Single housing but not changes in group composition causes stress-related immunomodulations in horses

Differences between facilities in horse welfare profiles: slight differences in management/working conditions may be enough

Many studies focus on animal welfare in terms of specific, either behavioural or physiological, indicators or on the impact of a particular management factor. However, an animal's welfare state results from the individual's perception of its general environment, which has consequences at both behavioural and physiological levels. Previous research on horses has shown that different riding schools could be characterised by different emotional/cognitive profiles of horses, in relation sometimes with one single management factor. In the present study, we aimed at determining if such facility-specific horse profiles could also be found in terms of welfare, i.e. facility-specific "welfare profiles", using a multifaceted approach where animals' welfare state was assessed based on detailed behavioural, health and physiological measurements. A total of 59 horses from three different riding schools, with a very similar global conventional management but differed slightly in terms of turn-out frequency and riding techniques were studied. A principal component analysis and statistical comparisons showed that, despite the close similarity in management between the three sites, the horses' welfare state was very different and specific to each structure. Thus, this study using behavioural, health and physiological measures, highlights the existence of facility horse welfare profiles and reveals that even apparently minor differences in management practices could have a major impact on the horses' welfare state. The quality of ridden work, which is often not taken into account in studies on horse welfare, could be a major issue.

Learning from eavesdropping on human-human encounters changes feeding location choice in horses (Equus Caballus)

When animals observe human signals, they may learn from them. Such learning from humans has been reported for intentional communication between humans with animals, but animals might also learn socially by observing unintentional information transfer when eavesdropping on humans-human encounters. In this study, 12 of 17 horses significantly changed their preference for a feeding location after observing approval in a human-human interaction there, and horses kept in social housing adapted in a higher percentage of trials to human-human demonstrations than those in individual housing. This indicates, for the first time, that some animals change their feeding strategies after eavesdropping on human-human demonstrations and that this adaptation may be dependent on social experience. As horses maintained the observed preference for a feeding location when the demonstrators were absent, we suggest that they learned by applying individual and social learning mechanisms. The horses social rank, age and sex did not affect their learning performance. However, particular demonstrators tended to have a stronger impact on the horses' performance. Future research should further investigate the durability of this preference change in the absence of repeated demonstrations, and establish whether long-term social learning sets in. This would have important implications for unintentional long-term impacts of human interactions on interspecies communication.

Global distribution and gap analysis of equine housing research: The findings so far and where to go next

As a free-ranging, social species, the housing of horses (Equus caballus) may limit their opportunity to display natural behaviour, compromising well-being. This review records and presents studies that have investigated horse housing design, evaluates the location and number of studies carried out to date, and reports the methods used to assess impact on equine well-being. A Boolean search was conducted in two databases: Web of Science and Scopus, filtered according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) protocol, resulting in 60 peer-reviewed papers for evaluation. Key findings are that a significant amount of work to date has been carried out in Europe and the USA, and the frequency of horse housing studies has steadily increased over the last 33 years, with 52% of them occurring in the last eight years. Health and welfare measures indicate benefits of housing horses in more natural management systems, particularly with conspecifics. Generally, the studies reviewed were only conducted in the short term, therefore future research should aim to increase the length of time over which housing is evaluated, particularly to ensure studies continue beyond an adaptation period. The review also highlights a requirement for more standardised methodology in housing welfare evaluation to allow for more meaningful comparisons to be made. Studies seeking to improve horse welfare in existing housing systems, in the face of limited space or other management constraints, are of high value to the end user and are encouraged. The studies reviewed here represent a significant and diverse body of work from which gaps in knowledge and future research directions can be determined.

Horse Owners' Knowledge of Fundamental Care and their Perceptions on the Implementation of a Mandatory Certificate of Knowledge

