Topic:Animal Studies
Animal studies involving horses encompass a range of research focused on understanding equine biology, behavior, and health. These studies often investigate various aspects of horse physiology, genetics, nutrition, and disease pathology. Researchers utilize animal studies to explore the effects of different treatments, management practices, and environmental factors on horse welfare and performance. The findings from such studies contribute to the development of improved care strategies and health interventions. This page gathers peer-reviewed research studies and scholarly articles that explore the methodologies, findings, and implications of animal studies conducted on horses, providing insights into their application in advancing equine science.
Development and performance of an automated fecal egg count system for small ruminant strongylids. An automated equine fecal egg count test, known as the Parasight System, was modified for use with small ruminants. Modifications included the introduction of a short centrifugation step in a floatation medium, an adjustment in pre-test sample filtering, and training of an image analysis-based egg counting algorithm to recognize and enumerate trichostrongylid eggs. In preliminary assessments, the modified method produced trichostrongylid egg counts comparable to manual McMaster analyses of the same samples from both ovine and caprine sources. The coefficient of determination (R) for the linear...
Evaluating the Reaction to a Complex Rotated Object in the American Quarter Horse (Equus caballus). It is dangerous for both riders and horses when a horse suddenly startles. Sometimes horses do this in familiar environments because familiar objects may look different when rotated. The purpose of this study was to determine whether horses that had been habituated to a complex object (children's playset) would react to the object as novel when rotated 90 degrees. Twenty young horses were led past the playset 15 times by a handler. Next, the rotated group was led past the rotated playset 15 times. Each time the horse was led by the object was a pass. The behavioral responses observed and analy...
An ex vivo biomechanical comparison of two suture materials and two pattern combinations for equine superficial digital flexor tendon tenorrhaphy. To compare biomechanical characteristics of three-loop pulley (3LP) pattern versus Bunnell technique (BT) using polydioxanone (PDS) suture; to determine the influence of polyester tape (PT) versus PDS on the BT for equine superficial digital flexor tendon (SDFT) tenorrhaphy; to compare BT with PT versus 3LP with PDS. Methods: Ex vivo biomechanical study. Methods: Forty equine forelimb SDFT. Methods: Two experiments were performed: (1) 10 SDFT pairs were repaired with 3LP or BT using PDS; (2) 10 SDFT pairs were repaired with PDS or PT using BT. Load at failure, mode of failure, load at 2 mm g...
Recombinant fibroblast growth factor-18 (sprifermin) enhances microfracture-induced cartilage healing. Posttraumatic osteoarthritis is a disabling condition impacting the mostly young and active population. In the present study, we investigated the impact of intra-articular sprifermin, a recombinant truncated fibroblast growth factor 18, on the outcome of microfracture treatment, a widely used surgical technique to enhance cartilage healing at the site of injury. For this study, we created a cartilage defect and performed microfracture treatment in fetlock joints of 18 horses, treated joints with one of three doses of sprifermin (10, 30, or 100 μg) or with saline, hyaluronan, and evaluated a...
To start or stop an action depends on which movement we perform: An appraisal of the horse-race model. In order to gauge the executive processes underlying adaptive behavior, a central criterion in psychology is the extent to which experimental findings generalize across response types. The latency of two major acts of control, action initiation and inhibition, was evaluated using a stop-signal paradigm with two response types, involving either a finger key-pressing or a wrist pen-swiping response. In both conditions, 40 participants were instructed to respond quickly to a GO stimulus but to cancel their responses when a STOP signal was presented, which occurred randomly in 25% of the trials. T...
Use of Electrical Impedance Tomography (EIT) to Estimate Tidal Volume in Anaesthetized Horses Undergoing Elective Surgery. This study explores the application of electric impedance tomography (EIT) to estimate tidal volume (VT) by measuring impedance change per breath (∆Z). Seventeen healthy horses were anaesthetised and mechanically ventilated for elective procedures requiring dorsal recumbency. Spirometric VT (VT) and ∆Z were recorded periodically; up to six times throughout anaesthesia. Part 1 assessed these variables at incremental delivered VT of 10, 12 and 15 mL/kg. Part 2 estimated VT (VT) in litres from ∆Z at three additional measurement points using a line of best fit obtained from Part 1. During pa...
