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.
Addressing Heterogeneity in Equine PRP Therapies: A Scoping Review of Methods, Evidence, and Commercial Validation. (1) Background: Platelet-rich plasma (PRP) therapy has become a cornerstone of equine regenerative medicine, yet significant methodological variability compromises reproducibility and clinical comparability. (2) Methods: This scoping review systematically mapped and analyzed peer-reviewed studies describing equine PRP preparation methods and commercial systems (2000-2024) following PRISMA-ScR guidelines. (3) Results: Twenty-four studies met the inclusion criteria, encompassing 317 horses and both manual and commercial devices. Double-spin manual protocols predominated, though centrifugation pa...
A GPS-based investigation into the relationship between exercise irregularity and osteochondritis dissecans in Thoroughbred weanlings: A case-control study. Osteochondritis dissecans (OCD) is a developmental orthopedic condition in young horses. Exercise and management affect OCD development, but the impact of exercise patterns during the 6-12 months growth period remains unclear. This study examined the association between OCD lesions in Thoroughbred foals and irregular exercise patterns. Forty foals wore halter-mounted Global Positioning System devices that recorded velocity every five seconds during turnout. Foals were routinely turned out for approximately 13 h daily, except on rainy days. Radiographs were taken at six and twelve months of a...
Effect of surgical antimicrobial prophylaxis duration for colic surgery on complications and resistome. Based on human studies, surgical antimicrobial (AMD) prophylaxis (SAP) beyond 24 h is unnecessary and potentially detrimental. Objective: To compare clinical and microbiological outcomes in patients receiving 24- or 72-h of SAP for colic surgery. Methods: Prospective randomised clinical trial. Methods: Horses that recovered from colic surgery were considered. Exclusion criteria were (1) age <2 years; (2) Miniature Horses, pony, and draught breeds; (3) azotaemia; (4) recent hospitalisation, colic surgery, or AMDs; (5) local AMD administration. Eligible horses were randomly assigned to recei...
Leucine, pyridoxine and resveratrol supplementation alter metabolic parameters in ponies with equine metabolic syndrome. Supplements claiming to improve metabolic profiles in equine metabolic syndrome (EMS) often lack scientific validation. Objective: To evaluate the effect of a supplement containing leucine, resveratrol and pyridoxine on the metabolic profile in ponies with EMS. Methods: Unmasked randomised, placebo-controlled field trial. Methods: Thirty-eight ponies completed the trial across five farms. Ponies were age and sex matched per farm and randomly assigned to the supplement (n = 20) or placebo group (n = 18) with owners masked to group assignments. Ponies were sampled at days -1/0 (T1), 7/8 ...
Time Attenuation Curves for Equine Intravenous Contrast Enhanced Skull CT Using the Medial Saphenous and Cephalic Veins. Intravenous (IV) contrast administration during computed tomography (CT) of the equine head is routinely performed to delineate the extent of disease and differentiate between vascular and nonvascular tissue. Current equine scan protocols are extrapolated from human and canine studies. There have been no prospective equine studies describing the optimal time to image the patient after administration of contrast or the optimal site of contrast administration. Therefore, the current postcontrast times to scan and sites of contrast administration may not be appropriate for use in horses. The obje...
Sequential changes in serum protein profiles in pregnant Spanish purebred mares. This study investigates sequential changes in serum protein fractions during gestation in 31 pregnant Spanish Purebred mares compared to 15 non-pregnant control. Total serum proteins (TSP) were measured using the Biuret method, while albumin (ALB), total globulins (tGLOB), and their subfractions (α₁, α₂, β₁, β₂, γ-GLOB) were analyzed by agarose gel electrophoresis. Pregnant mares showed significant changes in serum protein profiles throughout gestation. TSP and tGLOB concentrations increased from mid to late pregnancy (months 6-11), while ALB concentrations declined between months...
Effect on equine sperm of post-thaw glycerol dilution using two different semen extenders. Glycerol, a penetrating cryoprotectant, is most employed for deep freezing spermatozoa. However, it can induce toxic, chemical, and osmotic effects, altering the lipid structure of the sperm membrane. Rapid glycerol addition has been demonstrated to have fewer toxic effects than its removal. Objective: To minimize both the toxic and osmotic effects of glycerol on equine sperm through post-thaw dilution using two different extenders. Methods: Samples of equine semen frozen with 5% glycerol from nine stallions were thawed, re-diluted 1:2, and incubated for 30 minutes at 22°C in Tyrodes (Tyr) an...
