Responses of horses in behavioural tests correlate with temperament assessed by riders

The Easiest Becomes the Rule: Beliefs, Knowledge and Attitudes of Equine Practitioners and Enthusiasts Regarding Horse Welfare

Inadequate management conditions can impair the welfare of captive-bred horses. Understanding individuals' viewpoints and the factors influencing their decisions about adopting or avoiding certain practices may provide insights into their motivations and decision-making processes. This is particularly relevant in the equestrian community, where equine practitioners and enthusiasts often engage in harmful practices. We explored the beliefs, knowledge, and attitudes of equine practitioners and enthusiasts about horse welfare and the barriers that prevent them from employing better management practices that are essential to promoting horses' welfare. The study consisted of in-depth semi-structured interviews conducted in person with 31 individuals directly involved in the equestrian environment in Brazil. Responses were analyzed through thematic analysis with a data-driven deductive approach. Participants' beliefs, knowledge and attitudes to horse welfare were divided into three themes. The first theme, "Let the horse be a horse", captured participants' perceptions about how physical and mental aspects related to the nature and welfare of horses. The second theme, "Everyone does it like that", includes the social norms that influence decisions about the practices that impact on the welfare of the horses. The third theme, "Beyond utopia: how and why horses are managed the way they are", covered barriers that participants perceived as impediments to the use of best practices for the welfare of horses. While participants demonstrated awareness of welfare issues and acknowledged factors that negatively impact horses, there was a notable discrepancy between this knowledge and the implementation of improved management practices. This could be explained by several perceived barriers to implementing management practices that could enhance horse welfare, including lack of financial resources, limited physical space, shortage of qualified labor, time constraints, inadequate tools, and insufficient knowledge. Additionally, we identified deeply rooted social norms within the equestrian community and culturally established practices that limit approaches to horse welfare. Participants underscored the influence of these norms and different interpretations of "letting the horse be a horse" based on the horse's value and purpose. Concerning low-value horses, the primary justifications for stall housing and concentrated feeding were linked to elevated costs involved in spatial demands and labor; in contrast, for high-value horses used in performance and aesthetics, the arguments shifted to potential benefits to the horses' well-being. From an ethical perspective, ideally, individuals should refrain from owning horses if they cannot ensure the animals' welfare. Additionally, if the equestrian community neglects public attitudes towards animal welfare, it risks eroding its social license.

The Behavioral Cost of Care: Changes in Maintenance Behavior during Equine-Assisted Interventions

This study examined human-animal symbiosis in an animal-assisted intervention through observations of animal maintenance behaviors. The rise of psychotherapy, learning, and recreation incorporating animals warrants exploration of the welfare of the animals involved in these interventions. The analysis of welfare in multispecies engagements can be discussed in terms of symbiosis. Regarding an intervention's animal provider (e.g., therapy horse) and human recipient (psychotherapy client), the balance of cost and benefit is important. Research describing human and animal interactive behavior during interventions is limited, whether focusing on client outcomes or animal welfare. The present study adapted ethological methods to study humans and animals in an equine-assisted intervention, observing equine maintenance behaviors and equid-human interactive behavior. Maintenance behaviors were recorded before, during, and after equine-assisted (psychosocial) learning sessions with youth, providing 1600 observations. Equine alertness, eating behavior, and ambulation varied significantly before, during, and after the equine-assisted sessions. Such interruptions of typical behavior are an important aspect of welfare and unit of analysis when examining symbiotic relationships. A total of 267 sequences of equid-human approach-response behavior were also recorded, indicating that human-animal interaction was predominantly from humans toward equids. Equids' dominant response to human approach was no response, followed by avoidance, while humans' dominant response to equid approach was reciprocation. The findings are discussed in terms of symbiosis and animal welfare.

Behavioral observations, heart rate and cortisol monitoring in horses following multiple oral administrations of a cannabidiol containing paste (part 2/2)

