Salivary cortisol and behavior in therapy dogs during animal-assisted interventions: A pilot study

How to Measure Human-Dog Interaction in Dog Assisted Interventions? A Scoping Review

Human-dog interaction is the working tool through which the therapeutic, educational and recreational goals of dog-assisted interventions (DAIs) are achieved. A better understanding of the characteristics of this interaction could improve the effectiveness of DAIs. This scoping review addresses the question: how has the human-dog connection been measured in the context of DAIs? After searching the Web of Science and Scopus platforms, only peer-reviewed, primary research studies reporting measures of therapy dog-human interaction, relationship and bond were included. A total of 70 included articles provided information on what was measured (interaction, relationship or bond) and how, as well as the general context (DAIs or experimental situations with therapy dogs). While the majority of the articles identified use behavioural analysis methods to analyse the interaction between the participant/recipient and the therapy dog during DAIs, it was possible to identify some more structured tools that assess the participant/recipient's interaction, relationship or bond with the therapy dog, as well as tools that consider the animal's perspective or focus on the dog-handler dyad, indicating growing areas of research. The tools and methods identified can be used by both practitioners and researchers to further explore aspects of human-dog interaction in the field of DAIs.

Why do dogs wag their tails?

Tail wagging is a conspicuous behaviour in domestic dogs (Canis familiaris). Despite how much meaning humans attribute to this display, its quantitative description and evolutionary history are rarely studied. We summarize what is known about the mechanism, ontogeny, function and evolution of this behaviour. We suggest two hypotheses to explain its increased occurrence and frequency in dogs compared to other canids. During the domestication process, enhanced rhythmic tail wagging behaviour could have (i) arisen as a by-product of selection for other traits, such as docility and tameness, or (ii) been directly selected by humans, due to our proclivity for rhythmic stimuli. We invite testing of these hypotheses through neurobiological and ethological experiments, which will shed light on one of the most readily observed yet understudied animal behaviours. Targeted tail wagging research can be a window into both canine ethology and the evolutionary history of characteristic human traits, such as our ability to perceive and produce rhythmic behaviours.

Hair Cortisol in Service Dogs for Veterans with Post-traumatic Stress Disorder Compared to Companion Dogs (Canis Familiaris)

Service dogs are trained to assist humans. This assistance potentially exposes them to stressors To investigate if service dogs are exposed to more stressors than companion dogs we questioned whether hair cortisol levels differed between both groups. We studied this by cutting a tuft of hair from the neck of 19 companion and 11 service dogs. Cortisol levels were subsequently analyzed via immunoassay and compared via a simple linear regression model. The influence of coat color, season, sex, other dogs, pets, or mental health diagnoses in the household was also checked . Results showed that cortisol values did not differ between service and companion dogs. Furthermore, none of the additional variables had an influence on cortisol levels. This lead to the conclusion that the service dogs in this study did not have higher hair cortisol levels than companion dogs Further study should be conducted as to why no difference did occur between groups and if this difference is persistent over time given that we only studied a period of up to two months' worth of hair cortisol.

A pilot study into the effects of PTSD-assistance dogs' work on their salivary cortisol levels and their handlers' Quality of life

Assistance dogs for people with Posttraumatic Stress Disorder (PTSD) support their handlers by performing tasks that are supposed to mitigate the effects of their mental disability. This study examined the Quality of Life (QoL) of PTSD-assistance dogs' handlers in Austria and Germany using a qualitative online questionnaire based on the Capability Approach. To correspondingly explore whether the involved assistance dogs experience distress triggered by their daily schedules, we measured their salivary cortisol values. These were compared to the cortisol levels of companion dogs without special tasks, as well as diabetic-signal dogs that have a similar workload. Our results showed that people suffering from PTSD-symptoms can improve their QoL with the aid of their assistance dog. However, being accompanied by an assistance dog creates new social barriers. Surprisingly, we found significantly lower salivary cortisol levels in PTSD-assistance dogs compared to the control groups. We conclude that a positive relationship between PTSD-assistance dogs and their handlers can reduce stress on both sides, and that training well tuned to the requirements of an assistance dog can prevent stress in their daily lives.

Developing and Planning a Protocol for Implementing Health Promoting Animal Assisted Interventions (AAI) in a Tertiary Health Setting

The Ottawa Charter identifies that multiple levels of government, non-government, community, and other organizations should work together to facilitate health promotion, including in acute settings such as hospitals. We outline a method and protocol to achieve this, namely an Action Research (AR) framework for an Animal Assisted Intervention (AAI) in a tertiary health setting. Dogs Offering Support after Stroke (DOgSS) is an AR study at a major tertiary referral hospital. AAI has been reported to improve mood and quality of life for patients in hospitals. Our project objectives included applying for funding, developing a hospital dog visiting Action Research project, and, subsequent to ethics and governance approvals and finance, undertaking and reporting on the Action Research findings. The Action Research project aimed to investigate whether AAI (dog-visiting) makes a difference to the expressed mood of stroke patients and their informal supports (visiting carers/family/friends), and also the impact these visits have on hospital staff and volunteers, as well as the dog handler and dog involved. We provide our protocol for project management and operations, setting out how the project is conducted from conception to assess human and animal wellbeing and assist subsequent decision-making about introducing dog-visiting to the Stroke Unit. The protocol can be used or adapted by other organizations to try to avoid pitfalls and support health promotion in one of the five important action areas of the Ottawa Charter, namely that of reorienting health services.

Sensor-supported measurement of adaptability of dogs (Canis familiaris) to a shelter environment: Nocturnal activity and behavior

Every shelter dog is faced with the challenge to adapt to a kennel environment. To monitor the welfare of individual shelter dogs, evaluating behavioural and physiological parameters, potentially useful as indicators for adaptability of individual dogs is crucial. Nocturnal activity, i.e. resting patterns, has already been identified as a candidate indicator of adaptability and can be easily measured remotely with the help of sensors. We investigated the usefulness of a 3-axial accelerometer (Actigraph®) to monitor nocturnal activity in shelter dogs every night during the full first two weeks in-shelter starting directly at shelter intake, as a measure of welfare. Additionally, urinary cortisol/creatinine ratio (UCCR), body weight and behaviour data were collected to evaluate stress responses. A control group of pet dogs in homes, matched to the shelter dog group, was also monitored. Shelter dogs had higher nocturnal activity and UCCRs than pet dogs, especially during the first days in the shelter. Nocturnal activity, both accelerometer measures and activity behaviour, and UCCRs decreased over nights in the shelter. Smaller dogs had higher nocturnal activity and UCCRs than larger dogs and showed less autogrooming during the first nights. Dogs with no previous kennel experience had higher nocturnal activity and UCCRs, and showed less body shaking, than dogs with previous kennel experience. Overall, sheltered dogs also showed less body shaking during the first night. The number of dogs showing paw lifting decreased over days. Age class and sex effected only few activity behaviours. Shelter dogs significantly lost body weight after 12 days in the shelter compared to the moment of intake. Shelter dogs had disrupted nocturnal resting patterns and UCCRs compared to pet dogs and seem to partly adapt to the shelter environment after two weeks. Sensor-supported identification of nocturnal activity can be a useful additional tool for welfare assessments in animal shelters.

