Human–Canine Interaction: Exploring Stress Indicator Response Patterns of Salivary Cortisol and Immunoglobulin A

Psychophysiological mechanisms underlying the potential health benefits of human-dog interactions: A systematic literature review

While the symbiotic nature of human-dog relationships and perceived benefits to human health have attracted much scientific interest, the mechanisms through which human-dog interactions may confer health benefits to humans are still poorly understood. The aim of this systematic literature review was to synthesize evidence of physiological changes associated with human-dog interactions with relevance to human health. Electronic databases were systematically searched (PubMed, MEDLINE with full text, Scopus, PsycINFO, CINAHL Plus with Full Text, and Web of Science Core Collection) for relevant studies. Of the 13,072 studies identified, 129 met the inclusion criteria, with approximately half being randomized trials (Level 2) based on the Oxford Centre for Evidence Based Medicine level system. Measures employed to study human physiological changes associated with human-dog interactions most commonly involved cardiac parameters and hormones, with negligible research of brain activity. The main positive findings were increases in heart rate variability and oxytocin, and decreases in cortisol with human-dog interactions. These physiological indicators are consistent with activation of the parasympathetic nervous system (PNS) and oxytocinergic system (OTS), and down-regulation of hypothalamic-pituitary-adrenal (HPA) axis activity. These results provide evidence of specific pathways through which human-dog contact may confer health benefits, likely through relaxation, bonding, and stress reduction. However, these findings should be interpreted contextually due to limitations and methodological differences. Previous research using other biological variables was limited in quantity and quality, thus impeding firm conclusions on other possible mechanisms. Further research is needed in some psychophysiological domains, particularly electroencephalography, to better understand central nervous system (CNS) effects. The findings of this review have implications for human-dog interactions to positively affect several stress-sensitive physiological pathways and thus confer health benefits. This supports their incorporation in various clinical, non-clinical, and research settings to develop evidence-based interventions and practices for cost-effective and efficacious ways to improve human health.

Critical Review of Research Methods Used to Consider the Impact of Human-Animal Interaction on Older Adults' Health

BACKGROUND AND OBJECTIVES

Most research on human-animal interaction (HAI) and human health focuses on one of three perspectives: (a) health effects of pet ownership; (b) health effects of contact with a companion animal; or (c) health effects of animal-assisted interventions including animal-assisted therapies, and animal-assisted activities.

METHODS

We reviewed research methods used to address each perspective, within the context of human aging, and identified challenges associated with these methods.

RESULTS

The complex challenges involved in designing studies to address all three perspectives and examples of research design elements that can be used to alleviate issues raised in each type of study are provided.

DISCUSSION AND IMPLICATIONS

We suggest emerging methodologies that may be helpful for answering important questions from all three perspectives about the relationship of HAI to health outcomes for older adults.

Effects of Animal-Assisted Activity on Mood States and Feelings in a Psychiatric Setting

BACKGROUND: Research has shown that animal-assisted activity (AAA) effectively improves physiological, psychological, emotional, and social well-being in various environments. AIMS: To identify how AAA affects mood states and feelings among both patients and staff on inpatient psychiatric units. METHODS: This study used a quasi-experimental, pre-/posttest design with nonequivalent comparison groups. Quantitative data were collected using the Visual Analog Mood Scale. Demographic data, with an open-ended question, were obtained postsessions. RESULTS: Significant changes were observed pre- and postexposure to AAA sessions with a therapy dog. Negative moods decreased, and positive moods increased as measured by the Visual Analog Mood Scale. Content analysis identified themes of feeling happy, feeling relaxed, and feeling calm. CONCLUSIONS: This research expands scientific evidence associated with AAA by identifying changes in mood states and feelings among individuals in a psychiatric setting.

Paws for Thought: A Controlled Study Investigating the Benefits of Interacting with a House-Trained Dog on University Students Mood and Anxiety

Simple Summary

This study investigates whether interacting with a dog would have a positive effect on university students’ mood and anxiety. Students were assigned to either watch videos of a dog or interact directly with a dog. Several measures were collected both before and after their assigned conditions to evaluate their mood and anxiety levels and to assess for possible changes. The results indicated that participants in both conditions experienced a reduction in their anxiety and an improvement in their mood across time, however those who directly interacted with a dog experienced a greater decline in anxiety and improved mood scores.

Abstract

University students have been found to have higher rates of psychological distress than that of the general population, which reportedly rises significantly upon starting university and does not return to pre-university levels throughout their time in university. It is therefore highly important to find ways to improve student health and well-being. One way that may help is by interacting with animals. Therefore, the purpose of this study was to determine whether interacting with a dog would have a positive effect on university students’ mood and anxiety. This study assigned 82 university students to either the experimental condition (dog interaction, n = 41) or to the control condition (dog video, n = 41). The students completed the Positive and Negative Affect Schedule-Expanded Form (PANAS-X), State-Trait Anxiety Inventory (STAI) and the Pet Attitude Scale before their assigned conditions, to evaluate their mood and anxiety levels and attitudes to animals. The participants again completed the STAI and PANAS-X Form after their condition, to assess for possible changes in anxiety and mood. The findings of the study indicated that all participants, regardless of condition, experienced a reduction in their anxiety and an improvement in their mood across time. However, directly interacting with a dog resulted in greater declines in anxiety and improved mood scores, more so than watching a video. Consequently, it appears there are psychological benefits to be gained by students from interacting with dogs and it is hoped this study will help to inform future best practices in designing student dog interventions.

