Identification Of Horses Research Articles

82 Relationships between performance traits and osteochondrosis of the hock in Standardbred racehorses

Abstract Equine osteochondrosis (OC) is a developmental orthopedic disease that results in abnormal articular cartilage and often the formation of osteochondral bone chips (osteochondrosis dissecans). Standardbreds, a breed predominately used in harness racing, are prone to the development of OC. This study aimed to quantify the relationship between OC and key performance traits, fastest mile time, annual earnings, and consistency in race times over career, using a cohort of 347 North American Standardbred horses. Radiographic examination of the tarsi was previously performed to identify horses as OC-affected (n = 155) or healthy (n = 192). Performance data was acquired from the United States Trotting Association (USTA) detailing horse identification, performance, and lifetime race record. Linear mixed multiple regression models were constructed to evaluate the relationship between OC and performance. A total of 24 performance related variables (e.g., age, gait, track) were evaluated for inclusion in the model through subset variable selection and goodness of fit as determined by Schwarz’s Bayesian Information Criterion (SBC). Preliminary results indicate that healthy horses exhibit significantly faster mile times (P < 0.001) compared with their OC-affected counterparts. However, no significant association was detected between OC status and annual earnings (P > 0.2) or consistency in race times over career (P > 0.2). Ongoing analyses are currently being conducted to assess additional predictors and performance variables for a potential association with osteochondrosis. This study emphasizes the importance of implementing effective strategies for OC management and improving breeding selection practices when producing offspring with desired performance characteristics.

Fractures in Thoroughbred racing and the potential for pre-race identification of horses at risk.

Risk rates for and predisposing factors to fractures occurring in Thoroughbred racing that have been published in peer reviewed journals are documented. The potential for currently available techniques to identify horses at increased risk for fracture is discussed on the bases of principles, practicalities, advantages, disadvantages and current data. All are reviewed in light of justifiable decision making and importance of fractures to horseracing's social license.

Breed predispositions to congenital and juvenile cataracts in horses at two academic institutions.

Determination of horse breeds predisposed to congenital and juvenile cataracts will enable investigations into potential genetic mechanisms for cataracts in horses. To investigate horse breed predispositions to congenital and juvenile cataracts in two academic referral populations. Retrospective case series. Medical record identification of horses diagnosed with congenital or juvenile cataracts at the Cornell University Equine Hospital (2000-2022) and the University of California-Davis (UCD) Large Animal Clinic (1990-2021). Signalment, examination findings and treatments were recorded. Descriptive statistics were performed, and breed over-representations were determined using Chi-squared or Fisher's exact tests. Thirty-one (Cornell) and 70 (UCD) horses with congenital or juvenile cataracts were identified, for a total of 101 affected horses. Seventy-eight horses were affected bilaterally and 23 were affected unilaterally, for a total of 179 affected eyes. Standardbreds were significantly over-represented at both institutions, comprising 32.5% of congenital/juvenile cataract cases and 10% of the equine hospital population at Cornell (p < 0.001) and 4.3% of cataract cases and 1.3% of the equine hospital population at UCD (p = 0.03). Thoroughbreds were under-represented for congenital and juvenile cataracts at both institutions (p = 0.03 Cornell, p = 0.01 UCD). Retrospective study, potential for selection bias. The over-representation of the Standardbred breed for congenital and juvenile cataracts at two institutions suggests an underlying genetic basis in the breed. Future genetic and genomic studies are warranted to investigate heritable cataracts in Standardbred horses.

