Individual Horses Research Articles

Description and Analysis of Horse Swimming Strategies in a U-Shaped Pool.

Aquatic training has been integrated into equine rehabilitation and training programs for several decades. While the cardiovascular effects of this training have been explored in previous studies, limited research exists on the locomotor patterns exhibited during the swimming cycle. This study aimed to analyze three distinct swimming strategies, identified by veterinarians, based on the propulsion phases of each limb: (S1) two-beat cycle with lateral overlap, (S2) two-beat cycle with diagonal overlap, and (S3) four-beat cycle. 125 underwater videos from eleven horses accustomed to swimming were examined to quantify the differences in locomotor patterns between these strategies. Initially, a classifier was developed to categorize 125 video segments into four groups (CatA to CatD). The results demonstrated that these categories correspond to specific swimming strategies, with CatA aligning with S1, CatB with S2, and CatC and CatD representing variations of S3. This classification highlights that two key parameters, lateral and diagonal ratios, are indeed effective in distinguishing between the different swimming strategies. Additionally, coordination patterns were analyzed in relation to these swimming strategies. One of the primary findings is the variability in swimming strategies both within and between individual horses. While five horses consistently maintained the same strategy throughout their swimming sessions, six others exhibited variations in their strategy between laps. This suggests that factors such as swimming direction, pauses between laps, and fatigue may influence the selection of swimming strategy. This study offers new insights into the locomotor patterns of horses during aquatic training and has implications for enhancing the design of rehabilitation protocols.

Applying Multi-Purpose Commercial Inertial Sensors for Monitoring Equine Locomotion in Equestrian Training.

Inappropriate, excessive, or overly strenuous training of sport horses can result in long-term injury, including the premature cessation of a horse's sporting career. As a countermeasure, this study demonstrates the easy implementation of a biomechanical load monitoring system consisting of five commercial, multi-purpose inertial sensor units non-invasively attached to the horse's distal limbs and trunk. From the data obtained, specific parameters for evaluating gait and limb loads are derived, providing the basis for objective exercise load management and successful injury prevention. Applied under routine in-the-field training conditions, our pilot study results show that tri-axial peak impact limb load increases progressively from walk to trot to canter, in analogy to stride frequency. While stance and swing phases shorten systematically with increasing riding speed across subjects, longitudinal and lateral load asymmetry are affected by gait at an individual level, revealing considerable variability between and within individual horses. This individualized, everyday approach facilitates gaining valuable insights into specific training effects and responses to changing environmental factors in competitive sport horses. It promises to be of great value in optimizing exercise management in equestrian sports to benefit animal welfare and long-term health in the future.

Quantitative DNA metabarcoding reveals species composition of a macrocyclic lactone and pyrantel resistant cyathostomin population in the UK.

Cyathostomins are the most abundant equid endoparasites globally. There are approximately fifty cyathostomin species and, whilst they occupy distinct niches within the large intestine, they are generally considered to share similar characteristics in terms of pathogenicity and response to drug treatment. There are three classes of anthelmintic licensed in the UK to treat cyathostomins (benzimidazoles, tetrahydropyrimidines and macrocyclic lactones) and cases of resistance have been documented for all classes. Previously, faecal egg count reduction tests (FECRT) on four UK Thoroughbred studs revealed multidrug resistant cyathostomins on one stud (A), with evidence of resistance to the macrocyclic lactones (MLs) ivermectin (IVM) and moxidectin (MOX), and to pyrantel (PYR). The remaining three studs (B-D) lacked resistance to IVM and MOX but had a shortened egg reappearance period post treatment. To determine whether specific species could be associated with the observed resistance and shortened egg reappearance period, strongyle eggs collected from between six and 15 individual horses per stud were copro-cultured to third larval stage (L3), before and after anthelmintic treatment, over a three-year timeframe (2021-2023). Quantitative DNA metabarcoding of the ITS-2 region was carried out on all samples. On stud A, single but differing species were found to be responsible for ML and pyrantel resistance in yearlings, Cyathostomum catinatum and Cylicocyclus nassatus, respectively. On studs B-D, with shortened egg reappearance periods, species composition remained largely unchanged post treatment. This study is the first to quantitatively profile cyathostomin species composition pre- and post-treatment in a multidrug resistant population in the UK, revealing that resistance in cyathostomins was species specific. This raises the question of whether these species may be responsible for ML and PYR resistance more widely and indicates that anthelmintic resistance in cyathostomins may not be a multi-species phenomenon.