Relation of post-traumatic stress disorder symptom severity to the efficacy of an animal-assisted intervention for stress reduction after military aeromedical evacuation

Animal-assisted interventions (AAIs) have been found to decrease stress in some settings, but it is not known if AAI is feasible in an aeromedical staging facility or effective in reducing stress following aeromedical evacuation (AE) of military personnel. An experimental design was used to evaluate the efficacy of AAI at reducing stress in AE military patients (N = 120). Patients participated in a 20-min AAI (n = 60) or 20-min informational session about assistance dogs as an attention-control group (n = 60). Demographics, post-traumatic stress symptom severity (PTSSS), and stress biomarkers (cortisol, alpha-amylase, and immunoglobulin A) were collected regular intervals. AAI was found feasible and efficacious at reducing stress. Cortisol decreased significantly (p < .05) in the AAI group compared with the attention-control group. PTSSS moderated the immunoglobulin A responses to AAI as demonstrated by the interaction of PTSD Checklist-Military Version score, group, and time, F(1, 111.23) = 4.15 p = .044; effect size: d = 0.31. This research supports AAI as a stress-reducing modality in AE patients, particularly those who report higher PTSSS. Implications for future research are discussed.

Effect of Canine Play Interventions as a Stress Reduction Strategy in College Students

Forty-eight students engaged with a therapy dog for 15 minutes during finals week to evaluate the effect on stress. Psychological (Perceived Stress Scale, visual analog scales) and physiologic stress (vital signs, salivary cortisol) measures were collected before and after the intervention. Paired t tests showed significant reductions in all psychological and physiologic measures except diastolic blood pressure. This supports animal-assisted therapy as an effective stress management strategy for nursing and other college students.

Associations of Pet Ownership with Older Adults Eating Patterns and Health

Pet ownership has been shown to improve quality of life for older adults. The objective of this cross-sectional study was to compare older pet owners and older non-pet owners and assess differences between groups. This study was conducted on adults over 50 years of age, who owned either one cat or one dog versus nonowners based on age, race, gender, and education. Matched older pet owners (OPO) versus non-pet owners (NPO) pairs (n = 84), older cat owners (OCO) versus non-cat owners (NCO) (n = 29), and older dog owners (ODO) versus non-dog owners (NDO) pairs (n = 55) were analyzed. No differences were found between OPO and NPO for dietary, activity, or lifestyle, except OPO had fewer health conditions [p < 0.03]. Total OCO had greater body mass indices [BMI] (μ = 29.6 ± 8.2) than ODO (μ = 23.2 ± 5.2) [p < 0.02], less activity [p < 0.02], and shorter duration of activity [p < 0.05] and took fewer supplements [p < 0.003]. OCO and NCO differed on health conditions (μ = 0.8 ± 0.9 versus μ = 1.9 ± 1.3, [p < 0.008]) and ODO versus NDO differed on BMI (μ = 25 ± 4 versus μ = 27 ± 6, [p < 0.04]). Although there are limitations to this study, data may be useful for targeting marketing and health messages to older persons.

Forensic Interviews for Child Sexual Abuse Allegations: An Investigation into the Effects of Animal-Assisted Intervention on Stress Biomarkers

The use of therapy animals during forensic interviews for child sexual abuse allegations is a recommendation by the Therapy Animals Supporting Kids Program to help ease children's discomfort during the forensic interview process. Based on this recommendation, this study incorporated a certified therapy canine into the forensic interview process for child sexual abuse allegations. This study investigated changes in salivary cortisol, immunoglobulin A, blood pressure, and heart rate as a result of forensic interview phenomenon (e.g., outcry) incorporating animal-assisted intervention versus a control condition in children (N = 42) interviewed for alleged child sexual abuse. The results supported significantly greater heart rate values for the control group (n = 23) who experienced sexual contact and/or indecency than the experience of aggravated sexual assault compared to no difference in HR for the intervention group (n = 19). The results suggest that the presence of the canine in the forensic interview may have acted as a buffer or safeguard for the children when disclosing details of sexual abuse. In the intervention group, children's HR was lower at the start of the forensic interview compared to the control group. Finding an effect of having a certified handler-canine team available during the forensic interview on physiological measures of stress has real-world value for children, child welfare personnel, and clinical therapists. It is suggested that animal-assisted intervention be expanded to children facing other types of trauma and to treatment programs for child survivors of sexual abuse.

Salivary mental stress proteins

Of the major diagnostic specimen types, saliva is one of the most easily collected. Many studies have focused on the evaluation of salivary proteins secreted by healthy people and patients with various diseases during responses to acute mental stress. In particular, such studies have focused on cortisol, α-amylase, chromogranin A (CgA), and immunoglobulin A (IgA) as salivary stress markers. Each of these salivary stress markers has its own strengths and weaknesses as well as data gaps related to many factors including collection technique. In this review, we summarize the critical knowledge of the positive and negative attributes and data gaps pertaining to each salivary stress marker.