Investigating Dog Welfare When Interacting with Autistic Children within Canine-Assisted Occupational Therapy Sessions: A Single Case Study

Human-animal bond is defined as the mutually beneficial relationship between humans and animals. Recent years have seen increasing research regarding the benefits of interaction with animals for autistic children. However, there continue to be limited studies exploring the impact of this interaction on the welfare of therapy dogs. As part of a pilot randomised control trial assessing the efficacy of canine-assisted occupational therapy with autistic children, this project assessed welfare markers of the therapy dog involved. A total of twenty-one saliva samples were taken from the therapy dog to assess cortisol, alpha amylase, and oxytocin concentrations at home and throughout the treatment days. Additionally, six hours of therapy session videos were analysed for stress indicators of canine behaviour. No significant differences were found between days spent at home and treatment days for any of the biomarkers or stress indicators. Results suggest that the therapy dog involved did not experience increased stress resulting from interaction with the autistic children throughout the therapy sessions. This study supports the need for further research regarding therapy dog welfare when interacting with autistic children including an increased sample size of therapy dogs and therapists.

Understanding the Role of Therapy Dogs in Human Health Promotion

Dogs may provide humans with a range of physical, mental and social benefits. Whilst there is growing scientific evidence of benefits to humans, there has been less focus on the impact to canine health, welfare and ethical considerations for the dogs. The importance of animal welfare is increasingly acknowledged, indicating that the Ottawa Charter should be extended to include the welfare of non-human animals supporting the promotion of human health. Therapy dog programmes are delivered across a variety of settings including hospitals, aged care facilities and mental health services, highlighting the important role they play in human health outcomes. Research has shown that that there are biomarkers for stress in humans and other animals engaged in human-animal interactions. This review aims to assess the impact of human-animal interactions on therapy dogs engaged in providing support to human health. While challenging, it is paramount to ensure that, within the framework of One Welfare, the welfare of therapy dogs is included, as it is a key factor for future sustainability. We identified a range of concerns due to the lack of guidelines and standards to protect the wellbeing of the dogs engaged in these programmes. Extension of the Ottawa Charter to include the welfare of non-human animals with leveraging through a One Welfare approach would promote animal and human health beyond current boundaries.

Canine-Assisted Interventions and the Relevance of Welfare Assessments for Human Health, and Transmission of Zoonosis: A Literature Review

CAIs (canine-assisted interventions) include "canine-assisted therapy" in which a therapist sets client-oriented goals, 'canine-assisted activities' with recreational goals for clients, and 'canine-assisted education/learning' in which teachers or coaches create learning goals for students or clients. CAIs vary in nearly every way; their only common trait is the involvement of dogs to respond to human need. However, the benefits of involving dogs are highly dependent on the animal's health and behavior. A dog exhibiting negative behavior or an unwell dog might pose a risk, especially for CAI target groups, specifically individuals with immunosuppression, chronic illness, children, elderly, etc. Therefore, positive animal welfare as preventative medicine to avoid incidents or transmission of zoonosis is an attractive hypothesis, with implications for human and animal, health and well-being. This review aims to summarize the current published knowledge regarding different aspects of welfare in CAIs and to discuss their relevance in the light of health and safety in CAI participants. As method for this study, a literature search was conducted (2001-2022) using the Prisma method, describing issues of dog welfare as defined in the Welfare Quality® approach. This welfare assessment tool includes 4 categories related to behavior, health, management, and environment; it was, therefore, applicable to CAIs. Results indicate that dogs working in CAIs are required to cope with diverse variables that can jeopardize their welfare. In conclusion, we propose regular welfare assessments for dogs in CAIs, which would also protect the quality of the CAI sessions and the clients' safety and well-being.

Dog–Owner Relationship, Owner Interpretations and Dog Personality Are Connected with the Emotional Reactivity of Dogs

Simple Summary

The relationship between owner and the dog affects the dog’s attachment behaviors and stress coping. In turn, the quality of the relationship may affect owner’s interpretations about their dog’s behavior. Here, we assessed dogs’ emotional responses from heart rate variability and behavioral changes during five different situations. Dog owners evaluated the emotion (valence and arousal) of their dog after each situation. We found that both negative and positive incidents provoked signs of emotional arousal in dogs. Owners detected the dog’s arousal especially during fear- and stress-evoking situations. The dog–owner relationship did not affect owners’ interpretation of dogs’ emotion. However, the dog–owner relationship was reflected in the dog’s emotional reactions. Close emotional bond with the owner appeared to decrease the arousal of the dogs. Dog owners’ frequent caregiving of their dog was associated with increased attachment behaviors and heightened arousal of dogs. Owners rated the disadvantages of the dog relationship higher for the dogs that were less owner-oriented and less arousable. Dog’s arousal may provoke dog’s need to seek human attention, which in turn may promote the development of emotional bond.

Abstract

We evaluated the effect of the dog–owner relationship on dogs’ emotional reactivity, quantified with heart rate variability (HRV), behavioral changes, physical activity and dog owner interpretations. Twenty nine adult dogs encountered five different emotional situations (i.e., stroking, a feeding toy, separation from the owner, reunion with the owner, a sudden appearance of a novel object). The results showed that both negative and positive situations provoked signs of heightened arousal in dogs. During negative situations, owners’ ratings about the heightened emotional arousal correlated with lower HRV, higher physical activity and more behaviors that typically index arousal and fear. The three factors of The Monash Dog–Owner Relationship Scale (MDORS) were reflected in the dogs’ heart rate variability and behaviors: the Emotional Closeness factor was related to increased HRV (p = 0.009), suggesting this aspect is associated with the secure base effect, and the Shared Activities factor showed a trend toward lower HRV (p = 0.067) along with more owner-directed behaviors reflecting attachment related arousal. In contrast, the Perceived Costs factor was related to higher HRV (p = 0.009) along with less fear and less owner-directed behaviors, which may reflect the dog’s more independent personality. In conclusion, dogs’ emotional reactivity and the dog–owner relationship modulate each other, depending on the aspect of the relationship and dogs’ individual responsivity.