Pharmacokinetics of a fipronil pour-on formulation and its efficacy against Dermacentor nitens (Acari: Ixodidae) in horses. The objective of this study was to standardize a stall-trial methodology for horses in order to evaluate the pharmacokinetics and efficacy of a 1 % fipronil pour-on formulation against Dermacentor nitens. Brazilian pony breed horses were housed in individual stalls within a covered barn and artificially infested with D. nitens larvae on alternate days from day -31 to -1 before treatment. The animals were treated on day 0 with a fipronil 1 % pour-on at a dose of 1 mg/Kg body weight. To determine the therapeutic efficacy, the number of engorged females naturally detached from control and t...
Preliminary assessment of the leukocyte coping capacity as a point of care marker in horses with stress associated diseases. Stress represents a serious health and welfare concern; however, its objective assessment remains difficult. The equine gastric ulcer syndrome (EGUS) and orthopedic diseases that cause pain are among stress associated diseases in equine medicine. The leukocyte coping capacity (LCC) quantifies oxygen radical generation of neutrophil granulocytes which is altered under stress. Therefore, LCC could be a novel biomarker for stress in horses and we hypothesized that horses with stress associated diseases would have lower LCC values in comparison to horses without these diseases. Methods: In this ob...
Evaluation of the impact of acepromazine on tissue oxygenation in horses sedated with detomidine. Sedation with α₂-agonists can impair microcirculation and oxygen delivery. This prospective randomized crossover study investigated whether administering acepromazine maleate before detomidine hydrochloride maintains higher peripheral tissue oxygen saturation (StO₂) in sedated horses. Eight healthy adult horses randomly received intravenous detomidine (10 μg/kg) either alone (D) or in combination with acepromazine (20 μg/kg; DA), with a one-week washout. Hemoglobin concentration and central venous oxygen saturation (ScvO₂) were measured at baseline. Tissue oxygen saturation, tissue ...
Impact of exercise frequency, race distance, age, and pregnancy stage on oxidative stress and lipid metabolism in purebred Arabian mares. Pregnancy causes increased oxidative stress in mares, possibly harming both the mare and the foal, whereas the effects of different exercise levels on oxidative stress and lipid metabolism during pregnancy remain unclear. Objective: For this reason, the aim of this research was to explore the impacts of different training intensities on oxidative stress and lipid metabolism during pregnancy. Methods: The study comprised 22 clinically normal Purebred Arabian mares from Algeria, which were divided into three groups according to age and exercise frequency. Blood samples were collected during both...
Preliminary investigation of equine veterinary hospital staff attitudes towards pain assessment in a single centre. Despite the availability of several equine pain assessment tools, their use in equine veterinary practice appears limited compared to small animal practice. This study explores potential barriers to equine pain assessment, as reported by staff at a single UK equine teaching hospital. Methods: Nine hospital staff members were interviewed using semi-structured interviews. Key themes were identified through reflexive thematic analysis. Results: Participants acknowledged the importance of pain assessment, yet highlighted limitations in current methods and their inconsistent use. Key challenges inc...
A novel dataset of 2,362 equine fecal microbiomes from veterinary teaching hospitals across three countries reveals effects of geography and disease. Horses and other equids are reliant on the gut microbiome for health, and studies have reported associations between certain clinical conditions and features of the fecal microbiome. However, research to date on the equine fecal microbiome has often relied on small sample sizes collected from single and relatively localized geographic regions. Previous work also largely employs single timepoint analyses, or horses selected based on limited health criteria. Results: To address these limitations and expand our understanding of the core microbiome in health, and the changes associated with advers...
Pharmacokinetics and Safety of a Single Subcutaneous or Intramuscular Dose of Ketamine in Healthy Horses. Pharmacokinetics (PK) of intramuscular (IM) and subcutaneous (SC) ketamine in horses has not been described. This study aimed to evaluate the PK and safety of ketamine and its metabolites after a single SC or IM administration. In Phase 1, two horses received 0.5 or 1 mg/kg of ketamine via SC and IM routes. In Phase 2, eight horses received 0.5 mg/kg IM. Plasma or serum concentrations of ketamine and major metabolites were determined by a validated liquid chromatography-mass spectrometry method at baseline and selected intervals post-administration. Subcutaneous administration resulted in ...
Histomorphometric characterization of the endometrium in mules (Equus mulus): An approach to endometritis/endometrosis. Mules (Equus mulus), as sterile hybrids between mares and donkeys, present a unique uterine morphology and physiology that remains poorly characterized. This study provides the first histomorphometric evaluation and transcriptional profiling of the endometrium in adult mules. To achieve this, endometrial biopsies were analysed using quantitative stereology, histological classification (Kenney-Doig system), and qPCR of key immune-related and fibrotic genes. Histometric analyses revealed that the stratum spongiosum was the predominant component of the mule endometrium (mean volume density: 84.7...