Enhanced Understanding of Horse-Human Interactions to Optimize Welfare. Horses () have been domesticated for millennia and are regularly utilized for work, sport, and companionship. Enhanced understanding of human-horse interactions can create avenues to optimize their welfare. This review explores the current research surrounding many aspects of human-horse interactions by first highlighting the horse's sensory capabilities and how they pertain to human interactions. Evidence exists that suggests that horses can read humans in various ways through our body odours, posture, facial expressions, and attentiveness. The literature also suggests that horses are capable...
Imported Hyalomma ticks in the Netherlands 2018-2020. Ticks of the genus Hyalomma, which are vectors for several tick-borne diseases, are occasionally found in areas outside their endemic range including northern parts of Europe. The objective of this study was to analyse adult Hyalomma ticks that were recently found in the Netherlands. Methods: Hyalomma ticks were morphologically identified. Cluster analysis, based upon sequence data (cox1 barcoding) for molecular identification, and pathogen detection were performed. Additionally, a cross-sectional survey of horses was conducted to actively search for Hyalomma ticks in summer 2019. Analysis of...
Rein Tension Signals Elicit Different Behavioral Responses When Comparing Bitted Bridle and Halter. When a rider maintains contact on the reins, rein tension will vary continuously in synchronicity with the horse's gait and stride. This continuous variation makes it difficult to isolate the rein tension variations that represent a rein tension signal, complicating interpretation of rein tension data from the perspective of horse-rider interaction. This study investigated (1) the characteristics of a rein tension signal and (2) horse response to a rein tension signal for backing, comparing pressure applied by a bit (bridle), or by a noseband (halter). Twenty Warmblood horses (10 young, 10 adu...
Epigenetic Changes in Equine Embryos after Short-Term Storage at Different Temperatures. In embryos subjected to assisted reproductive techniques, epigenetic modifications may occur that can influence embryonic development and the establishment of pregnancy. In horses, the storage temperature during transport of fresh embryos before transfer is a major concern. The aim of this study was, therefore, to determine the effects of two storage temperatures (5 °C and 20 °C) on equine embryos, collected at day seven after ovulation and stored for 24 h, on: (i) morphological development; (ii) expression of candidate genes associated with embryo growth and development, maternal recognitio...
IgE-Binding Monocytes Have an Enhanced Ability to Produce IL-8 (CXCL8) in Animals with Naturally Occurring Allergy. IL-8 is a potent chemokine that recruits neutrophils and basophils to promote inflammation in many species. IL-8 is produced by many cell types, including monocytes. In this study, we report a novel role for IgE-binding monocytes, a rare peripheral immune cell type, to promote allergic inflammation through IL-8 production in a horse model of natural IgE-mediated allergy. We developed a mAb with confirmed specificity for both recombinant and native equine IL-8 for flow cytometric analysis. Equine IL-8 was produced by CD14/MHC class II/CD16 monocytes, including a subpopulation of IgE-binding mon...
Summer Diet of Horses (Equus ferus caballus Linn.), Guanacos (Lama guanicoe Müller), and European Brown Hares (Lepus europaeus Pallas) in the High Andean Range of the Coquimbo Region, Chile. For an adequate management of natural grasslands, the knowledge and understanding of the dietary habits of herbivores and their trophic interactions are fundamental. During two summer seasons, in a mountain range of a sector of the Coquimbo Region, Chile, the botanical composition, diversity, and similarity of the diets of horses, European brown hares, and guanacos were studied, as was the selectivity of the main grassland plant species, using feces microhistology. The contribution of hydromorphic grasses was similar in the diets of guanacos (35.90 ± 7.27%) and horses (32.25 ± 4.50%), differ...
Equids engineer desert water availability. Megafauna play important roles in the biosphere, yet little is known about how they shape dryland ecosystems. We report on an overlooked form of ecosystem engineering by donkeys and horses. In the deserts of North America, digging of ≤2-meter wells to groundwater by feral equids increased the density of water features, reduced distances between waters, and, at times, provided the only water present. Vertebrate richness and activity were higher at equid wells than at adjacent dry sites, and, by mimicking flood disturbance, equid wells became nurseries for riparian trees. Our results suggest t...