Development of a novel real-time PCR multiplex assay for detection of Streptococcus equi subspecies equi and Streptococcus equi subspecies zooepidemicus

Strangles is a contagious bacterial disease of horses caused by Streptococcus equi subspecies equi (SEE) that occurs globally. Rapid and accurate identification of infected horses is essential for controlling strangles. Because of limitations of existing PCR assays for SEE, we sought to identify novel primers and probes that enable simultaneous detection and differentiation of infection with SEE and S. equi subsp. zooepidemicus (SEZ). Comparative genomics of U.S. strains of SEE and SEZ (n = 50 each) identified SE00768 from SEE and comB from SEZ as target genes. Primers and probes for real-time PCR (rtPCR) were designed for these genes and then aligned in silico with the genomes of strains of SEE (n = 725) and SEZ (n = 343). Additionally, the sensitivity and specificity relative to microbiologic culture were compared between 85 samples submitted to an accredited veterinary medical diagnostic laboratory. The respective primer and probe sets aligned with 99.7 % (723/725) isolates of SEE and 97.1 % (333/343) of SEZ. Of 85 diagnostic samples, 20 of 21 (95.2 %) SEE and 22 of 23 SEZ (95.6 %) culture-positive samples were positive by rtPCR for SEE and SEZ, respectively. Both SEE (n = 2) and SEZ (n = 3) were identified by rtPCR among 32 culture-negative samples. Results were rtPCR-positive for both SEE and SEZ in 21 of 44 (47.7 %) samples that were culture-positive for SEE or SEZ. The primers and probe sets reported here reliably detect SEE and SEZ from Europe and the U.S., and permit detection of concurrent infection with both subspecies.

Identification of horse, donkey and pig ingredients by species-specific ERA-based methods to assess the authenticity of meat products

Ensuring the authenticity of horse-, donkey- and pig-related meat products is of great religious and economic significance. In this study, with the mitochondrial genes of ATPase 6 or ND2 as targets, the species-specific real-time enzymatic recombinase amplification (real-time ERA) and ERA combined with lateral flow strip (LFS ERA) assays for horse, donkey and pig ingredients were developed. The optimization results showed that both ERA assays had the same optimal temperature for the detection of horse, donkey and pig ingredients, i.e., 39 °C for real-time ERA and 37 °C for LFS ERA, respectively. The assays could be performed simultaneously and the results could obtained within 25 min. Both developed assays showed good specificity and no cross-reactions with other common meat species were observed. The limit of detection of the developed ERA assays for horse, donkey and pig ingredients was 10 pg genomic DNA/per reaction and 0.1% target meat (w/w). Their applicability were verified with 45 donkey meat products (both raw and marinated minced meat), and the results showed that the detection rate of horse or pig ingredient was as high as 53.33%, including a complete substitution or partial substitution of donkey meat. The results were consistent with those of the standard real-time PCR in China, but the whole detection time was significantly reduced from 2 h to 35 min. It is concluded that the developed real-time ERA and LFS ERA assays are feasible for the rapid authentication of horse, donkey and pig meats and identification of the adulteration of donkey meat-related products.

The hygienic aspects in the management of strangles

SummaryStreptococcus equi subsp. equi (S. equi) is a frequently encountered pathogen in equine practice. S. equi causes infection of the upper airways of horses, a condition known as strangles. Strangles is a highly contagious disease and may be economically devastating as well. Difficulties in the eradication of the disease using vaccines and medical treatments make hygienic measures crucial in order to limit transmission of the pathogen during outbreaks. This review aims to elucidate the challenges in handling an outbreak of strangles as well as develop a basic plan on how such an outbreak is handled in a hygienically optimal fashion. The results of this review suggest a longer environmental survival time of S. equi than previously assumed and support the importance of modification of surfaces for proper disinfection with appropriate disinfectants. Furthermore, the efficiency of using a colour‐coding system in dividing healthy, exposed and clinically affected horses is discussed. Individual temperature monitoring twice daily is recommended for the identification of diseased horses before they pose a contagious risk. Additionally, changing clothes between visiting different stable units is likewise recommended, to minimise transmission of disease. In conclusion, veterinarians, personnel and horse owners at equestrian centres need to be aware of the importance of isolation, monitoring and dividing the site into zones according to the risk of infection. Finally, it can be concluded that regardless of size, practical biosecurity measures can be implemented within all equine facilities.

Short Insertion and Deletion Discoveries via Whole-Genome Sequencing of 101 Thoroughbred Racehorses.