As a remedy against stress and anxiety, cannabidiol (CBD) products are of increasing interest in veterinary medicine. Limited data is available describing the actual effectiveness of CBD in horses. The aim of this study (part 2 of 2) was to analyze stress parameters via behavioral observation, heart rate monitoring and assessment of blood and saliva cortisol levels in healthy horses treated repeatedly with a CBD containing paste. Twelve horses were randomly assigned to a treatment or a control group. Two pastes were orally administered in a double-blinded study design, one paste containing CBD and one paste without active ingredient. Both pastes were administered twice daily over 15 days (dose: 3 mg CBD/kg). Behavioral observations were conducted daily using a sedation score and a rating of facial expressions, based on the previously described facial sedation scale for horses (FaceSed) and the Horse Grimace Scale. Blood and saliva samples were obtained regularly to determine cortisol levels throughout the study. Cortisol levels were analyzed by means of liquid chromatography/tandem mass spectrometry (LC/MS/MS). Behavioral observations and cortisol levels were compared between groups. Prior to paste administration, a novel object test was performed and the horses' reaction to loading on a trailer was recorded. Both tests were repeated after 13 days of paste application. Movement patterns such as different gaits during the novel object test were evaluated and an ethogram was designed to assess exhibited behavioral traits. Cardiac beat-to-beat (R-R) intervals were recorded throughout and evaluated using heart rate (HR) and heart rate variability (HRV) parameters. Blood and saliva samples for cortisol analysis were taken before and after the tests. Daily behavioral observations and cortisol levels did not differ between the treatment and the control group. Similarly, analysis of movement patterns, HR, HRV and cortisol levels during the novel object test and trailer test did not identify significant differences between the groups. Regularly administered oral CBD (3 mg/kg BID over 15 days) had no statistically significant effect on behavioral observations, cortisol levels, HR and HRV in horses. Further research is required to establish adequate doses and indications for the use of CBD in horses.

Behavioral observations, heart rate and heart rate variability in horses following oral administration of a cannabidiol containing paste in three escalating doses (part 1/2)

Cannabidiol (CBD) products have been proposed to exert stress- and anxiety-relieving effects in animals. Despite the increasing popularity of CBD for veterinary use, the available research detailing the effects of CBD in horses is limited. The aim of this study (part 1 of 2) was to analyze stress parameters via behavioral observations and heart rate monitoring in healthy horses following single oral administration of a CBD containing paste in different doses. Study products were two pastes for oral administration, one containing CBD and one containing no active ingredient. Pastes were applied as single administrations in consecutive trials with escalating dosages (doses: 0.2, 1.0, 3.0 mg CBD/kg) to a treatment (trial 1: n = 3, trial 2: n = 3, trial 3: n = 5 horses) and a control group (trial 1: n = 3, trial 2: n = 3, trial 3: n = 6 horses) with minimum wash-out periods of seven days in between. Behavioral parameters were evaluated using video recordings to score the levels of sedation including the horses' reactions to acoustic and visual stimuli. Facial expression was assessed using photographs. Evaluation was based on the previously described facial sedation scale for horses (FaceSed) and the Horse Grimace Scale. For baseline values, identical observations were recorded on the day before each paste administration. Both paste administration and behavioral evaluation were performed double blinded. Cardiac beat-to-beat (R-R) intervals were continuously recorded throughout the trial and assessed using heart rate and heart rate variability parameters. Statistical analysis included comparison between treatment and control group over escalating doses and time points using linear mixed models. The CBD paste was well tolerated, and no side effects were observed. Analysis of sedation scores and facial expressions did not indicate significant differences between treatment and control group over the escalating doses. The heart rate was neither reduced, nor were significant changes in heart rate variability observed compared to the control group. Main limitation of this study is the small sample size. Further research is required to determine adequate doses and indications for the use of CBD products in horses.

Impact of oral Phytozen® EQ supplementation on plasma cortisol and behavior responses of young horses exposed to stressful stimuli

Calming supplements are common in the equine industry. This study tested the hypothesis that Phytozen® EQ, a blend of citrus botanical oils, magnesium, and yeast would reduce startle response as well as reduce behavioral and physiological signs of stress in young (1.5-6 years of age) horses (n = 14) when tied in isolation and when trailered in isolation. During the 59-day (d) trial, horses were assigned to either the control (CON; n=7) or treatment (PZEN; n=7) group that received 56 g of Phytozen® EQ daily. Horses underwent a 10 min isolation test on d 30 and a 15 min individual trailering test on day 52 or 55. For both tests, blood samples were obtained pre, immediately after, and 1-hour (h) post for analysis of plasma cortisol concentrations, which were analyzed by repeated measures ANOVA. On d 59, horses underwent a startle test, for which time to travel 3 m and total distance traveled were recorded. These data were analyzed using a T-test. During trailering, PZEN horses tended to have lower overall geometric mean (lower, upper 95% confidence interval) cortisol concentrations than CON (81 [67, 98] vs. 61 [48, 78] ng/mL; P = 0.071). For the startle test, PZEN horses tended to have longer geometric mean times to travel 3 m than CON horses (1.35 [0.39, 4.70] vs. 0.26 [0.07, 0.91 seconds [s], P = 0.064). Other data points were not different between treatments (P > 0.1). It is possible that this dietary supplement could have beneficial calming effects on horses undergoing trailering or in novel situations.