The Importance of Evaluating Positive Welfare Characteristics and Temperament in Working Therapy Dogs

To date, investigations of the welfare of therapy dogs have focused largely on examining physiological and behavioral measures that could indicate if the animal is experiencing stress or distress. However, this approach does not fully address the definition of welfare which is often described as existing on a continuum from negative (or stressful) to positive. With therapy dogs, it would be worth addressing if they experience positive emotional affect while working since the quality and efficacy of animal-assisted interventions for the human recipient is likely to be influenced by the animal's emotional state during the interaction. The purpose of this review is to articulate how objective measurements of the HPA axis and measurements of behavioral observations and standardized questions can be used to evaluate positive welfare in therapy dogs. A potentially relevant indicator of positive welfare is the peripheral concentration of the neurohormone oxytocin, which has been found to increase in systemic circulation within a variety of species during positive social and affiliative contexts, including during human-dog interaction. Oxytocin is also a negative-feedback regulator of the Hypothalamic-Pituitary-Adrenal (HPA) axis, which culminates with the production of the stress hormone cortisol. Cortisol is widely used as a physiological indicator to assess negative welfare states in animals, including therapy dogs. Observable behavior during interactions with humans that may convey enjoyment could provide indicators of positive welfare in dogs such as engagement in play, or human-directed affiliative behaviors including leaning against, nudging, or licking the patient. However, in assessing positive welfare, it is also critical to consider that all animal behavioral displays and physiological responses are dependent on the dog's individual (and breed) temperament. Temperament directly drives how the animal copes and responds to its current physical and social environment, including during stressful situations such as when therapy dogs interact with unfamiliar humans in novel healthcare settings. Coupled with both positive and negative physiological and behavioral welfare indicators, questionnaire data can provide further context to, and enhance interpretations of, therapy dog welfare assessment results. Overall, to date, no studies have measured all of these factors to assess therapy dog welfare.

Chronic Stress Indicators in Canines

With a growing number of dogs abandoned, living in shelters, and being rehomed, it is important to distinguish behavioural responses due to stress in our domestic companions. Cortisol is involved in the stress responses in animals which generally enters the individual’s body into a “state of emergency”. Prolonged stress can lead to exhaustion, disease, and death. Chronic stress can be detected by evaluating cortisol concentration in hair. Most domesticated dogs respond well to hair collection, thus avoiding further stressors. The method is simple, relatively inexpensive, and non-invasive. Our experiment focused on assessing multiple parameters using a modified Canine Behavioural Assessment and Research Questionnaire to evaluate their significance with cortisol in hair samples from a diverse range of dogs. Each stress parameter was tested against cortisol concentration using a t-Test, i. e., the Paired Two Sample for Means. The effect of weight on cortisol levels was statistically significant (P = 0.03). This fact revealed that an increase in body weight correlated with an increase in cortisol levels.

Molecular Biomarkers of Adult Human and Dog Stress during Canine-Assisted Interventions: A Systematic Scoping Review

Simple Summary

Interactions between people and dogs may lower participants’ stress levels. However, this is a fairly new area of research and there has not been a review of what we know across studies. We examined the existing research and found that human–dog interactions consistently improve some indications of human stress levels and don’t seem to negatively affect dogs. However, we need to do more research to gain a better understanding of the impacts on people and dogs with a wider lens that looks at more markers of stress.

Abstract

Positive relationships, including those between humans and other animals, particularly dogs, may be a way to reduce stress in humans. However, research into this area is relatively new, and a comprehensive review of the impacts of these interactions on humans and dogs has not been conducted. A scoping review of the scientific literature was conducted to explore what is known about the impacts of canine-assisted interventions on molecular biomarkers (e.g., cortisol and oxytocin) and associated measures (e.g., heart rate and blood pressure) of human and canine stress. As reported across 27 identified studies, canine-assisted interventions have consistently been demonstrated to elicit positive changes in human stress markers, and typically do not cause negative impacts on the studied canine stress markers. However, results were inconsistent across measures of stress. For example, in humans, it was common for a study to show improvements to cortisol levels but no change to self-reported stress, or vice versa. Many of the reviewed studies also had significant methodological issues, such as not aligning the timing of sample collections to when the analyzed stress biomarkers could be expected to peak. More rigorous research should be conducted on the impacts of canine-assisted interventions on a wider range of stress biomarkers.

Handlers’ Representations on Therapy Dogs’ Welfare

Simple Summary

Most research about Animal-Assisted Interventions (AAI) has focused on the benefits on human health. In contrast, very little has been made on the impact of this work on therapy dogs, although it is part of the ethics of the practice to ensure their welfare. This study aimed to contribute to the knowledge on the welfare of therapy dogs by interviewing 111 handlers through an online questionnaire. The qualitative assessment of handlers’ representations underlined that the welfare of therapy dogs is multidimensional and can be impacted by various variables. Its consideration is important for the quality and safety of the sessions, both for the dog and for the beneficiaries involved. Handlers have a central role in the welfare of their therapy dog and must be trained on stress-related behaviors. Research needs to focus on the impact of interactions on therapy dogs.

Abstract

While research on the benefits of animal-assisted interventions is beginning to build a significant body of work, studies on the well-being of therapy dogs are still in their infancy. Since handlers are the people responsible for their therapy dog’s welfare, we interviewed 111 French handlers through an online questionnaire. Our results underlined that (i) therapy dogs’ welfare is multidimensional when physical and psychological welfare, a balance between work and dog life and the settings and interactions of sessions are all taken into consideration. (ii) The response of our handlers emphasized that considering therapy dog welfare is important for the quality and safety of AAI. (iii) Three categories of risks factors were highlighted: the spatio-temporal framework (planning and environment), the interactions with beneficiaries and the handler themselves. It is particularly important that handlers talk about the negative impact of interactions with beneficiaries since they are at the heart of AAI, however there are few studies focusing on interactions as a stressor for dogs in this practice. Moreover, since there is a potential for positive bias in the handlers’ representations, it is important that they be trained to identify and manage the stress in their dogs. Future research is particularly needed on the impact of interactions during sessions on therapy dog welfare.

