Topic:Animal Study
Animal studies involving horses encompass a wide range of research activities aimed at understanding various aspects of equine biology, behavior, health, and management. These studies can include investigations into equine physiology, nutrition, reproduction, and disease processes. Research often involves controlled experiments or observational studies to gather data on how horses respond to different interventions, environments, or management practices. This topic includes peer-reviewed research studies and scholarly articles that explore methodologies, findings, and implications of animal studies in equine science, contributing to the broader understanding of horse welfare and management.
Computed tomographic myelography of the cranial cervical vertebral column in unaffected Warmblood horses – comparison of transverse vertebral ratios in the flexed and neutral cranial cervical vertebral column. Computed tomographic myelography (CTM) is diagnostic for extradural spinal cord compression but knowledge about vertebral ratios from transverse images in flexion and normal position of unaffected horses is lacking. Objective: To compare the ratios of the cross-sectional areas (CSAs) of the spinal cord, the vertebral canal and of the contrast enhanced dural tube on transverse CTM images at C3-C4 in neutral and flexed positions in unaffected Warmbloods. Methods: CTM was performed in 13 neurologically unaffected Warmbloods in neutral and flexed cervical vertebral column positions. Ratios were ca...
Validation of a smart textile device for long-duration heart rate variability and detection of physiological arrhythmias in resting horses. A smart textile device has been developed for the recording of electrocardiograms (ECGs) in horses; however, the utility of this device for long-duration heart rate variability (HRV) monitoring and detection of physiological arrhythmias is unknown. Therefore, the objective of this study was to validate a smart textile device for HRV over long durations (6 h) in resting horses. ECGs were recorded simultaneously via the Myant Skiin Equine textile device and a reference device (Televet 100) in 12 horses. ECGs were evaluated by a blinded observer for arrhythmias, and HRV metrics were calculated. ...
Metformin in the Horse: Pharmacokinetics and Detection Times Using Monte Carlo Simulations. The racehorse industry has strict regulations regarding the detection of prohibited substances in horses. Metformin, a diabetes medication, is a prohibited substance that has been reported in post-race blood and urine samples collected from racehorses. For further characterization of the disposition of metformin, 12 Thoroughbred horses were administered metformin orally and intravenously in a randomized, balanced, two-way crossover design. Serum and urine samples were collected, and drug concentrations determined via liquid chromatography-tandem mass spectrometry. The serum data were analyzed ...
Detection of Nandrolone Decanoate and Its Metabolites in Equine Hair After Intramuscular Administration. This paper describes the detection of nandrolone decanoate and its metabolites in mane hair collected from horses that have been treated with nandrolone decanoate (Deca-Durabolin). The intramuscular administration study of nandrolone decanoate in three Thoroughbred castrated horses (each received 800 mg weekly for 3 consecutive weeks) was previously conducted to investigate its metabolism and detection time in plasma and urine for doping control purposes. In this work, segmental analysis of the post-administration hair has revealed that (i) nandrolone decanoate and its metabolites, nandrolon...
In Vitro Investigation of Equine Gut Microbiota Alterations During Hypoglycin A Exposure. Hypoglycin A is a plant-derived protoxin that causes atypical myopathy in equids. In atypical myopathy-affected horses, metabolomic and microbiome studies have reported alterations in metabolic markers and faecal microbiota composition, pointing to a potential disruption of microbial homeostasis. However, in vivo observations are strongly confounded by host-related factors, underscoring the need for controlled in vitro approaches. To address this, we used an in vitro static batch fermentation model simulating the equine colon to investigate the direct effects of hypoglycin A on microbiota comp...
Beyond nocardioform: Transcriptionally active microbes and host responses in equine mucoid placentitis. Nocardioform placentitis (NP) is an understudied form of equine placentitis historically attributed to nocardioform bacteria, yet it remains uncertain whether these organisms are the sole pathogens involved. Objective: To elucidate the pathophysiology of NP and the host-pathogen interaction. Methods: In vivo clinical multi-omics study. Methods: Dual RNA sequencing was performed to profile transcriptionally active microbial communities and concurrent placental transcriptome responses in samples from 31 placentas with and without NP. Untargeted metabolomics was performed to study the associated ...
Multi-Omics Analysis Reveals Biaxial Regulatory Mechanisms of Cardiac Adaptation by Specialized Racing Training in Yili Horses. Yili horses undergo coordinated physiological adaptations across systems in response to customized training. This study aimed to clarify the molecular mechanisms of these adaptations by integrating analyses of cardiac function and multi-omics (lipidomics, transcriptomics, miRNomics). We collected whole blood samples from ten Yili horses before and after 12 weeks of specialized racing training to perform these analyses. Results showed training induced adaptive cardiac remodeling, with substantial increases in LVIDd and LVIDs. At the molecular level, this was accompanied by extensive blood lipid...