A blinded crossover study design to evaluate midazolam as an adjunct for equine standing sedation for routine oral examinations

This study aimed to evaluate the effects of including midazolam to a common equine standing sedation protocol for routine oral examination. Twelve horses underwent two examinations at least seven days apart. Horses were randomly assigned to receive midazolam intravenously (IV) (0.02mg/kg) or a placebo injection of saline (2-2.5mL IV). Five minutes later, detomidine (0.01mg/kg) and butorphanol (0.01mg/kg) were administered IV and horses were placed in standing stocks. A veterinarian blinded to the treatment protocol used a descriptive scoring system to assess degree of ataxia, acceptance of speculum, chewing on the speculum, headshaking, tongue movement, resistance to palpation, and eye appearance as related to the grimace score. During each examination, additional sedation of IV detomidine (0.006mg/kg) and butorphanol (0.006mg/kg) was administered at the discretion of the blinded practitioner to facilitate safe examination. At the second examination horses received the opposite treatment protocol and, following examination, a routine occlusal adjustment. Scores were compared using JMP software with a repeated measures mixed effects model, treatment as a fixed effect and horse and horse/treatment interaction as random effects. Significance was set at P<0.05. There were no significant differences in any of the single or overall sedation scores between treatment groups or within individual horses (P=0.3). Trends towards improvement of some assessed characteristics of sedation, including decreased tongue movement and less resistance to acceptance of speculum were observed. The use of midazolam may prove beneficial for routine oral examination, as well as other standing procedures, with no obvious undesired side effects.

55 Establishing grain-based modified protocols for re-feeding malnourished horses

Abstract Increased feed costs, forage availability, and the increasing number of malnourished horses present major challenges to the equine industry. The goal of this project was to test an adapted refeeding protocol using Bermuda hay and two commercial grain products in severely malnourished horses. So, an 8-wk study from January to March 2023 was conducted to evaluate the effects of Total Equine in the refeeding of 10 emaciated horses. Horses were previously destined for slaughter and purchased from an auction with an average body condition score (BCS) of 2.01 (S.D. ± 0.69), then quarantined for 30 d before starting the study following recommended biosecurity protocols. During quarantine, horses were evaluated by a veterinarian and received treatment as needed, vaccinations, deworming, and mares were pregnancy checked. All horses were provided with ad libitum Bermuda hay and water. Upon completion of the quarantine period, horses were blocked into two groups based on age, BCS, pregnancy status, and gender and randomly assigned to a diet. The Control (Ctrl) diet consisted of a commercial grain diet recommended and used by five local West Texas horse rescue groups and the Treatment (Trt) diet consisted of Total Equine. Both diets included ad libitum access to water and Bermuda hay (TDN 56.5) offered twice daily in port-a-grazer tubs to control waste and the amount was adjusted daily to maintain a 3% refusal rate. Grain was offered at a rate of 0.005% BW + 227 kg per the manufacturer’s suggestion, divided into 2 equal feedings with amounts adjusted weekly. Individual horses were weighed weekly using an electronic scale and BCS was evaluated at wk 0, 4, and 8. All horses were allowed a 1-h turnout in a dry-pen per day for 6 d each week. Blood samples were collected at wk 0, 4, and 8 for analysis. Health parameters were measured weekly throughout the study. Samples (grain, hay, hay orts) were collected twice weekly for DM, NDF, ADF, EE, CP, and Ash analysis. Data was analyzed using Proc Mixed in SAS. Overall, there was no significant difference between DMI by diet (Ctrl 8.74 kg/d and Trt 9.44 kg/d). However, a tendency for increased ADG (P = 0.06) for the Trt diet (Ctrl 0.20 kg/d &amp; Trt 1.34 kg/d) was noted. Efficiency calculated as (ADG/DMI) was significantly improved (P = 0.04) indicating an improvement in the efficiency of BW gain for the Trt diet compared with the Ctrl. Improved BW gain and efficiency of gain are of interest when rehabilitating malnourished horses. The establishment of accessible modified feeding protocols may improve efficiency and reduce the cost involved in the rehabilitation of malnourished horses and would be a step forward for the equine industry.