Thoroughbreds are some of the most famous racehorses worldwide and are currently animals of high economic value. To understand genomic variability in Thoroughbreds, we identified genome-wide insertions and deletions (INDELs) and obtained their allele frequencies in this study. INDELs were obtained from whole-genome sequencing data of 101 Thoroughbred racehorses by mapping sequence reads to the horse reference genome. By integrating individual data, 1,453,349 and 113,047 INDELs were identified in the autosomal (1-31) and X chromosomes, respectively, while 18 INDELs were identified on the mitochondrial genome, totaling 1,566,414 INDELs. Of those, 779,457 loci (49.8%) were novel INDELs, while 786,957 loci (50.2%) were already registered in Ensembl. The sizes of diallelic INDELs ranged from -286 to +476, and the majority, 717,736 (52.14%) and 220,672 (16.03%), were 1-bp and 2-bp variants, respectively. Numerous INDELs were found to have lower frequencies of alternative (Alt) alleles. Many rare variants with low Alt allele frequencies (<0.5%) were also detected. In addition, 5955 loci were genotyped as having a minor allele frequency of 0.5 and being heterogeneous genotypes in all the horses. While short-read sequencing and its mapping to reference genome is a simple way of detecting variants, fake variants may be detected. Therefore, our data help to identify true variants in Thoroughbred horses. The INDEL database we constructed will provide useful information for genetic studies and industrial applications in Thoroughbred horses, including a gene-editing test for gene-doping control and a parentage test using INDELs for horse registration and identification.

Race-Level Reporting of Incidents Using an Online System during Three Seasons (2019/2020-2021/2022) of Thoroughbred Flat Racing in New Zealand.

In the 2019/20 Thoroughbred racing season, the paper-based reporting process of stipendiary steward reports was upgraded to an online system ('Infohorse database') to allow for the rapid entry of precise event and injury data. The objectives of this study were to describe the incident and non-incident examinations during the 2019/20, 2020/21, and 2021/22 Thoroughbred flat racing seasons in New Zealand and describe the primary injury and reporting outcomes. The introduction of the online system was associated with fewer miscoding events with horse identification (0.1%). An improvement in the definition and prompts in reporting within the online system compared with the previous paper-based system resulted in a greater frequency of non-incident examinations being undertaken. The increased frequency of reporting the clinical outcome, 'no observable abnormalities detected' (NOAD), demonstrates the role of stipendiary stewards to carry out routine screening. The frequency of most clinical findings, such as musculoskeletal fractures (0.5 per 1000 starts, 95% CI = 0.3-0.6), remained similar compared to previously reported data using the paper-based system. The online system provided a more structured dataset compared with the paper-based system, making it a useful tool for the monitoring of incidents, injuries, and potential risk factors within Thoroughbred racing in New Zealand. Therefore, evidence-based changes to the management and structure of racing can be undertaken to ensure the industry meets its duty of care for racehorse and jockey welfare.

Race-Level Reporting of Incidents Using the New Online System During Two Seasons (2019/2020–2020/2021) of Harness Racing in New Zealand

After establishing a baseline of stipendiary stewards’ reporting using the paper-based system in the 2015/16 and 2016/17 seasons of harness racing, it is important to examine if the implementation of an online system has altered frequency and descriptors used for clinical outcomes. The objective of this study was to describe the race level injury and reporting outcomes, and horse- and race-level variables associated with the rate of the reporting of these outcomes during the 2019/20 and2020/21 harness racing seasons in New Zealand. The introduction of the online system was associated with few (0.01%) miscoding events associated with horse identification. There was a shift in the frequency of reporting non-incident examinations, possibly due to better definition and prompts within the online system. The coding category, no observable abnormalities detected (NOAD) had the greatest number of entries, reflecting that the majority of examinations were associated with general screening rather than adverse events occurring during warm-up or the race. The frequency of recordings for most clinical findings was consistent between the old paper-based system and the new online system. The incidence of musculoskeletal fractures remained low (0.12 per 1,000 starts, 95%CI = 0.05–0.28). The online system has the potential to provide a useful tool to prospectively monitor the reporting of injuries and conditions associated with harness racing in New Zealand.

