Measuring stress and immune response in healthcare professionals following interaction with a therapy dog: a pilot study

A Review of the Benefits of Nature Experiences: More Than Meets the Eye

Evidence that experiences of nature can benefit people has accumulated rapidly. Yet perhaps because of the domination of the visual sense in humans, most research has focused on the visual aspects of nature experiences. However, humans are multisensory, and it seems likely that many benefits are delivered through the non-visual senses and these are potentially avenues through which a physiological mechanism could occur. Here we review the evidence around these lesser studied sensory pathways—through sound, smell, taste, touch, and three non-sensory pathways. Natural sounds and smells underpin experiences of nature for many people, and this may well be rooted in evolutionary psychology. Tactile experiences of nature, particularly beyond animal petting, are understudied yet potentially fundamentally important. Tastes of nature, through growing and consuming natural foods, have been linked with a range of health and well-being benefits. Beyond the five senses, evidence is emerging for other non-visual pathways for nature experiences to be effective. These include ingestion or inhalation of phytoncides, negative air ions and microbes. We conclude that (i) these non-visual avenues are potentially important for delivering benefits from nature experiences; (ii) the evidence base is relatively weak and often based on correlational studies; and (iii) deeper exploration of these sensory and non-sensory avenues is needed.

The Buffer Effect of Therapy Dog Exposure on Stress Reactivity in Undergraduate Students

Stress is an insidious health risk that is commonly reported among university students. While research suggests that dog exposure may facilitate recovery from a stress response, little is known about the buffer effect of dog exposure on the stress response to a future stressor. This study examined whether interaction with a therapy dog could reduce the strength of the physiological stress response when exposed to a subsequent stressor. Sixty-one university students were randomly assigned to either a therapy dog (TD, n = 31) or a no-dog control (C, n = 30) group. The stress response was measured by electrodermal activity (EDA) in response to the Paced Auditory Serial Addition Test (PASAT). Participants also completed questionnaires that assessed pet attitude, general stress levels, and affect. Analyses of covariance (ANCOVAs) showed that increase in EDA was significantly more pronounced in the C group than in the TD group (p < 0.01). Pet attitudes did not modulate the buffer effect of therapy dog exposure. Results suggest that therapy dog exposure may buffer the stress response in university students, which has implications for the promotion of a viable stress management program on university campuses.

Prevention of transmitted infections in a pet therapy program: An exemplar

The focus of the patient experience in health care delivery has afforded the opportunity to integrate pet therapy as a part of patient care. The purpose of this article is to present the implementation of a pet therapy program that includes guidelines for the prevention of transmitted infections. Consideration of infection prevention strategies has resulted in a 16-year program with no documented incidences of transmitted infections, averaging 20,000 pet therapy interactions per year.

Neural correlates for perception of companion animal photographs

Anthrozoological neuroscience, which we propose as the use of neuroscience techniques to study human-animal interaction, may help to elucidate mechanisms underlying the associated psychological, physiological, and other purported health effects. This preliminary study investigates the neural response to animal photographs in pet owners and non-pet owners, and both attraction and attachment to companion animals as modulators of human perception of companion animal photographs. Thirty male participants, 15 "Pet Owners" (PO) and 15 "Non-Pet Owners" (NPO), viewed photographs of companion animals during functional MRI (fMRI) scans at 3 T and provided ratings of attraction to the animal species represented in the photographs. Fourteen subjects additionally submitted and viewed personal pet photographs during fMRI scans, and completed the Lexington Attachment to Pets Scale (LAPS). PO exhibited greater activation than NPO during the viewing of animal photographs in areas of the insula, and frontal and occipital cortices. Moreover, ratings of attraction to animals correlated positively with neural activation in the cingulate gyrus, precentral gyrus, inferior parietal lobule, and superior temporal gyrus during the viewing of representative photographs. For subjects with household pets, scores on the LAPS correlated positively with neural activation during the viewing of owned pet photographs in the precuneus, cuneus, and superior parietal lobule. Our preliminary findings suggest that human perception of companion animals involve the visual attention network, which may be modulated at the neural level by subjective experiences of attraction or attachment to animals. Our understanding of human-animal interactions through anthrozoological neuroscience may better direct therapeutic applications, such as animal-assisted therapy.