145 Utilization of 16s sequencing data and physiological measurements to produce a comparative analysis of the equine microbiome

Abstract Rapid advancements in microbiome research, particularly in the technologies associated with next-generation sequencing have enabled unprecedented investigations into the composition of the equine microbiome. The large datasets produced from these studies often present challenges to researchers seeking to understand the applicability of these data to equine physiology. To that end, a multi-year project was conducted with the goal of determining the core bacterial population of the equine hindgut through analysis of rectal swabs collected from thousands of horses and applying logic to the association between these ecologies and equine health. Samples were obtained from horses that varied across a diverse range of considerations including location, breed, age, and diet, amongst other metadata points including disease state, health history, vaccination and deworming status, body condition, and pregnancy status. These data were used in the development of a comparative score, that authors defined as the Microbiome Quotient (MQ score). Rectal swabs were collected, and DNA was extracted using the Quick-DNA Fecal/Soil Microbe Miniprep kit (Zymo Research, Irvine, CA) and the V3-V4 hypervariable region of the 16S rRNA gene was sequenced by following the Illumina 16S Protocol (San Diego, CA). Sequences were denoised using DADA2 within the QIIME2 pipeline to obtain amplicon sequence variant composition. These data were filtered again in R (4.2.2) to remove samples with missing data and low sequencing depth. Sample metadata was used to classify samples as either typical or atypical. The MQ score was calculated by computing the Euclidean distance difference between a sample and the centroids representing typical and atypical microbial ecologies, and then subtracting these distances to obtain the individual score. This score quantifies how similar the microbiome in a sample is to those of typical and atypical horses. These scores were then categorized into tertiles, representing the status of the individual horse’s microbiome. These statuses indicate differences in bacterial ecology among samples and their subsequent relevance to the health of the horse. While a large portion of the equine fecal microbiome is conserved through homeostatic and other mechanisms, there remains a high degree of variability in the lesser abundant genera that may be responsible for the different physiological interactions between the microbes and their hosts. Utilizing this MQ score, feeding and management recommendations can be made, providing veterinarians and horse owners with a tool to support the health and performance of horses through modulation of the bacterial population and its functionality. Further research is necessary to fully elucidate the impact of the various metadata components on the bacterial ecology. Additionally, the function of the metagenome is a critical component of microbiome sciences. Prediction of metagenomic function is likely to provide insight into the regulation of physiological function by the microbial population residing within the host.

Whole-genome sequencing of Ganzi horse reveals the genetic diversity and provides unique insights into its plateau adaptation

Ganzi horse is distributed in the Ganzi Tibetan Autonomous Prefecture. As we all know, this region on the southeast of the Tibetan Plateau is characterized by low oxygen levels, low atmospheric pressure, and intense ultraviolet light. The extreme environment causes the genomic variation of plateau animals for environmental adaptation. At present, the genetic diversity and the genetic basis of high-altitude adaptation of Ganzi horses remain unclear. Here, an extensive genetic analysis was conducted utilizing whole-genome sequencing data from 145 individual horses. The analysis of autosomal genetic diversity confirmed that Ganzi horses had experienced low intensity artificial selection and had high genetic diversity. Examination of mitochondrial DNA information from whole-genome sequencing data revealed multiple maternal origins for Ganzi horses. Further, four different selective scanning methods were used to identify positive selected genomic regions and genes associated with high-altitude adaptation. We identified genes associated with altitude adaptation at selection windows in Ganzi horses, such as EPAS1, ABTB2, RHOQ, and TMEM247. Notably, EPAS1 and OR52A1J gene exhibited high select signal values, different nucleotide diversities, and haplotype patterns, and missense mutations in EPAS1 (A > T) and OR52A1J (C > T) were found to be more frequent in high-altitude horses. Moreover, our research illuminated significant gene flow between Ganzi and Chaidamu horses, which may be related to the formation of Ganzi horses. In general, these findings not only enhance our understanding of this unique native breed but also further our understanding of Ganzi horse's high-altitude adaptation.

Prevalence and Sequence Analysis of Equine Rhinitis Viruses among Horses in Poland.

