Movement Of Horses Research Articles

Bayesian Recursive and Structural Equation Models to Infer Causal Links Among Gait Visual Scores on Campolina Horses.

Gait visual scores are widely applied to horse breeding because they are a fast and easy phenotyping strategy, allowing the numeric interpretation of a complex biological process such as gait quality. However, they may suffer from subjectivity or high environmental influence. We aimed to investigate potential causal relationships among six visual gait scores in Campolina horses. The data included 5475 horses with records for at least one of the following traits: Dissociation (Di), Comfort (C), Style (S), Regularity (R), Development (De), and Gait total Scores (GtS). The pedigree comprised three generations with 14,079 horses in the additive relationship matrix. Under a Bayesian framework, (co)variance components were estimated through a multitrait animal model (MTM). Then, the inductive causation algorithm (IC) was applied to the residual (co)variance matrix samples. The resulting undirected graph from IC was directed in 6 possible causal structures, each fitted by a structural equation model. The final causal structure was chosen based on deviance information criteria (DIC). It was found that S significantly impacts the causal network of gait, directly and indirectly affecting C. The indirect causal effect of S on C was through the direct effect of S on De, then the direct effect of De on R, and finally, the direct effect of R on C. Di was caused by S, which is the reason for the genetic correlation between Di and GtS, due to causal effects being added to the model, they absorb the genetic correlation between Di and GtS. Those paths have biological meaning to horse movements and can help breeders and researchers better understand horses' complex causal network of gait.

Environmental impacts and daily voluntary movement of horses housed in pasture tracks as compared to conventional pasture housing

Pasture tracks are a modern equine housing trend often implemented as a weight control strategy due to the belief that they promote movement, though this is not proven experimentally. To test movement of horses housed in pasture tracks as compared to conventional pasture housing, two experiments were performed using a track (0.2ha, 3.5m in width, 561 m total distance) created around the perimeter of a 2.0 ha pasture. In experiment 1, eight horses were paired and rotated between three treatment locations: track (T), small 2 ha pasture housed within the track (SP), and a larger 20 ha pasture on the same farm (LP). A GPS-equipped watch attached to the crown piece of a halter tracked movement of horses over a ten-week study as they rotated in pairs to each location, with testing in all locations occurring simultaneously. Environmental impacts of housing were evaluated by comparing vegetative biomass and soil relocation throughout the study. In experiment 2, the same horses (n = 8) were rotated in isolated pairs to T or SP, with only one pair of horses tested at a time to ensure that social influences did not confound movement data. Collective results indicate that horses traveled approximately the same distance in T as compared to SP or LP. However, detrimental environmental impacts resulted from the track, including a decrease in vegetative biomass and greater sediment deposition from runoff. Potential environmental impacts should be further investigated to develop best management practices to mitigate erosion caused by pasture tracks.

Analysis of changes in lower limb joints of athletes during the movement of wild horses’ mane parting based on biomechanics

In the era of fitness, more and more young people are familiar with Taijiquan, a kind of physical fitness exercise. By conducting biomechanical analyses of the movements of Taijiquan, it is possible to exercise the body better. Numerous techniques in Taijiquan make it difficult to study each individually. Therefore, this paper studied the movement of “wild horses’ mane parting” in terms of biomechanics by analyzing the joint angle, stiffness, and impulse during this movement. Twenty male athletes were selected as subjects and divided into a professional group and a beginner group according to their training periods. High-speed cameras were used to shoot the “wild horses’ mane parting” movement. The angles of lower limb joints in these athletes were measured to calculate joint impulse and stiffness. The results showed that, compared with the professional group, there were significant differences in the adduction and abduction angle and the internal and external rotation angle between the beginner group and the professional group in the single-leg support movement stage (P< 0.05). There were also significant differences in joint impulse and stiffness (P< 0.05). Compared with beginners, long-term professional practitioners can make their movements more standardized. By comparing movements and data analysis, beginners can make their movements more standardized when practicing Taijiquan and avoid the risk of sports injury. The novelty of this article lies in the use of high-speed cameras to capture athletes’ movements, enabling accurate analyses of their joints and providing effective references for precise training.