Correction: Integrated molecular and serological survey of Rhodococcus equi in horses from three regions of Kazakhstan. [This corrects the article DOI: 10.3389/fvets.2025.1650186.].
Agreement between veterinarians and three objective evaluation systems in naturally occurring equine lameness. Subjective lameness evaluations are critical components of equine musculoskeletal health assessments. Objective approaches can supplement diagnosis and may be preferred for specific cases and scientific purposes. Objective: Evaluate agreements between subjective evaluation of two veterinarians and standard clinical interpretations from outputs of an AI-based smartphone application (Sleip; AI-SPA), the inertial measurement unit (IMU) system Equinosis Q Lameness Locator (LL), and the IMU system Equisym (ES). Methods: In vivo experiment. Methods: Twenty-five research horses (10-30 years) were e...
Effects of Lidocaine Alone Versus Lidocaine-Dexmedetomidine Infusion on Pulmonary Gas Exchange and Respiratory Mechanics During Isoflurane Anesthesia in Horses. Dexmedetomidine improves pulmonary function in dogs and humans, but evidence in horses is scarce. This study evaluated dexmedetomidine infusion on oxygenation and respiratory mechanics in anesthetized horses. Twenty horses undergoing elective surgery were included in a prospective, non-randomized, observational study. Horses received either lidocaine alone (1.3 mg/kg over 15 min, then 3 mg/kg/hour; LIDO) or combined with dexmedetomidine (1.75 μg/kg over 15 min, then 1.75 μg/kg/hour; DL). Respiratory mechanics, gas exchange, and cardiovascular variables were recorded at baseline, post-loading...
The Concentration and Duration of Lipopolysaccharide Stimulation Produce Different Cytokine Responses in an Ex Vivo Whole Blood Model in Horses. Lipopolysaccharide (LPS) is frequently used in equine research to model clinical endotoxemia; however, there is no standardized protocol for inducing cytokine production in equine whole blood. To address this knowledge gap, the goal of this study was to compare the cytokine responses elicited by three different LPS stimulation protocols. Whole blood was collected from six healthy horses (aged 5-30 years; mixed breeds and genders) from the North Carolina State University teaching herd (IACUC #23-412). Sixty milliliters of heparinized blood were aseptically drawn and divided into 15 mL aliquots....
Dietary Proline Supplementation Promotes Growth and Development in Weaned Foals by Modulating Gut Microbial Amino Acid Metabolism. This study investigated the effects of varying proline supplementation doses in weaned foals. Twenty-eight weaned foals (approximately 5 months of age; body weight: 54.45 ± 11.33 kg; with an equal number of males and females) were randomly assigned to one of four groups-a control group, a low-dose group (20 mg/kg·d), a medium-dose group (40 mg/kg·d), and a high-dose group (60 mg/kg·d)- receiving continuous supplementation for 60 days. Blood samples were collected periodically for the analysis of hormones, antioxidants, immune parameters, and plasma amino acids. Concurrently, fecal 16S rRNA...
Effects of clodronate disodium on markers of inflammation and cartilage metabolism in juvenile horses challenged with intra-articular lipopolysaccharide. Perceived chondroprotective and anti-inflammatory benefits of bisphosphonates in the juvenile horse has led to extra-label use without supportive data regarding intra-articular effects on cartilage metabolism and inflammation. Thirty-two yearling Quarter Horses were stratified into 4 treatment groups by age (500 ± 13 d), BW (336 ± 26 kg), sex (n = 16 female; n = 16 male) and initial bone optical density for a 140-d study. The study consisted of two exercise phases: Phase 1 (d 0-84) emulated sales preparation and Phase 2 (d 99-140) mimicked early exercise training. Horses we...
L-Carnitine supplementation to the stallion semen extender attenuates the cryopreservation induced oxidative stress and ameliorates sperm functional attributes. The current study evaluated the effect of L-Carnitine supplementation to the stallion semen extender on pre-freeze and post-thaw semen quality and oxidative parameters in Marwari breed stallions. Methods: For this purpose, thirty-six semen ejaculates (6 ejaculates from each stallion) were collected using an artificial vagina (AV) from six adult Marwari stallions. The gel free semen was extended with different concentrations of L-Carnitine (LC) i.e. 0 mM (control), 2.5 mM (T1), 5 mM (T2) and 10 mM (T3). Pre-freeze and post-thaw semen evaluations were conducted for various seminal attributes and...
