Yet one more study highlights the powerful impact that dogs have on humans. A study published in March 2025, not only showed that canines can lower our stress levels and reduce our heart rate but also demonstrated that playing and interacting with humans had long acting beneficial effects for the dogs. Amazing.
A recent study published in the journal PLOS One demonstrated that playing with a dog for just 15 minutes can significantly reduce a person’s stress. College students, who reported feeling stressed, had their cortisol levels measured. After interacting with a friendly dog they reported less stress, had a reduced heart rate and had lower levels of the stress hormone cortisol in their saliva. “Even brief interactions with dogs can significantly reduce stress levels among university undergraduate students,” concluded the research team.
The Study
For the study, researchers recruited six friendly dogs 3 to 6 years old to interact with college students. They included five chihuahuas raised by veterinarians and a Shetland sheepdog raised by a psychologist. None of the dogs were certified for therapy work, researchers noted. This was the first time they’d participated in any sort of canine-assisted intervention, and they participated without the presence of their owner.
In the main library of the University, 122 students completed a stress assessment questionnaire, had their blood pressure and pulse taken, and provided a saliva sample for cortisol testing. They were then given 15 minutes to play with a dog after being told the pooch’s name, personality traits and preferred interactions. The students could do whatever they wanted—look at the dog, pet it, give treats, hug it, play with it.
Afterward, they went through another round of tests to assess their stress levels. The dogs provided fecal and saliva samples before and after their time with students, to see whether the play benefitted them as well.
Results
Students showed self-reported physical improvements in stress following their 15 minutes with a dog, the results show.
- “Compared to immediately before, students’ self-reported stress levels decreased by 33.5% after interacting with the dog.”
- The students also had improvements in their pulse rate and cortisol levels.
- There were no changes in salivary cortisol in the dogs on the day of play, but their fecal cortisol levels were lower a week after they spent time with the students.
“Overall, these findings contribute to our understanding of the beneficial impact of human-dog interactions on human stress levels and highlight the importance of addressing stress in both humans and animals during targeted interventions,” researchers concluded.
“In contexts where certified dogs and handlers are not readily available, non-certified dogs could still offer mental health benefits,” the team added.