Changes in Management Lead to Improvement and Healing of Equine Squamous Gastric Disease

Equine squamous gastric disease (ESGD) is common in horses and poses a serious welfare problem. Several risk factors have been identified and ESGD is routinely treated with omeprazole. Fourteen mares, previously used as embryo recipients and diagnosed with ESGD, were selected. Horses were confined to individual stalls, exercised once daily, and fed ad libitum hay, 1 kg of a low starch compound complementary feed and a mineral supplement. Half of the horses received a compound containing hydrolysed collagen (supplement) and the other half did not (control). At the start of the study, ESGD scores were 3.57 and 3.36 for the supplement and control group, respectively. After 4 weeks, the ESGD grades were significantly reduced in both groups (1.89 and 1.43, respectively, p < 0.01), and healing (ESGD < 2) occurred in 7 out of 14 horses. No treatment effect was observed (p = 0.75), and it was concluded that the change in husbandry overshadowed any potential effect of the compound. Severe ESGD can improve, and even heal, with the provision of a diet of ad libitum forage and a small amount of a compound complementary feed, without the use of omeprazole. A predictable daily routine, with a limited number of dedicated caretakers, may have contributed to the improvement of gastric health.

Behavioral and Physiological Reactions to a Sudden Novel Object in the Weanling Horse: Quantitative Phenotypes for Future GWAS

The startle response can be defined as a reflexive reaction to the sudden appearance of a novel stimulus that influences the survival and resilience of animals. In domesticated species, the behavioral component of the startle response can, in some cases, cause serious injury to the animal or human handlers if inappropriately expressed. Here, we describe a longitudinal study in a population of stock-type horses that quantified behavioral startle responses elicited by the presentation of a sudden novel object (rapidly opening umbrella). The study was performed in weanling foals across four consecutive years (n = 74, mean age = 256 days). Behavioral assays for the startle response phenotype focused on six behavioral variables: latency to return to the feed pan (seconds), maximum distance fled (meters), proportion of time spent walking or trotting (seconds), and how long a horse spent standing facing away from or toward the novel object. We observed behavioral startle response variables in relation to cardiac response, age, and sex for each individual. Each horse’s cardiac startle response pattern was determined and categorized into heart rate response cluster groups identified as accelerators and decelerators. Using principal component analysis (PCA) with a factor rotation, we identified “startle response” phenotypes that summarize the behavioral and physiological variables. The largest component of variation, Factor 1, comprised 32.5% of the behavioral variable with a positive correlation with latency and distance, and was not influenced by sex or age. Factor 2 comprised 23.2% of the variation, and was positively correlated with activity level performed such as proportion of time spent walking and/or trotting. Horses with the accelerator type cardiac response had significantly higher Factor 1 scores than decelerators but did not differ in Factor 2. Future work includes expanding our sample size to conduct a genome-wide association study (GWAS) to identify novel genetic loci influencing behavioral startle reactions using recorded behavioral and physiological phenotypes.

Horse odor exploration behavior is influenced by pregnancy and age

In spite of a highly developed olfactory apparatus of horses, implying a high adaptive value, research on equine olfaction is sparse. Our limited knowledge on equine olfaction poses a risk that horse behavior does not match human expectations, as horses might react fearful when exposed to certain odors, which humans do not consider as frightening. The benefit of acquiring more knowledge of equine olfaction is therefore twofold; (1) it can aid the understanding of horse behavior and hence reduce the risk of dangerous situations, and (2) there may be unexplored potential of using odors in several practical situations where humans interact with horses. This study investigated behavior and olfactory sensitivity of 35 Icelandic horses who were presented with four odors: peppermint, orange, lavender and cedar wood in a Habituation/Dishabituation paradigm. The response variables were sniffing duration per presentation and behavioral reaction (licking, biting, snorting, and backing), and data were analyzed for potential effects of age, sex and pregnancy. Results showed that habituation occurred between successive odor presentations (1st vs. 2nd and 2nd vs. 3rd presentations: P &lt; 0.001), and dishabituation occurred when a new odor was presented (1st vs. 3rd presentations: P &lt; 0.001). Horses were thus able to detect and distinguish between all four odors, but expressed significantly longer sniffing duration when exposed to peppermint (peppermint vs. orange, lavender and cedar wood: P &lt; 0.001). More horses expressed licking when presented to peppermint compared to cedar wood and lavender (P = 0.0068). Pregnant mares sniffed odors less than non-pregnant mares (P = 0.030), young horses (age 0-5 years) sniffed cedar wood for longer than old horses (P = 0.030), whereas sex had no effect (P &gt; 0.050). The results show that horses’ odor exploration behavior and interest in odors varies with age and pregnancy and that horses naïve to the taste of a substrate, may be able to link smell with taste, which has not been described before. These results can aid our understanding of horses’ behavioral reactions to odors, and in the future, it may be possible to relate these to the physiology and health of horses.

