Many soldiers experience traumas on the battlefield that leave them emotionally wounded, but something as simple as walking a dog might bring these veterans desperately needed psychic relief.
So suggests a new study where researchers compared how four weeks of walking with a shelter dog or with another person affected three biomarkers of stress in male and female veterans with post-traumatic stress disorder (PTSD).
The three biomarkers were: heart rate variability; cortisol (a "stress" hormone); and the enzyme alpha-amylase. The strongest indication that walking with a dog reduced stress came from heart rate variability findings.
"Based on heart rate variability, our study provides evidence that walking with a shelter dog may benefit veterans with higher symptoms of post-traumatic stress. Severity of symptoms and perceived stress tended to decrease more after walks with a dog than walks with a human," said study author Cheryl Krause-Parello. She is director of Canines Providing Assistance to Wounded Warriors and a professor in Florida Atlantic University's School of Nursing.
Heart rate variability was measured before, during and for 30 minutes after walking.
The veterans' responses to walking with a dog or another person were different, depending on their PTSD symptom severity.
Walking with another person did not change stress levels as measured with cortisol in those with high PTSD symptom severity, while walking with a dog or another person led to decreases in cortisol among those with low PTSD symptom severity.
For veterans with high PTSD symptom severity, walking with a dog did not change stress levels as indicated by alpha amylase, but walking with a person led to increased stress. For those with lower PTSD symptom severity, alpha amylase did not change significantly with either type of walk.
"Our findings emphasize the need for more research to determine if this form of human-animal interaction is beneficial to veterans with PTSD and to help us identify the optimal level of interaction that will be most impactful for them," Krause-Parello said in a university news release.
The study was published recently in the journal Anthrozoös.
Of the more than 21 million veterans in the United States, about 20% have PTSD.
"Considering the large number and availability of shelter dogs in the United States, it really makes sense to consider the potential for these dogs to be involved in a unique intervention that combines the benefits of human-animal interaction with the benefits of altruistic action like volunteerism," said study co-author Erika Friedmann, a professor and associate dean for research at the University of Maryland School of Nursing.
The U.S. National Institute of Mental Health has more on PTSD.