Post-operative benefits of animal-assisted therapy in pediatric surgery: a randomised study

Background

Interest in animal-assisted therapy has been fuelled by studies supporting the many health benefits. The purpose of this study was to better understand the impact of an animal-assisted therapy program on children response to stress and pain in the immediate post-surgical period.

Patients and Methods

Forty children (3–17 years) were enrolled in the randomised open-label, controlled, pilot study. Patients were randomly assigned to the animal-assisted therapy-group (n = 20, who underwent a 20 min session with an animal-assisted therapy dog, after surgery) or the standard-group (n = 20, standard postoperative care). The study variables were determined in each patient, independently of the assigned group, by a researcher unblinded to the patient’s group. The outcomes of the study were to define the neurological, cardiovascular and endocrinological impact of animal-assisted therapy in response to stress and pain. Electroencephalogram activity, heart rate, blood pressure, oxygen saturation, cerebral prefrontal oxygenation, salivary cortisol levels and the faces pain scale were considered as outcome measures.

Results

After entrance of the dog faster electroencephalogram diffuse beta-activity (> 14 Hz) was reported in all children of the animal-assisted therapy group; in the standard-group no beta-activity was recorded (100% vs 0%, p<0.001). During observation, some differences in the time profile between groups were observed for heart rate (test for interaction p = 0.018), oxygen saturation (test for interaction p = 0.06) and cerebral oxygenation (test for interaction p = 0.09). Systolic and diastolic blood pressure were influenced by animal-assisted therapy, though a higher variability in diastolic pressure was observed. Salivary cortisol levels did not show different behaviours over time between groups (p=0.70). Lower pain perception was noted in the animal-assisted group in comparison with the standard-group (p = 0.01).

Conclusion

Animal-assisted therapy facilitated rapid recovery in vigilance and activity after anaesthesia, modified pain perception and induced emotional prefrontal responses. An adaptative cardiovascular response was also present.

Trial Registration

ClinicalTrials.gov NCT02284100

Can therapy dogs improve pain and satisfaction after total joint arthroplasty? A randomized controlled trial

BACKGROUND

The use of animals to augment traditional medical therapies was reported as early as the 9th century but to our knowledge has not been studied in an orthopaedic patient population. The purpose of this study was to evaluate the role of animal-assisted therapy using therapy dogs in the postoperative recovery of patients after THA and TKA.

QUESTIONS/PURPOSES

We asked: (1) Do therapy dogs have an effect on patients' perception of pain after total joint arthroplasty as measured by the VAS? (3) Do therapy dogs have an effect on patients' satisfaction with their hospital stay after total joint arthroplasty as measured by the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS)?

METHODS

A randomized controlled trial of 72 patients undergoing primary unilateral THA or TKA was conducted. Patients were randomized to a 15-minute visitation with a therapy dog before physical therapy or standard postoperative physical therapy regimens. Both groups had similar demographic characteristics. Reduction in pain was assessed using the VAS after each physical therapy session, beginning on postoperative Day 1 and continuing for three consecutive sessions. To ascertain patient satisfaction, the proportion of patients selecting top-category ratings in each subsection of the HCAHPS was compared.

RESULTS

Patients in the treatment group had lower VAS scores after each physical therapy session with a final VAS score difference of 2.4 units (animal-assisted therapy VAS, 1.7; SD, 0.97 [95% CI, 1.4-2.0] versus control VAS, 4.1; SD, 0.97 [95% CI, 3.8-4.4], p<0.001) after the third physical therapy session. Patients in the treatment group had a higher proportion of top-box HCAHPS scores in the following fields: nursing communication (33 of 36, 92% [95% CI, 78%-98%] versus 69%, 25 of 36 [95% CI, 52%-84%], p=0.035; risk ratio, 1.3 [95% CI of risk ratio, 1.0-1.7]; risk difference, 23% [95% CI of risk difference, 5%-40%]), pain management (34 of 36, 94% [95% CI, 81%-99%], versus 26 of 36, 72% [95% CI, 55%-86%], p=0.024; risk ratio, 1.3 [95% CI of risk ratio, 1.1-1.6]; risk difference, 18% [95% CI of risk difference, 5%-39%]). The overall hospital rating also was greater in the treatment group (0-10 scale) (9.6; SD, 0.7 [95% CI, 9.3-9.8] versus 8.6, SD, 0.9 [95% CI, 8.3-8.9], p<0.001).