Inclined treadmill short-duration exercise for walk regularity of recreation horses

Knowledge on horse symmetry and regularity is essential for every training/rehabilitation programs. Present studies compare biomechanical parameters for different treadmill positions, but not the effect of such exercise. The aim of the presented work was to study recreation horse movement parameters before and immediately after inclined short-duration exercise in walk. The hypothesis was that inclined short-duration exercise gave greater stride regularity and symmetry. Walk biomechanical parameters of 12 Warmblood recreation horses were monitored as temporal data using video analysis [50 frames/s] before and after 5-minute inclined work on a treadmill at 3% incline. Control group (6 horses) consisted from earlier evaluated horses that performed on the other day the same walk exercise without incline. Analysis of variance was conducted for temporal and spatial parameters of walk (237 measurements for incline and 109 for control) using the Mixed SAS procedure. For both data sets the statistical model with the random effect of horse, fixed effects of exercise and successive stride was applied. Control group showed not differences before/after short walk exercise. The influence of inclined exercise was statistically significant for the lateral limbs sequence, regularity and standard deviation of strides regularity (p<0.05). The lateral limbs sequence and regularity increased after inclined exercise (3–5%). The standard deviation of regularity was almost 2-fold lower. Inclined treadmill exercise has a positive effect on walk regularity.

Hippotherapy Used in Medical Recovery

Hippotherapy, also known as equine-assisted therapy, falls into the category of alternative therapies that involve human-horse interaction for therapeutic purposes. Horse therapies are especially used for children with various physical, cognitive, and emotional disorders. They can also be successfully used with adults and the elderly. The horse's movement is what stimulates the development of motor skills, balance, and coordination. Direct interaction with the horse, including caring for it, riding, and other related activities, is effective in developing social, emotional, and cognitive skills in both children and adults, as well as in the elderly. Hippotherapy encourages self-confidence, concentration, and motor coordination, making it suitable for people who are anxious, antisocial, depressed, have language difficulties, or low self-esteem. Studies highlight that the presence of horses changes the frequency of the human brain, with subjects becoming more aware and focused when around horses. Horses help therapy beneficiaries stay connected to the present, becoming more aware of their experiences. Additionally, patients learn to pay more attention to the feelings and nonverbal language transmitted by the being they come into contact with. Numerous studies show that horseback riding improves balance, coordination, and reflexes, induces muscle relaxation, reduces spasticity, increases joint mobility, and improves respiratory function and blood circulation. The main objective of the paper is to identify therapies that use horses for patients diagnosed with various conditions, the benefits of these therapies on patients' motor skills, and their effects on patients' mental state. Additionally, we aim to identify horse-related activities that enhance concentration, help address behavioral issues, and facilitate patients' integration into social groups.

Applying equineRSU and seasonal livestock correction to wider equine stud farm types

ABSTRACT To adjust for potential overestimations in the nitrogen excretion by horses within Overseer®, a revised stock unit system has been proposed (equineRSU). These equineRSU were generated and validated using a medium-sized equine farm as a model farm. The aim of this study was to test the application of the equineRSU and seasonal stock number adjustment on a more complex farming model. Livestock numbers and management data were captured prospectively for the base property (128.8 ha) of a large multi-property commercial breeding stud (3 support properties, 556 ha total area) between June 2022 and May 2023. The monthly on-farm metabolisable energy (ME) requirement and pasture demand were deterministically modelled with both a customised feed budget using livestock class and weight or using the equineRSU and monthly adjusted stock numbers. There were multiple complex movements of horses on and off the property in the different stock classes across the year, with stock management reflecting seasonal periods of high stocking density. There was good agreement (6% variance) between actual ME demand (complex feed budget) and estimated feed demand (simplistic equineRSU model) of 4,387,187 MJ vs 4,102,770 MJ. This suggests that the equineRSU could be used on complex equine farm systems within Overseer®.

Antimicrobial Resistance in Equines: A Growing Threat to Horse Health and Beyond-A Comprehensive Review.