Relationship of horse temperament with breed, age, sex, and body characteristics: a questionnaire-based study

Background

Temperament is an important issue that must be taken into consideration when purchasing horses for leisure, racing, or even work in the fields. Those who work with horses have various opinions about the relationship between a horse’s body characteristics and its temperament, but few scientific papers on this issue have been published. The objective of this study was to clarify the relationships of horse temperament with sex, breed, age, and body characteristics to help purchasers when selecting a horse with the desired temperament. A web-based survey consisting of a 32-item questionnaire was used to clarify the associations of sex, breed, age, and body characteristics with a horse’s temperament. The owners of a total of 112 horses from different countries (Egypt, Jordan, Palestine, and Iraq) were recruited to fill in the questionnaire about their horses.

Results

The results showed statistically significant associations of sex and breed with temperament with 89.7% and 108.3%, respectively (p values < 0.001), while there was no significant association between age and temperament (chi-square p value 0.58). The results also clarified significant associations between body characteristics (color, head and body marks, leg marks, and whorls) and temperament (all chi-square p-values < 0.001).

Conclusion

Purchasers can predict a horse’s temperament from its sex, breed, and body characteristics, including coat color, body and leg marks, and whorls

Interest in Humans: Comparisons between Riding School Lesson Equids and Assisted-Intervention Equids

Simple Summary

Very little is known about the impact of equine-assisted interventions on equids’ perception of humans. Different factors can influence human–horse relationships: animal characteristics, daily interactions with the caretakers, and working and living conditions. In this study, 172 equids working in equine-assisted interventions, ‘classical’ riding school lessons, or both were submitted to a standardised human–horse relationship test in order to test if EAI had an impact on the equid reactions to humans. The possible influence of intrinsic (age, sex, type) or other extrinsic factors (housing and feeding conditions) was also considered. The results showed that the number (more than the type) of experimenter-directed behaviours varied significantly between individuals and that the activity was the most important factor of influence: Equids working in riding school lessons performed more interactive behaviours than those working in equine-assisted interventions or having mixed activity. Other factors such as daily hay quantity, the horses’ age, and sex also influenced secondarily the horse’s motivation to interact, although no interaction was found between factors. These results suggest that equine-assisted interventions do influence horses’ perception of humans outside work. Further studies are needed in order to understand the processes involved.

Abstract

Little is known about the impact of equine-assisted interventions (EAI) on equids’ perception of humans. In this study 172 equids, living in 12 riding centres, were submitted to a standardised human–horse relationship test: the motionless person test. Age, sex, type (horse/pony), housing, and feeding conditions of subjects were recorded. Overall, 17 equids worked in EAI, 95 in riding school lessons (RS), and 60 in both (EAI-RS). There were high inter-individual variations in the number of interactive behaviours directed towards the experimenter: negative binomial general linear models showed that activity was the most important factor: RS equids performed more interactive behaviours than EAI (p = 0.039) and EAI-RS (p < 0.001) equids. Daily quantity of hay appeared as the second most important factor (equids with more than 3 kg interacted more than equids with less than 3 kg, p = 0.013). Individual characteristics were also important as horses interacted more than ponies (p = 0.009), geldings more than mares (p = 0.032), and 3–15-year-old equids more than equids over 15 years (p = 0.032). However, there was no interaction between factors. The lower number of interactive behaviours of EAI equids leads to different hypotheses—namely, selection on temperament, specific training, or compromised welfare (apathy). In any case, our results raised new lines of questions on EAI.

