IHAC Researches if Pet Dogs Decrease Stress

Did you know that studies have found dogs to be more successful at reducing stress levels in individuals than romantic partners, parents, or close friends? Since the COVID-19 pandemic, United States citizens have reported increased stress levels, and individuals around the world are claiming to be more worried and sadder than in previous years. A growing interest in medicinal-free methods of stress relief research has shown that mindfulness activities, time spent in nature, and physical activity is helpful. 

The Institute for Human-Animal Connection (IHAC) was interested in researching the impact of the physical presence of a pet dog on their owner's stress response. 

With one in three households owning a pet dog globally, this could be a potentially easily accessible mental health intervention that could impact individual health, well-being, and lifespan. To test the hypothesis that the presence of a pet dog decreases the stress response of the owner, IHAC conducted a stress test on 44 people who had dogs. Participants were randomly selected to bring their pet with them to the stress test or to leave their pet at home. Those who were selected to bring their dog had their pet with them for the entirety of the test. They were directed to keep their dog on a six-foot leash and interact as they normally would with their pet. 

Upon arrival at the testing site, participants were asked to sit in a resting room for thirty minutes to lessen any potential stressors that occurred before arrival. After this resting period, their stress levels were taken for the first time and then they were taken to their stress test. This test was composed of three researchers in white lab coats, who asked the participant to write a speech for why they are the best candidate for their dream job and then recite the speech in front of them and a video camera. After the speech they were asked to subtract the number 17 from 2023, and to continue subtracting down, for 5 minutes. Immediately following the test, their stress levels were measured again. Then, they were asked to return to the resting room for 45 minutes after the stress test. After this time had passed, their stress levels were assessed for the third and final time. 

How were stress levels recorded?

Stress levels were recorded in a variety of ways including self-reports of anxiety, heart rate, salivary alpha-amylase, and plasma cortisol levels. 

Levels were taken right after the stress test to assess peak stress levels and 45 minutes after the test to determine stress recovery rates. In both the dog and no dog groups, there was an increase in anxiety, heart rate, and cortisol levels after the stress test. Salivary alpha-amylase only increased in the group with a dog present. 

Cortisol is known as “the stress hormone” because it is released by the body in response to stress.

When comparing the results between the dog and no dog groups, there are several statistics to look at. Self-reported anxiety levels of participants were statistically insignificant between groups, suggesting the presence of a dog does not have an impact on these scores. However, there was a drastic difference in the heart rate responses to the stress test between groups. Individuals without their pet present, on average, had an increased heart rate of 26.7%, compared to only 14.6% of those whose dog was present. Cortisol levels were also shown to be much higher after the stress test for the no dog group. Participants without a dog exhibited more than 50% higher cortisol response than the dog group. The dog group was found to have cortisol levels that were lower at the end of the recovery period than when they first arrived at the facility. The salivary alpha amylase increased by 97.6% in the dog group, compared to an insignificant increase in the no dog group; the increase in salivary alpha amylase in the dog group could represent a healthier, more balanced response to stress.

The significantly lower response to the stress test shown in the dog group through their heart rate and cortisol levels supports the thought that the presence of a dog could be associated with lower stress responses. The decrease of cortisol levels from the first sample before the stress test, to the final sample after the recovery period, also suggests that dogs can provide a faster stress recovery response. 

The Institute for Human-Animal Connection’s study on social stressors found evidence to support the hypothesis that the presence of a pet dog can assist in a healthy stress response. This study was the first of its kind to test levels on multiple physiological systems, allowing us to come to the presumption that dogs may be able to support a balanced, intermediate stress response. Instead of just reducing the stress response, a dog can actually help to maintain regular stress levels.