Does Experience Make Hucul Horses More Resistant to Stress? A Pilot Study

The aim of the study was to determine whether experience related to horse age and number of starts in championships influences stress level, measured by salivary cortisol concentration. The study involved 18 clinically healthy Hucul mares who participated in the Polish Championships for Hucul Horses. Evaluation of performance value was carried out in accordance with the guidelines specified in the breeding and genetic resources conservation program for this breed. The championship lasted two days, consisting of conformation evaluation, endurance, and Hucul path. Saliva was collected at baseline (T1), after arena assessment (T2), after endurance (T3), and on the second day after the Hucul path (T4). Cortisol levels increased from an average of 2.73 ± 1.18 ng/mL (T1) to 10.46 ± 8.03 ng/mL after T3. Significantly lower levels of free cortisol were detected in the saliva of the younger mares, up to 9 years old, and mares who participated in only one qualifying path after each element of the championship. The highest levels of cortisol (T3) were found in mares competing repeatedly on the qualifying path. No correlation was found between cortisol levels and the championship results. Participation of mares in the championship was associated with stress, which was reflected in the increase in cortisol levels in saliva.

Dogs as Therapeutic Partners, Not Therapeutic Tools: Ethical Considerations for AAT in the Correctional Setting

Although the benefits of animal assisted therapy for people are well established, the ethical considerations for the welfare and safety of the non-human animals involved are not. Without an accrediting body responsible for creating and overseeing national standards, therapy animal organizations are forced to create their own guidelines, creating inconsistencies within the field. Based on interviews conducted with therapy teams who have worked with Parenting, Prison & Pups (PPP), a parenting program provided to incarcerated jailed women that is integrated with the use of animal-assisted therapy (AAT), this article explores the extent of ethics training offered for AAT teams and will examine how agencies and handlers promote and ensure the safety of canine partners, especially in a correctional setting. The research suggests that specific protocols put forth by individual AAT organizations, which can provide for a national model, can afford for the safety and comfortability of canine partners, especially in a corrections environment, but implies that in order to maintain consistency and increase therapy team professionalism, national standards are a necessity. Guidelines are specifically essential for mental health professionals, who lack guidelines from their own accrediting bodies’ code of ethics, and may incorporate non-human therapy partners into their work settings, without proper supervision.

Therapy Dog Welfare Revisited: A Review of the Literature

During the past decade, the field of human-animal interaction(s) research has been characterized by a significant increase in scientific findings. These data have contributed to our current understanding of how humans may benefit from contact with animals. However, the animal experience of these interactions is still an under-researched area. This paper addresses the welfare of dogs who participate in animal-assisted interventions (AAIs) to improve health in human recipients. This paper builds on previous work by Glenk (2017) and provides an updated review of the literature on therapy dog welfare published from 2017-2021. New advances in scientific methodology, such as the determination of salivary oxytocin, breath rate and tympanic membrane temperature, are analyzed regarding their value and limitations for research in AAIs. Moreover, welfare-related social and environmental factors (e.g., freedom of choice, exploration of novel environments, inequity aversion, individual development, working experience, relationship with handler and handler skills) that profoundly influence dog perception and well-being are reviewed and discussed. Accounting for the globally increasing interest and the number of dogs utilized in AAIs, safeguarding therapy dog well-being, and identifying situations, circumstances and protocols that may challenge animal welfare remains an emerging and crucial area of scientific effort.

Neuroendocrine and Cardiovascular Activation During Aggressive Reactivity in Dogs

Our aim was to investigate cardiovascular activation by measuring changes in facial and body surface temperature using infrared thermography, and neuroendocrine activation using salivary cortisol (CORT) and serotonin concentration (SER) in dogs exhibiting aggressive reactivity in real time. Based on two factors, owner-reported past aggressive behaviors, and detailed behavioral observations collected during a Socially Acceptable Behavior test consisting of 16 subtests and, each individual was categorized as aggressive or non-aggressive. CORT and SER showed no difference in neuroendocrine activity between dogs, but aggressive dogs with higher levels of aggression were found to have lower SER. Aggressive dogs also had an increase in facial temperature from pre-test values. The discovery of a correlation between tail wagging and left tail wagging with aggression level and aggression-related behaviors in aggressive dogs is further evidence of the right hemisphere specialization for aggression previously reported in the literature. This study provides the first evidence that both cardiovascular and neuroendocrine systems are activated during an active act of aggression in dogs.

A Systematic Literature Review of Animal-Assisted Interventions in Oncology (Part I): Methods and Results

Animal-assisted interventions (AAIs) use human-animal interactions to positive effect in various contexts including cancer care. As the first installment of a 2-part series, this systematic literature review focuses on the research methods and quantitative results of AAI studies in oncology. We find methodological consistency in the use of canines as therapy animals, in the types of high-risk patients excluded from studies, and in the infection precautions taken with therapy animals throughout cancer wards. The investigated patient endpoints are not significantly affected by AAI, with the exceptions of improvements in oxygen consumption, quality of life, depression, mood, and satisfaction with therapy. The AAI field in oncology has progressed significantly since its inception and has great potential to positively affect future patient outcomes. To advance the field, future research should consistently improve the methodological design of studies, report data more completely, and focus more on the therapy animal’s well-being.

Two Ends of the Leash: Relations Between Personality of Shelter Volunteers and On-leash Walking Behavior With Shelter Dogs

Human personality influences the way people interact with dogs. This study investigated the associations between the personality of animal shelter volunteers and behavior during on-leash walks with shelter dogs. Video recording and a canine leash tension meter were used to monitor the on-leash walking. Personality was measured in five dimensions (neurotic, extroverted, open, agreeable and conscientious) with the NEO Five-Factor Inventory (NEO-FFI). Neurotic volunteers pulled the leash harder and tended to interact with dogs using more body language; dogs being walked by neurotic volunteers in turn displayed more lip-licking and body shaking and were more likely to be rated as well-behaved. Extroverted volunteers were associated with stronger maximal leash tension at both the human and dog ends of the leash, and they praised the dog more, often in a high pitched voice. These volunteers eliciting more tail-wagging and body shaking by the dog. Extroverted volunteers were also more tolerant of different dog behaviors. Volunteers with personalities characterized by “openness to experiences” were less likely to verbally attract the attention of dogs, praise dogs and talk to them in a high-pitched voice; however, dogs walked by these volunteers were more likely to pull on the leash, and engaged in more lip-licking but less sniffing. “Agreeable” volunteers liked to verbally attract the attention of the dogs and more commonly initiated hand gestures and physical contact, causing the dogs to pull less frequently; dogs in these dyads displayed more gazing and lip-licking behaviors. Conscientious volunteers were less likely to pull the leash and tended to have more physical contact with the dogs but did not favor verbal communication and did not use a high pitched voice.

