"Horses" is a broad topic that encompasses various aspects of equine biology, behavior, and management. This category includes studies on the anatomy, physiology, and genetics of horses, as well as their behavior, nutrition, and care. Research in this area may also cover the historical and cultural significance of horses, their roles in agriculture, sport, and therapy, and the challenges associated with their conservation and welfare. The page aggregates peer-reviewed research articles and scholarly studies that explore the multifaceted relationships between humans and horses, examining both scientific and socio-economic perspectives.
Olitsky PK, Harford CG.Young (12 to 15 day old) mice are approximately as susceptible to the virus of equine encephalomyelitis, Eastern or Western strain, when it is given intraperitoneally as are adult mice when the virus is injected intracerebrally. With this susceptibility by the intraperitoneal route as a basis, the injection of immune serum-virus mixtures intraperitoneally was found to result in protection in dilutions which give rise to infection after intracerebral inoculation. The difference of protective power by the two indicated routes was shown not to depend on the amount of inoculum nor on the age of th...
Tenbroeck C, Hurst EW, Traub E.Equine encephalomyelitis of the eastern type is a disease of the late summer and fall and cases are found in greatest numbers near salt marshes. The epidemiological findings are against its transmission by contact and favor the view that it is insect borne. Although virus can be demonstrated in the blood of infected horses it is present for a relatively short time, and the possibility that the disease is not primarily an infection of horses but that it is transmitted to them from another host is considered.
Hurst EW.The virus of equine encephalomyelitis (eastern strain) evokes in the horse, calf, sheep and dog an unusually intense encephalomyelitis characterized by acute primary degeneration of nerve cells, the appearance in neurons of the brain stem and elsewhere of nuclear inclusions resembling those in Borna disease and poliomyelitis, polymorphonuclear infiltration in the nervous tissues with early microglial proliferation, and perivascular cuffing with mononuclears and polymorphonuclears in varying proportions. The grey matter is affected more than the white. Lesions may be less marked in the striatum...
Olitsky PK, Cox HR, Syverton JT.We have studied certain properties, additional to those previously described (3), of the virus of vesicular stomatitis of horses, and of the characteristic biological reactions of the virus of equine encephalomyelitis. It has been found that the virus of stomatitis, ordinarily dermotropic, can acquire neurotropism and the neurotropic encephalomyelitis virus can, in turn, be rendered dermotropic in its action. The neurotropism in both instances is associated with definite, although not pronounced, viscerotropism. Both viruses can bring about a similar infection in the white mouse, rat, guinea p...
Woods AC, Chesney AM.A filterable agent has been obtained from the humors and tissues of the eyes of horses suffering from active periodic ophthalmia. The intra-vitreous injection of this filtrate produced in normal horses the same clinical and pathological picture observed in the natural disease. This filtrate injected into rabbits produced a different clinical picture, but the essential pathological lesions closely resembled those found in horses. After passage of the filterable agent through six generations of rabbits, it again produced the clinical and pathological picture of the natural disease when injected ...
Badr C, Handous M, Nsiri J, ElBehi I, Arbi M, Maaroufi A, Bennour MA, Ben Osman R, Dachraoui K, Abbes M, Mahmoudi A, Khosrof I, Abrougui S, Lachheb J....West Nile virus (WNV) is an arthropod borne virus, the most widely distributed of the encephalitic Orthoflaviviruses. It can cause severe neurological symptoms in both humans and horses. It poses an emerging threat to both public and animal health. In this study, we retrospectively screened 25 suspected WNV samples collected from 2018 to 2023. Methods: A total number of 25 samples (brain tissue and blood) were collected from clinically affected horses and those already deceased across several locations in Tunisia. All samples were tested for the presence of WNV NS2A gene using qRT-PCR. Eleven ...
Gomes ÉR, Felix LA, Gonzaga LWF, da Silva NFD, Soares BCF, de Almeida JVFC, Souza GP, Pereira RN, Taffarel MO, Ferrante M.The combination of detomidine and midazolam may provide safer sedation with muscle-relaxant effects, which are particularly necessary during standing procedures. Unassigned: Thus, the objective of this study was to evaluate the sedative and muscle-relaxant effects of the detomidine/midazolam combination in horses through a pharmacodynamic study. Unassigned: Five horses were used and subjected to four experimental protocols: 15 µg/kg of detomidine (D15); a combination of detomidine (15 µg/kg) with 25 µg/kg (DM25), 50 µg/kg (DM50), or 75 µg/kg (DM75) of midazolam administered intravenously....