The equine industry holds substantial economic importance not only in the USA but worldwide. The occurrence of various infectious bacterial diseases in horses can lead to severe health issues, economic losses, and restrictions on horse movement and trade. Effective management and control of these diseases are therefore crucial for the growth and sustainability of the equine industry. While antibiotics constitute the primary treatment strategy for any bacterial infections in horses, developing resistance to clinically important antibiotics poses significant challenges to equine health and welfare. The adverse effects of antimicrobial overuse and the escalating threat of resistance underscore the critical importance of antimicrobial stewardship within the equine industry. There is limited information on the epidemiology of antimicrobial-resistant bacterial infections in horses. In this comprehensive review, we focus on the history and types of antimicrobials used in horses and provide recommendations for combating drug-resistant bacterial infections in horses. This review also highlights the epidemiology of antimicrobial resistance (AMR) in horses, emphasizing the public health significance and transmission dynamics between horses and other animals within a One Health framework. By fostering responsible practices and innovative control measures, we can better help the equine industry combat the pressing threat of AMR and thus safeguard equine as well as public health.

Trunk kinematics and limb movement of horses walking backwards and forwards in hand and lifting a single limb

Equine physiotherapy commonly includes basic exercises such as walking backward (BW) and voluntary lifting of single limbs (SLL), but trunk movements during these have not been studied. In order to compare the trunk kinematics during BW and SLL with forward walking (FW), nine horses were measured in FW, BW and during SLL triggered by tactile cue. Kinematics were obtained from skin markers captured by ten high-speed video cameras. Trunk angles were calculated in sagittal and horizontal planes from withers, dorsal to spinous processes of the 16th thoracic vertebra (T16), 2nd and 4th sacral vertebrae (S2, S4), WT16S2 and T16S2S4 respectively. From the hooves, maximum hoof height during swing phase and horizontal distance between hoof and median body plane during swing and stance phases were determined.Dorsoventral range of motion (ROM) and maximum flexion of WT16S2 was significantly larger in BW than in FW, while laterolateral ROM was significantly smaller during hindlimb swing phase in BW and SLL than in FW. In contrast, dorsoventral ROM of T16S2S4 was significantly smaller during stance and swing phases of hindlimbs in BW compared to FW, and throughout the movement. During forelimb swing phase, T16S2S4 ROM was significantly larger in BW than SLL. Hindhoof height in SLL was significantly higher than in FW. Distance between median body plane and hooves was significantly larger in BW than in FW, and significantly larger in BW than in SLL for hindlimb swing phase. In BW, increased lumbosacral stabilisation and the larger area of support created by fore- and hindlimbs may represent a strategy to enhance body stabilisation, as BW entails some insecurity.

Use of a poll-mounted accelerometer for quantification and characterisation of equine trigeminal-mediated headshaking.

Equine trigeminal-mediated (TGM) headshaking (HS) is a neuropathic facial pain syndrome characterised by varying intensity and frequencies of head movements and signs of nasal irritation. An accurate method for quantification and/or characterisation of HS severity is lacking. To develop and validate an objective measure of TGMHS. Prospective case control study. Horses presenting for investigation of HS were recruited alongside those presenting for forelimb lameness (LAME) and pre-purchase examination as well as healthy controls (CONTROL). Head movement data were collected for 5 min whilst trotting on the lunge using a tri-axial accelerometer, with a range of ±16 g and sampling rate of 800 Hz, attached to the bridle headpiece. Recordings were exported for processing. Peak detection was performed using minimum and maximum thresholds of -1 g and +1 g (corrected for gravity) and a minimum peak width of 10 samples. Fifty-six horses were included in the study; 18 TGMHS, 10 non-TGMHS, 12 LAME and 16 CONTROL. Characteristics and frequency of vertical (Z axis) head movements of TGMHS horses differed significantly from other horses. TGMHS horses had peaks with greater mean and maximum positive g-force (P < 0.005) and lower mean and minimum negative g-force (P < 0.001), greater frequency of peaks/min (P < 0.001) and over 12 times greater percentage of peaks >+2 g compared with other horses (P < 0.001). Receiver operator curve characteristics of percentage of peaks >+2 g (CI 0.72-0.95), percentage of peaks <-2 g (CI 0.66-0.92) and percentage of peaks <-2 g and >+2 g (CI 0.72-0.96) showed excellent discrimination of TGMHS horses from LAME, CONTROL and non-TGMHS horses. Referral population of horses, small sample size and control horses were not evaluated for orthopaedic disease. Accelerometer data from trotting exercise on the lunge provides an objective measure of HS and can differentiate between TGMHS, non-TGMHS, normal head movements and those associated with forelimb lameness. Accelerometer use may aid HS diagnosis and monitoring of management strategies.