Use of polyamide cable ties during experimental omentectomy in adult horses with histopathological assessment. To report the use of nylon cable ties (NCT) for omentectomy in the horse. Methods: Experimental study. Methods: Eight healthy adult horses. Methods: Horses underwent nylon cable tie (NCT) ligation of the greater omentum after ventral midline celiotomy. The time required to complete the omentectomy was recorded. Horses were recovered for 14 days before repeat celiotomy, adhesions assessment, and histological examination of the omentectomy site using a proposed histologic grading scheme. The total time for omentectomy procedure and histologic score was assessed for normality. Data are expresse...
Sex-based limits to running speed in the human, horse and dog: The role of sexual dimorphisms. Elite performing men continue to record faster record times in running events compared to women. These sex-based differences in running speed and endurance in humans are expected based on sexual dimorphisms that contribute to differences in the determinants of aerobic performance. Comparatively, the sexual dimorphisms contributing to sex-based differences in elite aerobic performance are not ubiquitous across other species that compete in running events. The purpose of this review is to offer a framework and model for ongoing discussions of the physiological determinants and ultimately limits ...
First isolation of Trichophyton bullosum from a horse with dermatophytosis in Japan. Trichophyton bullosum is a zoophilic dermatophyte that has been rarely isolated from horses and humans in Africa and Europe. This is the first reported isolation of T. bullosum from a horse with dermatophytosis in Japan. The isolate from a skin lesion formed a cream-colored and waxy colony that was slightly elevated in the center. Sequencing of the internal transcribe spacer region of the isolate revealed that it was 100% identical to that of T. bullosum.
Evaluation of Villus Synovium From Unaffected Metacarpophalangeal Joints of Adult and Juvenile Horses. Horses are a widely accepted model for osteoarthritis (OA) research. Synovial tissue sampling is commonly used in studies to evaluate and grade the progress of OA or to assess treatment effects. Synovial explants play an important role in ex-vivo studies, increasingly replacing the use of living animals. To understand histomorphological changes in the process of joint-related diseases such as OA, detailed information about histomorphometric parameters of unaffected synovial villi is necessary. The objective of the present study was to evaluate the mean width of the intimal synovial lining and ...
Air Speed to Increase Rate of Cool Out for Horses After Intense Exercise. Cooling out horses is a common practice after intense exercise. Typical cooling procedures include both walking and drenching (often with scraping). The cool out is performed to ensure the horses physiologic responses returned to a baseline range as quickly as possible. The use of water in cool out provides the greatest potential for removing heat from the animals. However, adding air velocities that can increase evaporation rates from the horses can potentially increase the rate of cool out; thereby reducing the time until the horses' physiologic measurements return to baseline. This study me...
Ischaemic postconditioning reduces apoptosis in experimental jejunal ischaemia in horses. Ischaemic postconditioning (IPoC) refers to brief periods of reocclusion of blood supply following an ischaemic event. This has been shown to ameliorate ischaemia reperfusion injury in different tissues, and it may represent a feasible therapeutic strategy for ischaemia reperfusion injury following strangulating small intestinal lesions in horses. The objective of this study was to assess the degree cell death, inflammation, oxidative stress, and heat shock response in an equine experimental jejunal ischaemia model with and without IPoC. Methods: In this randomized, controlled, experimental in...
Social buffering in horses is influenced by context but not by the familiarity and habituation of a companion. Social buffering occurs when the presence of one animal attenuates another's stress response during a stressful event and/or helps the subject to recover more quickly after a stressful event. Inconsistent previous results might reflect previously unrecognised contextual influences, such as the nature of the stimulus presented or social factors. We addressed these issues in a two-part study of horses paired with familiar (16 subjects) or unfamiliar (16 subjects) companions. Each subject performed 4 tests in a counterbalanced order: novel object test (static ball)-alone or with companion; and um...
The presence of Wormian bones increases the fracture resistance of equine cranial bone. Wormian (intrasutural) bones are small, irregular bones, that are found in the cranial sutures of the skull. The occurrence of Wormian bones in human skulls has been well documented but few studies have detected the presence of such bones in domestic animals. Although some research has linked the presence of Wormian bones to bone pathology, its anatomical significance in healthy individuals is not known. To the best of our knowledge, no previous study has examined the biomechanical features of Wormian bone. This study uses microCT imaging of the parietal bone region to determine the frequency ...