Freeman DE, Smith B, Bauck AG, Denagamage T, Moyer EK, Chanutin S.To develop a modified stapled (MS) jejunocecostomy (JC) in healthy horses. Methods: In vivo experimental study. Methods: Six healthy adult horses underwent ventral midline celiotomy, a jejunal resection, and an MS. Methods: Time to complete anastomosis and anastomotic length at necropsy were recorded. Horses were assessed by physical examination every 6 h for 5 days after surgery, then once daily until euthanasia at 7 days. A group of seven horses that had a stapled side-to-side JC and were euthanized 28 days postoperatively was used as an historical control (SS). Results: All MS horse...
Melly V, Ortved KF, Stewart HL, Stefanovski D, Richardson DW, Bubeck KA, Hogan PM, García-López JM.To present fracture cases selected for plate fixation (PF), describe surgical techniques and assess their association with postoperative complications and return-to-work outcomes in horses undergoing PF for small metacarpal/metatarsal (SMCT) fractures. Methods: Multicenter retrospective study. Methods: A total of 27 horses. Methods: Horses treated with PF of a SMCT fracture between 2008 and 2023 across three hospitals were included. Medical records and imaging were reviewed. Long-term outcomes were established by readmission to the hospital, telephone interviews, and/or race records. Univariab...
Morgan JM, Gentille SR, Goyette FD, Lehman ML, Boss AL, Cassano JM, Knych HK, White SD.To determine the safety and pharmacokinetics of a single dose of the oral ectoparasiticide fluralaner at 10 and 25 mg/kg in healthy horses. Unassigned: 12 clinically healthy university-owned horses, 9 to 17 years of age, were administered a single oral dose of fluralaner at 10 or 25 mg/kg. Physical examinations, neurological examinations, plasma samples, hematology and biochemistry panels, and skin biopsies were collected throughout the 84-day trial period. Fluralaner concentrations were measured in plasma and skin by liquid chromatography-tandem mass spectrometry, and pharmacokinetics were ev...
Yamashita N, Hatazoe T, Misumi K, Hobo S.The Tokara horse is a breed of native Japanese horse, for which hematological and biochemical data are lacking. The aim of this study was to obtain current hematological and biochemical data on Tokara horses. We enrolled 90 Tokara horses kept at the Kaimon Foothills Nature Park (Kagoshima) that underwent physical examinations and blood sampling between 2022 and 2024. All horses in this study were regarded as clinically healthy, based on physical examinations. Hematological and biochemical parameters also showed no abnormal values. Based on the above results, we consider that the data from this...
Hartl B, Strohmayer C, Vali Y, Lyrakis M, Kneissl SM.Horses with hyoid bone disease may present with clinical symptoms such as exercise intolerance, resistance to ridden work, anorexia, or headshaking. This study aims to describe the computed tomographic (CT) signs and prevalence of hyoid disease and to evaluate their association with other CT changes of the head. Unassigned: In this study, four investigators conducted a retrospective analysis of their findings after reviewing the medical records of 200 horses that had undergone CT scans between 2009 and 2019. A total of 32 parameters were analyzed, and associations were evaluated between those ...
Kawashima M, Kuroda T, Minamijima Y, Yamazaki Y, Mita H, Nomura M, Ohta M.Remimazolam (RMZ) is a new short-half-life benzodiazepine used in humans. We compared the pharmacokinetics and sedative effects of RMZ with those of midazolam (MDZ) in Thoroughbred horses. Six Thoroughbreds received a single IV dose of RMZ 0.05 mg/kg or MDZ 0.05 mg/kg in a randomized crossover design. Blood samples were collected, and plasma RMZ and MDZ concentrations were measured by LC-MS/MS. Plasma concentrations were analyzed by using non-compartmental analysis and a nonlinear mixed effect model. The half-life of RMZ (0.77 ± 0.15 h) was significantly shorter than that of MDZ (3....