Changes in trunk postural control with different types of mounts with relevance for hippotherapy

BackgroundHippotherapy uses horseback riding movements for therapeutic purposes. In addition to the horse's movement, the choice of equipment and types of positions are also useful in the intervention. Trunk postural control demands can be manipulated through varying mounting materials and patient positioning on the horse. The quantification of trunk dynamic parameters under the interaction of the different types of riding material and the position variations act upon trunk postural control provides insight into how children with neurotypical development respond to a similar hippotherapy session. This study aimed to evaluate the postural control of the trunk of children with neurotypical development when the riding materials and positioning of the feet and hands support were modified during horse riding. MethodsFifteen children with neurotypical development, aged 6–12 years old, of both sexes, participated in a hippotherapy session. Postural control was measured by the mean amplitudes of oscillation of the lumbar (L5) and thoracic (T5) segments in the mediolateral, anteroposterior and rotational planes with a portable inertial measurement system, in situations using the saddle or blanket, hands resting on the straps or thigh and feet free or supported on the stirrup. ResultsDifferences were observed in lumbar and thoracic oscillation in the mediolateral direction. Values were significantly higher with the use of the blanket when the hands were on the handle and feet in the stirrups, compared to the use of the saddle. When using the blanket and feet positioned in the stirrups, statistical differences with higher values occurred with the hands on the handle compared to the thigh positioning. ConclusionThe use of the blanket equipment associated with the support of the hands on the handles and feet on the stirrups produces greater mediolateral oscillation in the subjects. DescriptorsBalance. Stability. Children. Hippotherapy. Kinematics.

Isotopic biographies reveal horse rearing and trading networks in medieval London.

This paper reports a high-resolution isotopic study of medieval horse mobility, revealing their origins and in-life mobility both regionally and internationally. The animals were found in an unusual horse cemetery site found within the City of Westminster, London, England. Enamel strontium, oxygen, and carbon isotope analysis of 15 individuals provides information about likely place of birth, diet, and mobility during the first approximately 5 years of life. Results show that at least seven horses originated outside of Britain in relatively cold climates, potentially in Scandinavia or the Western Alps. Ancient DNA sexing data indicate no consistent sex-specific mobility patterning, although three of the five females came from exceptionally highly radiogenic regions. Another female with low mobility is suggested to be a sedentary broodmare. Our results provide direct and unprecedented evidence for a variety of horse movement and trading practices in the Middle Ages and highlight the importance of international trade in securing high-quality horses for medieval London elites.

Efficacy of hippotherapy simulator exercise program in patients with stroke: a randomized single-blind clinical trial

ABSTRACT Objectives The aim of this study was to investigate the effect of hippotherapy simulator on balance, postural control, mobility, functional capacity and independence level in people with stroke. Methods This study involved 26 people with stroke aged 18–65, who were randomly assigned to a Hippotherapy Simulator Group (HSG; n = 13) and a Conventional Exercise Group (CEG; n = 13). Patients underwent assessments using the Berg Balance Scale (BBS), Postural Assessment Scale for Stroke (PAS-S), Timed Up and Go Test (TUG), Rivermead Mobility Index (RMI), 2-Minute Walking Test (2-MWT), and Barthel Daily Living Activity Index (BI) to evaluate balance, postural control, mobility, functional capacity, and independence before and after treatment. In the HSG, participants received 30 sessions of conventional exercises and hippotherapy simulator – a mechanical and robotic equipment with a dynamic saddle simulating horse movement – exercises over 6 weeks. Meanwhile, the CEG underwent 30 sessions of conventional exercises alone for 6 weeks. Results In the post-therapy evaluation between groups, BBS (p = 0.004) and 2-MWT (p < 0.001) scores were higher in HSG compared to CEG. However, no statistically significant difference was found between the two groups in terms of PAS-S, RMI, TUG and BI scores (p > 0.05). Statistically significant differences were found between BBS, PAS-S, RMI, TUG, BI and 2-MWT scores before and after treatment in both groups (p < 0.05). Conclusions Hippotherapy simulator can be added to conventional exercises to improve balance and functional capacity in people with stroke.

