For veterans living with post-traumatic stress disorder, a service dog may provide more than companionship or emotional comfort. New research suggests their presence can actually change how a veteran’s body responds to stress. Researchers from the Department of Veterans Affairs’ National Center for PTSD found that veterans with PTSD experienced smaller physical stress reactions to loud, unpleasant noises when a service dog was nearby.

The findings provide another piece of scientific evidence explaining something many veterans with service dogs have reported for years: having that dog beside them can make stressful situations easier to handle.

Researchers Put That Calming Effect to the Test 

The study involved veterans receiving residential PTSD treatment who were also participating in a service-dog training program.

Over four to six weekly sessions, researchers exposed participants to loud, unpleasant sounds designed to trigger measurable physical stress responses. Sometimes their service dogs were present. Sometimes they weren’t.

Researchers measured physiological reactions including changes in heart rate and sweating.

When the dogs were nearby, veterans with PTSD-related hyperarousal showed smaller physical reactions to the sounds. The dogs also appeared to help veterans recover from the stress response and become accustomed to the sounds more quickly. That’s particularly interesting because hyperarousal is one of PTSD’s hallmark symptoms.

For veterans, it can mean feeling constantly on guard, startling easily, having difficulty sleeping, or reacting strongly to unexpected noises and situations.

More Than Feeling Better … 

Service dogs are often discussed in terms of how veterans say the animals make them feel.

This study looked at something different. Researchers were measuring what veterans’ bodies were doing. The reduced heart-rate and sweating responses suggest the presence of a service dog may help regulate the physiological stress response itself. That’s consistent with other research.

A 2024 study involving 156 military members and veterans found that those partnered with trained psychiatric service dogs had lower PTSD symptom severity, anxiety, and depression after three months compared with veterans receiving usual care while waiting for a dog.

The newer research helps scientists begin answering the next question: Why might service dogs help?

One possibility is that their presence provides a stabilizing signal during stressful situations, helping the nervous system respond less intensely and recover more quickly.

Service Dogs Aren’t a Replacement for PTSD Treatment … 

There’s an important caveat.

Service dogs shouldn’t be viewed as a substitute for evidence-based PTSD treatment. VA’s National Center for PTSD continues to recommend established treatments, including trauma-focused psychotherapy and appropriate medications. VA also notes that research into service dogs and PTSD remains limited enough that stronger conclusions are still needed.

The better way to think about psychiatric service dogs is as a potential complement to treatment.

For some veterans, having that additional support may make daily life, public spaces, stressful situations, or recovery itself more manageable. And as researchers continue studying the relationship, we’re beginning to understand that the benefit may involve more than emotional comfort. The body may be responding differently, too.

Final Thoughts … 

Veterans partnered with service dogs probably didn’t need a laboratory to tell them their dogs can make stressful situations easier. But science matters. Measuring smaller heart-rate and sweating responses gives researchers objective evidence that a service dog’s presence may influence the physical hyperarousal associated with PTSD.

It doesn’t mean every veteran with PTSD needs a service dog.
It doesn’t make service dogs a cure.

But it does help explain why these partnerships can be so powerful for some veterans. Sometimes the difference between a nervous system sounding every alarm and beginning to settle down may have four paws sitting quietly beside you.

Veterans interested in psychiatric service dogs should talk with their healthcare providers about their individual needs and carefully research reputable, properly accredited service-dog organizations.

Veterans experiencing PTSD symptoms should also know that effective treatment is available through VA and other qualified mental-health providers.

Stay connected with DisabledVeterans.org as we continue following new research into PTSD, traumatic brain injury, mental health, and treatments that could improve veterans’ lives.