Their sensitive noses can detect an impending attack, spot signs of Covid and even uncover cancer.
Now scientists have successfully trained two dogs to smell trauma from someone’s breath.
The researchers trained 25 dogs to detect the chemical signs of stress in a person’s breath.
However, only two were skilled and motivated enough to complete the study: Ivy, a Red Golden Retriever, and Callie, a German Shepherd/Belgian Malinois mix.
In the future, the scientists think these talented puppies might be able to identify when someone is about to have a terrifying flashback.
The researchers trained 25 dogs to detect the chemical signs of stress in a person’s breath. However, only two of them were skilled and motivated enough to complete the study. In the photo: Ivy, a red golden retriever
In the future, the scientists think these talented puppies might be able to identify when someone is about to have a terrifying flashback. Pictured: Callie, a German Shepherd/Belgian Malinois mix
PTSD is caused by exposure to a traumatic event and can lead to debilitating symptoms, including re-experiencing the event in the form of a flashback.
Currently, service dogs are used to help patients with PTSD by alerting and interrupting when their companions are struggling with their symptoms.
By training dogs to recognize the signs of an episode just by breathing, the scientists hope that service dogs can intervene earlier and keep their companions safe.
Researchers from Dalhousie University in Canada recruited 26 people who had experienced some form of trauma as scent donors for their study.
Half of the participants had been diagnosed with post-traumatic stress disorder (PTSD), a mental illness caused by a frightening event.
To donate scents, participants attended sessions in which they were reminded of their trauma experiences while wearing various face masks.
One face mask provided a quiet breath sample, while the other provided a ‘target’ breath sample that was worn while they remembered their ordeal.
The dogs learned to detect volatile organic compounds in human breath, which indicated that a PTSD episode was imminent. This could help them intervene earlier in their work as a guide dog (stock image)
In the meantime, the scientists recruited 25 dogs to train in scent detection.
Both were trained to recognize the ‘target odor’ and were shown a series of samples to see if they could accurately detect the stress odors.
All humans have an odor profile consisting of volatile organic compounds (VOCs) determined by our genetics, age and other variables.
Previous studies have suggested that dogs may be able to smell VOCs associated with human stress.
Scientists from Queen’s University Belfast have trained dogs to detect stress in sweat and breath with an accuracy of 93.75 percent.
However, this is the first study to show that dogs can also sense the chemical signatures associated with PTSD.
First author Laura Kiroja says: ‘Both Ivy and Callie found this work inherently motivating, their boundless appetite for delicious treats was also a plus.
“In fact, it was much harder to convince them to take a break than it was to get to work.”
When tested with donated face masks, both dogs were able to distinguish between stressed and non-stressed samples with 90 percent accuracy.
And when tested with pure VOC samples, Ivy achieved 74 percent accuracy and Callie achieved 81 percent accuracy.
Ms Kiiroja said: “PTSD service dogs are already trained to assist people during periods of need.
‘However, dogs are currently trained to respond to behavioral and physical cues. Our research showed that at least some dogs can also detect these episodes through breathing.’
Further analysis revealed that Ivy was more likely to recognize participants who were feeling particularly anxious, while Callie was more likely to recognize when people were feeling shame.
“Although both dogs performed with very high accuracy, they seemed to have a slightly different idea of what they considered a ‘stressed’ breath sample,” Ms Kiiroja said.
“We speculated that Ivy was attuned to the hormones of the sympathetic-adrenal-medullary axis, such as adrenaline, and that Callie was attuned to the hormones of the hypothalamic-pituitary-adrenal axis, such as cortisol.”
The researchers said their findings, published in the journal Frontiers in Allergy, could one day lead trained dogs to potentially interrupt PTSD episodes at an earlier stage, making their interventions more effective.