Cross-Sectional Survey of Horse Owners to Assess Their Knowledge and Use of Biosecurity Practices for Equine Infectious Diseases in the United States.

Horses are transported in the United States more than any other livestock species and co-mingle at various events; therefore, they are considered to be at an increased risk for infectious disease transmission. The fragmented movement of horses combined with numerous sites of co-mingling makes tracing the potential spread of a disease outbreak a necessary part of an infection control plan, both locally and nationally. The cross-movement of personnel with horses and the persistence of endemic diseases make biosecurity implementation an ongoing challenge. Although many of the risks for infection are known, there is limited documentation about the usefulness of prospective control measures. The objective of this survey was to determine horse owners' understanding and knowledge of biosecurity practices for preventing infectious diseases in the United States. Questions covered owner demographic information, including horse use which was divided into 10 categories as follows: Pleasure/Trail Riding, Lessons/School, Western Show, English Show, Breeding, Farm/Ranch, Retired, Racing, Driving and Other. The survey was distributed by sending requests to a list of horse owner organizations, which then sent emails to their members. The email request described the survey and provided a website link to start the survey. A total of 2413 responses were collected. Analysis of the results included cross-tabulation to identify significant differences in biosecurity knowledge and awareness by horse use. Significant differences by horse use were identified for vaccination, biosecurity planning, use of isolation, disease risk, monitoring for diseases, co-mingling of horses, sanitation, medical decision making and health record requirements for horse events. In summary, the results suggest that most owners are not highly concerned about the risk of disease or the use of biosecurity. There are several biosecurity applications and techniques which can be increased and will benefit horse health and welfare. These include reliance on temperature monitoring, isolation of new horses at facilities, risks of horse mingling, entry requirements such as vaccination and health certificates at events, and an emphasis on having biosecurity plans for facilities and events where horses co-mingle. The information from this study will be used to create tools and information that horse owners and veterinarians can use to implement appropriate biosecurity practices for different types of horse uses and events.

Helminthological status of sports and breeding horses exported outside the Russian Federation

Every year a large number of animals are transported across the territory of the Russian Federation. In 2022, the movement of 156,229 heads of horses was recorded. To minimize the risks of spreading infections and invasions, strict veterinary requirements have been developed, including mandatory deworming during quarantine before shipment. The animals must arrive at their destination free of parasitic diseases. The study aimed to find out the possible risks of the spread of helminthiasis of horses with newly imported animals. Horses in transit through the city were examined. Blagoveshchensk from the farms of Central Russia to the country of East Asia. Feces were examined by flotation and larvoscopy methods, followed by determination of the systematic position of parasites. Helminthic invasion was detected in 64.3% of the examined animals with varying intensity. Both widespread helminthiasis of horses (trichonematosis, paraskaridosis) and dangerous diseases that are not registered in horses of equestrian clubs of Blagoveshchensk (alfortiosis, strongylosis, delafondiosis, anoplocephalidosis) have been identified. Taking into account the time of transportation, the duration of action of anthelmintic drugs in the body of horses and the timing of the preimaginal development of various types of helminths, the identification of these diseases indicates poor-quality deworming before transportation from the point of departure. When organizing the movement of horses, more careful control over the organization of the transportation process and compliance with regulatory requirements is needed to ensure the epizootic safety of animals, reduce the risks of spreading infections and invasions in safe territories.

Horse gait analysis using wearable inertial sensors and machine learning

Equestrian sports require horses to possess physical and mental attributes such as agility, strength, balance, and gymnastic skills. Performance analysis is critical in evaluating a horse’s performance, which involves assessing athleticism, gait quality, jumping ability, and general health. Assessing the kinematics of horses is crucial for selecting, training, and managing sports horses. Understanding a horse’s gait pattern and detecting Ground Reaction Forces (GRF) help diagnose lameness in the horse. Traditional gait analysis methods are performed visually, which can be biased due to subjectivity and human error. Optical motion capture (OMC) technology for equine gait analysis is expensive and ideal for indoor use. Wearable inertial measurement units (IMUs) offer a cost-effective alternative for analyzing kinematic parameters. This study has devised novel wearable sensor devices for horses and riders to measure forces acting on the legs and body of the horse and the orientation of their legs during field performance. Ground Reaction Forces (GRF) were measured using 100g accelerometer data from each leg to assist owners and riders in analyzing the magnitude of forces and detecting any anomalies. Machine-learning models were developed to classify horse movements, such as jumps, stands, gallops, and trots, using features extracted from the data collected by wearable sensor devices. These models were compared to identify the most effective model for accurately classifying horse movements. This approach provides a valuable tool for recognizing patterns and trends in the data, enabling owners and riders to make informed decisions about training and management strategies.