Equine rhinitis A (ERAV) and B (ERBV) viruses are respiratory pathogens with worldwide distribution. The current study aimed to determine the frequency of infection of ERAV and ERBV among horses and foals at Polish national studs, and to determine genetic variability within the viruses obtained. Virus-specific quantitative RT-PCR assays targeting a 5' untranslated region were used to screen nasal swabs collected from 621 horses at 16 national horse studs from throughout Poland, including 553 healthy horses and 68 horses with respiratory disease. A partial DNA polymerase gene was amplified and sequenced from the qRT-PCR-positive samples. The obtained sequences were analysed using phylogeny and genetic network analysis. None of the nasal swabs were positive for ERAV, whereas ERBV was found in 11/621 (1.78%) samples collected from 10 healthy horses and one foal affected by respiratory disease. Partial DNA polymerase gene sequence variability was correlated with individual horses and studs from which samples were collected when only Polish sequences were analysed, but there was no correlation between country of origin and ERBV sequence when Polish and international sequences were included in the network. The report presents the first detection of ERBV in Poland.

Single injection of intra-articular autologous protein solution in horses with acute interleukin-1B-induced synovitis decreases joint pathology scores.

Autologous protein solution (APS) has been shown to decrease lameness in horses with osteoarthritis (OA). Synovitis is an early driver of OA, providing an opportunity to intervene in the progression of disease via intra-articular (IA) therapeutics. The objective of this study was to investigate the effects of a single IA APS injection in horses with interleukin-1β (IL-1β)-induced synovitis. We hypothesised that APS would decrease joint swelling and lameness, improve synovial fluid parameters and improve joint pathology scores in horses compared with untreated controls. Randomised controlled in vivo experiment. Synovitis was induced with IL-1β (65 ng) in one randomly selected tarsocrural joint. Twenty-four hours later, joints were treated with APS (Pro-Stride®) (n = 12) or left as untreated controls (n = 6). Lameness examinations and joint circumference measurements were performed on Days 0 (prior to IL-1β), 1 (prior to APS), 2, 4, 7 and 14. Synovial fluid, obtained on the same days, was analysed for protein concentration, nucleated cell count, and cytokine (IL-1β, TNF-α, IFN-γ, IL-6, IL-10) and prostaglandin E2 (PGE2) concentrations. Gross pathology and synovial membrane histopathology scoring was performed on APS-treated (n = 5), untreated control (n = 4) and normal (n = 9) tarsocrural joints. APS did not decrease lameness or joint circumference compared with untreated controls. Synovial fluid parameters were not different between treatment groups. APS treatment did significantly decrease gross and histopathology scores. Main limitations included the use of an induced model of the synovitis, inter-horse variability in the response to IL-1β and likely variability in the constituents of APS from individual horses. APS treatment of tarsocrural joints with synovitis did not significantly improve lameness or alter synovial fluid parameters. APS did lead to significant improvement in gross joint appearance and synovial membrane histology suggesting that APS may have disease-modifying effects.

First report of Equine Parvovirus-Hepatitis (EqPV-H) in Argentina

The novel Equine Parvovirus-Hepatitis (EqPV-H) was first identified in the serum and liver of a horse that died of equine serum hepatitis, also known as Theiler's disease. Several reports in recent years strongly suggest that EqPV-H is the etiologic agent of Theiler's disease. Brazil is the only South American country where infection with this virus has been reported. This study investigated the presence of EqPV-H DNA in horse serum pools (n=51), commercial horse serum batches (n=5) and individual serum samples from donor horses (n=175) from Argentina. All serum samples were analyzed by quantitative polymerase chain reaction (qPCR) and samples with positive or indeterminate results were further analyzed by NS1 nested-PCR for phylogenetic studies.None of the serum pools was positive by qPCR but 9/51 pools were indeterminate (one or both test sample’s Ct values were higher than the limit of detection). The NS1 nested-PCR detected the EqPV-H DNA in 8 of these indeterminate samples (15.7 % of serum pools). Three of the commercial horse serum batches (60 %) contained EqPV-H DNA, detected either by qPCR and/or nested-PCR. From the 175 individual horse serum samples, three (1.71 %) were positive for EqPV-H by both techniques. The genetic analysis of the 12 partial NS1 sequences obtained showed that the local isolates were similar to EqPV-H sequences from Germany and China. This study provides the first evidence of the presence of EqPV-H in horses and in horse sera commercially available in Argentina and emphasizes the importance of controlling the biosecurity of commercial equine sera as well as any other blood-derived biological products of equine origin. Data availabilityViral sequences generated in this study were uploaded to the NCBI nucleotide database and are available with the accession numbers PP408676-PP408687.

