Equine Science encompasses the study of horses and their management, health, and performance. This field integrates various scientific disciplines such as biology, genetics, nutrition, physiology, and veterinary medicine to understand and improve the well-being and capabilities of horses. Areas of focus include equine anatomy, reproduction, behavior, and disease prevention. Research in equine science aims to enhance horse care, optimize training and performance, and address health challenges. This page compiles peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine science, providing insights into the latest advancements and methodologies in the field.
Christensen JW, Malmkvist J, Nielsen BL, Keeling LJ.In fear-eliciting situations, horses tend to show flight reactions that can be dangerous for both horse and man. Finding appropriate methods for reducing fearfulness in horses has important practical implications. Objective: To investigate whether the presence of a calm companion horse influences fear reactions in naive subject horses. Objective: The presence of a habituated (calm) companion horse in a fear-eliciting situation can reduce fear reactions in naive subject horses, compared to subject horses with a nonhabituated companion (control). Methods: Minimally handled (n = 36), 2-year-old s...
Sullivan KA, Hill AE, Haussler KK.Common methods used to treat back problems in horses need to be assessed objectively. Objective: To measure spinal mechanical nociceptive thresholds (MNTs) and evaluate the effects of chiropractic, massage and phenylbutazone, compared with active and inactive control groups. Methods: Baseline MNTs at 7 sites within the thoracolumbar and sacral regions were measured in 38 healthy mature horses exhibiting no clinical signs of lumbar pain. Horses were assigned to one of 3 treatment groups: instrument-assisted chiropractic treatment, therapeutic massage and phenylbutazone; or 2 control groups: rid...
Noble GK, Brockwell YM, Munn KJ, Harris PA, Davidson HP, Li X, Zhang D, Sillence MN.L-tryptophan is a common ingredient in equine calmative products, but its effectiveness has not been demonstrated in horses. Objective: To determine whether a commercial dose of L-tryptophan increases plasma tryptophan and alters behaviour in horses fed a roughage or concentrate meal. Methods: L-tryptophan (6.3 g) or placebo (water) was administered per os in a cross-over design, to 12 Thoroughbred horses (503 +/- 12.1 kg bwt), just before a meal of lucerne hay or oats. Plasma tryptophan was measured by gas chromatography. Horse behaviour was observed in an empty enclosure, then in the presenc...
Johnson L, Thompson DL, Varner DD.Testicular function is under the control of expression and repression of several genes and gene products, and many of these works through Sertoli cells. The capability of Sertoli cells to regulate spermatogenesis is dependent on Sertoli cell functions and Sertoli cell number. Sertoli cell number has long been thought to be stable in adults with no proliferation of Sertoli cells once adult numbers have been reached. However, adult horses do not have stable Sertoli cell numbers, and new studies indicate that adult Sertoli cells can be made to re-enter mitotic phase under certain experimental con...
Watanabe T, Imamura Y, Hosaka Y, Ueda H, Takehana K.By using ultramorphological and biochemical methods, we analyzed the regional differences between the three parts of the equine superficial digital flexor tendon (SDFT), namely, the myotendinous junction (MTJ), middle metacarpal (mM), and osteotendinous junction (OTJ). Cross-sectional images showed unique distributions of collagen fibrils of varying diameters in each region. Small collagen fibrils (diameter 200 nm). In the mM region, the collagen fibrils were intermediately distributed between the MTJ and OTJ. The results indicate a graded arrangement of collagen fibrils in the tendon. Type V ...
Kasashima Y, Takahashi T, Birch HL, Smith RK, Goodship AE.Tendons can be considered in two functional groups, those contributing to energetics of locomotion and those acting solely to position the limb. The energy-storing tendons in both human and equine athletes have a high frequency of injury with similar pathophysiology. In previous studies, high-intensity exercise appears to induce a disruption of the matrix rather than functional adaptation in adults. Here we explore the hypothesis that the introduction of controlled exercise during growth would result in an adaptive response without deleterious effects. Young horses were given a controlled exer...
Parillo F, Verini Supplizi A.The present work was undertaken to determine the glycoconjugates secreted by the epithelium of the equine ampulla ductus deferentis, using conventional (PAS, AB pH 2.5, AB pH 1.0) and lectin histochemical procedures in conjunction with enzymatic digestion and chemical treatment. The presence of abundant apical cytoplasmic blebs suggests that the equine ampulla secretes its products mainly in an apocrine manner. Glandular cells secrete neutral and acidic sialylated glycoconjugates as revealed by conventional histochemical procedures. Lectin histochemistry helped us to discover the following his...
Lefranc A-, Allen WR.The morphology and surface density of endometrial glands responsible for the nutrition of the placenta requires further study employing computer assisted morphometric analysis. Objective: To analyse changes in the morphology and surface density of endometrial glands situated adjacent to, and remote from, the conceptus during the first 30 days of gestation. Methods: Endometrial biopsies were recovered, under videoendoscopic control, from both nonpregnant and pregnant mares 12 days after ovulation, as well as from pregnant mares on Days 16, 20, 25 and 30 of gestation. One biopsy was taken at the...
Butcher MT, Hermanson JW, Ducharme NG, Mitchell LM, Soderholm LV, Bertram JE.Racing and training related lesions of the forelimb superficial digital flexor tendon are a common career ending injury to racehorses but aetiology and/or predisposing causes of the injury are not completely understood. Objective: Although the injury takes place within the tendon, the lesion must be considered within the context of the function of the complete suspensory system of the distal limb, including the associated muscles. Methods: Both muscle and tendon function were investigated in vivo using implanted strain gauges in 3 Thoroughbred horses walking, trotting and cantering on a motori...