CONCLUSIONS

The use of therapy dogs has a positive effect on patients' pain level and satisfaction with hospital stay after total joint replacement. Surgeons are encouraged to inquire about the status of volunteer-based animal-assisted therapy programs in their hospital as this may provide a means to improve the immediate postoperative recovery for a select group of patients having total joint arthroplasty.

LEVEL OF EVIDENCE

Level II, randomized controlled study. See Instructions for Authors for a complete description of levels of evidence.

The Therapeutic Effects Upon Dog Owners Who Interact With Their Dogs in a Mindful Way

This case study describes the experiences of three individuals who participated in a training program that taught them to work with their dogs in a mindful manner. That is to say, in a way that would help them intentionally pay attention in an open, accepting, and curious way, to the needs, body language, responses, and reactions of their dogs. The ways in which these external experiences led to an awareness of their internal experience are also discussed. The results suggest that this method not only positively influenced the relationship these women had with their dogs, but also enhanced their relationship with others and contributed to their own self-growth and increased happiness. A look at how incorporating the concepts of mindfulness, the use of self-as-a-change-agent, the practice of dog psychology in training, and how each of these affect change in one’s psychological well-being are discussed. In addition, this study describes an approach to understanding how clients can act as their own vehicles of change and resolve existential problems related to self-alienation by viewing the dog as part of nature and finding a reconnection to self and others through a mindful interaction with their dog.

Presence of a dog reduces subjective but not physiological stress responses to an analog trauma

Dogs are known to have stress and anxiety reducing effects. Several studies have shown that dogs are able to calm people during cognitive and performance stressors. Recently, therapy dogs have been proposed as a treatment adjunct for post-traumatic stress disorder patients. In this study we aimed to investigate, whether dogs also have anxiety- and stress reducing effect during "traumatic stressors." 80 healthy female participants were randomly assigned to one of four conditions. They were exposed to a "traumatic" film clip (trauma-film-paradigm). For one group of participants a friendly dog was present during the film, one group of participants was accompanied by a friendly human, another control group watched the film with a toy animal and the last group watched the film clip alone. Participants that were accompanied by the dog during the film reported lower anxiety ratings and less negative affect after the film clip as compared to the "toy dog group" and the "alone group." Results of the "dog group" were comparable to the group that was accompanied by a friendly human. There were no differences in physiological stress responses between the four conditions. Our results show that dogs are able to lessen subjectively experienced stress and anxiety during a "traumatic" stress situation. This effect was comparable to that of social support by a friendly person. Implications for PTSD patients are discussed.

Impact of animal-assisted intervention on rehabilitation of patients with spinal cord injury

Introduction: The animal-assisted programs represent an interdisciplinary approach. They can be integrated into preventive, therapeutic and rehabilitative processes as complementary methods. Aim: The aim of the study was to promote the psychological adaptation and social reintegration of patients who suffered spinal cord injury, as well as reducing depression and feelings of isolation caused by the long hospitalization. The hypothesis of the authors was that the animal-assisted intervention method can be effectively inserted into the rehabilitation process of individuals with spinal cord injury as complementary therapy. Methods: 15 adults with spinal cord injury participated in the five-week program, twice a week. Participants first filled out a questionnaire on socio-demographics, and after completion of the program they participated in a short, directed interview with open questions. During the field-work, after observing the participants, qualitative data analysis was performed. Results: The results suggest that the therapeutic animal induced a positive effect on the emotional state of the patients. Participants acquired new skills and knowledge, socialization and group cohesion had been improved. Conclusions: The authors conclude that the animal-assisted activity complemented by therapeutic elements can be beneficial in patients undergoing spinal cord injury rehabilitation and that knowledge obtained from the study can be helpful in the development of a future animal-assisted therapy program for spinal cord injury patients. Orv. Hetil., 2014, 155(39), 1549–1557.