Proof of concept of a wearable IoT-based system for monitoring respiratory rate and surface temperature in horses. This study presents the development and proof of concept of a wearable monitoring system designed to measure respiratory rate (RR) and coat surface temperature (CST) in horses. The device integrates an embedded system based on an ESP-32 microcontroller equipped with sensors for RR (strain gauge) and CST (DS18B20) Data are transmitted in real time via Wi-Fi and stored locally on SD cards. The system was validated against conventional manual methods under field conditions. Agreement between methods was evaluated using Intraclass Correlation Coefficients (ICC) and Bland-Altman plots. Results show...
Transcriptomic profiling reveals similarities between equine IVF and ICSI embryos. In vitro production of equine embryos has been performed using intracytoplasmic sperm injection (ICSI) for the last two decades. Since 2022, a repeatable protocol for conventional in vitro fertilization (IVF) provides a successful alternative. However, little is known about the influence of the fertilization method on embryo quality and the transcriptomic profile. In this study, we aimed to examine differentially expressed genes (DEGs) between ICSI and IVF embryos in the horse. Therefore, ten equine sibling blastocysts, produced in vitro by either ICSI or IVF from three different mares, were s...
Pharmacokinetics, pharmacodynamics, and local tolerance at injection site of penicillin and gentamicin administered by intravenous regional limb perfusion in standing horses: comparison between weightbearing and flexed limbs. Intravenous regional limb perfusion (IVRLP) of antibiotics is a therapeutic method used to treat distal limb infections in horses. The objectives of this study were to determine the pharmacokinetic parameters and tolerance of sodium benzylpenicillin (NaBP) administered via IVRLP; to compare the feasibility, tolerance, and efficacy of performing IVRLP on a flexed limb versus a weightbearing limb; and to predict the efficacy of IVRLP using gentamicin or NaBP. A prospective crossover study was conducted with six horses, each undergoing four phases of antibiotic infusion (gentamicin at 2.2 mg/kg ...
Quantitative assessment of gait alterations and variability in sulky-driven Standardbred trotters after a standardised exercise test. Assessment of equine metabolic and locomotory responses to quantified levels of physical exercise is needed to support the creation of tailored protocols for optimal training adaptation. The locomotory response to exercise in horses is not fully understood. Objective: To investigate the effect of a standardised exercise test (SET) on upper-body and limb kinematics and stride-to-stride variability in Standardbred Warmblood trotters. Methods: Experimental repeated-measures field study. Methods: Thirteen Standardbred trotters, equipped with nine inertial measurement units (IMUs), performed an inc...
Chronic State and Relationship to Humans Influence How Horses Decode Emotions in Human Voices: A Brain and Behavior Study. Current research on acoustic encoding of emotional content suggests that there are universal cues, allowing for decoding within and across taxa. This is particularly important for human-animal relationships, wherein domestic animals are supposed to be particularly efficient in decoding human emotions. Here we investigated whether the decoding of the emotional content in human voices shared universal acoustic properties, or whether it could be influenced by experience. Emotional human voices were presented to two populations of horses, in which behavioral, cardiac, and brain responses were meas...
Reliability, agreement and variability of a markerless computer vision algorithm for equine gait analysis under field conditions. Computer vision-based algorithms offer accessible alternatives for equine gait analysis but require thorough assessment under diverse conditions. Objective: To evaluate a proprietary vision-based algorithm's reliability in measuring vertical displacement signals (VDS) at the eye, withers and croup, alongside groundline estimation, for horses trotting on straight lines and circles under field conditions. Methods: Cross-sectional comparative study evaluating agreement, variability and reliability of a markerless computer vision algorithm. Methods: We obtained 67 handheld iPhone recordings from 3...
Field-applicable low-intensity exercise induces bronchodilation in horses with severe asthma. Airway dysfunction in severe equine asthma (SEA) often results in early retirement or euthanasia of affected horses. Exercise-induced bronchodilation occurs in horses with SEA after intense treadmill exercise, but the effects of a lighter, field-applicable, training regimen remain largely unexplored. Objective: To evaluate the impact of submaximal aerobic exercise on airway obstruction during exacerbation of SEA. Methods: The preliminary phase explored the effects of a 25-min standardised exercise on the lung function of eight SEA horses. As notable bronchodilation occurred, the results were c...
Free Plasma Amino Acid Concentrations in Horses Fed Different Dosing Regimens of Hydrolysed Collagen. Hydrolysed collagen is used as a supplement for horses with osteoarthritis, hoof horn growth problems, and gastric ulcers. To determine the oral availability of a specific hydrolysed collagen supplement and the appropriate dose, six Warmblood mares were fed two different concentrations of the supplement: 100 g HC (C), 50 g HC (C), and a control of 0 g HC (C) during one week in a randomised cross-over design. On day 7, 14 and 21, blood sampling for amino acid (AA) analysis was performed, just prior to feeding the supplement (t = 0) and every hour after feeding for 8 h (t = 1-8). Statistical ana...
