Research | Mad Barn Academy

Histological properties of the distal sesamoidean impar ligament in racing Thoroughbreds and Quarter horses.

Canadian journal of veterinary research = Revue canadienne de recherche veterinaire April 1, 2026 Volume 90, Issue 2 77-83

Faramarzi B, Lee D, Khamas W, Dong F.The distal sesamoidean impar ligament (DSIL) is a key component of the equine podotrochlear apparatus, yet its role in conditions such as caudal heel pain and navicular syndrome remains poorly understood. The objective of this study was to characterize the histological properties of the DSIL and evaluate how it is influenced by breed and age. Eighty-four cadaveric forelimb DSIL samples were collected from young, athletic Quarter horses (QHs), Thoroughbreds (TBs), and older, retired Quarter horses. Samples were stained and assessed for vessel size and count, number of nerve fascicles, and the r...

Journal of the American Association for Laboratory Animal Science : JAALAS April 1, 2026 1-10 doi: 10.30802/AALAS-JAALAS-25-152

Outouil M, Daugherity EK, Warnick LD, Perry PJ.Single-stall housing is a common system used for horses in various settings, including racing stables, riding schools, teaching and research facilities. Adequate stall space is necessary for horses to lie down and make postural adjustments, both of which are essential for equine rest and welfare. The Guide for the Care and Use of Laboratory Animals recommends a stall size of 144 ft2. However, not all stalls meet this size requirement, and there is limited literature supporting its use in terms of animal welfare. This study used a crossover design to compare behavioral and physiologic variables...

Biology April 1, 2026 Volume 15, Issue 7 563 doi: 10.3390/biology15070563

Chang X, Shi X, Luo P, Yao X, Meng J, Wang J, Ren W, Li L, Zeng Y.Fat color is one of the most important economic traits influencing consumer preference and the market value of meat products. To explore the molecular mechanisms underlying abdominal adipose tissue color differentiation in the Kazakh horse, this study employed a multi-omics strategy, integrating targeted metabolomics (fatty acid and amino acid profiling), untargeted metabolomics, and transcriptomic analyses. Two types of adipose tissue, white adipose tissue (WAT, = 8) and yellow adipose tissue (YAT, = 8), were selected for systematic comparative analysis. Fatty acid composition analysis reve...

Veterinary anaesthesia and analgesia April 1, 2026 Volume 53, Issue 4 101227 doi: 10.1016/j.vaa.2026.101227

Auckburally A, Grubb TL, Perchiazzi G, Högman M, Nyman G.To outline historical aspects of nitric oxide, including its discovery and biological effects, to describe the current use of inhaled nitric oxide (iNO) in human healthcare, and to review the available evidence on the use of pulsed iNO (PiNO) for the management of hypoxaemia in anaesthetised horses. Methods: Google Scholar and PubMed databases were searched using the search terms nitric oxide, PiNO, environment, discovery, acute respiratory distress syndrome, COVID-19, SARS-CoV-2, horse, pony, hypoxaemia, and anaesthesia. Conclusions: Inhaled NO is licensed in the management of hypoxic respira...

Tierarztliche Praxis. Ausgabe G, Grosstiere/Nutztiere April 1, 2026 doi: 10.1055/a-2794-3137

Herschel TL, Pelli A, Winter K, Scharner D.Penetrating wounds of the hoof are common and potentially life-threatening injuries in equine veterinary practice. The aim of this study was the systematic data analysis of horses presenting to the clinic with a solar puncture wound.In this retrospective study, patient data from horses presented with a puncture wound to the hoof in the period from September 2008 to August 2024 were collected. The analyzed data covered signalment, intended use, and insurance status. The following were also considered: previous history including the period between injury and presentation to the clinic, affected ...

PloS one April 1, 2026 Volume 21, Issue 4 e0344530 doi: 10.1371/journal.pone.0344530

Nadal-Desbarats L, Dupuy C, Montigny F, Bertevello PS, Douet C, Gesbert A, Reigner F, Goudet G.Saliva is a relevant biofluid for real-time welfare-friendly monitoring of systemic events in animals, because some bioanalytes have a systemic origin and its collection is painless, stress-free and non-invasive. Our aim was to analyze the metabolome of equine saliva during the five days before foaling, with a focus on identifying metabolites whose level significantly changed before parturition, that could be potential salivary biomarkers of the onset of parturition. We compared the saliva and plasma metabolomes to investigate their relationship. Saliva and blood samples were collected from tw...