Animal-Assisted Activity: Effects of a Complementary Intervention Program on Psychological and Physiological Variables

Animal-assisted activity is the use of trained animals for the therapeutic, motivational, or educational benefit of patients. Subjects of this study were 218 patients hospitalized on the mental health unit of a community hospital with an existing, complementary animal-assisted activity program. Half of the patients participated in a 1-hour session of animal-assisted activity. The other half, who served as a comparison group, participated in a 1-hour stress management program. It was hypothesized that an animal-assisted activity program would improve ratings of depression, anxiety, and pain and the associated physiological measures of stress and discomfort. Self-report ratings of depression, anxiety, and pain were collected before and after treatment sessions, and blood pressure, pulse, and salivary cortisol were measured. There were significant decreases in depression ( P < .0001), anxiety ( P < .0001), pain ( P < .0001), and pulse ( P < .04) after animal-assisted activity program, comparable to those in the more traditional stress management group.

Genetic and Environmental Influences on Individual Differences in Frequency of Play with Pets among Middle-Aged Men: A Behavioral Genetic Analysis

There is growing evidence that pet ownership and human-animal interaction (HAI) have benefits for human physical and psychological well-being. However, there may be pre-existing characteristics related to patterns of pet ownership and interactions with pets that could potentially bias results of research on HAI. The present study uses a behavioral genetic design to estimate the degree to which genetic and environmental factors contribute to individual differences in frequency of play with pets among adult men. Participants were from the ongoing longitudinal Vietnam Era Twin Study of Aging (VETSA), a population-based sample of 1,237 monozygotic (MZ) and dizygotic (DZ) twins aged 51-60 years. Results demonstrate that MZ twins have higher correlations than DZ twins on frequency of pet play, suggesting that genetic factors play a role in individual differences in interactions with pets. Structural equation modeling revealed that, according to the best model, genetic factors accounted for as much as 37% of the variance in pet play, although the majority of variance (63-71%) was due to environmental factors that are unique to each twin. Shared environmental factors, which would include childhood exposure to pets, overall accounted for <10% of the variance in adult frequency of pet play, and were not statistically significant. These results suggest that the effects of childhood exposure to pets on pet ownership and interaction patterns in adulthood may be mediated primarily by genetically-influenced characteristics.

Impact of animal-assisted therapy for outpatients with fibromyalgia

OBJECTIVES

Animal-assisted therapy using dogs trained to be calm and provide comfort to strangers has been used as a complementary therapy for a range of medical conditions. This study was designed to evaluate the effects of brief therapy dog visits for fibromyalgia patients attending a tertiary outpatient pain management facility compared with time spent in a waiting room.

DESIGN

Open label with waiting room control.

SETTING

Tertiary care, university-based, outpatient pain management clinic.

SUBJECTS

A convenience sample of fibromyalgia patients was obtained through advertisements posted in the clinic.

INTERVENTIONS

Participants were able to spend clinic waiting time with a certified therapy dog instead of waiting in the outpatient waiting area. When the therapy dog was not available, individuals remained in the waiting area. OUTCOME MEASURES.: Self-reported pain, fatigue, and emotional distress were recorded using 11-point numeric rating scales before and after the therapy dog visit or waiting room time.

RESULTS

Data were evaluated from 106 therapy dog visits and 49 waiting room controls, with no significant between-group demographic differences in participants. Average intervention duration was 12 minutes for the therapy dog visit and 17 minutes for the waiting room control. Significant improvements were reported for pain, mood, and other measures of distress among patients after the therapy dog visit, but not the waiting room control. Clinically meaningful pain relief (≥2 points pain severity reduction) occurred in 34% after the therapy dog visit and 4% in the waiting room control. Outcome was not affected by the presence of comorbid anxiety or depression.

CONCLUSIONS

Brief therapy dog visits may provide a valuable complementary therapy for fibromyalgia outpatients.

Animal-assisted therapy at an outpatient pain management clinic

OBJECTIVE

The objective of this study was to evaluate the effects of brief therapy dog visits to an outpatient pain management facility compared with time spent in a waiting room.

DESIGN

The design of this study is open-label. Setting.  This study was conducted in a university tertiary care adult chronic pain outpatient clinic.

SUBJECTS

The subjects of this study include outpatients, adults accompanying outpatients to their appointments, and clinic staff. Intervention.  Participants were able to spend clinic waiting time with a certified therapy dog instead of waiting in the outpatient waiting area. When the therapy dog was not available, individuals remained in the waiting area.

OUTCOME MEASURES

Self-reported pain, fatigue, and emotional distress were recorded using 11-point numeric rating scales before and after the therapy dog visit or waiting room time.

