Equine-Assisted Interventions (EAIs) for Children with Autism Spectrum Disorders (ASD): Behavioural and Physiological Indices of Stress in Domestic Horses (Equus caballus) during Riding Sessions

Behavioral and physiological responses of horses to ground-based adaptive horsemanship lessons for veterans with post-traumatic stress disorder (PTSD)

Little literature exists on horses in adaptive horsemanship (AH) despite concerns about their well-being. The study objective was to evaluate behavioral and physiological responses of horses to ground-based AH lessons for veterans with post-traumatic stress disorder (PTSD). Lessons were expected to alter horses' hormone concentrations, behavior, and muscle activity. Geldings were assigned to AH (n=6; 20.3 ± 1.9 yrs., mean ± SE) or control (CON; stall in arena, n=6; 13.8 ± 1.7 yrs.) conditions for 8-week sessions based on current occupation (AH = equine-assisted services; CON = recreational riding). Plasma cortisol, epinephrine, norepinephrine, and oxytocin concentrations from samples at 0 (start of lesson), 3, 5, 25, and 30 (end) min were determined using assays validated in horses. Surface electromyography (sEMG) (masseter and brachiocephalic; Noraxon, Scottsdale, AZ, USA) and video were recorded continuously. Average rectified values (ARV) and median frequency (MF) were calculated (100 ms) after sEMG data were normalized, rectified, and filtered. The number, number of unique, and duration of stress related behaviors (ethogram) were recorded by three trained (ĸ ≥ 0.7) observers. Data were analyzed with repeated measures ANOVAs (significance P ≤ 0.05) with fixed effects of treatment, time point, week, and their interactions as appropriate and random effect of horse. CON horses had elevated cortisol concentrations (P = 0.0023) at 25 and 30 min. AH horses displayed fewer (P ≤ 0.0491) stress related and unique behaviors. CON horses were described as more (P < 0.0001) anxious, nervous, and stressed than AH horses (calm, comfortable, patient, and relaxed) in qualitative behavior analysis (22 observers). AH horses were less stressed than CON horses.

Factors affecting measurement of basal adrenocorticotropic hormone in adult domestic equids: A scoping review

Measurement of basal adrenocorticotropic hormone (ACTH) concentration is the most commonly used diagnostic test for pituitary pars intermedia dysfunction (PPID). Although several pre-analytical and analytical factors have been reported to affect basal ACTH concentrations in equids, the extent to which these have been evaluated in the context of PPID diagnosis is unclear. The objectives of this scoping review were to identify and systematically chart current evidence about pre-analytical and analytical factors affecting basal ACTH concentrations in adult domestic equids. Systematic searches of electronic databases and conference proceedings were undertaken in June 2022, repeated in October 2022 and updated in August 2023. English language publications published prior to these dates were included. Screening and data extraction were undertaken individually by the authors, using predefined criteria and a modified scoping review data extraction template. After removal of duplicates, 903 publications were identified, of which 235 abstracts were screened for eligibility and 134 publications met inclusion criteria. Time of year, exercise, breed/type and transportation were the factors most frequently associated with significant increases in ACTH concentration (n = 26, 16, 13 and 10 publications, respectively). Only 25 publications reported inclusion of PPID cases in the study population, therefore the relationship between many factors affecting basal ACTH concentration and diagnostic accuracy for PPID remains undefined. However, several factors were identified that could impact interpretation of basal ACTH results. Findings also highlight the need for detailed reporting of pre-analytical and analytical conditions in future research to facilitate translation of evidence to practice.

A Relaxed Horse-A Relaxed Client? An Experimental Investigation of the Effects of Therapy Horses' Stress on Clients' Stress, Mood, and Anxiety

Equine-assisted therapies are becoming increasingly popular for addressing physical and psychological disabilities in clients. The role of the horse's welfare in equine-assisted service receives increasing attention in research. Several studies have shown that horses are able to perceive human emotions and respond to human stress responses. However, no research has yet looked at the other side of the coin-whether and how humans perceive and react to equine stress levels during equine-assisted services. To fill this gap in the research, we employed a within-subjects design, in which horse-naïve participants had a standardized interaction with both an experimentally stressed horse and an experimentally relaxed horse. We assessed physiological indicators of stress (heart rate, heart rate variability, and salivary cortisol) in participants and horses, as well as psychological indicators of stress (state anxiety and positive and negative affect) in participants. Although our stress and relaxation manipulations were successful (indicated by horses' physiological indicators of stress), we did not find any difference in the participants' physiological or psychological indicators of stress between the interaction with a stressed and the interaction with a relaxed horse. Together with results from previous studies, this suggests that humans cannot intuitively recognize the (physiological) stress level of horses, which has important implications for effective communication and bonding between humans and horses and for the safety of equine activities.

Equids in Equine Assisted Services: A Scoping Review

Equid welfare in equine assisted services (EAS) is an area that has received attention, but less attention than the documentation of human outcomes in response to EAS. To safeguard the well-being of equids and minimize human risk of injury, continued research on the effects of EAS programming and participants on equids needs to occur. The aims of this systematic scoping review were to identify the approaches taken for describing and understanding equids in EAS and the methods employed in evaluating equids' responses to EAS programming, participants, or both. Literature searches were performed in relevant databases to identify titles and abstracts for screening. Fifty-three articles were identified for full-text review. Fifty-one articles met the inclusion criteria and were retained for information and data extraction. The qualitative grouping of articles by study aim resulted in four categories: 1) characterization and description of equids in EAS; 2) the acute responses of equids to EAS programming, participants, or both; 3) the effects of management practices; and 4) the chronic responses of equids to EAS programming and participants. The latter three areas are in need of more research, especially as it relates to differentiating acute and chronic effects of EAS on the equids involved. Detailed reporting of information on study design, programming and participant characteristics, equid demographics, and workload are needed to facilitate comparison among studies and permit eventual meta-analysis of studies. Multi-faceted approaches including an array of measurements as well as relevant and informative control groups or conditions are required to identify the complex effects of EAS work on equids, their welfare, well-being, and affective states.