Assessment of fecal bacterial viability and diversity in fresh and frozen fecal microbiota transplant (FMT) product in horses

BackgroundCurrently, lack of standardization for fecal microbiota transplantation (FMT) in equine practice has resulted in highly variable techniques, and there is no data on the bacterial metabolic activity or viability of the administered product. The objectives of this study were to compare the total and potentially metabolically active bacterial populations in equine FMT, and assess the effect of different frozen storage times, buffers, and temperatures on an equine FMT product. Fresh feces collected from three healthy adult horses was subjected to different storage methods. This included different preservation solutions (saline plus glycerol or saline only), temperature (-20 °C or -80 °C), and time (fresh, 30, 60, or 90 days). Samples underwent DNA extraction to assess total bacterial populations (both live and dead combined) and RNA extraction followed by reverse transcription to cDNA as a proxy to assess viable bacteria, then 16s rRNA gene amplicon sequencing using the V1-V2 region.ResultsThe largest difference in population indices and taxonomic composition at the genus level was seen when evaluating the results of DNA-based (total) and cDNA-based (potentially metabolically active) extraction method. At the community level, alpha diversity (observed species, Shannon diversity) was significantly decreased in frozen samples for DNA-based analysis (P < 0.05), with less difference seen for cDNA-based sequencing. Using DNA-based analysis, length of storage had a significant impact (P < 0.05) on the bacterial community profiles. For potentially metabolically active populations, storage overall had less of an effect on the bacterial community composition, with a significant effect of buffer (P < 0.05). Individual horse had the most significant effect within both DNA and cDNA bacterial communities.ConclusionsFrozen storage of equine FMT material can preserve potentially metabolically active bacteria of the equine fecal microbiome, with saline plus glycerol preservation more effective than saline alone. Larger studies are needed to determine if these findings apply to other individual horses. The ability to freeze FMT material for use in equine patients could allow for easier clinical use of fecal transplant in horses with disturbances in their intestinal microbiome.

Investigation of the Use of Environmental Samples for the Detection of EHV-1 in the Stalls of Subclinical Shedders.

In populations of healthy show horses, the subclinical transmission and circulation of respiratory pathogens can lead to disease outbreaks. Due to recent outbreaks of equine herpesvirus-1 myeloencephalopathy (EHM) in the USA and Europe, many show organizers have instituted various biosecurity protocols such as individual horse testing, monitoring for early clinical disease and increasing hygiene and cleanliness protocols. The aim of this study was to determine the accuracy of detecting EHV-1 in the various environmental samples collected from the stalls of subclinical shedders. Four healthy adult horses were vaccinated intranasally with a modified-live EHV-1 vaccine in order to mimic subclinical shedding. Three additional horses served as non-vaccinated controls. All the horses were stabled in the same barn in individual stalls. Each vaccinated horse had nose-to-nose contact with at least one other horse. Prior to the vaccine administration, and daily thereafter for 10 days, various samples were collected, including a 6" rayon-tipped nasal swab, an environmental sponge, a cloth strip placed above the automatic waterer and an air sample. The various samples were processed for nucleic acid purification and analyzed for the presence of EHV-1 via quantitative PCR (qPCR). EHV-1 in nasal secretions was only detected in the vaccinated horses for 1-2 days post-vaccine administration. The environmental sponges tested EHV-1 qPCR-positive for 2-5 days (median 3.5 days) in the vaccinated horses and 1 day for a single control horse. EHV-1 was detected by qPCR in stall strips from three out of four vaccinated horses and from two out of three controls for only one day. EHV-1 qPCR-positive air samples were only detected in three out of four vaccinated horses for one single day. For the vaccinated horses, a total of 25% of the nasal swabs, 35% of the environmental stall sponges, 7.5% of the strips and 7.5% of the air samples tested qPCR positive for EHV-1 during the 10 study days. When monitoring the subclinical EHV-1 shedders, the collection and testing of the environmental sponges were able to detect EHV-1 in the environment with greater frequency as compared to nasal swabs, stationary strips and air samples.