Pedigree Analysis of Warmblood Horses Participating in Competitions for Young Horses. The aim of the study was to characterize the population structure and assess the genetic diversity of warmblood horses used in the show jumping discipline. Pedigree data of 1,048 horses participating in the Polish Championships for Young Horses were analyzed. The pedigree of these animals included 12 863 individuals. The study consisted in analysis of the pedigree structure of the horses and characterization of the homozygosity and genetic diversity in the population. It was found that pedigree completeness and depth were sufficient for reliable assessment of the genetic diversity in the analy...
A QTL for conformation of back and croup influences lateral gait quality in Icelandic horses. The back plays a vital role in horse locomotion, where the spine functions as a spring during the stride cycle. A complex interaction between the spine and the muscles of the back contribute to locomotion soundness, gait ability, and performance of riding and racehorses. Conformation is commonly used to select horses for breeding and performance in multiple horse breeds, where the back and croup conformation plays a significant role. The conformation of back and croup plays an important role on riding ability in Icelandic horses. However, the genes behind this trait are still unknown. Therefor...
Effects of Aleurone Supplementation on Glucose-Insulin Metabolism and Gut Microbiome in Untrained Healthy Horses. Aleurone, a layer of the bran fraction, is deemed to be responsible for the positive health effects associated with the consumption of whole-grain products. Studies on rodents, pigs, and humans report beneficial effects of aleurone in five main areas: the reduction of oxidative stress, immunomodulatory effects, modulation of energy management, digestive health, and the storage of vitamins and minerals. Our study is the first aleurone supplementation study performed in horses. The aim of this study was to investigate the effect of an increase in the dose levels of aleurone on the postprandial g...
Nutrition of Broodmares. Forage availability should cover most needs for mares bred during spring and summer. Out-of-season breeding, lack of access to pasture, or good quality forage calls for nutritional supplementation. Current evaluations of broodmare needs are based on fetoplacental tissue requirements, but do not consider endocrine changes or that the maternal diet quality affects long-term foal health. This article reviews pregnant mares' current nutritional recommendations. Secondly, fetoplacental developmental stages during gestation are outlined, defining critical periods in the context of the developmental ...
Ex Vivo Comparison of a UV-Polymerizable Methacrylate Adhesive versus an Inverting Pattern as the Second Layer of a Two-Layer Hand-Sewn Jejunal Anastomosis in Horses: A Pilot Study. Resection and anastomosis of small intestine during colic can lead to adhesions and recurrent colic. Several methods are available to reduce the rate of adhesions in the postoperative period, such as the use of serosal barriers. Surgical glues form a smooth surface, are fast to apply, and could reduce surgery time when performing anastomosis. A recently developed UV-polymerizable methacrylate adhesive (UV-PMA) is designed to anchor into the biological tissues' top surface offering sealant and a smooth cover over the anastomosis site. This adhesive was used ex vivo on fifteen samples of equine ...
Rethinking the evidence for early horse domestication at Botai. Despite its transformative impact on human history, the early domestication of the horse (Equus caballus) remains exceedingly difficult to trace in the archaeological record. In recent years, a scientific consensus emerged linking the Botai culture of northern Kazakhstan with the first domestication of horses, based on compelling but largely indirect archaeological evidence. A cornerstone of the archaeological case for domestication at Botai is damage to the dentition commonly linked with the use of bridle mouthpieces, or "bit wear." Recent archaeogenetic analyses reveal, however, that horse r...
The Influence of Diet Change and Oral Metformin on Blood Glucose Regulation and the Fecal Microbiota of Healthy Horses. Common treatments for Equine Metabolic Syndrome (EMS) and associated conditions include removal from pasture and adoption of an all-hay diet. Pharmacological treatments for EMS include metformin, a biguanide antihyperglycemic agent also administered to people to help improve glucose tolerance and insulin sensitivity. Both treatments may work, at least partially, through the gut microbiota, yet little is known regarding these effects in the equine host. To determine the influence on the fecal microbiota of this diet change and administration of metformin, six healthy horses were removed from pa...
A Critical Overview of the Use of Platelet-Rich Plasma in Equine Medicine Over the Last Decade. In the 1990s, the role of platelets in inflammation and tissue healing was finally recognized. Since then, the clinical use of platelet-derived products (hemocomponents), such as, platelet-rich plasma (PRP), markedly increased. The promise of a more economical option of a disease-modifying treatment led to the intensive and continuous research of PRP products and to its widespread clinical use. A number of protocols and commercial kits have been developed with the intention of creating a more practical and reliable option for clinical use in equine patients. Still, the direct comparison betwee...