Frippiat T, Bonhomme M, Dyson S, Votion DM.Equine gastric ulcer syndrome (EGUS) adversely affects the health, welfare, and performance of sports horses, requiring gastroscopy for definitive diagnosis. Owners frequently consider girth aversion as highly suggestive of EGUS. Objective: To evaluate whether owner-reported clinical signs or fecal occult blood tests (FOBTs) can help identify horses needing gastroscopy for EGUS diagnosis or monitoring treatment, thereby reducing unnecessary procedures in unaffected horses. Methods: Eighty competition dressage horses referred by veterinarians for EGUS evaluation. Methods: Case-control study in...
Söderroos D, Stefánsdóttir GJ, Ragnarsson S, Gunnarsson V, Jansson A.Weight-carrying capacity is important in riding horses both for performance and welfare, yet there is no standardized method to estimate individual horses' weight-carrying capacity. This study investigated the correlation between the physiological response during a (i) standardized incremental exercise test (SET) on a treadmill and a (ii) ridden incremental weight-carrying exercise test (WET). Sixteen horses (15 ± 3 years) performed both tests, including four steps with increased speed or weight load, respectively. Body weight ratio (BWR) in the WET was 20%, 25%, 30%, and 35% in each st...
Šarkūnas M, Schwahn A, Suleimanova K.The aim of present study was to examine the potency of moxidectin solution (Cydectin 1 %; Zoetis) and commercially available oral moxidectin gel (Equest®; Zoetis) to suppress the excretion of strongyle eggs in horses over a 6-week period. The horses naturally infected with strongyle nematodes (>500 eggs/g of feces) were divided into two comparable groups according age, sex and weight. On day 0 of the study, horses in Group OT (oral treatment; N=5) were dewormed with moxidectin gel (Equest®; Zoetis; 0.4 mg/kg of b.w.) according to the manufacturer's instructions, and horses in Group IT (intra...
Thane K, Voth R, Klee R, Warnken T, Chukwu V, Frank N.Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are promising treatments to manage hyperinsulinemia in horses with insulin dysregulation (ID). Objective: The SGLT2i velagliflozin decreases insulin concentration in horses with ID. Methods: Privately-owned adult horses (n = 37) with laboratory-confirmed ID (low-dose oral sugar test insulin concentration > 75 μIU/mL). Methods: Double-blind randomized placebo-controlled trial. Horses received placebo (n = 19) or velagliflozin 0.3 mg/kg PO q24h (n = 18) for 20 weeks (Study Period 1, SP1) immediately followed by a 20-week ope...
Minamijima Y, Kuroda T, Okano A, Wakuno A, Yuasa R, Ishikawa Y, Nomura M, Kinoshita K, Yamada M.We examined the pharmacokinetics of intravenous pridinol in six thoroughbred horses. Each horse received a single 20 mg dose of pridinol mesylate via the jugular vein, and plasma and urine samples were collected over 72 h. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to quantify pridinol concentrations in plasma and urine, allowing for the calculation of pharmacokinetic parameters. A three-compartment model best fit the plasma elimination data. Using the Toutain model, irrelevant plasma and urine concentrations were estimated to be 0.00284 and 0.000612 ng/mL, respec...
Kingsley NB, Sandmeyer L, Dwyer A, Langefeld CD, McMullen RJ, McCue M, Lassaline M, Bellone RR.Equine recurrent uveitis (ERU), an inflammatory eye disease, is the leading cause of blindness among horses. Insidious uveitis, a form of ERU, is especially pervasive within the Appaloosa breed and is highly heritable (h = 0.68-1.0). To date only one risk locus, leopard complex (LP), has been identified, and it explained 0.16-0.33 of the heritability estimate, suggesting that insidious uveitis is a complex genetic disease within the Appaloosa horse breed with multiple unknown predisposing loci. Results: A genome-wide association study (GWAS) using relatedness, LP genotype, sex, and age as ...
Steensma MJ, Doekes HP, Derks MFL, Ducro BJ.In Friesian horses, withers height is an important trait as a minimum has been set to be eligible to the studbook. Several loci for withers height have been identified in horses. However, withers height has not been studied in the Friesian horse. Therefore, our aim was to identify loci associated with withers height in the Friesian horse population. We performed a genome-wide association study using 70 K SNP data of 2192 Friesian horses. We found ECA1 and ECA9 to be significantly associated with withers height, explaining 19.6% and 3.5% of the phenotypic variance, respectively. In other hors...
