New Brunswick

Stress detector and therapy in one furry, four-legged package

Shediac dog trainer Bill Grimmer is teaching dogs how to detect, and then respond to, spikes in the stress hormone, cortisol.

Dogs trained to detect and respond to spikes in cortisol

Bill Grimmer has trained Foxy, a long-haired Chihuahua to detect cortisol. (Pierre Fournier/CBC)

Shediac dog trainer Bill Grimmer knows the limitless potential of man's best friend. 

From companionable couch potato to highly trained scent detection dogs, canines have been improving the lives of their human partners for thousands of years. 

Over the course of his long career, Grimmer has taught numerous breeds to do countless things. Everything from Chihuahuas to Great Danes; and scent detection to protection. 

Most recently, Grimmer is teaching dogs to detect cortisol, often called the stress hormone. As one's stress increases, the body produces more cortisol, which is secreted through the breath and can easily be detected by dogs. 

"There is science that says cortisol is getting the body ready to fight or flight," explained Grimmer. 

He said science also says "repetitious functions" can lower stress and cortisol levels. Things like deep-breathing, brushing your hair, or petting a pet. 

Cortisol-sniffing canines being trained to provide comfort and calm

2 years ago
Duration 3:19
Shediac dog trainer Bill Grimmer is teaching dogs to detect the stress hormone through scent.

"So if we can train the dog to smell cortisol and when it increases, it now knows that it will get petted or treated," said Grimmer.

It's detection and therapy in one furry package. 

He says "dogs have known about it longer than us." When people get stressed and then seek out the comfort of a dog, the dog begins to associate the smell of cortisol with an opportunity to get attention. 

"People have taught them inadvertently by their actions that cortisol levels equate basic rewards like food and touch."

Training them to detect cortisol and then react in a certain way uses the same principle of pairing the scent with a reward. In this case, it's food. It's the same concept for most scent training. 

In the beginning, Grimmer sets up a number of rounded tubes and places a sample of cortisol into each one. He then encourages the dog to put its face into the opening and he rewards with food from an opening at the back. The dog begins to associate the smell inside the training canister with the food reward. 

Foxy, a long-haired Chihuahua, is being trained to detect and respond to cortisol. (Pierre Fournier/CBC)

Then the food is removed and the dog only smells the cortisol and the reward is then given separately from cortisol, so that cortisol becomes the target smell and the food comes after the dog indicates it. 

Verbal praise and petting are additional rewards given to motivate the dog. 

The next step is to teach the dog how to respond to a spike in cortisol. Grimmer begins by rewarding the dog with food for bumping his hand. The end-goal is for the dog to continuously bump its nose into the person, in effect, demanding the repetitive stroking that will help lower cortisol levels. 

"Dogs have been doing this for years and eons without us understanding it, because if we get stressed, we seek the dog to pet so that we will calm down."

Unique breed characteristics

Grimmer said any breed of dog can be trained for any task, but some just aren't cut out for certain ones because of their size or temperament. 

"A Chihuahua can't track for four or five miles through rough terrain, and a Great Dane can't search in the small containers where he can't even get his body into."

Temperament is equally important, said Grimmer. 

"We need the highest confidence in the animal that we get," he said, since the dogs often have to work in a variety of locations under a myriad of conditions. 

For its versatility, the German shepherd has been Grimmer's favourite breed. He's trained them for police work, search and rescue, scent work, and as pets. 

Annie, a three-year-old black Lab, checks the training canisters for cortisol. (Pierre Fournier/CBC)

While the working breeds like the German shepherd, Belgian Malinois, or Doberman are tops when it comes to police-like work, they aren't typically the go-to breeds for most service dogs. Grimmer says they're a little too intimidating for certain situations. 

So far, he's trained a black Labrador retriever, a long-haired Chihuahua and a papillon to detect cortisol. 

Grimmer said cortisol-detection dogs can work one-on-one with their owner, or they can work in a wider setting, like a school. He said it would work well with students who are on the autism spectrum. If they're non-verbal, a dog could alert to a spike in cortisol and a meltdown could potentially be avoided if an adult is aware of increasing stress. 

Grimmer said dogs could also be used in high-stress workplaces, like police stations. They could work with people who have been victims of crime, but could also assist police officers who are feeling stress on the job. The same goes for ambulance and fire departments, he said. 

Over the years, Grimmer has taught his dogs to detect a wide range of material for a variety of purposes. He has a collection of about 200 different kinds of explosives, a bag of human teeth and a variety of human bones of varying ages. A dog he had years ago even found a body that had been under water and couldn't be located by divers. 

Annie showing off her repertoire of tricks, which includes rolling over, sitting pretty, and detecting cortisol. (Pierre Fournier/CBC)

He has searched for human remains in glaciers and after earthquakes in far-flung parts of the globe. 

The walls of his training room are dotted with the famous people — and their dogs — that he's worked with over the years, including supermodel Christie Brinkley, actor Alec Baldwin, and heiresses Paris Hilton and Patty Hearst. 

Grimmer said there's no end to the things a dog can detect, including cancer cells and low blood-sugar. He said service dogs can alert to potentially life-threatening conditions in diabetics. For example, if a diabetic's blood-sugar drops when they're asleep, they may not notice and slip into a coma. But a trained service dog can alert the person, and wake them up so they can take the proper medication.

Finding clubroot in canola

In 2019, Grimmer was asked if dogs could be used to detect a plant pathogen that was threatening Alberta's canola crop. 

Clubroot is a disease that also affects vegetables like cabbage, broccoli and cauliflower. The problem is that the signs are on the plant's roots, so not visible during a normal inspection. Roots have to be pulled and examined. 

But Grimmer trained four dogs to detect and indicate clubroot from above ground. Once detected, humans can then intervene to destroy the affected crops and ensure the disease isn't spread to other fields on equipment.

Shediac dog trainer Bill Grimmer has been teaching dogs to detect cortisol. (Pierre Fournier/CBC)

COVID-19 applications

Grimmer also sees scent detection possibilities during the pandemic. He said dogs could easily detect COVID-19. He's not suggesting that the dogs would replace laboratory testing, but says there are applications in larger public settings. 

For example, dogs could be used to detect the disease on school buses and other modes of mass transportation. Dogs would do a search at the end of a run, or a day, to ensure it was clear and safe for passengers again. Similarly, hotel rooms could be searched and cleared for the next guests. 

"Other countries have COVID-detection dogs. Why can't we do that here?" he wonders.


Mia Urquhart is a journalist with CBC New Brunswick, based in Saint John. She can be reached at