dogs Smell Your Emotional State and It Affects Their Mood.” Psychology Today. Oct. 25, 2017. https://www.psychologytoday.com/us/blog/canine-corner/201710/dogs-smell-your-emotional-state-and-it-affects-their-mood.