Study supports use of dogs to help veterans with PTSD

Purdue University’s recent research findings come as no surprise to K9s For Warriors


A recent research study released by Purdue University is reinforcing what K9s for Warriors has been saying all along: Dogs have a genuinely positive impact on the health and well-being of veterans and service members suffering from Post-Traumatic Stress Disorder.

Conducted by the Purdue University College of Veterinary Medicine and co-funded by the Human Animal Bond Research Institute and Bayer Animal Health, the study used physiological markers to document a service dog’s effect on veterans diagnosed with PTSD by measuring the stress hormone cortisol when they wake up.

The research was led by Maggie O’Haire, assistant professor of human-animal interaction in the College of Veterinary Medicine, and Kerri Rodriguez, human-animal interaction graduate student, with the help of K9s For Warriors, a nonprofit based in Ponte Vedra Beach that pairs veterans with PTSD with rescue dogs.

“We found that military veterans with a service dog in the home produced more cortisol in the mornings than those on the waitlist,” Rodriguez said in a news release. “This pattern is closer to the cortisol profile expected in healthy adults without PTSD. Having a service dog was also associated with less anger, less anxiety and better sleep.”

The veterans used in the research were part of the K9s for Warriors program. To measure morning cortisol, saliva samples of veterans with PTSD who had been paired with a service dog were compared to veterans with PTSD who are on the waitlist to get a service dog. In healthy adults without PTSD, there is generally a rise in morning cortisol or the “cortisol awakening response.” In people with PTSD, morning cortisol levels don’t show an increase. The Purdue study found veterans who have a service dog had an increase in morning cortisol as opposed to veterans without dogs.

“If you have a healthy brain with no PTSD, you wake up and get this slow morning cortisol rise that lasts throughout the day,” K9s for Warriors CEO Rory Diamond said. “Warriors with severe PTSD have no morning cortisol; they just flatline. So, we swabbed the warriors in the morning to test their morning cortisol, and the ones on the waitlist just flatlined. The ones who had a dog for the last six months had a near-normal morning cortisol. That’s the physiological biomarker we were able to prove.”

Diamond said the results of this study are important because they provide scientific support for what his organization is doing.

“For the last several years, we wanted to prove with hard science that our dogs work,” Diamond said. “We know they work. We see it every single day with these warriors that we work with. We see their lives change. We see them become the people they used to be before they went off to war. But the U.S. Department of Veterans Affairs and other funders have told us, ‘We don’t believe you and you can’t prove that your dogs work.’ Now we can.”

Diamond said an earlier study done by the organization focused on monitoring how the veterans felt mentally and emotionally in the months after getting a service dog, but that study was met with criticism by the US Department of Veterans Affairs (VA), which suggested respondents might not be completely honest about their feelings.

“This study, you can’t fake,” Diamond said. “It’s morning cortisol. And now we’ve proven that warriors, in the mornings, who have a dog for at least six months, have near healthy morning cortisol levels.”

The next step is a study currently being done by the National Institutes of Health (NIH). The new study will continue with the cortisol mouth swabs on veterans with PTSD, but will also use a Fitbit-like device to measure sleep patterns, overall anxiety, heart rate and how far warriors are straying from their homes before and after receiving a service dog.

“This is the first time anyone in the history of the world has shown that a service dog, or any dog, actually changes the physiology of the brain, which is kind of amazing,” Diamond said.

K9s for Warriors is also planning to conduct a study on how much money programs like theirs end up saving the VA per warrior, who are often prescribed medication to treat the symptoms of PTSD.

“Two-thirds of our warriors are off some of their medication within six months, and a third are off all of them,” Diamond said. “These prescription drugs are lethal cocktails. They have all sorts of terrible side effects. The worst thing that can happen if our program doesn’t work is that the warrior has a nicely trained dog. It’s a good tradeoff.”

K9s for Warriors is in the process of opening a second facility outside of Gainesville to assist more warriors, and Diamond said while the scientific studies will hopefully open the eyes of the VA and other government organizations, actually seeing the program in action was proof enough for him that it works.

“On the first day of the program, I typically welcome the warriors here, and you see what I call ‘dead eyes,’" Diamond said. “Just spacing out, overmedicated, anxious, nervous, suspicious, all those things. And then over the course of the three-week program, you see the warriors get more and more comfortable with their dogs, more and more comfortable going out into the world again, and then you start to see their personalities come back. And when we hear the warriors laughing together, we know we’ve broken through some pretty significant barriers.”

But Diamond appreciates that the studies back up what he already knows. 

“It is reassuring,” he said. “I personally knew with every fiber of my being it was true, but to have independent, really smart scientists prove it is really awesome.”

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