Computed Tomographic Assessment of Normal Ocular Dimensions and Densities in Cadaveric Horses (Equus ferus caballus). This study aimed to characterize the computed tomographic (CT) dimensions and contrast attenuation properties of the equine eye. CT scans from 21 horses without ocular abnormalities were analyzed to obtain detailed ocular measurements and attenuation values. In addition, cranial measurements, such as nasal-occipital length and zygomatic width, were incorporated to explore potential anatomical relationships between the skull and intraocular structures. Although most correlations between cranial and ocular parameters were weak, statistically significant associations-particularly those involving ...
Metabolism, pharmacokinetics, and bioavailability of cannabigerol in horses following intravenous and oral administration with micellar and oil formulations. Cannabigerol (CBG) is a non-psychoactive cannabinoid with growing interest in veterinary medicine; however, its pharmacokinetic profile in horses remains unknown. Understanding its absorption, distribution, metabolism, and elimination is essential to optimizing dosing strategies and evaluating its potential for clinical use in equine patients. Unassigned: A prospective crossover study was conducted in eight healthy adult horses to assess the metabolism and the pharmacokinetics after intravenous (IV) administration at 1 mg/kg and oral administrations at 10 mg/kg with two formulations (mice...
New Model of Disuse-Induced Bone Density Loss in Horses. Disuse-induced bone loss during stall confinement and immobilization is a major concern in horses because it impairs recovery and increases susceptibility to further injury. Experimental models are needed to evaluate therapeutic options, but most available equine models rely on cast immobilization, which is technically demanding and may be associated with complications. This study aimed to assess a simpler and less restrictive model to induce a quantifiable decrease in bone density in horses. Six French Standardbred horses underwent eight weeks of stall confinement, with a wooden wedge fitted ...
A comparison of fecal output determined by total fecal collection or titanium dioxide in horses. Total fecal collection studies to determine digestibility of nutrients are costly and laborious. The use of externally dosed indigestible markers, such as titanium dioxide (TiO2), to estimate digestibility using spot samples could be advantageous, but studies validating their use in horses are inadequate. Two experiments were conducted to determine if TiO2 in fecal spot samples effectively estimated fecal output in horses. In Exp. 1, four mature horses were fed a forage-based diet (85:15 forage: concentrate) split into two equal meals with 1.75 ± 0.03 g TiO2/kg DM (10 g TiO2) per day ...
Determinants of stride parameters in Thoroughbreds racing in Japan. To identify the race- and horse-level factors affecting stride parameters during Thoroughbred races in Japan. Unassigned: Global Navigation Satellite System sensors were attached to 921 horses (1,189 starts) participating in 83 races, with distances ranging from 1,000 to 1,800 m, held from April through July 2024. Stride frequency and stride length were calculated from speed spectrograms at 3 racing phases (phase 1, 200 m after gate open; phase 2, 10 m after reaching the final straight stretch; and phase 3, 130 m before the finishing line). Additionally, 10 variables (race distance, surface ty...
Arterial distribution to the tensor fasciae antebrachii muscle: a study in dogs, cattle, pigs, and horses. Arterial distribution to the tensor fasciae antebrachii (TFA) muscle is little described in the veterinary literature. In this study, we investigated TFA vascularity intra- and inter-specifically, using specimens obtained from dogs, cattle, pigs, and horses at necropsy. Canine TFA specimens showed vascularity from the collateral ulnar artery in all cases, and from the thoracodorsal artery in some cases, with no brachial or deep brachial arterial vascularity. Bovine TFA specimens showed vascularity from the thoracodorsal artery. All porcine TFA specimens showed deep brachial arterial vascularit...
Positron emission tomography using 18F-fluorodeoxyglucose reveals digital perfusion deficits associated with continuous weight-bearing in healthy standing horses. To characterize healthy foot perfusion patterns under static weight-bearing load using 18F-fluorodeoxyglucose (18F-FDG) PET. Unassigned: In 8 healthy adult light-breed horses (from May 2021 through September 2024), 18F-FDG was injected while horses stood continuously weight-bearing (CWB) for a 20-minute scan period. A repeat scan was then performed after 20 minutes of ambulation. On a separate occasion, scans were performed with ambulation allowed between injection and scanning (Amb_Control). 18F-fluorodeoxyglucose uptake was quantified via metabolic volume and standardized uptake values for c...