Composition and diversity of 16S rRNA based skin bacterial microbiome in healthy horses

Characterization of microbiota structure on the skin of healthy horses is important for further development of modulation strategies to ensure optimal bacterial composition for physiological processes. This requirement is also supported by the relatively high incidence of dermatological diseases in horses and thus the need to manage them therapeutically. The taxonomic analysis of skin samples (n = 30) from five different body parts of clinically healthy Shetlands ponies females (neck, back, abdomen, pastern, muzzle) kept under homogeneous conditions (in open stalls with paddock, feed with dry hay, green grass ad libitum and granulated feed) was performed using amplification of V3—V4 region of the 16S rRNA gene. Results indicate that bacteria associated with healthy equine skin represent 18 phyla, 29 classes and 119 families. The most abundant phyla were Proteobacteria (30.8 ± 9.1%) followed by Actinobacteriota (20.4 ± 7.6%), Firmicutes (19.5 ± 10.1%), Bacteroidota (8.5 ± 5.0%) and Deinococcota (7.2 ± 14.8%). Among 229 genera identified, Corynebacterium (7.4 ± 6.5%) was the most abundant genus in skin sites of horses, followed by Deinococcus (7.1 ± 14.9%) and Macrococcus (5.0 ± 8.2%). Indices for the richness and diversity of species within bacterial populations for five regions of horses skin revealed no significant variations observed for species richness (Chao1, p-value 0.2001) but significant result for species evenness (Shannon, p-value 0.0049) with maximum on the neck and minimum on the back skin site. The clustering was seen across samples from different skin sites but also across samples collected from individual horses.

Becoming a matter of veterinary concern.

Horses in Great Britain are living into increasingly older age and are often regarded as friends or family members by their owner. The horse is reliant on their owner to meet their needs and this paper discusses how horse owners frame an issue that becomes a matter of veterinary concern within the context of the older horse. Qualitative methods were used to explore the experiences of owners and veterinarians. Data were collected and analysed using a grounded theory approach during the period 2019-2022. Analysis identified that owners undertook an ongoing and iterative process of assessment, monitoring and decision making in relation to the animal and any changes they observed. Matters that became a veterinary concern required the owner to formulate the issue as something that fell within the knowledge domain of the veterinarian. Veterinarians had a medicalised view of older horse health and their perspectives on socially acceptable care were shaped by their understanding of species-specific needs, and whether owners were providing appropriately for those needs. The formulation of a matter of veterinary concern was itself shaped by an owner's experiential knowledge of both veterinary matters and their horse. The extent to which owners felt like they and their individual horse mattered during interactions with veterinarians affected whether they adopted veterinary advice and the nature of future veterinary employment. Findings demonstrate how matters of health, disease, and the role of professionalised forms of medical knowledge, are not static but constantly changing and interacting over time. An issue that became a matter of veterinary concern was contextual, and rooted in individual relationships. The significance of veterinarian-owner interactions in shaping future consumption of veterinary health care may be underestimated.

Emotional Natives: The Role of Prey-Animal Ontologies in Equine-Assisted Personal Development

Abstract In the psychological literature on the efficacy of equine-assisted therapies, it is common to read that horses are suitable for such work because of their evolutionary inheritance as “prey-animals,” making them highly attuned to the emotional states of others. Yet this assertion is rarely questioned. This article explores prey-animal ontologies within an ethnographic study of an Equine-Assisted Personal Development (EAPD) center in England, and how they helped facilitate client interpretations of individual horse behaviors. I argue that in this EAPD, prey-animal ontologies constructed horses as highly skilled “emotional natives” with significant, almost deistic powers. In some ways this was progressively relational. However, in other ways, it inscribed a problematic anthropocentrism, with the horse conceived as almost permanently in response to human agency. Moreover, it was sometimes empirically difficult to sustain. Prey-animality, then, in EAPD, both challenges and reinforces human power relations with horses in complex ways.

