3 min read


Can Dogs Smell Cortisol?



3 min read


Can Dogs Smell Cortisol?


Cortisol is commonly known as the "stress hormone." This important hormone helps regulate a wide range of processes throughout our bodies, including our metabolism and immune system responses. Usually, cortisol is released in response to stress and low blood sugar concentration.

As man's best friend, dogs have the incredible ability to understand and respond to humans. Studies show that a dog's sense of smell can detect everything from diabetes to cancer. But what about cortisol?


Signs Dogs Can Smell Cortisol

The sense of smell is the strongest sense in dogs - we can observe this by watching our buddies lead the way with their snouts to the ground. Dogs use their sense of smell to gather information about new places and people. Their powerful noses even allow them to predict threatening people or situations.  

When people are stressed, they release cortisol. We also rely on the production of cortisol when we need to kick into survival mode. When cortisol is produced, it begins flowing through our bloodstream, which dogs are able to pick up on. 

There are a few signs that a dog can sense when someone is feeling stressed, although your dog's reaction may depend on personality or breed. Some dogs may feel defensive when they sense a stressful situation. Defensive behavior can be exhibited by standing by their human, barking, sniffing. A dog will remain on alert until the stressful situation has ceased. 

On the other hand, dogs may also respond to stress with anxiety of their own. You'll be able to tell if a dog is anxious if their ears are lowered, they are pacing, or their head is lowered. Just make sure you pay attention to your pup as much as your pup pays attention to you!

Body Language

Some signs that your dog can smell cortisol include:

  • Alert
  • Barking
  • Ears Drop
  • Pacing
  • Sniffing

Other Signs

Other signs may include:

  • Guarding
  • Aggression
  • Other Defensive Behavior

The History Behind Dogs Smelling Cortisol


The world of early man was one that required battling for food and survival. Early homo sapiens lived surrounded by predators, meaning our basic flight or fight responses could mean life or death. Signs of predatory danger invoke hormonal changes in the body, including the production of cortisol. In today's day and age, the stressors that produce cortisol occur in our daily lives, which, in turn, can be detected by our dogs.

Dogs have used their sense of smell for thousands of years. Not only has it helped them survive, but it has helped them grow closer to humans. In order to fully bond with us humans, dogs have evolved to predict situations by being attentive and noting potential threats. Dogs learned to link cortisol production with stressful situations. 

Dogs came from wolves, allowing this observant ability to have evolved over the last 15,000 years. Throughout the course of domestication, different dogs were bred for different things. Depending on the dog, they were utilized for hunting, protection, and simply companionship. Regardless, dogs continue to use their sense of smell to understand humans and further bond.

The Science Behind Dogs Smelling Cortisol


Dogs have a truly outstanding ability to smell specific and small scents. Dogs have 200 to 300 million smell receptors in their noses, while humans just have around 6 million!  Throughout the years, our pups have learned to associate different smells with different situations. 

This has helped them understand human wants and needs. Both humans and dogs have a specific part of the brain that processes smell. Although we both (dogs and humans) have this section, the smell portion in dog brains is 40 times bigger than ours!

Using their super nose powers, dogs are able to sense rising cortisol levels in our sweat or breath, and react accordingly.

Training Dogs to Smell Cortisol


Because of their super-sensitive noses, dogs are able to smell changes in hormones, including cortisol. Building on this incredible trait are the trainers of service dogs. While dogs may have instinctive ability to smell the chemistry of cortisol, service dogs are typically trained to recognize other signals in the patients they serve. This can be great for service dogs that work in hospitals, in the military, or even in schools!

It can be extremely helpful to have a cortisol-sniffing dog to assist with children on the autism spectrum, children that exhibit symptoms of attention deficit disorder, or other challenges that can trigger anxiety or difficult emotions. 

For example, people on the autism spectrum tend to have higher levels of cortisol in their bloodstream. Cali, a Rhodesian Ridgeback, is the first cortisol-sniffing dog employed by a school. She has been taught to notice students with high levels of cortisol in their bloodstream, and then further notify her handler when she senses this hormone kicking in. Her handler can then work with that child before a meltdown occurs. Because Cali is calm, quiet, and unassuming, the students enjoy being around her.

This is one of the many ways dogs support us humans, making our lives happier and better one day at a time.

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Written by Olivia Gerth

Veterinary reviewed by:

Published: 04/11/2018, edited: 04/06/2020

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