Unhandled horses classified with broken/unbroken test (BUT) exhibit longer avoidance, flight reactions, and displacement behaviors when approached by humans.

Horses with a low level of tameness are at higher risk for transport-related disease and injury; hence, European regulations for the protection of animals during transport (EC 1/2005) are stricter for unhandled (unbroken) horses. However, the regulation does not provide adequate tools for unhandled horse identification. The Broken/Unbroken Test (BUT) was developed and validated to easily identify whether a horse is broken (handled) or not. As a further validation step, the aim of this study was to assess whether there is any correspondence between the BUT classification and the behavioral response of the horse. A total of 100 healthy Italian Heavy Draft horses were video recorded when assessed with the BUT. In total, 90 videos (48 handled and 42 unhandled horses) matched the inclusion criteria and were assessed. The behavior of each horse was evaluated by three observers blinded as to the horses' experience with a focal animal continuous recording method. Behaviors were classified in four categories: stress, avoidance, displacement, and aggression. A Mann–Whitney test was used to identify differences in behavioral patterns between horses classified as handled or unhandled with the BUT. Unhandled horses showed not only a significantly longer time to be approached by the handler but also more avoidance and flight reactions (p < 0.001). Unhandled horses showed significantly longer displacement behaviors, such as sniffing (p < 0.001). These findings further validate the BUT classification and confirm that horses classified as unhandled are more prone to show avoidance and flight reactions when approached by humans. For this reason, the adoption of the BUT could be helpful to minimize humans' horse-related injuries and, if applied regularly before loading, to contribute to safeguard the welfare of horses during transport.

Relationship between Thoroughbred workloads in racing and the fatigue life of equine subchondral bone

Fatigue life (FL) is the number of cycles of load sustained by a material before failure, and is dependent on the load magnitude. For athletes, ‘cycles’ translates to number of strides, with load proportional to speed. To improve previous investigations estimating workload from distance, we used speed (m/s, x) per stride collected using 5 Hz GPS/800 Hz accelerometer sensors as a proxy for limb load to investigate factors associated with FL in a Thoroughbred race start model over 25,234 race starts, using a combination of mathematical and regression modelling. Fore-limb vertical force (NKg-1) was estimated using a published equation: Vertical force = 2.778 + 2.1376x − 0.0535x2. Joint load (σ) was estimated based on the vertical force, scaled according to the maximum speed and defined experimental loads for the expected variation in load distribution across a joint surface (54-90 MPa). Percentage FL (%FL) was estimated using a published equation for cycles to failure (Nf) summed across each race start: Nf = 10(σ-134.2)/−14.1. Multivariable mixed-effects linear regression models were generated on %FL, adjusting for horse-level clustering, presented as coefficients; 95%CI. Scaled to the highest joint load, individual starts accrued a mean of 9.34%FL (sd. 1.64). Older age (coef. 0.03; 0.002–0.04), longer race-distances (non-linear power transformed), and firmer track surfaces (ref. Heavy 10: Good 3 coef. 2.37; 2.26–2.48) were associated with greater %FL, and males accrued less than females (p < 0.01). Most variables associated with %FL are reported risk factors for injury. Monitoring strides in racehorses may therefore allow identification of horses at risk, enabling early detection of injury.

UnsaddlingStreptococcus equiinfection of horses

Infection with Streptococcus equi, which forms abscesses in the lymph nodes of the head and neck in horses, is endemic in almost all countries around the world. The identification and isolation of horses with fever, an early sign of disease, is critical to minimising the number of horses affected and the severity of an outbreak, while the identification and treatment of persistently infected ‘carrier’ horses can reduce the risk of recurrent outbreaks and transmission between equine populations. Rapid diagnostic testing plays a key role in the identification of infected horses, which can then be isolated before the development of acute disease or treated to clear persistent infection. Vaccination can also be used to reduce the number of horses that become infected and the severity of their ensuing disease. This review describes the tools available to veterinarians and the journey towards the development and launch of a multi-component fusion protein vaccine that does not trigger positive diagnoses with any of the available diagnostic tests for strangles. The use of vaccination, alongside conventional methods of biosecurity and diagnostic testing, has the potential to unsaddle S. equi, reducing the number of strangles outbreaks and enhancing the health of horses.