Dexmedetomidine Prolongs the Duration of Ropivacaine Corneal Anesthesia After Subconjunctival Injection in Healthy Horses. To determine whether dexmedetomidine prolongs corneal anesthesia following subconjunctival ropivacaine injection in healthy equine eyes. Methods: Ten horses with normal ophthalmic exams were enrolled in a randomized, blinded, crossover experiment with a minimum 4-week washout between treatments. Baseline corneal touch thresholds (CTT, cm) were measured via esthesiometry and a subconjunctival injection was performed in the treatment eye with ropivacaine (R, 0.3 mL 0.5%) or dexmedetomidine-ropivacaine (DR, 0.1 mL 0.5 mg/mL + 0.2 mL 0.5%) and saline (control, 0.3 mL) in the contrala...
An in vitro investigation into the effects of postbiotic supplementation on stabilising equine hindgut pH. Dysbiosis of the intestinal microbiome is a precursor to hindgut acidosis. As microbial diversity and fermentation are influenced by diet, including a postbiotic could help maintain healthy gastrointestinal microbes and reduce acidosis risk. Objective: It was hypothesised that including a postbiotic in batch culture would reduce the degree of pH decline and lactate accumulation during fermentation. Methods: In vitro batch cultures with faecal inoculant were prepared with either low starch (LS) or high glucose (G) substrate to represent normal and acidic fermentation. Saccharomyces cerevisiae d...
Treatment evaluation using ultrasonographic scanning of the spleen in Arabian horses affected by babesiosis. Equine babesiosis is a widespread protozoan disease in Saudi Arabia. The most common finding of clinical babesiosis is splenomegaly, which can be detected using non-invasive splenic ultrasonography. Unassigned: This study aimed to investigate changes in the spleen size in horses infected with babesiosis using ultrasonography before and after treatment. Unassigned: This study employed 15 male and female Arabian horses. Each animal was examined clinically for clinical signs, and blood samples were collected in plain tubes to detect antibodies against . The spleens of healthy and affected horses ...
Maximal Lactate Steady State Prediction Using Two DMAX Methods in Horses Subjected to Treadmill-Graded Exercise Test. Maximal lactate steady state (MLSS) and its predictive thresholds, including the lactate threshold (LT), are widely used to estimate endurance capacity, prescribe training, and assess the effects of training. The human literature identified approximately twenty-five methods to predict the MLSS. This communication compares the concordance between the two D methods and the MLSS. Under laboratory conditions, ten teaching horses underwent a submaximal graded exercise test (GXT) on a treadmill to obtain their lactate-velocity curves (LVC). They performed three to five 30-min continuous running sess...
The Impact of MEI1 Alternative Splicing Events on Spermatogenesis in Mongolian Horses. Normal spermatogenesis in Mongolian horses depends on the mitotic division of spermatogonia, two successive meiotic divisions, and the morphological transformation of spermatids into mature spermatozoa. The gene is involved in the meiosis cycle and is required for normal chromosome association during meiosis. Previous studies have shown that alternative splicing of may promote spermatogenesis in Mongolian horses. In this paper, the regulatory effects of different alternative splicing events on Mongolian horse spermatogenesis are investigated. Results: In this study, two overexpressed lentiv...
A SLC45A2 mutation is strongly associated with the cream dilution in Baroque donkeys. Domestic Baroque donkeys are popular animals in many European parks and zoos. Although their cream coat color is very charismatic, the underlying genetics is still undiscovered. Addressing this question, a candidate approach was used to search for the causative mutation.Considering the knowledge from domestic horses, the () was identified as the most promising candidate. Samples from 77 domesticated donkeys, 11 wild equids, 1 mule and 2 domestic horses were included in comparison. All exons and the flanking intron sequences of the were sequenced (2774bp).Sequence comparison revealed that a m...
Physiological and behavioural effects of continuous remifentanil-xylazine administration in donkeys. Remifentanil and xylazine are used as continuous infusions to facilitate standing surgery in horses. Their use for this purpose has not been reported in donkeys. Objective: To evaluate the behavioural, sedative, and cardiorespiratory effects of continuous intravenous infusion of remifentanil and xylazine in donkeys. Methods: Non-blinded in vivo experiments. Methods: Ten donkeys were sedated with an intravenous bolus of xylazine (0.8 mg/kg). After 3 min, continuous infusions of xylazine (0.65 mg/kg/h) and remifentanil (6 μg/kg/h) were administered for 60 min. Cardiorespiratory physio...
A systematic review on the effect of individual characteristics and management practices on equine cognition. Equine cognition is relevant to the many roles that horses serve in society, such as leisure riding, competitions, or even animal-assisted therapy. Equine cognitive abilities have been explored in recent years. However, gaining an overview of horse cognition is challenging due to the broad range of abilities studied and the diverse methodologies employed. In addition, the subjects of existing equine cognition studies vary greatly in contextual factors such as their breed, age, sex, and management conditions - each of which may influence test performance in the following cognitive categories: D...