Do Service Dogs for Veterans with PTSD Mount a Cortisol Response in Response to Training?

Simple Summary

A growing number of people are supported by specialized service dogs. These dogs are highly trained to improve human welfare, yet not much is known about their own welfare. One of the ways in which welfare can be measured is through the expression of stress via the hormone cortisol. In this study, we investigated the level of cortisol in saliva, a measure for physiological stress, in 19 service dogs. We measured cortisol in the dogs’ saliva 15 min after arrival at a training ground, before partaking in a training session for service dogs, after participation in the training session, and after a 45-min free play period. We found no elevated levels of cortisol after the training session. Instead, we found that cortisol had lowered when compared to before the training. Additionally, we found that cortisol was highest 15 min after arriving at the training round and after 45 min of free play. This led to the conclusion that dogs in our study did not seem to have a stress response in response to participation in the training.

Abstract

Only a few studies have investigated the welfare of animals participating in animal-assisted interventions (AAIs). Most of these studies focus on dogs in therapeutic settings. There are, however, also dogs—service dogs—that are employed to continuously support a single human. Because the welfare of these service dogs is important for the sustainability of their role, the aim of this study was to investigate their stress response to service dog training sessions. To do this, we took repeated salivary cortisol samples from dogs who participated in a training session (n = 19). Samples were taken just after arrival at the training ground, before training, after training, and after a period of free play. Our results showed that mean cortisol levels in all samples were relatively low (between 1.55 ± 1.10 and 2.73 ± 1.47 nmol/L) compared to similar studies. Analysis further showed that samples taken before and after participation in the training’s session did not differ from one another. Mean cortisol levels in both situations were additionally lower than those upon arrival at the training site and after a period of free play. This led to the conclusion that the dogs in our study did not seem to experience training as stressful.

Cortisol Levels of Shelter Dogs in Animal Assisted Interventions in a Prison: An Exploratory Study

Simple Summary

Animal Assisted Interventions (AAI) are growing in popularity among professionals of psychological therapies due to their clear benefit for human health. However, to date, little attention has been paid to the welfare of the animals involved in the interventions. In this study we evaluated the potential impact of such activities on the welfare of dogs living in a kennel, which had weekly interactions with inmates held at a prison. To assess their stress levels, we analyzed their physiological response to a stressful situation by measuring the cortisol levels in saliva samples. We found a significant decrease in cortisol concentration at the end of the AAI program measured in the dogs’ living environment (i.e., kennel), which suggests a positive effect of the AAI activities on the welfare of kennel dogs. The results also suggest that transportation from the kennel to the prison could be perceived as a stressful event since it significantly increased dogs’ cortisol levels. Therefore, particular care should be taken in the management of this phase.

Abstract

Previous studies regarding the Animal Assisted Interventions (AAI) have mainly focused on the beneficial effects of human–animal interactions on human health; whereas the impact of such activities on the welfare of the animals involved has received limited attention. So far, few studies have addressed this issue by evaluating the physiological and behavioral reactions of therapy dogs during the interventions. The aim of this study was to evaluate the potential effect of AAI on the cortisol levels of shelter dogs. Five dogs participated in weekly AAI working activities with adult inmates held at a prison of the South of Italy for two months. Saliva samples were collected every two weeks in three conditions: at the kennel (baseline), after transportation and at the end of the working sessions. The results revealed a significant decrease in the cortisol baseline at the end of the AAI program, suggesting that the activities carried out with humans and in a different environment could improve the welfare of dogs housed in kennels. Moreover, we found that transportation significantly increased subjects’ cortisol levels, suggesting that it is a critical phase that deserves particular care.

Therapy Dogs' and Handlers' Behavior and Salivary Cortisol During Initial Visits in a Complex Medical Institution: A Pilot Study

Therapy dogs provide health benefits for individuals who suffer from illnesses, such as dementia, depression, loneliness, and aggression. Therapy dogs' impact on human health has been thoroughly studied; however, studies on dog welfare have been limited. Additionally, as dogs have evolved with humans, they have learned to read non-verbal social cues. Dogs can read humans' non-verbal body language and can react to their emotions. However, the body language of dogs is poorly understood and can lead to dog owner-directed aggression. Communication plays a vital role to be a cohesive therapy team. The purpose of this study was to assess perceived stress and cortisol concentrations in therapy dogs and their handlers during the first three visits in a hospital setting. Moreover, the study aimed to investigate whether, while in an overstimulating environment, a therapy dog handler can observe his or her dog's body language and correlate such observations to the dog's stress. Nine therapy dog teams from Mayo Clinic's Caring Canine Program participated in this study. A baseline salivary cortisol was collected from the handler and therapy dog each day of the visits. Once the team arrived, a pre-visit salivary cortisol was collected from the handler and therapy dog and, afterward, a post-visit salivary cortisol. Handlers were also asked to fill out a perceived stress survey on their own stress and that of their therapy dogs'. Behavior was documented by a staff member and the handler. For each visit, the therapy dogs were at the hospital on average 47 min and visited with nine people. There was significant correlation (P = 0.02) between the owner's perceived stress of his or her therapy dog and the dog's salivary cortisol concentrations. The handlers noted medium to high stress, and those dogs had higher cortisol concentrations post-visit. There was no significant difference in salivary cortisol for the handler and therapy dog over the course of the three visits and comparing pre- and post-visit. Overall, the dogs displayed mixed behaviors, with the three most reported being panting, lip licking, and yawning. However, salivary cortisol results suggest that the handlers and therapy dogs maintained their welfare state throughout the visits.

Where Do We Stand in the Domestic Dog ( Canis familiaris ) Positive-Emotion Assessment: A State-of-the-Art Review and Future Directions

Although there have been a growing number of studies focusing on dog welfare, the research field concerning dog positive-emotion assessment remains mostly unexplored. This paper aims to provide a state-of-the-art review and summary of the scattered and disperse research on dog positive-emotion assessment. The review notably details the current advancement in dog positive-emotion research, what approaches, measures, methods, and techniques have been implemented so far in emotion perception, processing, and response assessment. Moreover, we propose possible future research directions for short-term emotion as well as longer-term emotional states assessment in dogs. The review ends by identifying and addressing some methodological limitations and by pointing out further methodological research needs.