The aims of this study were to first determine the extent of owners' fundamental knowledge of equine care, second, gain their opinions on the implementation of a mandatory certificate of knowledge and third, to investigate the association of certification on horse owner knowledge. An online survey comprising 23 questions (18 closed, 5 open) was distributed worldwide via snowball sampling, and completed by 1847 horse owners who were all ≥18 years old from 17 different countries. Almost all (96%, n = 1781) completed surveys were usable. Just over half (52%) of participants held a current equine knowledge certification, and 59% believed a mandatory certificate of knowledge should be necessary to buy, own, or sell a horse. Horse owners with an equine certificate of knowledge were more likely to be in favor of a mandatory certificate (Pearson's Chi-squared = 50.79, df = 1, p < 0.0001). The mean correctly answered knowledge questions was 68%, indicating that approximately 1/3 of horse owners lacked fundamental horse care knowledge. Further examination indicated that participating horse owners showed the least understanding in the behavioral interactions domain (ANOVA F(4, 24) = 4.98, p < 0.01), specifically in relation to pain recognition and learning theory terminology. Arguably, this deficit in knowledge and likely correct application increases the risk of owners using misinformed or inappropriate techniques to manage horse behavior and training, predisposing the horse to experiencing a sub-optimal quality of life. Overall no significant difference was found between the total correct scores of horse owners with or without a certificate (ANOVA F(1, 56) = 0.78, p > 0.05); however, a series of Chi-squared tests revealed that for the more complex questions, horse owners with a certificate scored better than those without (all p < 0.05). Further work is needed to develop an evidence-based assessment framework if mandatory certification of horse owners is to become an effective tool for improving horse welfare and quality of life.

Prevalence and Risk Factors for the Presence of Gastric Ulcers in Pleasure and Breeding Horses in Italy

Equine Squamous Gastric Disease (ESGD) and Equine Glandular Gastric Disease (EGGD) are two terms used to indicate the presence of lesions of the squamous and glandular mucosa of the stomach. Prevalences, pathophysiology, and risk factors are different, and the latter have been investigated in different populations. The aim of this study was to investigate the prevalence and risk factors of ESGD and EGGD in a cohort of pleasure, breeding, and retired horses in Italy. To the authors' knowledge, this is the first study to investigate such a diverse population of animals and the first one that includes a large number of animals in Italy. Gastroscopies were performed in 316 animals, with and without clinical signs of gastric ulcers, and a questionnaire about signalment, management, activity, and health was given to the owners or caretakers. Prevalence of ESGD was similar to the current literature reports in comparable populations, and the disease was associated with signalment, time with the current owner or caretaker, management (time and type of paddock, hay, and supplementary feed administered), and activity performed. In this population, EGGD was present in a lower percentage of animals and, of the parameters evaluated, was associated only with the signalment, while management does not seem to influence the development of lesions in the glandular mucosa in this population.

Video Ethogram of Equine Social Behaviour

Equine social behaviour studies face challenges stemming from the absence of a comprehensive ethogram with unequivocal standardised definitions and the resulting limits to data comparison across studies. To address these constraints, this ethogram offers researchers a standardised framework, defining thirty-seven distinct equine social behaviours supplemented by video examples for enhanced clarity. These definitions amalgamate insights from existing ethograms and are fine-tuned through meticulous video observations, encompassing contextual cues such as distinguishing between aggressive and playful circling based on ear position and facial expressions and communicative nuances to provide a detailed representation of equine social behaviours. Video recordings complement the standardised definitions by capturing the dynamic flow and sequence of social interactions. By providing a dynamic and detailed representation, videos allow researchers to observe the temporal aspects of behaviour, including the sequence, duration, and rhythm of interactions. These detailed data are crucial for interpreting social behaviours and unravelling the complexities of equine societies. Standardized and video-illustrated definitions of equine social behaviour facilitate clear and consistent communication between researchers, enabling cross-study comparisons regarding the impact of husbandry practices and health conditions on equine social behaviour, which, in turn, can facilitate the assessment and optimisation of management practices and equine welfare.

Time-Budget and Welfare Indicators of Stabled Horses in Three Different Stall Architectures: A Cross-Sectional Study

Keeping horses in single stalls can lead to the development of abnormal and stereotypic behaviors (ASB). Opportunities for social interactions and stall architecture can influence behavior. The current study aimed to identify how three different stall architectures influenced time-budget and physiological parameters in horses. Stall types included: (1) 3.2 × 3.7 m with tactile contact between horses (B1); (2) 2.6 × 3.5 m with visual contact between horses and outside view (B2); (3) 2.3 × 3.4 m with visual contact and outside view (B3). Ten horses from B1 and B3, and nine from B2 were randomly selected, filmed for 24 hours and the video was analyzed with continuous behavioral sampling. Nine horses from B1, 8 from B2 and 7 from B3 were randomly selected for blood sampling used to determine cortisol levels, cortisol circadian rhythm (CCR), white blood cells (WBC) and neutrophil/lymphocyte ratio. The effects of different stall architectures were analyzed by ANOVA and post hoc Tukey test. B1 had higher social interaction time (2.77% of the time-budget) (P = .020), with no other differences. Time spent eating represented a low proportion of horses' time-budget (14.31%) and all horses demonstrated ASB behaviors (21.10% of the time-budget). Twenty-five percent of the horses presented low WBC, 38% of the horses had high cortisol levels, and 29% of the horses had an altered CCR. Those alterations along with high prevalence of ASB indicate that horses were in a state of chronic stress. The stalls' architecture did not affect the presence of abnormal behaviors or indicators of stress.

