Topic:Comparative Study
Comparative studies in equine research involve the systematic analysis of different horse breeds, management practices, or physiological responses to identify variations and similarities. These studies are instrumental in understanding how different factors influence health, performance, and behavior in horses. Common areas of comparison include genetic traits, nutritional requirements, disease resistance, and response to training. By evaluating these differences, researchers can develop targeted strategies for breeding, healthcare, and training. This page aggregates peer-reviewed research studies and scholarly articles that focus on the methodologies, findings, and implications of comparative studies in the context of equine science.
A topographic analysis of skin thickness in horses. A systematic study of regional skin thickness in different types of horses has not yet been described. Knowledge about regional skin thickness has long been used in human medicine to optimise wound care and skin grafting outcomes and similar knowledge could prove useful in equine wound management. The objective of the current study was to report the topographical variation in skin thickness of Warmblood (WB) and Coldblood (CB) type horses and to compare different methods for measuring skin thickness. Horses free of skin conditions and euthanised for reasons unrelated to this study were include...
Updates on Seizures and Epilepsy in the Horse. The goal of this article is to provide the equine practitioners with a framework for a diagnostic algorithm for the patient presented with possible seizures/epilepsy. Using a comparative approach, a review of companion animal and human research is provided with the intention of expanding our current knowledge on seizure/epilepsy, as well as diagnostic and treatment strategies for equine patients.
Comparative Evaluation of Follicular Flushing Frequency and Scraping Time During Ovum Pick-Up in Mares: Effects on Oocyte Recovery Rate and Technical Considerations. Transvaginal ultrasound-guided follicular aspiration or ovum pick-up (OPU) has become the standard technique for oocyte collection in mares for intracytoplasmic sperm injection (ICSI). Although repeated follicular flushes and wall scraping are commonly used to improve oocyte recovery rate (ORR), the relative contribution of each remains unclear. This study aimed to compare the effects of multiple flushes versus controlled scraping time on ORR in mares. A controlled trial was conducted in two phases: (1) an ex vivo phase using slaughterhouse ovaries (n = 32), and (2) an in vivo phase in c...
Genome-Wide DNA Methylation Analysis of Performance Variation in the 5000-m Speed Race of Yili Horses. Whole-genome bisulfite sequencing (WGBS) was employed in this article to map blood DNA methylation profiles at single-base resolution in Yili horses before a 5000 m speed race, with comparative analysis of epigenetic differences between the 'elite group' and 'ordinary group' across six four-year-old stallions. The overall methylation level in the elite group was generally higher than that in the ordinary groups, with a minority of regions showing hypomethylation. For instance, the promoter regions of key metabolic and neuro-related genes exhibited significant hypomethylation. The article ident...
Validation of a handheld smartphone markerless gait-analysis tool using an estimated groundline in horses. A handheld smartphone-based computer vision algorithm (RealHorse® [RH]) offers accessible alternatives for equine gait analysis but requires validation against a gold-standard three-dimensional multicamera optical motion capture system (Qualisys® [QS]). Objective: To evaluate the accuracy and precision of RH in measuring vertical displacement signals (VDS) at the eye, withers, back and croup in horses trotting on a straight line and on a circle. Methods: Cross-sectional comparative validation study of a markerless computer vision algorithm. Methods: Fifty-nine horses were recorded while trot...
Intraocular Tumors in Horses: Diagnosis, Tumor Classification, Oncologic Assessment and Therapy. Intraocular neoplasia in horses is rare and only few case reports and small case series exist. Intraocular neoplasia has various clinical signs and includes important differential diagnoses in ocular disease. This narrative review of the current literature aims to provide a clinically relevant overview and classification of intraocular tumors in horses and adds a comparative oncological perspective concerning diagnosis, treatment and future considerations. The available clinical and imaging examination techniques allow for a reliable and differentiated investigation of the tumor, even in the s...
Comparative analysis of 3 qPCR primer-probe sets for the detection of equid alphaherpesvirus 1. With the revision of the World Organisation for Animal Health (WOAH) Terrestrial Manual on equine rhinopneumonitis in 2024, 3 recommended qPCR primer-probe sets were added for the detection of equid alphaherpesvirus 1 (EqAHV1; formerly equine herpesvirus 1 [EHV1]; family , taxon species ), also known as equine abortion virus. We compared the sensitivity and specificity of the 3 qPCR primer-probe sets to determine the most reliable set. Sets gB1H and gB1P, which target the glycoprotein B () gene of EqAHV1, detected all 10 copies and even lower copy numbers. In contrast, set gC1 (ISO 17025-accre...