Journal of veterinary pharmacology and therapeutics April 1, 2026 doi: 10.1111/jvp.70071

Sakai DM, Ishikawa Y, Im JSY, Zhang S, Reed RA, Quandt JE, Barletta M, Knych HK.Administering large volumes of bupivacaine in the rectus abdominis sheath (RAS) block in horses could cause local anesthetic toxicity. This study aimed to evaluate the pharmacokinetics of 2 mg/kg bupivacaine in RAS blocks and the associated toxicity risk. Six healthy adult horses were sedated with xylazine and received an ultrasound-guided bilateral 2-point RAS block. Plasma samples were collected at baseline and from 5 min to 24 h after the block and analyzed using liquid chromatography-tandem mass spectrometry. A noncompartmental analysis was performed to determine the maximum concentr...

Animals : an open access journal from MDPI April 1, 2026 Volume 16, Issue 7 1082 doi: 10.3390/ani16071082

Young PL, Hyde R, Douglas J, Freeman SL.Artificial Intelligence (AI) is being increasingly used for equid health and welfare. This study aimed to establish consensus on where and how AI should be developed to achieve maximum benefit in this field. A workshop involving 41 stakeholders generated statements about current welfare concerns, areas for AI development, and barriers and solutions to AI use. Statements were circulated through Delphi surveys (acceptance set at 75% agreement). One-hundred-and-six statements reached agreement. Ethological needs not being met and poor equid management practices were key welfare concerns. Particip...

G3 (Bethesda, Md.) March 31, 2026 jkag085 doi: 10.1093/g3journal/jkag085

Gmel AI, Pirani A, McInnis L, Neuditschko M.Single nucleotide polymorphism (SNP) arrays are commonly used in livestock genetics to investigate complex traits including genome-wide associations and fine mapping, genomic prediction and genetic diversity analyses. In a European equine diversity study, we analysed the AxiomTM Equine 670K SNP genotype data from 2,768 equids representing 20 horse breeds and one donkey breed. Using a strict detection setting to identify genome-wide runs of homozygosity (ROH), 169 purebred horses displayed fewer ROH segments than F1 crosses. Under medium and relaxed settings, ROH counts increased, while some ho...

Frontiers in veterinary science March 31, 2026 Volume 13 1716790 doi: 10.3389/fvets.2026.1716790

Gehrke RS, Ehrle A, Müller EMT, Kraul RK, Schmitz P, Lischer CJ.A three-day-old male Warmblood foal presented with inability to urinate. Primary diagnostic findings included abdominal distension, hyperkalemia, azotemia, and ultrasonographic evidence for free anechoic fluid in the abdominal cavity. Abdominocentesis confirmed the diagnosis of an uroperitoneum [peritoneal fluid to serum creatinine ratio (>2:1)]. Suture repair of a dorsal urinary bladder wall defect was performed, but leakage along the suture tracts resulted in recurrent uroperitoneum confirmed by computed tomographic urography after two days. Repeated cystorrhaphy was performed but uroperi...

Journal of virology March 31, 2026 e0019926 doi: 10.1128/jvi.00199-26

Soni S, Eertink LG, Shuisong N, Loynachan A, Barnum SM, Adam EN, Kennedy MA, Wang D, Li F.Rotaviral diarrhea in foals is caused by two dominant G3P[12] and G14P[12] genotypes of equine rotavirus A (ERVA). Protection of foals against ERVA infection and disease is achievable by passive antibody transfer through colostrum from mares receiving inactivated monovalent G3P[12] vaccine. Simian rotavirus SA11 G3P[2] is also included in ERVA vaccines to protect foals. Here, we characterized cross-neutralization and protection among three distinctive rotaviruses carrying the same or different G (defined by VP7) or P (defined by VP4) genotype by using a rabbit and equine monospecific antisera ...

Animals : an open access journal from MDPI March 31, 2026 Volume 16, Issue 7 1062 doi: 10.3390/ani16071062

Kovács M, Hegedűs B, Mihók S, Knop R, Szabó C, Posta J.The conservation of genetic diversity in historically structured horse breeds requires fi-ne-scale population genetic evaluation beyond conventional pedigree-based approaches. The present study assessed genetic diversity, population structure, and mare family differentiation in a Lipizzan horse population using 16 ISAG/FAO-recommended microsatellite markers. A total of 172 mares representing 29 mare families were genotyped. All loci were polymorphic, with a mean number of alleles per locus of 6.69 and a mean effective number of alleles of 3.56. The average polymorphism information content (PIC...

