Abstract: Horses are known to show fear reactions when confronted with novelty and this can be a considerable hindrance in the context of working situations such as riding, dressage or racing. The aim of the present study was to measure the potential effects of a synthetic analogue of the Equine Appeasing Pheromone on saddled horses when subjected to a stressful situation using a double-blinded, placebo controlled study design. A group of 40 horses was analyzed during this study and horses were divided by sex, breed and reactivity into two homogenized groups. The test, which consisted of walking the horse through a fringed curtain, was selected from a range of tests which are used to assess behaviour for the selection of French breeding stock. Horses that could have been subjected to the test on a previous occasion, and therefore be familiar with it, were not included. Behavioural and physiological parameters were both taken into account with measures of time to go through the curtain, fear related typical behavioural patterns, based on available literature detailed in the bibliography, and heart rate being recorded. Parameters were analyzed by means of Mann-Whitney U-test. Significant differences were noticed between the two groups concerning heart rate data during the test (UMeanHR = 100.5, pMeanHR = 0.02; UMaxHR = 75, pMaxHR = 0.001) and during the whole measured period (UMeanHR = 67, pMeanHR = 0.005; UMaxHR = 58, pMaxHR = 0.002). Observation of the animals also revealed less behavioural items characteristic of fear within the treated group. As a result, horses performed the test with a better time performance when they received the pheromone analogue (U = 62, p = 0.002). The main parameter, area under the HR graph, is based on heart rate measure and performance. Differences noticed (U = 74, p = 0.002) for this parameter lead to the conclusion that horses who received EAP underwent less stress related consequences in terms of their cardiac physiology. As horses are subjected to a number of foreseeable stressful events this study suggests that the use of Equine Appeasing Pheromone could be a significant factor in improving the welfare of this species.

Abstract: The relationship between facial hair whorl position and reactivity, as assessed by behavioural measures (handling score = HS; startle reaction to a suddenly appearing novel object = SR; latency to touch a novel object = LNO) and heart rate measures (mean HR; increase in heart rate = IHR) were studied using 55 Konik horses reared either under conventional stable conditions or in the forest reserve. Horses were classified into four groups according to the whorl position and/or shape: (1) high, single whorl above the top eye line, n = 9; (2) medium, single whorl between the top and the bottom eye line, n = 30; (3) low, single whorl below the bottom eye line, n = 10; and (4) elongated or double whorl, n = 6. Horses with a high whorl position demonstrated a lesser degree of manageability as expressed by a lower HS compared to individuals with medium (P = 0.002) or low whorl positions (P = 0.016). Horses with different whorl positions did not differ significantly in their startle response to a suddenly appearing novel object (P = 0.685). The horses with an elongated or double whorl, which appeared only in the forest group, took significantly longer to approach the novel object than horses with medium (P = 0.006) or low (P = 0.005) whorl positions. No significant differences in mean HR and IHR between groups (HR: P = 0.629 and IHR: P = 0.214) were found. In conclusion, this study supports the relationship between the position of the hair whorl on the horses' head and their manageability during handling, as well as the latency to approach an unknown object.

Abstract: The aim of the study was to investigate whether heart rate variability (HRV) could assess alterations of the autonomic nervous system (ANS) at different levels of excitement. The behavioural and physiological responses of 20 warmblood horses to a challenging ground exercise task were studied. Prior to the experiment, the horses were evaluated at rest and during forward walking (FW). The horses were then forced to move backwards continuously during 3 min according to a standardised protocol (BW1). Subsequently, the horses were exposed to two training sessions, after which the backward walking (BW2) was re-evaluated. Heart rate (HR) and HRV-parameters such as the standard deviation of the beat-to-beat intervals (SDRR), the low (LF; sympathetic tone) and high frequency (HF) component of HRV (HF; parasympathetic tone) and their ratio (LF/HF; index representing the sympatho-vagal balance) were sampled at rest, and during FW, BW1 and BW2. Stress-related behaviour during BW1 and BW2 was determined from video recordings. The results of the different evaluations were compared to each other. Compared to rest and FW, the first backward experiment induced a significant rise in HR, LF and LF/HF and a significant decrease of HF. SDRR decreased from both FW and rest with only the latter reaching significance. In BW2 after the training sessions, HR and the parameters of the sympathetic branch of the ANS (LF, LF/HF) were decreased and the vagal tone (HF) increased compared to BW1; all changes were significant. The duration of stress indicating behavioural patterns revealed also a significant decrease of excitement after the training, when backward walking did not differ from forward walking in any parameter. Correlations between HRV-parameters and stress indicating behaviour as well as HR were found. We conclude that the HRV-parameters LF and HF are valuable measures to quantify sympatho-vagal balance, which allows a more precise assessment of the responses of HR and SDRR to mental stress during low intensity exercise.

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: Responses of horses towards fear-eliciting stimuli can have important consequences for both human and horse safety. This experiment was designed to investigate behavioural and heart rate (HR) responses of horses to novel visual, auditory and olfactory stimuli. Twenty-four 2-year-old, previously unhandled, stallions were habituated to receive a food reward from a container in a test arena. Each horse was exposed to three 2 min tests in a balanced design where in addition to the feed container, either a traffic cone (visual test), white noise (auditory test) or eucalyptus oil applied to the inside of the container (olfactory test) were used as the novel stimuli. Compared to the control, less time was spent eating during all tests. There was no difference in locomotion activity in the different test situations, but presentation of the novel visual and auditory stimuli elicited significantly increased HR responses in the horses, compared to their response to the arena without novel stimuli (control), whereas there was no increase in HR response to the olfactory stimulus. However, during the olfactory test, the horses had an increased number of eating bouts and became more vigilant towards their surroundings, whereas during the visual and auditory tests, more time was spent alert towards the stimulus. The horses also took significantly more steps backwards in response to the auditory test. The heart rate responses correlated between tests and reflect a non-differentiated activation of the sympathetic nervous system, while the behavioural responses were linked to the type of stimulus.