Luštrek B, Šimon M, Turk K, Bogičević S, Potočnik K.In small, closed populations such as the Lipizzan horse, maintaining genetic diversity while limiting inbreeding is a key challenge in conservation breeding. The Lipizzan is an indigenous Slovenian breed with a small population and restricted gene flow from other subpopulations. Inbreeding is traditionally monitored with pedigree-based coefficients, but these often underestimate realised autozygosity, particularly when pedigree depth is limited. This study compared pedigree-based inbreeding (F_PED) with four genomic estimators (F_HOM, F_ROH, F_HBD, F_GRM) in 329 Slovenian Lipizzan horses genot...
Corradini I, Jose-Cunilleras E, Nolis P, López-Murcia MM, Mayordomo-Febrer A.This study aims to generate foundational metabolomic data of aqueous humor (AH) in healthy horses and donkeys, and to investigate potential changes or trends in the metabolomic profile associated with age, sex or ocular pathology in horses. The AH metabolomic fingerprint from 5 donkeys and 35 equine eyes (17 controls, 8 with cataracts, 6 with retinal disease and 4 with anterior chamber disease (ACD)) were analyzed using nuclear magnetic resonance (NMR) spectroscopy. A linear mixed-effects model, with individual horse as a random effect and group as a fixed effect, with multiple testing correct...
Joseph EJ, Love L, Mayakis M, Varner K.Trazodone is administered to hospitalized equine patients to aid in behavioral management, but the effects on the anesthetic recovery period have not been investigated. This study sought to determine if there is an association between trazodone administration and recovery quality, recovery time, need for sedation, or need for reversal agent administration. We hypothesized that there would be no difference in recovery scores, recovery time, additional sedation, or reversal agent administration between horses that received preanesthetic trazodone and horses that did not. Records were reviewed to...
Nocera I, Moroni R, Fanelli D, Rota A, Di Franco C, Ungari C, Puccinelli C, Gandini M, Giusto G, Vannozzi I.Over the years, various diagnostic and surgical techniques have been developed to recognise and treat cryptorchidism in equid. This study retrospectively analysed cases of cryptorchidism referred to two centres between 2012 and 2025. Clinical data collected included species, breed, age, gender, location of retained testis, diagnostic approach, anaesthesia plan and surgical treatment, perioperative medical treatment, intra-operative complications and outcomes. A total of 37 clinical cases were included, 1/37 was a donkey and 1/37 was an intersex female. Most of the horses were three years old a...
Lewczuk D, Wypchło M, Hecold M, Buczkowska R, Korwin-Kossakowska A.Finding the causative mutations for musculoskeletal system development and health status is of a higher priority for all sport horse breeders' associations. Of the regulating proteins involved in animal ossification, 15 gene polymorphisms were chosen to be identified as connected with the nine fetlock and 14 hock bone structures measurements of 198 horses. All measurements were taken using X-rays of the limbs, which were available at the beginning and end of the horse training. The analysis of variance (GLM, SAS program) was performed taking into account identified training and horse-connected...
Villalba-Díez M, Benavente-Sánchez L, Bustamante R, Santiago-Llorente I, Villalba-Orero M.Several induction quality scoring systems (IQSS) have been described to evaluate drugs and risk factors of this anaesthetic period in horses, but no attempts to compare their reliability have been performed. Objective: To elucidate the reliability of three IQSS: the visual analogue scale (VAS), a simple descriptive scale (SDS), and a composite grading scale (CGS) proposed by the authors. Methods: Reliability study. Methods: Eight randomly selected video-recorded anaesthetic inductions from horses that underwent general anaesthesia were evaluated twice by four blinded evaluators with experience...
Ripollés-Lobo M, Perdomo-González DI, Azor P, Valera M.Investigate the genetic inbreeding depression load (IDL) on two dressage traits and two conformational defects in horses. Unassigned: The dataset included performance records for Walk and Points per Reprise (PPR) (N:43,838) and conformation data for Closed and Convergent hocks (N:57,949). Pedigree information spanned over 400,000 individuals. Inbreeding coefficients (F, F6, Fk) and partial inbreeding coefficient (Fij) were computed to quantify the IDL using Bayesian approach. Linear and ordinal logistic regressions were used to assess the relationship between inbreeding and phenotypic values. ...