Open veterinary journal March 31, 2026 Volume 16, Issue 3 1947-1953 doi: 10.5455/OVJ.2026.v16.i3.50

Brini ZE, Touzani CD, Bouzidi AA, Piro M.Testicular tumors are rare in horses, with seminoma being the most frequently described in the literature. In Morocco, many stallions used for Tbourida are intentionally kept intact, as uncastrated horses are traditionally viewed as symbols of prestige and cultural pride. This cultural practice increases the likelihood of detecting testicular pathology in mature stallions. Unassigned: A 15-year-old Arabian-Barbe stallion used in Tbourida was presented for evaluation after the owner noticed a slow, progressive enlargement of the right testis over a period of more than 1 year. Clinical examinati...

Journal of veterinary pharmacology and therapeutics March 31, 2026 doi: 10.1111/jvp.70070

Vandaele Z, Flyps J, Cuypers C, De Baere S, Devreese M, Schauvliege S.Subanaesthetic doses of ketamine (0.5 mg kg) provide analgesia in several species, but there is limited information on the pharmacokinetics and clinical effects of intramuscularly administered ketamine in horses. This study investigated the pharmacokinetics of ketamine and norketamine, and evaluated clinical effects, ataxia, and vital parameters, following intramuscular and intravenous administration of 0.5 mg kg ketamine in nine healthy horses, using a randomized two-period crossover design with a 1-week washout period. Plasma concentrations were analyzed using Ultra-High Performance ...

Theriogenology March 30, 2026 Volume 260 117917 doi: 10.1016/j.theriogenology.2026.117917

Sancler-Silva YFR, Costa LML, Freitas MS, Teixeira CS, Albino MV, García HDM, Fiala-Rechsteiner SMDE, Schultz ÉB, da Fonseca LA, Catalán J.The limited fertility of jennies inseminated with frozen donkey semen remains a major challenge for donkey reproduction and conservation, contrasting with the more favorable outcomes observed in mares. Species-specific differences in post-breeding uterine inflammation have been proposed as a key factor underlying this disparity. This study compared the uterine inflammatory response and pregnancy outcomes of jennies and mares inseminated with frozen donkey semen. Twelve jennies and eleven mares were monitored over 48 and 44 estrous cycles, respectively. Artificial insemination (AI) was performe...

Equine veterinary journal March 30, 2026 doi: 10.1002/evj.70152

Yoshitomi MD, Kuramoto T, Hatazoe T, Mitsuda K, Smith H, Misumi K.Culture protocols need to yield 100 million equine synovial fluid (SF)-derived mesenchymal stromal cells (SF-MSCs) in around 3 weeks are needed, before these cells can be evaluated as agents of articular repair in clinical trials. Objective: To investigate mass culture of equine SF-MSC culture protocols using nonwoven polyethylene terephthalate (PET) fabrics for the potential to meet the targets for clinical trials. Methods: In vitro experiments. Methods: SF samples were collected from the carpal joints in thoroughbred racehorses (n = 21) undergoing arthroscopic surgery and cultured in 10%...

Veterinary research communications March 30, 2026 Volume 50, Issue 3 239 doi: 10.1007/s11259-026-11187-3

Kellerer L, Conn KL.We investigated equine nucleolar proteins nucleophosmin 1 (NPM1) and nucleolin (NCL) during EHV1 infection to develop understanding of EHV1-nucleolar interactions. Equine NPM1 primarily localized throughout nucleoli whereas NCL accumulated in a peri-nucleolar ring and localized throughout the nucleoplasm. EHV1 did not notably affect NPM1 or NCL protein levels but did alter their subnuclear localization. NPM1 accumulated in EHV1 replication compartments and remained nucleolus-associated until very late infection stages, characterized by a kidney bean-shaped nucleus and round cell morphology. NC...

Preventive veterinary medicine March 30, 2026 Volume 252 106876 doi: 10.1016/j.prevetmed.2026.106876

Firdausy LW, Fikri F, Wicaksono AP, Maslamama ST, Purnama MTE.Equine viral arteritis (EVA) is a globally widespread infectious disease affecting equids, with significant consequences for reproductive efficiency and the regulation of international equine trade. Nevertheless, despite the accumulation of numerous region-specific investigations, an integrated synthesis of global seroprevalence estimates and overarching epidemiological patterns remains insufficiently developed. Objective: To calculate the pooled global seroprevalence of EVA and to explore sources of epidemiological heterogeneity. Methods: A systematic review and meta-analysis were undertaken ...