Transcriptomic signature related to poor welfare of sport horses

The improvement of horse welfare through housing conditions has become a real issue in recent years and have highlighted the detrimental effect of individual housing of horses on their health and behaviour. In this new study, we analysed the blood transcriptome of 45 sport horses housed individually that were previously examined for their behaviour and gut microbiota. We performed differential and regression analyses of gene expression, followed by downstream bioinformatic analyses, to unveil the molecular pathways related to the behavioural changes associated with welfare impairment in these sport horses. We found that aggressiveness towards humans was the behavioural indicator the most correlated to blood gene expression and that the pathways involved belonged mainly to systemic inflammation. In contrast, the correlations between genes, alert postures and unresponsiveness towards the environment were weak. When blood gene expression profiling was combined with faecal microbiota of a sub-population of horses, stereotypies came out as the most correlated to blood gene expression. This study shows that aggressiveness towards humans and stereotypies are behavioural indicators that covary with physiological alterations. Further studies are needed regarding the biological correlates of unresponsiveness to the environment and alert postures.

Equine Social Behaviour: Love, War and Tolerance

Sociality is an ethological need of horses that remained unchanged by domestication. Accordingly, it is essential to include horses' social behavioural requirements and the opportunity to establish stable affiliative bonds in equine management systems and welfare assessment. Thus, this systematic review aims to provide an up-to-date analysis of equine intraspecific social ethograms. A literature review yielded 27 papers that met the inclusion criteria by studying adult (≥2 years) equine social behaviour with conspecifics using a well-defined ethogram. Social interactions were observed in 851 horses: 320 (semi-)feral free-ranging, 62 enclosed (semi-)feral and 469 domesticated, living in groups averaging 9.1 (mean +/- 6.8 s.d., range: 2-33) horses. The ethograms detailed in these 27 studies included a total of 40 (mean: 12.8/paper, range: 2-23) social behaviours, of which 60% (24/40) were agonistic, 30% (12/40) affiliative, 7.5% (3/40) investigative and 2.5% (1/40) neutral. The 27 publications included 67.7% agonistic and only 26% affiliative, 5.1% investigative and 1.2% neutral social behaviours in their methodology, thus focusing predominantly on socio-negative interactions. The strong emphasis on agonistic behaviours in equine ethology starkly contrasts with the rare occurrence of agonistic behaviours in stable horse groups and the well-established importance of affiliative interactions for equine welfare. The nuanced and complex equine social behaviour requires refinement of the ethogram with a greater focus on affiliative, ambivalent and indifferent interactions and the role of social tolerance in equine social networks to advance equine welfare assessment.

Horse Housing on Prince Edward Island, Canada: Attitudes and Experiences Related to Keeping Horses Outdoors and in Groups

Limited research has assessed the "human dimension" of horse care. The aims of this study were to (1) understand horse owner attitudes toward horse welfare when kept outdoors versus indoors and in groups versus individually, (2) compare horse owner attitudes toward horse welfare with the ways in which they house their horses, and (3) explore horse owner reasons for and challenges with their horses' housing. Seventy-six horse owners in Prince Edward Island, Canada completed a questionnaire. Non-parametric tests and quantitative content analysis were used for data analysis. Consistent with the way horses were kept, most (82-96%) owners agreed that horses' physical health, mental well-being, and natural living were better when kept outdoors and in groups. Fewer (64-68%) participants agreed that the horses' standard of care was better when kept outdoors or in groups. Results show associations between owners whose attitudes suggest indoor and/or individual housing is better for horse welfare and keeping their horses indoors part-time and/or individually. Two overarching themes were developed from owners' responses regarding their reasons and challenges related to the ways in which horses were housed: horse-centered and owner-centered care. The results indicate that horse owners' choices about their horses' housing correspond to beliefs about improved horse welfare.