Salivary cortisol as a marker of acute stress in dogs: a review

Public interest in the welfare of domestic dogs has increased in recent years. Dogs under human care should experience as little stress as possible, and as such it is necessary to measure and quantify their levels of stress. Stress parameters that can be measured noninvasively may help to identify the poor welfare of animals. This review aimed to determine whether and under what conditions the hormone cortisol in dog saliva can be used as a noninvasive acute stress marker. The use of salivary cortisol as a stress marker has some disadvantages, which can lead to data misinterpretations. A key factor is the standardized method of sampling and subsequent processing before analysis. In addition, possible circadian alternation and individual variability of cortisol hormone levels should be consistently considered during the preparation of the experimental scheme, statistical data processing and final interpretation of the results. Because of the complex nature of the stress response, the observation of salivary cortisol should be supplemented with behavioral observations, but it should be noted that behavioral stress symptoms may not always be positively correlated with stress hormone production. Besides behavioral observations, it is advisable to supplement the measurement of cortisol by other salivary stress markers of sympathetic-adrenal-medullary and hypothalamic-pituitary-adrenal pathways. This comprehensive assessment of the stress impact on the individual will enable one to characterize the level and type of stress.

Dogs' Stay in a Pet Hotel - Salivary Cortisol Level and Adaptation to New Conditions

The aim of this study was to assess salivary cortisol level in dogs during admission and a three-day stay in a pet hotel. The study involved 20 dogs admitted to a pet hotel for a stay lasting for at least three consecutive days. The study group consisted of 10 small dogs and 10 medium-sized dogs, eight females and 12 males. Saliva was collected each day to assess cortisol levels. A stay in a hotel is a stressful situation for dogs, as evidenced by the increase in the salivary cortisol level. The highest salivary cortisol level was observed on the day of admission to the hotel. The median salivary cortisol level in the dogs on the consecutive days was 2.7 ng/ml on admission, 2.1 ng/ml after 24 hours, and 1.9 ng/ml after 48 hours. Depending on the size of the dog, the median salivary cortisol level was 2.8 ng/ml, 2.9 ng/ml and 2.4 ng/ml in the small dogs and and 2.2 ng/ml, 1.7 ng/ml and 1.2 ng/ml in the medium sized dogs on the consecutive days.

Physiological State of Therapy Dogs during Animal-Assisted Activities in an Outpatient Setting

Therapy dogs are increasingly being incorporated into numerous clinical settings. However, there are only a handful of studies that have focused on the impact of animal-assisted activity or therapy sessions on the wellbeing of the therapy dogs. Furthermore, these studies show mixed results. The goal of this study was to provide an in-depth picture of the effects of these interactions on the dogs involved by considering multiple physiological measures known to be associated with emotional state (continuous heart rate, heart rate variability, pre- and post-session tympanic membrane temperatures, and salivary cortisol and oxytocin concentrations). Nineteen Mayo Clinic Caring Canine therapy dogs completed five 20-minute animal-assisted activity (AAA) visits each in an outpatient clinical setting (Mayo Clinic Fibromyalgia and Chronic Fatigue Clinic). From a physiological perspective, the dogs showed a neutral to positive response to the AAA sessions. Heart rate (HR) was significantly lower at the end of the session compared with the beginning of the session (F = 17.26, df1 = 1, df2 = 29.7, p = 0.0003). The right tympanic membrane temperature was lower post-session (F = 8.87, df1 = 1, df2 = 107, p = 0.003). All other emotional indicators remained stable between pre- and post-session. These results suggest that the dogs involved were not negatively affected by their participation in the AAA. Moreover, there was some evidence suggesting the dogs may have been in a more relaxed state at the end of the session (lower HR and lower right tympanic membrane temperature) compared to the beginning of the session.

Salivary Cortisol Interactions in Search and Rescue Dogs and their Handlers

Simple Summary

Stress affects both people and animals every day. Working dogs are exposed to the same stressors as their handlers during work. Our research was conducted during search and rescue dog exams. The aim of the study was to investigate if handler stress during the exam affects his or her dog’s stress level. We observed a strong relationship of salivary cortisol between the dogs and their handlers, which was most prevalent in female dogs and female handlers.

Abstract

Search and rescue dogs are an important link in the search for missing persons. The aim of the study was to assess exam stress in search and rescue dogs and their handlers. The study included 41 rescue teams taking exams of field and rubble specialties. The level of cortisol, which is the main glucocorticosteroid modulating stress reactions in humans and dogs, was analyzed. The biological material used to assess the hormone concentration was saliva collected in a non-invasive way. In total, 164 test samples were collected: two from the dog and two from the handler before and immediately after the exam. Rescue exams were shown to significantly increase salivary cortisol in both dogs and their handlers. Strong interactions between cortisol levels in human–dog teams were also found with a more pronounced effect in female dog–female handler dyads.

Animal-assisted therapy for dementia

BACKGROUND

Dementia is a chronic condition which progressively affects memory and other cognitive functions, social behaviour, and ability to carry out daily activities. To date, no treatment is clearly effective in preventing progression of the disease, and most treatments are symptomatic, often aiming to improve people's psychological symptoms or behaviours which are challenging for carers. A range of new therapeutic strategies has been evaluated in research, and the use of trained animals in therapy sessions, termed animal-assisted therapy (AAT), is receiving increasing attention.

OBJECTIVES

To evaluate the efficacy and safety of animal-assisted therapy for people with dementia.

SEARCH METHODS

We searched ALOIS: the Cochrane Dementia and Cognitive Improvement Group's Specialised Register on 5 September 2019. ALOIS contains records of clinical trials identified from monthly searches of major healthcare databases, trial registries, and grey literature sources. We also searched MEDLINE (OvidSP), Embase (OvidSP), PsycINFO (OvidSP), CINAHL (EBSCOhost), ISI Web of Science, ClinicalTrials.gov, and the WHO's trial registry portal.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster-randomised trials, and randomised cross-over trials that compared AAT versus no AAT, AAT using live animals versus alternatives such as robots or toys, or AAT versus any other active intervention.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of Cochrane Dementia. Two review authors independently assessed the eligibility and risk of bias of the retrieved records. We expressed our results using mean difference (MD), standardised mean difference (SMD), and risk ratio (RR) with their 95% confidence intervals (CIs) where appropriate.