Comparison of Oocyte Collection Yield Between Conventional Follicle Scraping and Ultrasound-Guided Follicle Aspiration in Postmortem Excised Horse Ovaries. Post-mortem oocyte collection serves to preserve the genetic material of valuable mares and to obtain recipient oocytes for cloning purposes. Therefore, the number of oocytes retrieved per ovary is a critical factor in increasing the likelihood of obtaining a viable embryo. This study evaluated the efficiency of two post-mortem oocyte retrieval techniques: follicular scraping (Scraping) and ultrasound-guided follicular aspiration (OPU). The comparison was based on several parameters, including the number of follicles aspirated per ovary, oocyte recovery rate (ORR), number of oocytes obtained p...
BCG Immunotherapy in Equine Sarcoid Treatment: Mechanisms, Clinical Efficacy, and Challenges in Veterinary Oncology. Equine sarcoids are the most common dermatological neoplasm in horses worldwide, associated with bovine papillomavirus (BPV) infection and characterized by high recurrence rates after conventional therapies. Bacillus Calmette-Guérin (BCG) immunotherapy has historically been used for sarcoid treatment, yet its role in contemporary veterinary oncology remains debated. This narrative review critically examines the immunological mechanisms, clinical efficacy, and limitations of BCG in equine sarcoid therapy, while integrating insights from comparative oncology and One Health perspectives. A syste...
Horses (Equus caballus) successfully solve an object choice task using a human pointing gesture and a physical marker: A partial replication of Proops et al. (2010). Like other domesticated species, most notably dogs, horses have been reported to follow human gestures and successfully use them to gain rewards in an object choice task. Empirical support for the hypothesis that a domain-general mechanism may underlie this ability comes from studies in which horses have successfully solved the task by using not just a human pointing gesture but also an arbitrary physical cue, namely a wooden marker. Here, we replicated the two conditions in which these two cues were used by Proops et al. (2010) with two critical changes: first, we positioned the marker out of...
Evaluation of a Chemically Defined, Long-Term Extender for Liquid Storage of Stallion Semen. Efficient use of stallion semen in liquid state is limited by its relatively short shelf-life. A chemically defined extender (Beyond) is now available for long-term liquid semen preservation. The objectives of the present study were to compare Beyond with milk extenders for the preservation of semen at two temperatures, and to evaluate fertility of semen cooled for 4-8 days before artificial insemination. Semen was processed using different extenders: milk, cholesterol (BotuSemen Special); milk-based (INRA 96); and Beyond. Sperm motility, membrane and acrosome integrity, and chromatin struct...
Comparing the Difference in Traction Between the Bare Hoof, Iron Horseshoes and Two Glue-On Models on Different Surfaces. The interaction between equine hooves and various ground surfaces is a critical factor for injury prevention and performance in modern equestrian sports. Accurate measurement of surface grip is essential for evaluating the effectiveness of different hoof protection systems. This study introduces the Vienna Grip Tester (VGT), a novel sensor-based device developed to quantify rotational resistance-an important parameter for assessing hoof-surface interaction. The VGT utilizes a torque wrench and spring-loaded mechanism to simulate lateral hoof movements under a standardized vertical load (~700 N...
Bridging Breeds: Transcriptomic Insights into Immune Traits of Yili, Thoroughbred, and Kazakh Horses. Studying the genetic characteristics and molecular mechanisms of immune regulation in horses is of great significance for protecting their genetic resources, improving breeding strategies, and enhancing their disease resistance, thereby ensuring their healthy performance in both sports and production. Objective: This study investigates the genetic characteristics and molecular mechanisms underlying immune regulation in Yili horses, comparing them with Thoroughbreds and Kazakh horses. Methods: Blood samples from each breed were analyzed for physiological, biochemical, and immune indices alongsi...
Evaluation of the Effectiveness of Single-Nucleotide Polymorphisms Versus Microsatellites for Parentage Verification in Horse Breeds. This study aimed to generate information for parentage testing in horse breeds using microsatellites (STRs) and single-nucleotide polymorphisms (SNPs). Genotype data were obtained from 189 horse hair root samples, including 38 Thoroughbreds (TBs), 17 Jeju horses (JHs), 20 Quarter horses (QHs), 21 American Miniatures (AMs), and 93 Mongolian horses (MHs), using 15 STR markers and 71 SNP markers. Comparative analysis revealed that the mean expected heterozygosity ranged from 0.468 (AM) to 0.491 (JH) for SNPs and from 0.695 (TB) to 0.791 (MH) for STRs. The mean observed heterozygosity ranged from ...
Comparison Between Tracheal Wash and Bronchoalveolar Lavage Cytology for the Assessment of Airway Inflammation in Racehorses Affected by Exercise-Induced Pulmonary Hemorrhage. Exercise-Induced Pulmonary Hemorrhage (EIPH) results from alveolar capillary stress failure after strenuous exercise, leading to bleeding and pulmonary inflammation. Bronchoalveolar lavage fluid (BALF) cytology is considered the gold standard for the assessment of airway inflammation; however, it is often considered more invasive compared to tracheal wash (TW). It has been demonstrated that TW is a reliable diagnostic tool that may substitute BALF to diagnose and grade the severity of EIPH in racehorses; however, no information about airway inflammation in EIPH-affected horses has been reporte...