An Ethnographic Account of the British Equestrian Virtue of Bravery, and Its Implications for Equine Welfare

This article describes the virtue of bravery in British equestrian culture and suggests that riders' tactics for bolstering bravery may have negative implications on equine welfare. These observations are based on 14 months of ethnographic research among amateur riders and the professionals who support them (n = 35), utilising participant observation and Dictaphone recordings. Riders suffering from 'confidence issues' could be belittled and excluded. Instructors' approaches towards bolstering bravery involved encouraging riders to 'get tough'-on both themselves and on their horses. Narrative theory is employed in this article to show that riders could demonstrate their own bravery through describing the horse as defiant. Alternate narrative possibilities existed, including describing the horse as needy patient and the rider as care provider. Riders were critically aware that veterinary diagnoses could be sought or avoided in line with riders' own dispositions. 'Diagnoses-seeking' behaviours could be judged negatively by others and seen as evidence of unresolved fearfulness. In conclusion, the British equestrian cultural orientation towards bravery can be associated with stressful or painful training techniques, delayed or missed diagnoses of physiological pathologies, and poor training outcomes. Programs that aim to help riders to develop confidence without instilling a sense of 'battle' with the horse, and without ridiculing the rider, are likely to have positive implications on equine welfare and human safety.

Association Between Disease Severity, Heart Rate Variability (HRV) and Serum Cortisol Concentrations in Horses with Acute Abdominal Pain

Simple Summary

Acute abdominal pain is a major cause for emergency treatment in horses and associated with a high stress level leading to an increased serum cortisol concentration. Stress can also be assessed by analyzing the heart rate variability (HRV). We investigated whether the stress level was different between horses with different causes of abdominal pain and, therefore, demanding a different treatment strategy. Heart rate, its variability in the time domain analyses, and cortisol level indicated a decrease in the stress level the day after admission and the day of discharge from the hospital in comparison to admission for both conservatively and surgically treated patients. However, such changes, over time, were not seen in horses that were euthanized during the hospitalization. Furthermore, the difference in the parameters measured between horses that were eventually euthanized and those that survived was best visible the day after admission. Therefore, we concluded that HRV can give further important information on the stress level in horses with colic and might be helpful in assessing possible outcome. However, further studies are required to assess the validity of HRV analyses in horses with colic.

Abstract

Heart rate variability (HRV) is a noninvasive technique to detect changes in the autonomous nervous system. It has rarely been investigated in horses with colic. Therefore, the objective was to assess the evolution of HRV parameters and cortisol concentrations in horses with colic. The 43 horses included in this study were categorized into three groups according to the treatment (1, surgical; 2, conservative; 3, euthanized). The HRV and laboratory variables were measured at admission (T1), the day after admission (T2), and at discharge (T3) and compared between groups and over time with an ANOVA with Bonferroni correction. Relationships between the HRV parameters themselves and the laboratory variables was assessed by Pearson correlation coefficients. Evolution of the heart rate (HR) over time, mean normal to normal R intervals (meanNN) and cortisol concentrations indicate a decreased sympathetic stimulation over time in group 1 and 2, in contrast to group 3. For group 3, the meanNN and HR differed significantly to group 2 at T1 and to group 1 and 2 at T2. Treatment induced a change in the HRV and cortisol response in horses managed conservatively or surgically but not in horses that required euthanasia. However, further studies are required to assess the validity of HRV analyses in horses with colic.

Individual differences in behavior and heart rate variability across the preweaning period in the domestic horse in response to an ecologically relevant stressor

The study of individual differences in behavior and physiology has attracted considerable interest among behavioral biologists. Important questions include how early in life such differences emerge and to what extent they remain stable across development. Due to the demanding nature of longitudinal studies, there is still a lack of information on this in mammals, especially in large, long-lived species. Our aim in this study was to look for stable individual differences in behavior and physiology during early development in the domestic horse and for correlations between the two parameters. We tested 30 Azteca-breed foals kept under standard conditions by briefly separating them from their mother in four repeated tests beginning at the first postnatal week until the foals were six months old, before they were weaned. Individual differences in behavior and heart rate variability of foals in response to brief maternal separations were consistent and were correlated from a very early age. These findings contribute to an understanding of the expression of individual differences in physiology and behavior from a developmental perspective and may help in the future selection of horses for functional contexts that require different levels of reactivity, thereby contributing to horse welfare and to human safety and economy.