Comparison of Reported Fatalities, Falls and Injuries in Thoroughbred Horse Jumps and Flat Races in the 2022 and 2023 Jumps Race Seasons in Victoria, Australia.

Jumps racing is a form of Thoroughbred horse racing that involves hurdles and steeples and typically longer distances, and heavier weights compared with flat racing, which does not incorporate obstacles. In Australia, jumps racing is carried out only in Victoria, one of eight states and territories. The continuation of jumps racing is contentious due to the higher risk of fatalities, falls and injuries for horses, compared with flat racing. While measures have been introduced by the industry to improve the safety of riders and horses, the rates of fatalities, falls and injuries in horses participating in jumps races have not been collectively reported in Australia since the 2012 to 2014 race seasons. Although information on individual horse fatalities, falls and injuries is published by Racing Victoria in Stewards' Reports, the data are not aggregated, and so cannot readily be used to assess trends or evaluate the efficacy of safety measures introduced by the industry. The aim of this study was to determine the fatality, fall and injury rates for horses participating in hurdle and steeplechase races in Victoria in the 2022 and 2023 Thoroughbred horse jumps racing seasons compared with horses participating in flat races at the same race meets. Data on horse fatalities, falls and injuries were extracted from the published Racing Victoria race results and Stewards' Reports for the jumps races (n = 150) and corresponding flat races (n = 157) held at the 38 jumps race meets in Victoria in 2022 and 2023. Overall, horse fatalities, falls and injuries occurred at higher rates in jumps races compared with flat races during the study period. The rate of horse fatalities in jumps races was 3.3 per 1000 starts, with no fatalities in flat races. The rate of horse falls in hurdle races was 24 per 1000 starts and 41.6 per 1000 starts in steeplechase races, comparable with rates previously reported in the 2012 to 2014 seasons. There were no falls in flat races. Horse injuries occurred at a rate of 68.9 per 1000 starts in jumps races compared with 18.8 per 1000 starts in flat races. In hurdle and steeplechase races, veterinary clearance being required following horse injury was 5.4 times (OR 5.4, 95% CI 2.8-10.2) and 7.2 times (OR 7.2, 95% CI 3.3-15.6) more likely, respectively, compared with flat races. The risk of trauma was 4 times more likely in hurdle and steeplechase races (OR 4.8, 95% CI 1.7-13.3 and OR 4.1, 95% CI 1.2-13.4, respectively) and the risk of lameness was increased by 2.5 times in hurdles (OR 2.5, 95% CI 1.2-5.2) and 5.1 times in steeplechase races (OR 5.1, 95% CI 2.3-11.5), compared with flat races. These findings support concerns about the welfare of horses involved in jumps racing and of the need for further safety measures to reduce these risks.

Mitigation of effects of heat and humidity at Tokyo 2020 Olympic Summer Games equestrian events

Abstract The physiological challenge of Tokyo 2020, the XXXII Olympic Summer Games held in July-August 2021, was adaptation to training and competing in the subtropical summer weather conditions. Dressage, Eventing, and Jumping horses (n = 248) arrived at 05:00-06:30 h on six European and two Australian overnight chartered flights 8-to-10 days prior to beginning competition. All horses were housed at Japan Racing Association Equestrian Park in Bagi Koen. Eventing Cross Country was held an hour’s drive away at Sea Forest. All stables and conveyances were air-conditioned. Cooling stations were available at both venues and consisted of tall arched tents with large containers of water chilled to ≤15 °C, cooling/misting fans, and rubberised flooring for traction safety. Training hours began at 06:00 h daily with a mandatory mid-day break between 11:00 and 15:00-16:00 h when arenas were re-opened until 22:00. Daytime temperatures ranged 28.8-36.8 °C and peak humidity remained high throughout the Games (58-97%). There were no heat-related illnesses in horses observed by clinic veterinarians who were present at all training and competition rings whenever horses were exercising. Individual horses received elective intravenous fluids (10 litre minimum) on arrival in Japan, after cross country, and/or before departure. Reported ailments included post-transport pneumonia, exercise-induced pulmonary haemorrhage, orthopaedic injury, laceration, impaction colic, acute piroplasmosis, and laminitis. A persistent brisk westerly wind began nightly around 17:00 h, making evening competition sessions cooler than daytime training sessions. It was concluded that safe competitions were held despite persistently elevated subtropical ambient heat and humidity conditions.