Horses' Tactile Reactivity Differs According to the Type of Work: The Example of Equine-Assisted Intervention

Tactile perception in humans varies between individuals and could depend on extrinsic factors such as working activity. In animals, there is no study relating the influence of animals' work and their tactile reactivity per se. We investigated horses' tactile reactivity using von Frey filament in different body areas and compared horses working only in equine-assisted interventions (EAI), in riding school (RS) lessons, and in both activities (EAI-RS). We further compared tactile actions by people with or without mental and/or developmental disorders during brushing sessions. The results indicated that EAI horses showed higher tactile reactivity compared to EAI-RS and RS horses, both in terms of number of reactions overall, and especially when the test involved thin filaments. All horses showed high tactile reactivity when tested on the stifle, and this was particularly true for EAI horses. These differences could be related to humans' actions, as participants diagnosed with disorders brushed more the hindquarters and showed more fragmented actions. This study opens new lines of thought on the influence of EAI working activity on horses' tactile reactivity, and hence, on horses' sensory perception. Tactile reactivity outside work, may be directly (via tactile stimulations) or indirectly (via the welfare state), influenced by working conditions.

Donkey Heart Rate and Heart Rate Variability: A Scoping Review

Heart rate (HR) and heart rate variability (HRV) are commonly used physiological measures in animals. While several studies exist on horse HRV, less information is available for donkeys. This scoping review aims to understand the extent and type of published evidence on donkey HR and HRV, their clinical and research applications, the devices used, and the analysis performed. Only quantitative primary studies published in English were considered. Four different databases were queried through the Web of Science platform, with additional evidence identified by citation chasing. After a two-stage screening phase, data were extracted considering study and population characteristics, information on HR/HRV analysis, and applications. The majority of the 87 included articles (about 80%) concerned a sample size of up to 20 individuals and were published since 2011 (about 65%). Forty-one articles employed an electronic device for signal acquisition (mainly electrocardiographs and heart rate monitors), yet only two articles reported HRV parameters. The literature on donkey HRV is lacking, and this gap can be filled by gaining knowledge on donkey characteristics and finding useful tools for welfare assessment. Comparison with what is known about the horse allows a discussion of the technical and interpretative difficulties that can be encountered with donkeys.

The Effect of Human-Horse Interactions on Equine Behaviour, Physiology, and Welfare: A Scoping Review

Simple Summary

Human–horse interactions (HHIs) are an important aspect of society, especially in the equine industry. HHIs are diverse and can be focused on horses as an economic means, pleasure, or companionship for humans. As a result, the welfare of horses during these interactions, including their mental and physical health, is an important consideration. Although the physical health of horses can be readily measured during equestrian activities, their mental health is more difficult to assess. This review was conducted to evaluate what is known about the horse’s mental state during common HHI in an attempt to better understand the welfare of the horse.

Abstract

Human–horse interactions (HHIs) are diverse and prominent in the equine industry. Stakeholders have an invested interest in making sure that HHIs are humane. Assessment of equine welfare goes beyond physical health and includes assessment of the emotional state of the animal. HHIs can have a permanent effect on human–horse relationships, thereby influencing welfare. Therefore, an understanding of the horse’s affective state during HHIs is necessary. A scoping review was conducted to: (1) map current practices related to the measurement of HHIs; (2) explore the known effects of HHIs on horse behaviour and physiology; and (3) clarify the connection between HHIs and equine welfare. A total of 45 articles were included in this review. Studies that used both physiological and behavioural measures of equine response to human interactions accounted for 42% of the included studies. A further 31% exclusively used physiological measures and 27% used behavioural observation. Current evidence of equine welfare during HHIs is minimal and largely based on the absence of a negative affective state during imposed interactions. Broadening the scope of methods to evaluate a positive affective state and standardization of methodology to assess these states would improve the overall understanding of the horse’s welfare during HHIs.

Zoonotic Risk of Encephalitozoon cuniculi in Animal-Assisted Interventions: Laboratory Strategies for the Diagnosis of Infections in Humans and Animals

The involvement of animals for therapeutic purposes has very ancient roots. To date, it is clear that animal-assisted interventions (AAIs), in addition to ensuring the replacement of missing or deficient affects, improves psychophysiological parameters connected to human health. However, AAI could potentially present risks related to the transmission of infectious agents from animals to humans. Among these microorganisms, E. cuniculi is a microspore which induces pathological effects (fever, headache, nausea, vomiting, diarrhea, breathlessness, respiratory symptoms, and weakness) in both humans and animals. Consequently, an accurate and fast diagnosis of E. cuniculi infection, as well as the identification of new diagnostic approaches, is of fundamental importance. This literature review was carried out to provide an extensive and comprehensive analysis of the most recent diagnostic techniques to prevent and care for E. cuniculi-associated risks in the AAI field.