Equine Personality: Association With Breed, Use, and Husbandry Factors

Temperament can be defined as innate properties of the nervous system, whereas personality includes the complex behavioral traits acquired through life. Association between personality and behavior is important for breeding, selection, and training of horses. For the first time, we evaluated if equine personality components previously identified in Japan and Europe were consistent when applied to American horses. We examined the association of personality with breed, age, sex, management, training, stereotypies, and misbehaviors. The owner directed personality survey consisted of 25 questions. An online version of the survey was created. The principal component analysis method was used to associate behavioral traits with personality components. Factor analysis with orthogonal transformation was performed on scores for personality-related questions. A total of 847 survey responses were used. Quarter Horses, "other" breed, and Thoroughbred were the most common breeds. Three principal personality components were extracted as each behavioral trait belonged to one of these three components. Arabians, Thoroughbreds, Saddlebreds, and Walking horses were the most nervous and Quarter Horses, and Paints, Appaloosas, and Drafts were the least nervous. No trained discipline was significantly associated with any personality component. There were no significant associations between stereotypies and misbehaviors and nervous or curious personality. For the first time in predominantly American horses, we have evaluated personality components and their association with breed, age, sex, training discipline, and stereotypies. We refute links between personality and trained discipline and confirm the lack of association between nervous personality and stereotypies and misbehaviors.

Personality, abnormal behaviour, and health: An evaluation of the welfare of police horses

An animal's welfare depends on an individual's capacity to adapt to the environment in which it lives. This adaptation is directly associated with the quality of the environment and to the possibility of expressing natural behaviours. Horses kept in stables often display a range of abnormal behaviours related to lack of control over their environment, which can lead to behavioural and health problems. An individual's personality also plays an important role in its susceptibility and resilience to the development of diseases and abnormal behaviour; thus, an evaluation of horses' personalities could be crucial to selecting individuals best able to cope with different work activities. This study aimed to assess the well-being of police horses maintained in a semi-confinement regime in Brazil by associating their personalities to the occurrence of abnormal behaviours and disease. Using a non-invasive approach, different tests were performed to investigate the horses' behaviour, personality and welfare. A frustration test and a novel object test were conducted with 46 horses and the individuals' personalities were assessed using questionnaires and behaviour tests. In addition, we evaluated their physical health through a survey of their veterinary records. The data for horses were evaluated individually. The results demonstrated the occurrence of multiple abnormal behaviours motivated by factors such as diet and lack of social contact. Moreover, the personality tests indicated this is an important component when evaluating welfare, since correlations were found between personality traits and abnormal behaviour expression, and between personality traits and health problems. According to our results, passive, stubborn, and confident horses are better suited to be selected as police horses. The ability to classify horses according to their personalities could help in selecting horses most suitable for patrolling, thereby helping to reduce behavioural problems and increasing animal well-being.

Equine Assisted Interventions (EAIs): Methodological Considerations for Stress Assessment in Horses

Equine assisted interventions (EAIs) are recently facing an increasing popularity, and are characterized by a wide diversity of practices. However, information on the welfare of animals involved in this kind of activity is often lacking. Horses are highly susceptible to work stressors related to physical constraints and/or to the need to control emotions while interacting with humans. Considerations of the emotional state of horses involved in EAIs have multiple valences: for the safety of humans and animals involved, for the quality and efficacy of interventions, as well as for ethical reasons. The aim of this unsystematic narrative review is to summarize the different approaches used for the evaluation of horses' stress responses, investigate their application in the context of EAIs, and discuss some methodological considerations for researchers and practitioners involved in EAI. The sources of information are mostly based on electronic databases (i.e., Medline, Scopus and Google scholar), as well as on hand searches of the references of retrieved literature, and discussions with experts in the field. At present, a few studies have investigated horses' stress responses during EAIs, and further studies are recommended, with the final aim to derive a reliable multidimensional method for assessing a horse's reaction during therapeutic programs, ultimately helping professionals to better develop interventions by taking into consideration the animal's perspective.

Effects of handling on fear reactions in young Icelandic horses

REASONS FOR PERFORMING THE STUDY

Inclusion of objective temperament tests at practical horse breeding evaluations is of increased interest. It has been debated whether such tests may involve human handling, since there may be considerable differences in horses' handling experience.

OBJECTIVES

To investigate the effect of a short-term standardised handling procedure on reactions of young horses in 2 types of fear tests (including and excluding human handling).

STUDY DESIGN

An experimental study with 3-year-old Icelandic horses (n = 24).

METHODS

Handled horses (n = 12) were trained according to a standardised handling procedure whereas controls (n = 12) remained untrained. Behavioural and heart rate responses in a novel object test and 2 handling fear tests (HFTs) were measured. The HFTs were conducted with both an unknown (HFT-unknown) and a known handler (HFT-known).

RESULTS

There was no effect of the handling procedure on the horses' behavioural and heart rate responses in the novel object test, nor in the HFT-unknown. In the HFT-known, however, handled horses showed a significantly shorter duration of reluctance behaviour compared with controls, whereas heart rates did not differ. Heart rates correlated significantly between tests.

