Animal-assisted intervention for stress reduction in non-urgent patient transport


Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) resulted in increased combat operations and increased signature wounds such as Post Traumatic Stress (PTS) and combat-related Traumatic Brain Injury (TBI) in warriors who returned from deployment. According to the U.S. Department of Veterans Affairs (2009), PTS(Disorder) is defined as an anxiety disorder that occurs after exposure to a traumatic event. Many wounded warriors returned home from combat in the Middle East without knowing that they experienced PTS symptoms and believed their strong emotions were normal. Recovery for PTS is a gradual journey, and subsequent feelings of loneliness and isolation are consequences of PTS that make it difficult to complete activities of daily living. Effective long-term treatments and support are needed for this heroic population.

Prior studies have found that animal assisted intervention (AAI) had a positive effect on reducing salivary alpha-amylase during a traumatic event. This study examined the relationships between biological stress markers and PTSD symptoms in a randomized, repeated measures experimental design for patients recruited from the En Route Patient Staging Facilities (ERPS).


A collaborative study developed by Dr. Cheryl Krause-Parello, founder of Canines Providing Assistance to Wounded Warriors (C.-P.A.W.W.) at Florida Atlantic University, measured the effectiveness of a service dog in two ERPS. This two-phased study first described the stress levels in this patient population, then compared intervention to control groups on the effects of stress using survey and salivary biomarker measurements. In phase 1, participants agreed to repeated measurement collections on biobehavioral surveys as well as providing a saliva sample for biomarkers. In Phase 2, the control group received a 20-minute presentation about service dogs; the AAI group interacted with a service dog during the presentation. Biobehavioral surveys measured stress, quality of life, coping, combat exposure, and pet attitude. Salivary biomarkers (cortisol, alpha-amylase, immunoglobulin A [IgA]), blood pressure, and heart rate were collected at multi-time points in both groups.


In Phase 1, psychobiologic data were not significantly correlated with biobehavioral measures; however, high Post-Traumatic Stress (PTS) scores were weakly correlated with increased perceived stress, r (35) = .01, p = .01. In Phase 2, while not statistically significant, the mean differences before and after AAI suggested decreased stress, except for cortisol. Cortisol significantly decreased following AAI, t(49) = -3.347, p < 0.05, CI [-.26, -0.7]. When comparing groups, repeated measures of psychobiologic stress was increased in the control group: IgA, t (91) = -1.92, p <0.05, CI [-.01, .31], cortisol, t (92) = -0.137, p <0.05, CI [-.29, .02]. The differences in stress psychobiologic indicators depended on the quality of life, perceived stress, resilience, pet attitude and PTS symptoms.


TriService Nursing Research Program HT9404-12-1-TS06