Development of a 19-plex short tandem repeat typing system for individual identification and parentage testing of horses (Equus caballus).

Individual identification of horses for pedigree verification and registration is important for the sustainable development of the horse industry. Horse individual identification and parentage tests commonly use the 17 short tandem repeats (STRs) recommended by the International Society for Animal Genetics (ISAG) and the locus LEX33. While many multiplex STR typing systems have been established for the horse, a sex determining marker is usually absent, and none of them can simultaneously detect all 17 ISAG recommended loci and the locus LEX33. Here, we present a 19-plex STR typing system that contains the 17 ISAG recommend loci, the locus LEX33 and amelogenin as sex determining loci. The results of our sensitivity, species specificity, stutter analysis and population data analysis, indicate that this system is a specific, sensitive, and robust tool for the identification of individuals, parentage testing and genetic research in the horse.

Case-Control Study of Risk Factors for Equine Asthma in Texas

Equine asthma is a common condition in horses, for which few host-related risk factors have been identified. The objective of this study was to identify host-related risk factors for the development of equine asthma. A retrospective, case-control study was performed, utilizing horses presented to the Texas A&M University, Veterinary Medical Teaching Hospital from January 2014 December 2018. Incident cases of mild to severe equine asthma (n = 37), diagnosed clinically with cytologic support of disease were examined. For each case, two control populations were identified, including one temporal control (n = 37) and one age-matched control (n = 37). Data collected included signalment, dietary and stable management, prior medical history, metabolic status, physical examination findings, and results of cytologic evaluation via bronchoalvelolar lavage or tracheal wash. Conditional logistic regression was used to compare data on equine asthma cases with data from each set of controls. Results indicated that obesity (Body Condition Score ≥ 7) was the only statistically significant risk factor for equine asthma in this population of horses. These results may aid in identification of targets for management, prevention, and further investigation into the pathogenesis of equine asthma. Early identification and intervention of horses at risk of lower airway disease could ameliorate the impact of disease.

The Risk Factors for Musculoskeletal Injuries in Thoroughbred Racehorses in Queensland, Australia: How These Vary for Two-Year-Old and Older Horses and with Type of Injury.