Veterinary medicine and science March 30, 2026 Volume 12, Issue 3 e70903 doi: 10.1002/vms3.70903

Rodrigues GJ, Monteiro FDO, Teixeira PPM.This case report describes the successful application of video-assisted hysteroscopy to evaluate endometrial recovery in a 6-year-old mare following treatment for complete uterine prolapse secondary to dystocia. Upon presentation, the uterus was manually reduced and supported with a Buhner's suture. A multimodal medical protocol, including broad-spectrum antibiotics, anti-inflammatory drugs and uterine lavage, was initiated. Five days after reduction, an endoscopic evaluation was performed using a dedicated videovaginoscope without uterine insufflation. The procedure provided high-resolution i...

Veterinary sciences March 30, 2026 Volume 13, Issue 4 332 doi: 10.3390/vetsci13040332

West Nile virus (WNV) is a mosquito-borne flavivirus of growing importance for both human and equine health in Europe. Horses are highly susceptible to neurological disease and, because they share ecological exposure with humans, they represent valuable sentinels for detecting local viral circulation within a One Health framework. However, diagnosis of WNV infection in equines is complicated by the short and low-level viraemia, which limits the sensitivity of molecular assays, and by serological cross-reactivity with related flaviviruses and the confounding effects of vaccination. In this narr...

Parasitology international March 30, 2026 Volume 114 103274 doi: 10.1016/j.parint.2026.103274

Dos Santos Pinto M, Angeluci GC, Neto JABC, Dos Santos Barbosa I, da Silva Tito RK, Lima SG, Braga VG, Lima VMF, Lucheis SB, Sabioni MS, Kawai JGC....In this research, a seroepidemiological survey was conducted on 202 horses located on 21 properties in the northwestern region of the state of São Paulo (Brazil) to estimate exposure to Leishmania spp., Toxoplasma gondii, and Trypanosoma cruzi. Antibodies against Leishmania, T. gondii and T. cruzi, were detected in 48 (23.76%), 29 (14.36%) and 2 (0.99%) of the 202 horses, respectively. We found a significantly higher occurrence of antibodies against Leishmania compared to those against the other protozoa (Chi-Square = 46.7, 2 d.f., P < 0.001). Seropositivity for the aforementioned prot...

Equine veterinary journal March 29, 2026 doi: 10.1002/evj.70160

Papas M, Stout TAE, Vernooij JCM, Leemans B, Arnold L, Beitsma MM, Wijnands LI, de Ruijter-Villani M, Colleoni S, Lazzari G, Galli C, Claes A.The success of in vitro embryo production (IVEP) is influenced by donor mare and stallion. Objective: To determine whether donor mare and stallion influence the pregnancy rate after transfer of in vitro produced (IVP) blastocysts and to identify factors influencing the likelihood of obtaining one or more pregnancies from a single IVEP session. Methods: Retrospective clinical study. Methods: The influence of the following variables on pregnancy outcome was assessed in 2292 transfers of IVP blastocysts: speed of in vitro embryo development, embryo grade after thawing, age of the donor mare, blas...

Journal of veterinary internal medicine March 29, 2026 Volume 40, Issue 2 aalag052 doi: 10.1093/jvimsj/aalag052

Pinnell E, Shoemaker S, Wang Y, Tang Y, Sellon D, Leguillette R, Gold J, Sanz M, Bayly WM.Environmental risk factors could contribute to the development of exercise-induced pulmonary hemorrhage (EIPH) in racing Thoroughbreds. Objective: To identify environmental risk factors that might contribute to differences in EIPH prevalence and severity across 12 Thoroughbred racetracks in the United States. Methods: Eight hundred fifteen 2-year-old and 122 >2-year-old Thoroughbred racehorses. Methods: Prospective blinded observational study. Videoendoscopy was performed 30-60 min post-race. Three observers independently assigned an EIPH grade to each videorecording, and prevalence and se...

Animals : an open access journal from MDPI March 29, 2026 Volume 16, Issue 7 1043 doi: 10.3390/ani16071043

Martins NA, Patterson Rosa L, Frank MI, Dellbrigge CF, Marafon WL, Paz LB, Schmidt CH, De La Côrte FD.The Criollo horse is prized for its endurance, yet its specific biomechanical signatures remain under-researched. This study investigated diagonal dissociation and support patterns in eleven clinically sound Criollo horses to understand the influence of head and neck position (HNP), surface compliance, and morphometry. Using high-speed video (120 fps) and kinematic analysis, we found that diagonal dissociation occurred in 85.24% of hoof contacts, while HNP1 showed a higher frequency of positive (hindlimb-first) dissociation and HNP2 had a higher incidence of negative (forelimb-first) dissociat...