International Cross-border Movements of Horses in the State of Rio Grande do Sul - Brazil: Zoonoses, Biosafety, and Biodefense.

There is a growing integration between countries on the same continent in search of solutions to various issues, including food and technology. In this exchange scenario, countries and their populations are exposed to the spread of zoonoses and pathological agents, including bioterrorism. Rio Grande do Sul (RS) actively participates in the foreign trade of horses, and its modes of transport facilitate territorial capillarity. Equine piroplasmosis is a zoonosis that causes several economic losses and poses a danger to the human component involved in the process. At the borders of RS, the movement of horses is significant, in the last five years the movements of approximately one thousand horses have been declared, with the Crioulo and Thoroughbred Horses being the most sought after, due to misuse and smuggling an estimated 50% of these numbers for more. For an effective Biological Defense at the borders of the RS, it would be necessary at least one of the Agricultural Security and Defense Units, in the places with the highest traffic, equipped with laboratories, animal quarantine, and specialized personnel. That would have physical control actions and monitoring and gathering information, which can be performed with other species of animals and plants.

Current and Future Advances in the Detection and Surveillance of Biosecurity-Relevant Equine Bacterial Diseases Using Loop-Mediated Isothermal Amplification (LAMP).

Horses play an important role throughout the world, whether for work, culture, or leisure, providing an ever-growing significant contribution to the economy. The increase in importation and movement of horses, both nationally and internationally, has inevitably allowed for the global equine industry to grow. Subsequently, however, the potential for transmission of fatal equine bacterial diseases has also escalated, and devasting outbreaks continue to occur. To prevent such events, disease surveillance and diagnosis must be heightened throughout the industry. Current common, or "gold-standard" techniques, have shown to be inadequate at times, thus requiring newer technology to impede outbreaks. Loop-mediated isothermal amplification (LAMP) has proven to be a reliable, rapid, and accessible tool in both diagnostics and surveillance. This review will discuss equine bacterial diseases of biosecurity relevance and their current diagnostic approaches, as well as their respective LAMP assay developments. Additionally, we will provide insight regarding newer technology and advancements associated with this technique and their potential use for the outlined diseases.

The effect of acute equine temporomandibular joint inflammation on response to rein-tension and kinematics.

Although the temporomandibular joint (TMJ) is the major contact point between the reins in the riders' hand, the bit in the mouth, and the rest of the horse under saddle, the role of inflammation of this joint on equine locomotion and rein tension is unknown. To determine the effect of acute TMJ inflammation on rein-tension and horse movement when horses were long-reined on a treadmill. A randomized, controlled, cross-over design. Five horses were trained by one clinician to walk and trot on a treadmill wearing long-reining equipment instrumented with a rein-tension device and reflective optical tracking markers. Subjective assessment of horse's dominant side, and movement, were determined without rein-tension (free walk and trot); and with rein-tension (long-reined walk and trot). Continuous rein-force data from both sides were collected over ~60s from each trial. Movement was recorded using a 12-camera optical motion capture system. One randomly assigned TMJ was subsequently injected with lipopolysaccharide and the treadmill tests repeated by investigators blinded to treatment side. A second, identical assessment was performed 10 days later with the opposite TMJ being the target of intervention. All horses showed reduced rein-tension on the injected (inflamed) side. Increased rein-tension was required on the non-injected side at trot, to maintain them in the correct position on the treadmill post-injection. The only kinematic variable to show any significant change due to rein tension or TMJ inflammation during the walk or trot was an increase in forward head tilt in the presence of rein tension in the trot after injection. Low number of horses and investigation of response to acute inflammation only. TMJ inflammation changed, subjectively and objectively, the response to rein-input, but the horses did not become lame.