Simple SummaryMusculoskeletal injuries (MSI) continue to affect Thoroughbred racehorses internationally, despite over thirty years of research into this problem. Studies of risk factors for musculoskeletal injuries report inconsistent findings. Consequently, developing training strategies to mitigate the risk of MSI is difficult. We identified factors associated with particularly high odds of injury in this population of racehorses. Two-year-old horses from primiparous mares (first foals born) are at increased odds of MSI, particularly dorsal metacarpal disease (“shinsoreness”). Two-year-old horses that have had a total preparation length of between 10 and 14 weeks also have increased odds of injury. Horses of all ages that travelled a total distance of 2.4–3.8 km (12–19 furlongs) at a gallop (faster than 15 m/s; 13 s/furlong; 900 m/min; 55 km/h) in the last four weeks and horses three years and older that travelled 3.0–4.8 km (15–24 furlongs) at three-quarter pace and above (faster than 13 m/s; 15 s/furlong; 800 m/min; 48 km/h) also have increased odds of injury. We recommend that these horses should be monitored closely for impending signs of injury. We also observed a non-linear relationship between high-speed exercise and musculoskeletal injuries. This highlights the importance of high-speed exercise to enable tissue adaptation to training. Finally, in some situations, increasing the number of days worked at a slow pace may be more effective for preventing MSI, if horses are perceived at a higher risk, than resting the horse altogether. Early identification of horses at increased risk of injury and appropriate intervention could substantially reduce the impact of musculoskeletal injuries in Thoroughbred racehorses.Musculoskeletal injuries (MSI) continue to affect Thoroughbred racehorses internationally. There is a strong interest in developing training and management strategies to reduce their impact, however, studies of risk factors report inconsistent findings. Furthermore, many injuries and fatalities occur during training rather than during racing, yet most studies report racing data only. By combining racing and training data a larger exposure to risk factors and a larger number of musculoskeletal injuries are captured and the true effect of risk factors may be more accurately represented. Furthermore, modifications to reduce the impact of MSI are more readily implemented at the training level. Our study aimed to: (1) determine the risk factors for musculoskeletal injuries and whether these are different for two-year-old and older horses and (2) determine whether risk factors vary with type of injury. This was performed by repeating analyses by age category and injury type. Data from 202 cases and 202 matched controls were collected through weekly interviews with trainers and analysed using conditional logistic regression. Increasing dam parity significantly reduced the odds of injury in horses of all age groups because of the effect in two-year-old horses (odds ratio (OR) 0.08; 95% confidence interval (CI) 0.02, 0.36; p < 0.001). Increasing total preparation length is associated with higher odds of injury in horses of all ages (OR 5.56; 95% CI 1.59, 19.46; p = 0.01), but particularly in two-year-old horses (OR 8.05; 95% CI 1.92, 33.76; p = 0.004). Increasing number of days exercised at a slow pace decreased the odds of injury in horses of all ages (OR 0.09; 95% CI 0.03, 0.28; p < 0.001). The distance travelled at three-quarter pace and above (faster than 13 m/s; 15 s/furlong; 800 m/min; 48 km/h) and the total distance travelled at a gallop (faster than 15 m/s; 13 s/furlong; 900 m/min; 55 km/h) in the past four weeks significantly affected the odds of injury. There was a non-linear association between high-speed exercise and injury whereby the odds of injury initially increased and subsequently decreased as accumulated high-speed exercise distance increased. None of the racing career and performance indices affected the odds of injury. We identified horses in this population that have particularly high odds of injury. Two-year-old horses from primiparous mares are at increased odds of injury, particularly dorsal metacarpal disease. Two-year-old horses that have had a total preparation length of between 10 and 14 weeks also have increased odds of injury. Horses of all ages that travelled a total distance of 2.4–3.8 km (12–19 furlongs) at a gallop in the last four weeks and horses three years and older that travelled 3.0–4.8 km (15–24 furlongs) at three-quarter pace and above also have increased odds of injury. We recommend that these horses should be monitored closely for impending signs of injury. Increasing the number of days worked at a slow pace may be more effective for preventing injury, if horses are perceived at a higher risk, than resting the horse altogether. Early identification of horses at increased risk and appropriate intervention could substantially reduce the impact of musculoskeletal injuries in Thoroughbred racehorses.

Detection of meat from horse, donkey and their hybrids (mule/hinny) by duplex real-time fluorescent PCR.

Meat adulteration is currently a common practice worldwide. In China, adulteration of donkey meat products with the similar species (horse and mule/hinny) meat and mislabeling are becoming widespread concerns. In this study, a sensitive and species-specific duplex real-time PCR assay based on the simultaneous amplification of fragments of the creatine kinase muscle gene family, was developed and optimized for the identification of horse, donkey and mule /hinny species in raw and heat-processed meat products. Duplex real-time PCR results showed different fluorescence amplification curves for horse and donkey. Both kinds of fluorescence amplification curves appeared simultaneously for mule/hinny. The limit of detection (LOD) of the method was up to 0.01 ng /μL. The method and strategy developed in this study could be applied to detect the presence of adulterants from horse and mule /hinny meat in raw donkey meat and meat products.