RESULTS

Two hundred ninety-five therapy dog visits (235 with patients, 34 family/friends, and 26 staff) and 96 waiting room surveys (83 from patients, 6 family/friends, and 7 staff) were completed over a 2-month study period. Significant improvements were reported for pain, mood, and other measures of distress among patients after the therapy dog visit but not the waiting room control, with clinically meaningful pain relief (decrease ≥2 points) in 23% after the therapy dog visit and 4% in the waiting room control. Significant improvements were likewise seen after therapy dog visits for family/friends and staff.

CONCLUSIONS

Therapy dog visits in an outpatient setting can provide significant reduction in pain and emotional distress for chronic pain patients. Therapy dog visits can also significantly improve emotional distress and feelings of well-being in family and friends accompanying patients to appointments and clinic staff.

Developing effective animal-assisted intervention programs involving visiting dogs for institutionalized geriatric patients: a pilot study

AIM

An ever increasing interest in the therapeutic aspects of the human-animal bond has led to a proliferation of animal-assisted interventions (AAI) involving dogs. However, most of these programs lack a solid methodological structure, and basic evaluative research is needed. The purpose of this study was to test the value of dog-assisted interventions as an innovative tool to increase quality of life in the geriatric population.

METHODS

Nineteen patients (men and women) with a mean age of 85 years participated in the study. Interactions between patients and visiting dogs occurred either in a social situation (socialization sessions) or in a therapeutic context (physical therapy sessions). We derived and characterized a specific ethogram of elderly-dog interactions aimed at evaluating the effectiveness of visiting dogs in improving mood, catalyzing social interactions and reducing their everyday apathetic state. Cortisol levels were also measured in the saliva, and depressive state was evaluated.

RESULTS

Overall, results show a time-dependent increase in social behaviour and spontaneous interactions with the dogs. Dog-mediated interactions affected the daily increase in cortisol levels, thus having an 'activational effect', in contrast to the apathetic state of institutionalized elderly.

CONCLUSIONS

Dog-mediated intervention programs appear to be promising tools to improve the social skills and enrich the daily activities of the institutionalized elderly.

Psychosocial and psychophysiological effects of human-animal interactions: the possible role of oxytocin

During the last decade it has become more widely accepted that pet ownership and animal assistance in therapy and education may have a multitude of positive effects on humans. Here, we review the evidence from 69 original studies on human-animal interactions (HAI) which met our inclusion criteria with regard to sample size, peer-review, and standard scientific research design. Among the well-documented effects of HAI in humans of different ages, with and without special medical, or mental health conditions are benefits for: social attention, social behavior, interpersonal interactions, and mood; stress-related parameters such as cortisol, heart rate, and blood pressure; self-reported fear and anxiety; and mental and physical health, especially cardiovascular diseases. Limited evidence exists for positive effects of HAI on: reduction of stress-related parameters such as epinephrine and norepinephrine; improvement of immune system functioning and pain management; increased trustworthiness of and trust toward other persons; reduced aggression; enhanced empathy and improved learning. We propose that the activation of the oxytocin system plays a key role in the majority of these reported psychological and psychophysiological effects of HAI. Oxytocin and HAI effects largely overlap, as documented by research in both, humans and animals, and first studies found that HAI affects the oxytocin system. As a common underlying mechanism, the activation of the oxytocin system does not only provide an explanation, but also allows an integrative view of the different effects of HAI.

The human-companion animal bond: how humans benefit

The human-animal bond is extremely important to most clients of small animal veterinary practices. Pet ownership, or just being in the presence of a companion animal, is associated with health benefits, including improvements in mental, social, and physiologic health status. This article provides the research data regarding the human health benefits of companion animals, animal-assisted therapy, animal-assisted activities, and assistance animals; reviews measures that can be taken to enable safe pet ownership for the immunocompromised, and discusses the veterinarian's role in supporting immune-compromised clients and clients who have assistance animals. Client education and enhanced veterinary care can reduce the risk from zoonotic diseases, even for the immunocompromised.

