Does interacting with pets reduce stress hormones?
Moderate EvidenceIT DEPENDS
Moderate evidence supports that human-animal interaction acutely reduces cortisol and increases oxytocin, though effects are variable across individuals and long-term health benefits of pet ownership are inconsistent.
The Verdict
Moderate evidence supports that human-animal interaction acutely reduces cortisol and increases oxytocin, though effects are variable across individuals and long-term health benefits of pet ownership are inconsistent.
What the Evidence Shows
Multiple experimental studies demonstrate that interacting with animals—particularly dogs—produces measurable neuroendocrine changes. A 2019 study found that just 10 minutes of petting a dog significantly reduced salivary cortisol in stressed university students. A 2018 meta-analysis pooling experimental studies confirmed that human-animal interaction moderately reduces cortisol and self-reported stress, with effects most pronounced when interacting with familiar animals. The proposed mechanism involves activation of the oxytocin system: mutual gaze and tactile contact between humans and dogs increases oxytocin in both species, which suppresses the HPA axis stress response. However, a 2011 review of pet ownership and health outcomes found that the evidence is surprisingly inconsistent when moving from acute laboratory interactions to long-term health benefits. Pet owners do not consistently show lower blood pressure, reduced physician visits, or better cardiovascular outcomes compared to non-owners, suggesting that acute stress-buffering effects may not translate into sustained health advantages.
Evidence Quality
2
Meta-Analyses
5
RCTs
15
Observational
Important Caveats
- ⚠️ Acute cortisol reduction in lab settings may not reflect long-term stress management
- ⚠️ Effects are strongest with familiar animals—interactions with unfamiliar animals may increase stress
- ⚠️ Pet ownership observational studies are confounded by self-selection (healthier people may choose pets)
- ⚠️ Caregiving burden of pet ownership can itself be a source of stress
- ⚠️ Individual differences in animal affinity moderate the stress-reducing response
- ⚠️ Publication bias likely inflates reported effect sizes in animal-assisted intervention studies
Population Studied
University students (experimental); community-dwelling adults (observational); children and elderly in animal-assisted therapy programs
Dosage
Studies measured effects of 10-30 minute interactions with dogs or cats; animal-assisted interventions typically involve 1-2 sessions per week
Duration
Acute cortisol effects measured within 15-60 minutes post-interaction; long-term ownership studies span years
Supporting Studies (3)
Animal-Assisted Stress Reduction in University Students
RCTPendry P, Vandagriff JL. · AERA Open (2019)
University students who participated in a 10-minute hands-on interaction with dogs and cats showed significantly reduced salivary cortisol compared to control groups who watched videos of animals or waited, with effects persisting 30 minutes post-interaction.
View paper (DOI) →The effects of human-animal interaction on cortisol and health: A meta-analysis
Meta-AnalysisEin N, Li L, Vickers K. · Psychoneuroendocrinology (2018)
Meta-analysis of 28 studies found a small-to-moderate reduction in cortisol following human-animal interaction (d = -0.28), with effects moderated by interaction type, animal familiarity, and participant stress level.
View paper (DOI) →Neurophysiological correlates of affiliative behaviour between humans and dogs
experimentalOdendaal JSJ, Meintjes RA. · South African Journal of Science (2003)
Positive interaction between humans and dogs increased plasma oxytocin, prolactin, and beta-endorphins while decreasing cortisol in both species, demonstrating a bidirectional neurochemical bond.
View paper (DOI) →Contradicting Studies (1)
The impact of HAI on health: A critical review
reviewHerzog H. · Current Directions in Psychological Science (2011)
Critical review found that evidence for long-term health benefits of pet ownership is surprisingly weak and inconsistent. Large-scale studies show no consistent cardiovascular, psychological, or longevity advantages for pet owners compared to non-owners.
Why this disagrees:
Argues that while acute stress-reduction effects exist in controlled settings, they do not translate into meaningful long-term health benefits. The gap between laboratory demonstrations of cortisol reduction and real-world pet ownership outcomes suggests that other factors (caregiving stress, financial burden, lifestyle confounders) may offset acute benefits.