CONCLUSIONS

Previous handling may affect the behavioural fear response of horses when handled by their usual handler, whereas this effect did not apply to an unknown handler. Heart rates appeared unaffected by handling and may be a more reliable indicator of fearfulness. Known handlers may 'mask' behavioural responses of horses in fear tests and thus handling by a known handler during testing may not be appropriate for objective evaluation of fearfulness in a practical situation.

Stress modulates instrumental learning performances in horses (Equus caballus) in interaction with temperament

The present study investigates how the temperament of the animal affects the influence of acute stress on the acquisition and reacquisition processes of a learning task. After temperament was assessed, horses were subjected to a stressor before or after the acquisition session of an instrumental task. Eight days later, horses were subjected to a reacquisition session without any stressor. Stress before acquisition tended to enhance the number of successes at the beginning of the acquisition session. Eight days later, during the reacquisition session, contrary to non-stressed animals, horses stressed after acquisition, and, to a lesser extent, horses stressed before acquisition, did not improve their performance between acquisition and reacquisition sessions. Temperament influenced learning performances in stressed horses only. Particularly, locomotor activity improved performances whereas fearfulness impaired them under stressful conditions. Results suggest that direct exposure to a stressor tended to increase acquisition performances, whereas a state of stress induced by the memory of a stressor, because it has been previously associated with the learning context, impaired reacquisition performances. The negative effect of a state of stress on reacquisition performances appeared to be stronger when exposure to the stressor occurred after rather than before the acquisition session. Temperament had an impact on both acquisition and reacquisition processes, but under stressful conditions only. These results suggest that stress is necessary to reveal the influence of temperament on cognitive performances.

The effect of ocular blinkers on the horses' reactions to four different visual and audible stimuli: results of a crossover trial

OBJECTIVE

To determine the effect of ocular blinkers on driving horses' reactions to visual and audible stimuli.

DESIGN

Balanced crossover trial with horses randomly assigned to either wear blinkers or not wear blinkers first or second, then subjected to repeated sequences of four distinct stimuli (chain rattle, cap gun, umbrella opening, and shaking of an aluminum can containing coins). Two weeks later, this process was repeated with the ordering of wearing blinkers reversed.

ANIMAL STUDIED

Eight driving horses of various breeds.

PROCEDURES

Responses were recorded quantitatively as inter-beat times (the time between each heart beat in msec) and qualitatively via video recording. Statistical analysis of the first 10 s of inter-beat times poststimulus assessed the effect of the presence of blinkers, order of blinker application and stimulus type using a linear regression model with a random effect for horse.

RESULTS

Wearing blinkers is significantly associated with a decrease in the inter-beat times (increase in heart rate) when they are worn by horses experiencing an unfamiliar sound. However, wearing blinkers is significantly associated with an increase in the inter-beat times (decrease in heart rate) when worn by horses experiencing a primarily visual, familiar stimulus.

CONCLUSIONS AND CLINICAL RELEVANCE

Trained driving horses, when they wear blinkers, have a decrease in inter-beat time (an increase in heart rate) when there is an unfamiliar sound. This may have relevance to horses who have limited vision caused by trauma or disease.

The influence of challenging objects and horse-rider matching on heart rate, heart rate variability and behavioural score in riding horses

A good horse-rider 'match' is important in the context of equine welfare. To quantify the influence of repetition and horse-rider matching on the stress of horses encountering challenging objects, 16 Warmblood horses were ridden in a test-setting on three occasions. On each occasion the horse was ridden by a different rider and was challenged by three objects (A-C). Heart rate (HR), heart rate variability (HRV) of horse and rider, and behaviour score (BS) of the horse were obtained for each object and as a total for each test. The horse-rider interaction was evaluated with each combination and assessed as 'matching' or 'mismatching', and the horses were categorised as 'compliant', 'partly-compliant' or 'non-compliant'. Horses exhibited a decreased HR (P=0.015) and a decreased BS (P=0.004) within and across different tests. 'Matching' horse-rider combinations exhibited less stress as indicated by reduced HR ('match' 69±10 vs. 'mismatch' 72±9, P=0.001) and BS ('match' 1.9±1.1 vs. 'mismatch' 3.8±1.4, P=0.017) of the horse. 'Compliant' (68±8, P<0.001) and 'partly-compliant' (71±9, P=0.002) horses had significantly lower HR than 'non-compliant' (75±9) animals. The findings of the study indicate that HR and BS measurements support a subjective 'match' diagnosis and HR measurement may be a valuable tool in assessing horse compliance.