Dog's gaze at its owner increases owner's urinary oxytocin during social interaction

Oxytocin (OT) has been shown to play an important role in social bonding in animals. However, it is unclear whether OT is related to inter-species social bonding. In this study, to examine the possibility that urinary OT concentrations of owners were increased by their "dog's gaze", perhaps representing social attachment to their owners, we measured urinary OT concentrations of owners before and after interaction with their dogs. Dog owners interacted with their dogs as usual for 30 min (interaction experiment) or were instructed not to look at their dogs directly (control experiment). We observed the behaviors of owners and their dogs during the experiments, and measured OT concentrations by radioimmunoassay in urine samples from the owners collected just before and 20 min after interaction with their dogs. Using a cluster analysis, owners could be divided into two groups: one received a longer duration of gaze from their dogs and reported a higher degree of relationship with their dogs (LG); the other received a shorter duration of gaze and reported a lower degree of relationship (SG). Urinary OT was higher in LG than SG after usual interaction with their dogs, but not in the control experiment. In the interaction experiment, a high correlation was found in LG between the frequency of behavioral exchanges initiated by the dog's gaze and the increase in urinary OT. We conclude that interactions with dogs, especially those initiated by the dog's gaze, can increase the urinary OT concentrations of their owners as a manifestation of attachment behavior.

Effects of an attachment-based intervention on daily cortisol moderated by dopamine receptor D4: A randomized control trial on 1- to 3-year-olds screened for externalizing behavior

The effect of the Video-Feedback Intervention to Promote Positive Parenting and Sensitive Discipline (VIPP-SD) on daily cortisol production was tested in a randomized controlled trial with 130 families with 1- to 3-year-old children screened for their relatively high levels of externalizing behavior. Six 1.5-hr intervention sessions focusing on maternal sensitivity and discipline were conducted with individual families at their homes. Children in the intervention group showed lower cortisol levels, with a moderating role of the dopamine receptor D4 (DRD4) VNTR exon III polymorphism. The VIPP-SD program proved to be effective in decreasing daily cortisol production in childrenwiththeDRD47-repeat allele, but not in childrenwithouttheDRD47-repeat allele. Our findings indicate that children are differentially susceptible to intervention effects dependent on the presence of the 7-repeatDRD4allele.

Animal-assisted therapy with farm animals for persons with psychiatric disorders: effects on self-efficacy, coping ability and quality of life, a randomized controlled trial

BACKGROUND

The benefits of Animal-Assisted Therapy (AAT) for humans with mental disorders have been well-documented using cats and dogs, but there is a complete lack of controlled studies using farm animals as therapeutic agents for psychiatric patients. The study was developed in the context of Green care, a concept that involves the use of farm animals, plants, gardens, or the landscape in recreational or work-related interventions for different target groups of clients in cooperation with health authorities. The present study aimed at examining effects of a 12-week intervention with farm animals on self-efficacy, coping ability and quality of life among adult psychiatric patients with a variety of psychiatric diagnoses.

METHODS

The study was a randomized controlled trial and follow-up. Ninety patients (59 women and 31 men) with schizophrenia, affective disorders, anxiety, and personality disorders completed questionnaires to assess self-efficacy (Generalized Self-Efficacy Scale; GSE), coping ability (Coping Strategies Scale), and quality of life (Quality of Life Scale; QOLS-N) before, at the end of intervention, and at six months follow-up. Two-thirds of the patients (N = 60) were given interventions; the remaining served as controls.

RESULTS

There was significant increase in self-efficacy in the treatment group but not in the control group from before intervention (SB) to six months follow-up (SSMA), (SSMA-SB; F1,55 = 4.20, p= 0.05) and from end of intervention (SA) to follow-up (SSMA-SA; F1,55 = 5.6, p= 0.02). There was significant increase in coping ability within the treatment group between before intervention and follow-up (SSMA-SB = 2.7, t = 2.31, p = 0.03), whereas no changes in quality of life was found. There were no significant changes in any of the variables during the intervention.

CONCLUSION

AAT with farm animals may have positive influences on self-efficacy and coping ability among psychiatric patients with long lasting psychiatric symptoms.

The benefits of human-companion animal interaction: a review

This article provides a review of research published since 1980 on the benefits of human-companion animal interaction. Studies focusing on the benefits of pet ownership are presented first, followed by research on the benefits of interacting with companion animals that are not owned by the subject (animal-assisted activities). While most of the published studies are descriptive and have been conducted with convenience samples, a promising number of controlled studies support the health benefits of interacting with companion animals. Future research employing more rigorous designs and systematically building upon a clearly defined line of inquiry is needed to advance our knowledge of the benefits of human-companion animal interaction.