Towards understanding mare endometrosis: ex vivo study on the role of relaxin. Mare endometrosis remains a poorly understood pathological process. Objective: Mare endometrial tissue with endometrosis was used to determine the effects of relaxin (RLX). Healthy tissues that were left untreated (H), or treated with vehicle (Hveh), and tissues with endometrosis that were left untreated (E), treated with vehicle (Eveh), and treated with RLX (10, 25, 50 nM; ER) were used for an ex vivo system for 72 h. Methods: Tissue histological examination, and immunoenzymatic measurement of the concentrations of transforming growth factor β (TGF-β), interleukins (IL-6 and IL-8), and pr...
Isolation and differentiation of endometrial mesenchymal stem cells from Arabian mares. This study aimed to extract and isolate endometrial stromal cells from Arabian mares and investigate their growth and differentiation potential. Endometrial biopsies were obtained from three healthy 6-year-old Arabian mares using a standardized, minimally invasive protocol. The isolated cells were characterized using flow cytometry and differentiation analysis. Flow cytometry revealed mesenchymal markers CD90 (95.2%) and CD105 (97.4%) and hematopoietic markers CD34 (1.17%) and CD45 (0.339%). The cells exhibited differentiation potential into adipocytes, osteoblasts, and chondrocytes. The findi...
Preliminary Assessment of Leisure Horses’ Preferences for Different Forms of Carrot (Daucus carota subsp. sativus). Cultivated carrot ( subsp. ) is a valuable component of equine diets due to its high β-carotene content (a precursor of vitamin A) and desirable sensory properties. However, its use may be limited by short shelf life, susceptibility to spoilage, and firm texture, which can be challenging for horses with dental problems. This study aimed to evaluate horses' preferences for different physical forms of carrots. Twenty-one leisure horses aged 3-22 years were individually evaluated in a free-choice test. Each horse was simultaneously offered equal portions (150 g) of five carrot forms: raw, grated...
Oral administration of pimobendan in healthy horses results in low plasma concentrations. To describe the pharmacokinetics of a single dose of pimobendan (Vetmedin) in healthy adult horses and provide preliminary evidence of the absorption of 2 compounded pimobendan formulations. Unassigned: From August 2022 through November 2022, 6 healthy adult horses were administered a single dose of 0.5 mg/kg pimobendan orally. A subset of 2 horses was also administered pimobendan, compounded as an oil-based suspension and a capsule formulation. Plasma was collected at times 0, 15, 30, and 45 minutes and 1, 2, 4, 8, 12, and 24 hours after administration. The plasma concentrations of pimobendan...
Reining in strangles: Absence of disease in horses vaccinated with a DIVA-compatible recombinant fusion protein vaccine, Strangvac, following natural exposure to Streptococcus equi subspecies equi. Strangles, caused by Streptococcus equi subspecies equi (S. equi), is a prevalent infectious disease of horses. This is the first report on the use of a new vaccine, Strangvac, in a natural outbreak of strangles. Objective: To measure the effects of Strangvac vaccination during an outbreak of strangles at a Swedish farm. Methods: Longitudinal cohort study. Methods: Healthy horses (n = 17) were vaccinated on day 0, which occurred 23 days after strangles was first confirmed in three unvaccinated horses on the same farm. Blood serum samples were collected on day 0, day 28 and day 489. A com...
Liposomal bupivacaine caudal epidural in horses results in adverse effects without analgesia. To evaluate the analgesic properties and adverse effects of liposomal bupivacaine administered via caudal epidural in horses. Methods: Pharmacodynamic study. Methods: A total of 10 healthy adult horses. Methods: Liposomal bupivacaine (10 mL; 1.3%) was administered into the caudal epidural space via an indwelling epidural catheter inserted to a length of 15 cm. Mechanical nociceptive threshold (MNT) testing with pressure algometry was used to measure analgesia at four anatomic locations for 72 h following injection. Physical examinations (including rectal temperature, heart rate, respirat...
Agreement of the performance of equine electrocardiogram recording devices for ECG complexity analysis. Non-linear equine electrocardiography (ECG) analysis is an actively developing study area which has the potential to lead to novel, artificial intelligence-based diagnostic tools in equine cardiology. As more ECG recording devices are becoming available, there is a need to ensure results are interchangeable regardless of the equipment used to record the equine ECG. Objective: To evaluate the agreement of ECG complexity values obtained using the Televet™ and Equimetre™ systems. Methods: Cross-sectional clinical. Methods: ECGs were recorded using two devices simultaneously from 37 healthy Th...