Polymerase chain reaction with lateral flow sensor assay for the identification of horse meat in raw and processed meat products

A simple, rapid and accurate detection method for the authentication of animal species is urgently required in the food detection field. The present study established a horse-specific polymerase chain reaction integrated with a lateral flow sensor assay (Horse-PCR-LFS) for the rapid detection of horse meat. In this test, a cytb gene sequence of horse was amplified using PCR, the PCR amplicon was checked with the lateral flow sensor assay, and the result of the sensor can be read within 2–3 min by the naked eye. The detection limit of the test was up to 0.01% horse meat in artificially adulterated meat mixtures, the assay also successfully detected horse DNA in various commercial food samples. As a rapid and user-friendly molecular detection tool, this test provides an accurate detection format for the identification of horse and offers solutions to problems related to animal meat adulteration and animal-origin food safety and traceability.

Application of a Ridden Horse Pain Ethogram to horses competing at 5‐star three‐day‐events: Comparison with performance

SummaryA Ridden Horse Pain Ethogram (RHpE) was previously developed to facilitate the detection of musculoskeletal pain. The objectives were to apply the RHpE during warm‐up for the dressage phase of two 5* three‐day events and to correlate the RHpE scores with subsequent performance. It was hypothesised that there would be a higher rate of failure to complete the cross‐country phase in horses which exhibited ≥7 behaviours compared with those showing &lt;7 behaviours. The RHpE, comprising 24 behaviours, was applied for 10–12 min during warm‐up. Gait abnormalities in trot and canter were recorded. Dressage penalties, cross‐country performance, showjumping penalties and final placings were documented. Horses were categorised as those which completed cross‐country, or those which did not complete because of elimination or retirement. RHpE scores (n = 137) ranged from 0 to 9/24 (median 3 [range 0–9] for nonlame horses; median 5 [range 1–9] for horses with gait abnormalities in trot or canter). There was a moderate correlation between dressage penalty scores and the RHpE score (rho = 0.4, P&lt;0.001, Spearman rank). Fifty‐nine per cent of horses (n = 10/17) with a RHpE score ≥7 failed to complete cross‐country, compared with 33% (n = 39/117) with a score &lt;7. Horses that failed to complete the cross‐country phase had higher RHpE scores compared with those that completed (P = 0.04, W = 8.3, Kruskal–Wallis; pairwise comparison Bonferroni, P = 0.06). There was a significant (rho = 0.3) relationship between total RHpE score and final horse placings (n = 80, P&lt;0.01, Spearman rank). Horses with lameness or gait abnormalities in canter had significantly higher RHpE scores (P&lt;0.01, χ2 = 35, chi‐square test) compared with other horses. There was a strong correlation between the RHpE scores for horses which competed at both events (P&lt;0.001, rho = 0.6, Spearman rank). The RHpE should facilitate earlier identification of horses which may benefit from diagnosis and treatment, resulting in improvement in both performance and equine welfare.

Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry (MALDI-TOF MS) for Identification of Bacterial Isolates From Horses

Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) is used for bacterial identification by analyzing the spectra of isolates and comparing them against a database of reference spectra; it is known for its rapidity and accuracy. Although MALDI-TOF MS is used for identification of bacterial isolates from animals, not all animal pathogens are identified correctly. In this study, we used a commercial MALDI-TOF MS identification system to examine 3724 bacterial isolates from horses and their environments. Isolates that could not be identified with MALDI-TOF MS were identified by 16S rRNA gene sequence taxonomic analysis. MALDI-TOF MS could identify 86.2% of the isolates from horses to the species level, showing that this method could be successfully applied for bacterial identification in horses. However, some species known to be equine pathogenic agents including Taylorella equigenitalis and Rhodococcus equi were difficult to identify with MALDI-TOF MS, which might be the result of an inadequate reference database. Some Prevotella, Staphylococcus, and Streptococcus isolates, which could not be identified with either MALDI-TOF MS or 16S rRNA gene sequencing analysis, formed clusters in the 16S rRNA phylogenic tree, and might be unknown species isolated from horses. Adding the spectra of isolates identified in this study to an in-house database might make MALDI-TOF MS a more useful tool for identifying equine isolates.

Arabian Horse Identification and Gender Determination System based on Feature Fusion and Gray Wolf Optimization

Arabian Horse Identification and Gender Determination System based on Feature Fusion and Gray Wolf Optimization