BEVA primary care clinical guidelines: Equine parasite control.

There is a lack of consensus on how best to balance our need to minimise the risk of parasite-associated disease in the individual horse, with the need to limit the use of anthelmintics in the population to preserve their efficacy through delaying further development of resistance. To develop evidence-based guidelines utilising a modified GRADE framework. A panel of veterinary scientists with relevant expertise and experience was convened. Relevant research questions were identified and developed with associated search terms being defined. Evidence in the veterinary literature was evaluated using the GRADE evidence-to-decision framework. Literature searches were performed utilising CAB abstracts and PubMed. Where there was insufficient evidence to answer the research question the panel developed practical guidance based on their collective knowledge and experience. Search results are presented, and recommendation or practical guidance were made in response to 37 clinically relevant questions relating to the use of anthelmintics in horses. There was insufficient evidence to answer many of the questions with any degree of certainty and practical guidance frequently had to be based upon extrapolation of relevant information and the panel members' collective experience and opinions. Equine parasite control practices and current recommendations have a weak evidence base. These guidelines highlight changes in equine parasite control that should be considered to reduce the threat of parasite-associated disease and delay the development of further anthelmintic resistance.

A cross-sectional survey to describe practices associated with retraining and rehoming of former racehorses in Great Britain

The fate of Thoroughbred racehorses leaving the horseracing industry is one of the primary public concerns about the sport. A Thoroughbred’s racing career typically represents only a small fraction of their potential lifespan. Rehabilitating and retraining former racehorses for post-racing careers in the non-racing equestrian sector is a key strategic focus of many racing jurisdictions globally. In Great Britain, the racehorse aftercare sector is highly fragmented and currently unregulated. This study aimed to improve understanding of the aftercare sector for former racehorses in Great Britain. An online cross-sectional survey of individuals and organisations located in Great Britain and involved in retraining, rehoming and/or selling former racehorses was conducted (n=57). Respondents had spent a median of 10 (IQR 5–20) years retraining, rehoming/selling former racehorses. Responses highlighted the considerable variation in practices within this sector, particularly in how respondents described themselves and their work with former racehorses. An individual horse’s circumstances and their specific requirements informed decisions taken around rehabilitation, retraining and rehoming/selling; 61% of respondents had had former racehorses that they were unable to rehome/sell. Most respondents in this study worked with small numbers of former racehorses on the side of their main focus of employment, typically taking a tailored approach to suit each individual horse they worked with. While the lack of standardisation has reportedly been a concern of the racing industry, it is possible that such a tailored approach is advantageous for the individual horses involved, providing them the best opportunity to succeed in a career outside of racing.

Rein tensions and behaviour with five rein types in international-level vaulting horses.

Health and performance of vaulting horses cantering with reins might be affected by rein tensions. The primary aim of this present study was to measure rein and lunge line tensions in international-level vaulting horses with several types of reins adjusted in accordance with the requirements of the FEI Vaulting Rules and study the effect of reins types on it. The secondary aim was to evaluate behavioural signs of discomfort under the same conditions and study the effect of reins types on it. The relationship between tensions and behavioural signs of discomfort was then explored. Thirty-nine international-level vaulting horses took part in this study and tested side reins either with an elastic part, all elastic or without elastic, draw reins with an upper adjustment triangle and side reins fixed on the noseband. Tensions of the left and right reins and the lunge line were measured with sensors at a rate of 80 Hz for a canter of 1min30 on a 15-meter circle, without a vaulter, and behavioural analyses (on the locomotion, tail, head, mouth and ears movements) were performed using video filmed by a camera attached to the lunger's chest. Mixed models revealed that the Root mean square (RMS) of the tensions of the left and right reins, of the total, as well as the lunge line, were significantly influenced by rein type (p<0.001) in all cases). Total RMS tension ranged from 6.2 kg to 11.7 kg with a right RMS tension superior to left RMS (p < 0.001). When tension was high, mouth opening increased (p = 0.007). It was with draw reins that total tension (p < 0.05) and mouth openings were lower (p = 0.005), even if a high proportion of variance of these discomfort behaviours could be explained by the individual horse.