Sande A, Santosuosso E, Scharf JE, Shoemaker SJ, Temple S, Hemmerling K, Kell T, Leguillette R, Bayly WM.To compare maximal lactate steady-state (MLSS) speeds determined using a treadmill-dependent invasive reference method (RM) with 2 noninvasive methods based on heart rate variability-focused analysis of exercise ECGs. Unassigned: This was a randomized, blinded study using 7 fit Thoroughbreds. A standardized incremental exercise treadmill test (SET) where blood lactate concentration ([La]) was measured after every step facilitated calculation of speeds at which [La] was 1.5, 2.0, and 2.5 mmol/L. The RM required steady-state exercise (SS) at each of these speeds for 25 minutes or until [La] incr...
Wonghanchao T, Sanigavatee K, Pongnarudech P, Suchairat T, Jitsopin S, Wanichayanon B, Rattanakarn D, Jantakanangkoon P, Jaraswutiwong T, Kalanuson N....Horses competing in eventing competitions encounter significant challenges that increase their risk of severe injuries and metabolic disorders. Numerous studies have focused on the risk of such injuries and disorders during the cross-country segment. While one study has examined autonomic responses during this segment, research on these responses across all three phases of competition, particularly during one-day events, is still limited. The objective of this study was to analyse the autonomic responses of horses by measuring heart rate (HR) and heart rate variability (HRV) during three exerc...
Kuroda T, Knych HK, Noble GK, Minamijima Y, Leung GN, Nomura M, Mizobe F, Ishikawa Y, Kusano K, Toutain PL.Flunixin meglumine is widely used to manage pain and inflammation in horses, and its regulation requires robust pharmacokinetic analysis for harmonization. In this study, we conducted a meta-analysis of flunixin disposition using plasma and urine concentration data from 65 horses across four countries to robustly estimate pharmacokinetic parameters in setting screening limits (SLs) for controlling medications in horses. A population (POP) model was developed using nonlinear mixed-effects model analysis. The irrelevant plasma concentration (IPC) and irrelevant urine concentration (IUC) were det...
Barbosa B, Santi TF, Rodak AC, Nogara MF, Leite LMB, Weber SH, Niels C, Daros RR, Michelotto PV.The analysis of equine exhaled breath condensate (EBC) lacks standardized methodology, and current collection devices are often adapted for research. This study evaluates a novel horse-specific EBC collector and assesses the variability of EBC pH and hydrogen peroxide (HO) levels, exploring potential correlations with bronchoalveolar lavage (BAL) and tracheal wash (TW) cytology. Eleven healthy mixed-breed mares from a teaching herd, with no evidence of airway abnormalities, were included in this randomized observational study. The collection efficiency of the proposed device was assessed, and ...
Fowler AL, Pyles MB, Hayes SH, Crum AD, Lawrence LM.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 ...
Wesołowska M, Szczuka E. In animals, staphylococci constitute a significant part of the normal skin microbiota and mucous membranes. There is limited information available on staphylococci isolated from healthy horses. These skin-associated bacteria can be easily transferred between animals and horse riders via direct contact. Patients undergoing hippotherapy (i.e., medical or therapeutic sessions with horses) are especially at risk of being colonized by horse skin-associated bacteria. However, it remains unclear whether equine skin is colonized by antimicrobial-resistant (AMR) opportunistic pathogens, which may be o...
Saitua A, Pérez-Umbría J, García-Álamo K, Muñoz A.Dynamic mobilization exercises (DME) are an effective strategy to prevent musculoskeletal injuries and promote back health in sport horses. Previous studies focused mainly on multifidus muscle cross-sectional area, with limited data on locomotion and adaptation timing. This study evaluated locomotor changes using accelerometry, over 8 weeks of DME application in 14 sedentary horses: a DME group ( = 8) performing 10 different DME (3 neck flexions, 1 neck extension and 3 lateral bending exercises to each side), 5 repetitions of each DME per session, 3 sessions/week, and a control group ( = 6), t...
Klinck M, Lovett A, Sykes B.Equine gastric ulcer syndrome (EGUS) refers to mucosal gastric disease in horses, including equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD), which present as two distinct disease entities differing in pathophysiology and approach to disease management. Both diseases are a source of pain in affected horses, partly explaining why EGUS continues to receive substantial attention in the equine medical, welfare and equitation research sectors. There is a complex interplay between EGUS and a variety of physical and psychological stressors. Horses with EGUS are often...