Prevalence and genetic diversity of Theileria equi from horses in Xinjiang Uygur Autonomous region, China

Theileria equi is a tick-borne intracellular apicomplexan protozoan parasite that causes equine theileriosis (ET). ET is an economically important disease with a worldwide distribution that significantly impacts international horse movement. Horses are an essential part of the economy in Xinjiang which is home to ∼10% of all the horses in China. However, there is very limited information on the prevalence and genetic complexity of T. equi in this region. Blood samples from 302 horses were collected from May to September 2021 in Ili, Xinjiang, and subjected to PCR examination for the presence of T. equi. In addition, a Bayesian latent class model was employed to estimate the true prevalence of T. equi, and a phylogenetic analysis was carried out based on the 18S rRNA gene of T. equi isolates. Seventy-two horses (23.8%) were PCR positive. After accounting for the imperfect PCR test using a Bayesian latent class model, the estimated true prevalence differed considerably between age groups, being 10.8% (95%CrI: 5.8% - 17.9%) in ≤ 3-year-old horses and 35.7% (95%CrI: 28.1% - 44.5%) in horses that were > 3 year-old. All T. equi isolates had their 18S rRNA gene (430bp) sequenced and analyzed in order to identify whether there were multiple genotypes of T. equi in the Xinjiang horse population. All of the 18S rRNA genes clustered into one phylogenetic group, clade E, which is thus probably the dominant genotype of T. equi in Xinjiang, China. To summarize, we monitored the prevalence of T. equi in horses of Xinjiang, China, with a focus on the association between age and the occurrence of T. equi by Bayesian modelling, accompanied by the genotyping of T. equi isolates. Obtaining the information on genotypes and age structure is significant in monitoring the spread of T. equi and studying the factors responsible for the distribution.

102 Influence of localized massage on biobehavioral responses of mature horses during exposure to unfamiliar stimuli

Exposure to unfamiliar stimuli can lead to increased heart rate (HR), an increased incidence of locomotor behaviors, and changes in facial expressions. Responses of horses to unfamiliar stimuli can have important consequences for both horse and human safety. Horses preferentially groom conspecifics along the base of the neck, in front of the shoulder blade and across the withers. Imitated grooming of horses in this location has been shown to decrease horse HR. The objective of this study was to determine if localized massage along the base of the horse's neck and withers would influence HR, behavior, and facial expressions during exposure to an unfamiliar stimulus (cordless hair clippers) Eleven Quarter Horse mares (11.6 ± 4.9 yr) were fitted with a Polar H10 Equine HR monitor and led by the same handler to an open-front, 3.1 × 3.1 m grooming stall in a barn. After a 5 min acclimation period (P1: pre-stimulus), the clippers were turned on and held approximately 30.5 cm from the horse's left ear for a 3 min interval that consisted of: stimulus/pre-massage (45 s; P2), stimulus/massage (90 s; P3) and stimulus/post-massage (45 s; P4). The clippers were then turned off and the horse remained in the stall for 5 min (P5: post-stimulus). HR and video recording occurred throughout the 13 min session. Scan sampling of video footage every 15 s (P1 and P5) or every 5 s (P2-P4) was used to determine counts. Data wereanalyzed using PROC MIXED in SAS v. 9.4. Significant differences in HR, locomotor behaviors, and facial expressions were observed between horses in the study, highlighting the role of individual variation among horses. Although HR decreased once localized massage was initiated, no significant differences were observed in HR during exposure to the stimulus, with or without localized massage, compared with the pre- and post-stimulus periods. No differences were observed in the movement of horses’ front feet during exposure to the clippers; however, horses moved their hind feet more frequently during exposure to the clippers once the localized massage stopped (P < 0.05). Although the frequency of ears facing the same or different directions in a relaxed position was greater when localized massage was performed during exposure to the unfamiliar stimuli (P < 0.01), no differences were observed in nostril dilation, inner brow movements, or eye white increase during exposure to the stimuli compared with the pre- and post-stimulus periods. Localized massage may reduce stress-related behaviors during exposure of horses to unfamiliar stimuli; however, more research in this area is needed