Abstract: The benefits to humans of equine-assisted therapy (EAT) have been well-researched, however few studies have analyzed the effects on the horse. Understanding how differing mental states of humans affect the behaviour and response of the horse can assist in providing optimal outcomes for both horse and human. Four humans clinically diagnosed and under care of a psychotherapist for Post-Traumatic Stress Disorder (PTSD) were matched physically to four neurotypical control humans and individually subjected to each of 17 therapy horses loose in a round pen. A professional acting coach instructed the control humans in replicating the physical movements of their paired PTSD individual. Both horses and humans were equipped with a heart rate (HR) monitor recording HR every 5secs. Saliva samples were collected from each horse 30 min before and 30 min after each trial to analyze cortisol concentrations. Each trial consisted of 5 min of baseline observation of the horse alone in the round pen after which the human entered the round pen for 2 min, followed by an additional 5 min of the horse alone. Behavioural observations indicative of stress in the horse (gait, head height, ear orientation, body orientation, distance from the human, latency of approach to the human, vocalizations, and chewing) were retrospectively collected from video recordings of each trial and analyzed using a repeated measures GLIMMIX with Tukey's multiple comparisons for differences between treatments and time periods. Horses moved slower (p < 0.0001), carried their head lower (p < 0.0001), vocalized less (p < 0.0001), and chewed less (p < 0.0001) when any human was present with them in the round pen. Horse HR increased in the presence of the PTSD humans, even after the PTSD human left the pen (p < 0.0001). Since two of the PTSD/control human pairs were experienced with horses and two were not, a post-hoc analysis showed that horses approached quicker (p < 0.016) and stood closer (p < 0.0082) to humans who were experienced with horses. Horse HR was lower when with inexperienced humans (p < 0.0001) whereas inexperienced human HR was higher (p < 0.0001). Horse salivary cortisol did not differ between exposure to PTSD and control humans (p > 0.32). Overall, behavioural and physiological responses of horses to humans are more pronounced based on human experience with horses than whether the human is diagnosed with a mental disorder. This may be a reflection of a directness of movement associated with humans who are experienced with horses that makes the horse more attentive. It appears that horses respond more to physical cues from the human rather than emotional cues. This knowledge is important in tailoring therapy programs and justifying horse responses when interacting with a patient in a therapy setting.

Abstract: Equine welfare can be enhanced by applying species specific training. This may incorporate social learning, as horses are highly social and social stimuli are of primary importance. Social learning is comparable to individual learning in its learning mechanisms, differing primarily in the way it is stimulated. Our initial study showed that horses of different breeds (N = 38) follow humans after observing other horses doing so, but only if the observed horse was familiar to and higher ranking than the observer (Fisher's exact test: N = 12, P = 0.003). A second study showed that horses and ponies (N = 25) learned to pull a rope to open a feeding apparatus after observing demonstrations by conspecifics, again, only if the demonstrating horse was older and higher ranking than the observer (Fisher's combination test, N = 3, v2 = 27.71, p = 0.006). Our third approach showed that horses and ponies (N = 24) learned to press a switch to open a feeding apparatus after observing a familiar person (GzLM: N = 24, z = 2.33, P = 0.02). Most recently, we confronted horses and ponies (N = 50) with persons demonstrating different techniques for opening a feeding apparatus. In this study we investigated whether the horses would copy the demonstrators' techniques or apply their own. Here only some horses copied the technique, and most of the successful learners used their mouths irrespective of the demonstrators' postures (Chi Square Test: N = 40, df = 2, &#967;2 = 31.4, p < 0.001). In all the approaches social stimuli elicited learning processes in the test horses, while only a few individuals in the control groups mastered the tasks by individual learning. The following behaviour observed in the initial study may have been facilitated by a social stimuli (social facilitation), and the opening of the feed boxes in the subsequent studies appear to be mostly the result of enhancement (social enhancement). Some horses may have used the social stimuli at first and continued their learning process by individual trial and error. However, the horses were also selective in whom and some in how to copy. This may have been conditioned (socially conditioned) or the result of simple forms of reasoning on the reliability of the particular information provided by demonstrators of certain social ranks or social positions, as high ranking and familiar horses and familiar persons were copied and some imitated exactly.
Lay person message: Traditional riding instructions suggest that horses learn by observing other horses. For example, older, more experienced driving horses are used for initial training of young driving horses. We have shown that horses indeed use learning stimuli provided by other horse, as well as by humans. Horses readily accept stimuli observed in high ranking and familiar horses, and familiar persons. Such stimuli elicit learning processes which are comparable to individual learning. We suggest applying social learning whenever possible, as it is much faster and less stressful than individual learning, where learners experience negative outcomes in trial and error learning.

Abstract: Objective: This systematic review examines the empirical literature in an emerging body of evidence for the effectiveness of biopsychosocial interventions involving equines across populations with chronic illness or health challenges. Method: Selected quantitative studies published in peer-reviewed journals were reviewed for inclusion; the gray literature and white papers were also explored. Population, Intervention, Comparison, and Outcome (PICO) criteria and Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) were applied to all studies. Fourteen full reports meeting a priori inclusion criteria were extracted from 103 studies accessed through 16 electronic databases and a hand search. Data were synthesized in relation to three research questions informing evidence-based practice. Results: No randomized clinical trials were located. Two studies provided a moderate level of evidence for effectiveness. Nine studies demonstrated statistically significant positive effects. Three studies did not find significant psychosocial effects for the target group, although one found significant positive effects for the comparison group. Conclusion: In the aggregate, the evidence is promising in support of the effectiveness of complementary and adjunct interventions employing equines in the treatment of health challenges. Future studies are needed that utilize rigorous and creative designs, especially longitudinal studies and comparisons with established effective treatments.

Abstract: To understand the relative benefits of social and personal information use in foraging decisions, we developed an agent-based model of social learning that predicts social information should be more adaptive where resources are highly variable and personal information where resources vary little. We tested our predictions with bumblebees and found that foragers relied more on social information when resources were variable than when they were not. We then investigated whether socially salient cues are used preferentially over non-social ones in variable environments. Although bees clearly used social cues in highly variable environments, under the same conditions they did not use non-social cues. These results suggest that bumblebees use a 'copy-when-uncertain' strategy.