MAIN RESULTS

We included nine RCTs from 10 reports. All nine studies were conducted in Europe and the US. Six studies were parallel-group, individually randomised RCTs; one was a randomised cross-over trial; and two were cluster-RCTs that were possibly related where randomisation took place at the level of the day care and nursing home. We identified two ongoing trials from trial registries. There were three comparisons: AAT versus no AAT (standard care or various non-animal-related activities), AAT using live animals versus robotic animals, and AAT using live animals versus the use of a soft animal toy. The studies evaluated 305 participants with dementia. One study used horses and the remainder used dogs as the therapy animal. The duration of the intervention ranged from six weeks to six months, and the therapy sessions lasted between 10 and 90 minutes each, with a frequency ranging from one session every two weeks to two sessions per week. There was a wide variety of instruments used to measure the outcomes. All studies were at high risk of performance bias and unclear risk of selection bias. Our certainty about the results for all major outcomes was very low to moderate. Comparing AAT versus no AAT, participants who received AAT may be slightly less depressed after the intervention (MD -2.87, 95% CI -5.24 to -0.50; 2 studies, 83 participants; low-certainty evidence), but they did not appear to have improved quality of life (MD 0.45, 95% CI -1.28 to 2.18; 3 studies, 164 participants; moderate-certainty evidence). There were no clear differences in all other major outcomes, including social functioning (MD -0.40, 95% CI -3.41 to 2.61; 1 study, 58 participants; low-certainty evidence), problematic behaviour (SMD -0.34, 95% CI -0.98 to 0.30; 3 studies, 142 participants; very-low-certainty evidence), agitation (SMD -0.39, 95% CI -0.89 to 0.10; 3 studies, 143 participants; very-low-certainty evidence), activities of daily living (MD 4.65, 95% CI -16.05 to 25.35; 1 study, 37 participants; low-certainty evidence), and self-care ability (MD 2.20, 95% CI -1.23 to 5.63; 1 study, 58 participants; low-certainty evidence). There were no data on adverse events. Comparing AAT using live animals versus robotic animals, one study (68 participants) found mixed effects on social function, with longer duration of physical contact but shorter duration of talking in participants who received AAT using live animals versus robotic animals (median: 93 seconds with live versus 28 seconds with robotic for physical contact; 164 seconds with live versus 206 seconds with robotic for talk directed at a person; 263 seconds with live versus 307 seconds with robotic for talk in total). Another study showed no clear differences between groups in behaviour measured using the Neuropsychiatric Inventory (MD -6.96, 95% CI -14.58 to 0.66; 78 participants; low-certainty evidence) or quality of life (MD -2.42, 95% CI -5.71 to 0.87; 78 participants; low-certainty evidence). There were no data on the other outcomes. Comparing AAT using live animals versus a soft toy cat, one study (64 participants) evaluated only social functioning, in the form of duration of contact and talking. The data were expressed as median and interquartile ranges. Duration of contact was slightly longer in participants in the AAT group and duration of talking slightly longer in those exposed to the toy cat. This was low-certainty evidence.

AUTHORS' CONCLUSIONS

We found low-certainty evidence that AAT may slightly reduce depressive symptoms in people with dementia. We found no clear evidence that AAT affects other outcomes in this population, with our certainty in the evidence ranging from very-low to moderate depending on the outcome. We found no evidence on safety or effects on the animals. Therefore, clear conclusions cannot yet be drawn about the overall benefits and risks of AAT in people with dementia. Further well-conducted RCTs are needed to improve the certainty of the evidence. In view of the difficulty in achieving blinding of participants and personnel in such trials, future RCTs should work on blinding outcome assessors, document allocation methods clearly, and include major patient-important outcomes such as affect, emotional and social functioning, quality of life, adverse events, and outcomes for animals.

The State of Animal-Assisted Interventions: Addressing the Contemporary Issues that will Shape the Future

As the worldwide popularity of animal-assisted interventions (AAIs) increases, the fieldis quickly approaching a paradigm shift, adjusting its image to incorporate more evidence-basedresearch and aligning its purpose for advancing a new future. Contemporary critical issues thatconfront the field today include, but are not limited, to research, animal welfare, practice guidelines,and public policy. This article will provide an overview of the history of AAI and the majormilestones that the field has undergone. The current state of AAI research will be scrutinized, andthe areas that warrant further study will be recommended. Special attention will be given to thecurrent state of animal welfare in AAI, the research that has been done in the area, and practiceguidelines that safeguard animal wellbeing. This article will then discuss how evidence-basedresearch and animal welfare guidelines inform the development of comprehensive professionalstandards and influence changes in public policy regarding AAI. The authors' perceptions for thefield's future trajectory will be presented, which will include solutions to move the field in thedirection that best advances the human-animal bond in research, practice, and public perception.

Physiological stress reactivity and recovery related to behavioral traits in dogs (Canis familiaris)

This study investigated whether stress responsiveness (in one context) can be used to predict dog behavior in daily life. On two occasions (N_T1 = 32 puppies; N_T2 = 16 young adults), dogs’ physiological stress response after a behavioral test at home was measured in terms of reactivity (10 min post-test) and recovery (40 min post-test) for three salivary markers: cortisol, chromogranin A (CgA) and secretory immunoglobulin A (sIgA). For each marker, it was determined whether dogs with a strong physiological response displayed different behavior in daily life compared to dogs with a weaker physiological response. The results revealed three main findings: first, for CgA and cortisol, different patterns were identified according to sample time. High reactivity related to desirable traits, whereas slow recovery after the behavioral test related to undesirable traits. The findings suggest that increased levels of CgA and cortisol 10 minutes after the behavioral test reflected an adaptive stress response, whereas elevated levels 40 minutes after the test reflected unsuccessful coping. Second, patterns for sIgA differed from CgA and cortisol: significant associations were only found with behavioral traits at T2, mostly considered desirable and related to Trainability. Possibly, the delayed reaction pattern of sIgA caused this difference between markers, as sIgA reflects the (secondary) immune response to stress, due to immunosuppressive effects of cortisol. Third, predictive capacity of puppies’ physiological stress response (T1) was inconclusive, and contrary relations were found with behavioral traits at T2, suggesting that developmental factors play an important role. This study provides new insights about the relation between stress physiology and behavioral traits, and methodological advice is given to study these patterns further. In conclusion, physiological markers could provide additional insights in dogs’ tendencies to display certain behaviors, especially at the young adult stage. Further studies are needed to confirm these patterns.