A case-matched controlled retrospective performance indexed analysis of Thoroughbred racehorses that underwent surgical repair of proximal phalanx and third meta-carpal/tarsal condylar fractures. Standing fracture repair has become established as an acceptable technique with a good long-term prognosis. However, no study has compared racing outcomes with case-matched controls. Objective: To compare racing outcomes between a large dataset of horses undergoing standing fracture repair against case-matched controls. Methods: Retrospective case-matched controlled comparative study. Methods: Thoroughbred racehorses undergoing standing repair of distal limb fracture(s) over 10 years (2012-2022) at five hospital centres across North America and Europe were included. Data retrieved included...
Comparison of Two Surgical Techniques for the Treatment of Equine Hindlimb Proximal Suspensory Desmopathy. Suspensory desmopathy is a frequently documented cause of lameness in performance horses; proximal suspensory desmopathy is the most frequent site of injury in dressage horses [...].
Retrospective Evaluation of Neutrophil-to-Lymphocyte Ratio in Horses That Required Emergency Laparotomy: 341 Cases of Noninfectious Causes of Gastrointestinal Colic (2019-2024). To (1) compare total nucleated cell count (TNCC) and neutrophil-to-lymphocyte ratio (NLR) at admission between horses with medically managed, large intestinal (LI) and small intestinal (SI) surgical colic; (2) compare TNCC and NLR between survivors and nonsurvivors; and (3) investigate associations between TNCC, NLR, surgical intervention, and outcome. Methods: Case-control study. Methods: Single, academic institution. Methods: A total of 341 adult horses diagnosed with noninfectious medical or surgical colic. Results: Admission TNCC did not differ between the medical and combined surgical gro...
Cytoplasmic and nuclear Survivin expression in healthy gastric mucosae of equids: A comparative study between horses, donkeys, and mules. Information regarding Survivin protein expression in the gastric mucosa of equids is scarce. This protein has been associated with functions related to modulating apoptosis and promoting mitosis in epithelial cells and is considered part of gastric cytoprotection mechanisms in humans and mice, maintaining mucosal integrity and regulating cellular renewal. Objective: This study aimed to determine the expression of cytoplasmic and nuclear Survivin in gastric mucosae of equids (horses, donkeys, and mules). Methods: A total of 30 healthy stomachs, 10 from each species, were evaluated using histolo...
Comparison of Gait Characteristics for Horses Without Shoes, with Steel Shoes, and with Aluminum Shoes. Differences in horseshoe materials may have effects on gait that could change perceived esthetic qualities. Objective information regarding effects of shoeing on gait characteristics of horses is scant. The aim of this study was to determine differences in gait characteristics for horses under various experimental shoeing conditions (barefoot, aluminum shoes, steel shoes) on two surfaces (asphalt and soft footing) using body- and hoof-mounted sensors. We hypothesized that shoeing would affect hoof arc height during early (arc height a) and late (arc height b) swing phases but would not affect ...
Comparison of 3.5- and 4.0-mm Cortical Bone Screws for Stabilization of an Equine Navicular Bone Fracture Model. The aim of this study was to compare the strength (load at failure) and the number of cycles to failure of 3.5- and 4.0-mm cortical screw-bone constructs for repair of navicular bone fractures in horses.This was an in vitro biomechanical study that used a four-point bending apparatus to determine the load at failure of 3.5- and 4.0-mm cortical screw-bone constructs subjected to static and cyclic loading.In static testing, pairwise comparison of 4.0-mm cortical screw-bone constructs demonstrated significantly greater strength (mean increase: +16%, = 0.0135) compared with those in the 3.5-m...
Phylogenetic variation of layer II cortical immature neurons in dog and horse confirms covariance with brain size and neocortical surface. Recent research in brain structural plasticity has identified "immature" or "dormant" neurons in layer II of the cerebral cortex (cortical immature neurons; cINs), cells that remain in a prolonged state of arrested development but retain the ability to resume maturation and integrate functionally into mature cortical circuits. These immature cells are far more abundant in large-brained mammals, being restricted to paleocortex (piriform cortex) in small-brained rodents and extending in the widely expanded neocortical mantle of species with large gyrencephalic brains. In a previous systematic an...