Journal of veterinary internal medicine March 29, 2026 Volume 40, Issue 2 aalag053 doi: 10.1093/jvimsj/aalag053

Alvarado Soto GJ, Maldonado M, Armentrout A, Woolard K, Aleman M, Giaretta P, Willis AT.Achalasia is the most common motility disorder of the esophagus in humans and has been diagnosed in cats and dogs. We describe a 4-month-old Quarter Horse colt with failure to thrive, recurrent colic episodes, and aspiration pneumonia, in which fluoroscopic evaluation identified a caudal esophageal motility disorder consistent with achalasia. Necropsy examination confirmed achalasia.

Metabolomics : Official journal of the Metabolomic Society March 28, 2026 Volume 22, Issue 2 45 doi: 10.1007/s11306-025-02393-2

Becerro-Rey L, Martín-Cano FE, Silva-Rodríguez A, Ortega-Ferrusola C, da Silva-Álvarez E, Gil C, Peña FJ.Oxidative phosphorylation is the main source of ATP for the stallion spermatozoa. Consequently, metabolites that favor mitochondrial function are receiving increased interest. However, glycolysis itself may be the major source of pyruvate and acetyl-CoA. Objective: To determine the contribution of glycolysis to feed the tricarboxylic acid cycle to generate the reducing equivalents for the electron transport chain. Methods: We stored stallion spermatozoa in the presence of different concentrations of glucose and pyruvate (1mM glucose /1mM pyruvate, 1mM glucose /10 mM pyruvate, 40 mM glucose / 1...

Australian veterinary journal March 28, 2026 Volume 104, Issue 7 457-462 doi: 10.1111/avj.70079

Hoong J, Boyd C, Secombe C, Byrne D.Antimicrobial resistance (AMR) may lead to increasing inefficacy and treatment failure of bacterial infections in the future. Antimicrobial stewardship (AMS) programmes are critical to ensuring the continued efficacy of available antimicrobials. There is a lack of published evidence-based data on the susceptibility of isolates from common reproductive infections encountered in mares. This study aims to provide equine veterinarians in Western Australia (WA) with the most appropriate first-line empirical antimicrobials for infections of the mare reproductive tract. Methods: A retrospective study...

Veterinary immunology and immunopathology March 28, 2026 Volume 296 111111 doi: 10.1016/j.vetimm.2026.111111

Kapadia CL, Crook RA, Coleman S, Unger G, Douglas RH, Fedorka CE.Altrenogest is commonly used in equine veterinary medicine for the control of estrus, behavioral modifications, and maintenance of pregnancy. Recent studies have found that altrenogest may impact aspects of the immune system, including altering cytokine production in circulation and within the reproductive tract. Therefore, we hypothesize that this alteration may lead to a deviated immune response to vaccination. Sixteen mares were divided into two groups, with ten mares (n = 10) receiving long-acting injectable altrenogest (100 mg/mL; IM) administered every 10 days, and six mares (n =...

Veterinary surgery : VS March 27, 2026 doi: 10.1111/vsu.70099

Clarysse M, Leps A, Haspeslagh M, Schauvliege S, Martens A, Vlaminck L.To assess long-term outcome, complications, and return to function in horses with maxillofacial fractures. Methods: Retrospective observational study. Methods: A total of 30 horses with skull fractures (2020-2024). Methods: Clinical records were reviewed for signalment, fracture characteristics, imaging, treatment, and hospitalization. Long-term outcome was obtained via structured owner questionnaires addressing healing, complications, cosmetic appearance, and performance. Descriptive statistics were applied. Results: A total of 29 of 30 horses received treatment (25 surgical, 4 conservative);...

Veterinary sciences March 27, 2026 Volume 13, Issue 4 328 doi: 10.3390/vetsci13040328

Pimenta J, Martins B, Mexedo A, Campilho R, Silva F, Cotovio M.Equine Gastric Ulcer Syndrome is a highly prevalent condition, yet its clinical diagnosis remains challenging due to the nonspecific nature of many associated signs. The relationship between the anatomical location of gastric ulcers and clinical presentation is still poorly defined. This retrospective study aimed to evaluate the association between gastric ulcer location and the clinical signs observed in horses. Medical records of 52 horses diagnosed with gastric ulcers by gastroscopy were retrospectively reviewed. Clinical signs were classified as physical, behavioral, or mixed, and ulcer lo...