Equine behaviour and heart rate in temperament tests with or without rider or handler

The aim of the present study was to compare horses' heart rate (HR), heart rate variability (RMSSD, pNN50) and behaviour in the same temperament test when being ridden, led, and released free. Behavioural measurements included scores and linear measurements for reactivity (R), activity (A), time to calm down (T) and emotionality (E), recorded during the approach (1) and/or during confrontation with the stimulus (2). Sixty-five horses were each confronted 3 times (1 ridden, 1 led, 1 free running in balanced order) with 3 novel and/or sudden stimuli. Mixed model analysis indicated that leading resulted in the lowest (P<0.05 throughout) reactions as measured by A1, A2, E1, E2, R2, and pNN50 while riding produced the strongest (A1, T2, HR, RMSSD, pNN50) or medium (E1, E2, R2) reactions. Free running resulted either in the strongest (A2, E1, E2, R2) or in the lowest (A1, T2, HR, RMSSD, pNN50) reactions. The repeatability across tests for HR (0.57), but not for RMSSD (0.23) or pNN50 (0.25) was higher than for any behavioural measurement: the latter ranged from values below 0.10 (A1, A2, T2) to values between 0.30 and 0.45 (E1, E2, R2). Overall, the results show that a rider or handler influences, but not completely masks, the horses' intrinsic behaviour in a temperament test, and this influence appeared to be stronger on behavioural variables and heart rate variability than on the horses' heart rates. Taking both practical considerations and repeatabilities into account, reactivity appears to be the most valuable parameter. Emotionality and heart rate can also yield valid results reflecting additional dimensions of temperament although their practical relevance may be less obvious. If a combination of observed variables is chosen with care, a valid assessment of a horse's temperament may be possible in all types of tests. However, in practice, tests that resemble the practical circumstances most closely, i.e. testing riding horses under a rider, should be chosen.

Does work affect personality? A study in horses

It has been repeatedly hypothesized that job characteristics are related to changes in personality in humans, but often personality models still omit effects of life experience. Demonstrating reciprocal relationships between personality and work remains a challenge though, as in humans, many other influential factors may interfere. This study investigates this relationship by comparing the emotional reactivity of horses that differed only by their type of work. Horses are remarkable animal models to investigate this question as they share with humans working activities and their potential difficulties, such as "interpersonal" conflicts or "suppressed emotions". An earlier study showed that different types of work could be associated with different chronic behavioural disorders. Here, we hypothesised that type of work would affect horses' personality. Therefore over one hundred adult horses, differing only by their work characteristics were presented standardised behavioural tests. Subjects lived under the same conditions (same housing, same food), were of the same sex (geldings), and mostly one of two breeds, and had not been genetically selected for their current type of work. This is to our knowledge the first time that a direct relationship between type of work and personality traits has been investigated. Our results show that horses from different types of work differ not as much in their overall emotional levels as in the ways they express emotions (i.e. behavioural profile). Extremes were dressage horses, which presented the highest excitation components, and voltige horses, which were the quietest. The horses' type of work was decided by the stall managers, mostly on their jumping abilities, but unconscious choice based on individual behavioural characteristics cannot be totally excluded. Further research would require manipulating type of work. Our results nevertheless agree with reports on humans and suggest that more attention should be given to work characteristics when evaluating personalities.

Novel environmental enrichment may provide a tool for rapid assessment of animal personality: a case study with giant pandas (Ailuropoda melanoleuca)

Historically, the assessment of nonhuman animal personality has included a variety of methods--from direct behavioral observations in a variety of test situations to assessments provided by animal caretakers or trainers. Careful observation of how animals in zoos interact with novel enrichment may provide reliable insight into their personality. This study sought to describe a process for evaluating whether different methods of assessing personality result in similar conclusions. The study exposed 4 giant pandas at the Smithsonian National Zoological Park and Zoo Atlanta to 10 novel enrichment items and recorded their behavior. Keepers also rated each panda on 23 behavioral characteristics on a survey. The study obtained individual behavior profiles for each panda. Significant differences across individuals in both the novel enrichment trials and keeper surveys formed the basis for the profiles. These methods also provided some insight into differences between the sexes that--based on the natural history of giant pandas--are qualitatively similar to what would be expected. The study found some consistency between assessment methods. However, there is a need for further study to validate these measures in a larger sample of giant pandas.