Exploring the distinctive characteristics of gut microbiota across different horse breeds and ages using metataxonomics. Gut microbiota exerts a pivotal function in host nutrient metabolism and maturation of the mucosal immunity. Analyzing the reciprocal interaction between horses and gut microbiota constitutes a crucial aspect of scientific feeding practices. This study aims to investigate the differences in gut microbiota among Hequ horses, Mongolian horses, and Thoroughbred horses, as well as between Thoroughbred horses at two age stages. Unassigned: Paired-end sequencing with a read length of 2×250 bp targeting the V3-V4 region of the 16S rRNA gene in fecal samples was carried out. Subsequently, differences...
Endocrine profile and OPU-ICSI outcomes in mares: a comparative study. Despite recent improvements in equine ovum pick-up (OPU) combined with intracytoplasmic sperm injection (ICSI), there is still significant inter-individual variability. In this study, serum concentrations of the oocyte-secreted factors growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15), as well as the GDF9/BMP15 complex, anti-Müllerian hormone (AMH), progesterone (P4), and free and conjugated estradiol-17β (E2), were determined in 59 mares (3-24 years) at the time of OPU. Mares were classified retrospectively, based on the number of embryos obtained, into low or...
CENP-A and centromere evolution in equids. While the centromeric function is conserved and epigenetically specified by CENP-A, centromeric DNA, typically composed of satellite repeats, is highly divergent and rapidly evolving. In the species of the genus Equus (horses, asses and zebras), also known as equids, the numerous centromeres devoid of satellite repeats enabled us to carry out molecular analysis of centromeric chromatin establishing a unique model system for mammalian centromere biology. In this review, after a brief description of the rapid evolution of equids, we outline one of our most relevant initial discoveries: the posit...
What ‘knot’ to do whilst castrating donkeys. A retrospective comparison of ligation method on spermatic cord haemorrhage in 261 donkeys castrated by vet students in rural Malawi using transfixing and modified millers’ ligatures. Special considerations for donkeys undergoing castration compared with horses include the presence of large scrotal vessels, larger testicular artery and vein and the consequential increased risk of post-operative haemorrhage which necessitates spermatic cord ligation. Objective: This retrospective study compares haemorrhagic complication rates between two methods of spermatic cord ligation in donkeys castrated in rural Malawi. Methods: All donkeys presenting to Veterinary Education Malawi / Lilongwe Society for the Protection and Care of Animals rural large animal outreach clinics for castrat...
Comparative genomic and virulence analyses of a novel sequence type 420 Streptococcus equi subspecies zooepidemicus isolated from donkey. The zoonotic pathogen subspecies (SEZ) frequently colonizes equines harmlessly but can occasionally cause disease or cross species barriers. Currently, growing evidence suggests SEZ can lead to severe clinical manifestations in horses and other animals, posing a threat to human and companion animal health. In this study, we sequenced the complete genome of the SEZ strain HT321, a novel sequence type 420 isolated from a donkey with a respiratory infection in China. Subsequently, we conducted comparative genomics, core genome single nucleotide polymorphisms (cgSNP), phylogenetic analysis multi...
Measurements of equine foot parameters show limited agreement between radiographs and low-field magnetic resonance imaging. Equine foot radiographs are commonly obtained to measure anatomical conformation parameters. Comparison of measurements between radiographs and low-field magnetic resonance imaging (MRI) has not been extensively explored. Objective: To compare foot parameter measurements between radiographs and low-field MRI, and assess the effect of hoof wall markers on visualising the hoof capsule (during MRI) and facilitating measurements. Methods: Comparative cadaveric analytical study. Methods: Radiography and MRI of nine equine cadaver front feet were performed with and without hoof wall markers, which w...
A comparison of the efficacy of three commercial human embryo vitrification kits for cryopreservation of in vivo produced equine embryos. Different cryoprotectants can influence the ability of embryos to successfully survive vitrification and subsequent warming before transfer. Objective: To compare pregnancy rates for embryos ≤500 μm vitrified, without puncture or aspiration of the blastocoele cavity, with one of three commercial human embryo vitrification kits containing the same penetrating cryoprotectants (DMSO and EG) but varying in their non-penetrating cryoprotectants (NPCPAs; sucrose, trehalose, dextran serum supplement [DSS], and hydroxypropyl cellulose [HPC]). Methods: In vivo experiments. Methods: Embryos (n =...
Donkey and Hybrid Anaesthetic Mortality in an Observational, Prospective, Multicentre Cohort Study. Equid anaesthetic mortality is of interest to practitioners. Data for donkey and hybrid mortality have not been specifically described. The main aim of this worldwide observational, prospective, multicentre cohort study was to report on mortality in the 7 days following a general anaesthetic or standing sedation in donkeys and hybrids. This study hypothesised that donkeys and hybrids would have higher mortalities compared to horses. Data were collected as part of the fourth Confidential Enquiry into Perioperative Equine Fatalities (CEPEF4). A total of 825 cases were included, with 757 donkeys ...