Enhancing Success of Veterinary Visits for Clients With Disabilities and an Assistance Dog or Companion Animal: A Review

Despite increasing information on enhancing client communication and compliance/adherence in veterinary medicine, literature focusing on special cases remains limited: working with clients with special needs, challenges or disabilities, or when the patient is an assistance or emotional support animal. This paper summarizes current recommendations on how best to build successful working relationships with these clients, including action items to implement in practice. In addition, this paper reviews current literature on important considerations for care of assistance dogs as patients.

Investigation of Physiological and Behavioral Responses in Dogs Participating in Animal-Assisted Therapy with Children Diagnosed with Attention-Deficit Hyperactivity Disorder

This study evaluated the impact that participation in sessions with children with Attention-Deficit Hyperactivity Disorder (ADHD) has on therapy dogs. Nine certified therapy dogs were paired for 6 sessions with groups of 3-4 children. Sessions consisted of 5 different activities. Activities 1 and 5 involved interactions solely with each dog and their owner, as a control. Activities 2-4 consisted of interactions with the dogs and the children which included social skills training, dog training, and reading in the company of dogs. One-zero interval sampling of stress-associated behaviors was conducted at 20-second intervals for a 10-minute duration during each of the 5 activities. At the end of each activity, heart rate was monitored, and a saliva sample was obtained for cortisol analysis. Dogs demonstrated only occasional behavioral responses and no significant findings related to cortisol or heart rate when the different activities were compared. The results indicate that with proper supervision and well-trained therapy staff, including suitable therapy dogs and their handlers, canine stress can be minimal in a therapy setting.

Describing the Use of Animals in Animal-Assisted Intervention Research

Currently, there has been growing attention to animal welfare in animal-assisted interventions (AAI). However, there is a lack of scrutiny regarding what steps to take to ensure animal wellbeing during AAI research. The Institutional Animal Care and Use Committee (IACUC) reviews, monitors, and approves all research involving animal subjects in order to ensure an animal's ethical and humane treatment. However, AAI publications rarely report IACUC approval. The purpose of this critical review was to determine the frequency of IACUC approval and to report the descriptions of animal use in AAI research publications. In the 139 articles reviewed, 14 (10%) studies reported attaining IACUC approval; 4/139 (3%) reported an adverse outcome on at least one animal used in the study. The publications inconsistently reported the training or certification and veterinary care of the animals. Lacking IACUC approval in AAI studies indicates that the field underutilizes this method of monitoring animal health and welfare. The IACUC should assess, approve, and monitor research protocols involving animals prior to conducting every study to safeguard AAI animal welfare.

The Effect of Breed, Gender, and Acid Stimulation in Dog Saliva Proteome

Saliva gained interest as a potential noninvasive source of biomarkers in humans and that interest starts to be extended also to other animal species. For this purpose, the knowledge of the salivary proteome in healthy conditions and the factors that affect it and how they affect it are necessary. The aim of the present study was to assess the effect that gender and breed have in saliva proteome and the changes in it induced by stimulation with acid. Saliva from 4 different purebred dogs (Portuguese Podengo, Greyhound, Rafeiro Alentejano, and Beagle) of both genders was collected without and after stimulation with lemon juice. SDS-PAGE and two-dimensional gel electrophoresis (2-DE) profiles were compared and the proteins of interest in-gel digested and identified by mass spectrometry. Acid stimulation decreased total protein concentration and the relative amounts of some protein bands/spots. Gender appeared to have minimal effect in saliva proteome, whereas the influence of breed varies. Beagles and Portuguese Podengos were the two breeds with higher differences. In conclusion, stimulation procedures and dog breed should be considered in data analysis when using salivary proteins for diagnostic purposes.

Behavioral and physiological reactions in dogs to a veterinary examination: Owner-dog interactions improve canine well-being

In order to improve well-being of dogs during veterinary visits, we aimed to investigate the effect of human social interactions on behavior and physiology during routine examination. Firstly, we assessed the impact of a standardized veterinary examination on behavioral and physiological indicators of stress in dogs. Secondly, we examined whether the owner's tactile and verbal interactions with the dog influenced behavioral and physiological stress-associated parameters. A randomized within-subjects crossover design was used to examine behavior (n=33), rectal temperature (n=33), heart rate (HR) (n=18), maximal ocular surface temperature (max OST) (n=13) and salivary cortisol concentrations (n=10) in healthy privately owned pet dogs. The study consisted of two experimental conditions: a) "contact" - owner petting and talking to the dog during the examination; b) "non-contact" - owner present during the examination but not allowed to interact with the dog. Our findings showed that the veterinary examinations produced acute stress responses in dogs during both "contact" and "non-contact" conditions, with significant increases in lip licking, HR, and max OST. A significant decrease in attempts to jump off the examination table (p=0.002) was observed during the examination in the "contact" compared to the "non-contact" condition. In addition, interactions of owners showed an attenuating effect on HR (p=0.018) and max OST (p=0.011) in their dogs. The testing order (first vs. second visit) had no impact on behavioral and physiological parameters, suggesting that dogs did not habituate or sensitize to the examination procedure. Moreover, the duration of the owner-dog interactions had no significant impact on the behavioral and physiological responses of their dogs. This study demonstrates that owner-dog interactions improve the well-being of dogs during a veterinary examination. Future research may assist in further understanding the mechanisms associated with reducing stress in dogs in similar settings.

Current Perspectives on Therapy Dog Welfare in Animal-Assisted Interventions

Research into the effects of animal-assisted interventions (AAIs) has primarily addressed human health outcomes. In contrast, only few publications deal with the therapy dog experience of AAIs. This paper provides an overview on potential welfare threats that therapy dogs may encounter and presents the results of a review of available studies on welfare indicators for therapy dogs during AAIs. Previous investigations used physiological and behavioral welfare indicators and dog handler surveys to identify work-related stress. Research outcomes are discussed in the light of strengths and weaknesses of the methods used. Study results suggest that frequency and duration of AAI sessions, novelty of the environment, controllability, age and familiarity of recipients modulate animal welfare indicators. However, this review reveals that currently, clear conclusions on how the well-being of dogs is influenced by the performance in AAIs are lacking due to the heterogeneity of programs, recipient and session characteristics, small dog sample sizes and methodological limitations. This paper further aimed to identify unresolved difficulties in previous research to pave the way for future investigations supporting the applicability of scientific findings in practice.