Sod GA, Mitchell CF, Hubert JD, Martin GS, Gill MS.To compare in vitro monotonic biomechanical properties of an equine spoon plate (ESP) with an axial 3-hole, 4.5 mm narrow dynamic compression plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws (DCP-TLS) inserted in lag fashion for equine proximal interphalangeal (PIP) joint arthrodesis. Methods: Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints. Methods: Cadaveric adult equine forelimbs (n=18 pairs). Methods: For each forelimb pair, 1 PIP joint was stabilized with an ESP (8 hole...
Arroyo LG, Stämpfli HR.Renal tubular disorders have been sporadically reported in horses. Only three types of tubular defects have been recognized: (1) nephrogenic diabetes insipidus, attributable to unresponsiveness of the renal tubules to antidiuretic hormone; (2) distal renal tubular acidosis (RTA; type I); and (3) proximal RTA (type II). The following review focuses on RTA and nephrogenic diabetes insipidus.
McKenzie EC.Polyuria and polydipsia provide a diagnostic challenge for the equine clinician. This article describes the various known causes of polyuria and polydipsia in horses and provides a description of a systematic diagnostic approach for assessing horses with polyuria and polydipsia to delineate the underlying cause. Treatment and management strategies for addressing polyuria and polydipsia in horses are also described.
Schumacher J.Hematuria and pigmenturia of horses are discussed in this article. Equine urine is normally straw colored. Discolored urine can be caused by contamination with red blood cells, hemoglobin, myoglobin, oxidizing agents normally found in urine, and plant-derived pigments.
Morel PC, Bokor A, Rogers CW, Firth EC.To mathematically describe the growth of a population of Thoroughbred foals reared on pasture in New Zealand from birth to weaning. Methods: Twice-monthly liveweight data (including birthweight; BW) from 218 foals (98 colts and 120 fillies) born over a 6-year period, and reared on four different pasture types, were available for analysis. Data truncated to the time of weaning (107-217 days old) provided 3,200 data points. After testing for non-linearity of the relationship of age and liveweight (LW), five non-linear regression equations were tested for goodness of fit. Results: Colts and filli...
Rogers CW, Gee EK, Firth EC.To obtain initial baseline data on the management of Thoroughbred stud farms in the North Island of New Zealand. Methods: Data on the management of Thoroughbred stud farms were collected from a sample of 22 stud farms located in the south Auckland/Waikato region (n=15) and lower North Island (n=7) of New Zealand, using a face-to-face survey. The studmaster provided information on the size, scope and management of the farms during the 2004/2005 breeding season. Analysis was based on the location of the farm and size of the breeding operation (number of resident mares). Results: Effective farm s...
de Mestre AM, Bacon SJ, Costa CC, Leadbeater JC, Noronha LE, Stewart F, Antczak DF.The chorionic girdle of the equine conceptus is comprised of specialized trophoblast cells which, at day 36-38 of equine pregnancy, gain an invasive phenotype and invade the endometrium to form endometrial cups. Studies of equine endometrial cups remain difficult to perform because of the invasive techniques required to obtain cup tissue and because sampling requires termination of the pregnancy. In this study we developed a system to model trophoblast differentiation and trophoblast-immune interactions in vitro and in vivo. We utilized a method of culturing chorionic girdle pieces in serum-fr...
Thorpe CT, Marlin DJ, Franklin SH, Colborne GR.Changes in shape of the equine thorax during locomotion are not well defined, although it has been shown recently that the transverse hemi-diameter changes its dimension by up to 80mm on the side of the trailing forelimb during gallop, despite minimal change in thoracic circumference. The aim of this project was to analyse transverse and dorso-ventral changes in shape of the thorax simultaneously, and to determine if leading limb, treadmill slope and speed have an effect on these shape changes. Reflective markers were placed on the horse's hemi-thorax and movement of the markers was recorded u...
Kaczensky P, Ganbaatar O, von Wehrden H, Enksaikhan N, Lkhagvasuren D, Walzer C.The Przewalski's horse (Equus ferus przewalskii Poljakov, 1881), or "Takhi" in Mongolian, became extinct in the wild by the mid 1960's. The last recorded sightings of Przewalski's horses occurred in the Dzungarian Gobi desert in SW Mongolia, today's Great Gobi B Strictly Protected Area (SPA). A re-introduction program was initiated in 1992 and the first group of captive-born Przewalski's horses was airlifted to the SPA. Given the logistical challenges associated with such a venture, the initial project focus has been on transport logistics and the well-being of the re-introduced horses. Today,...
Hülsemann F, Flenker U, Machnik M, Schänzer W.Sodium bicarbonate administration to horses prior to competition in order to enhance the buffer capacity of the organism is considered as a doping offence. The analysis of the isotopic composition of urinary bicarbonate/CO(2) (TCO(2)) may help to identify an exogenous bicarbonate source, as technical sodium bicarbonate exhibits elevated delta(13)C values compared with urinary total carbon. The isolation of TCO(2) from 60 equine urine samples as BaCO(3) followed by an isotopic analysis shows a significant variability of delta(13)C for TCO(2) of more than 10 per thousand. The delta(13)C of total...
Loomis PR, Graham JK.One of the challenges for those attempting to cryopreserve stallion spermatozoa is dealing with the stallion to stallion variability in the cryosurvival of their semen. In the dairy industry, each bull stud, essentially utilizes a single cryopreservation technique, and bulls that produce sperm that do not cryopreserve well using that technique are replaced by other bulls. However, replacing stallions is unlikely to prove acceptable to the equine industry, where specific genotypes are desired. Instead, to increase the number of stallions that can be effectively utilized for cryopreserved semen ...
Gehlen H, Sundermann T, Rohn K, Stadler P.This study measured plasma atrial natriuretic peptide (ANP) concentration in horses with heart valve regurgitations (HVR) with and without atrial and ventricular dilatation. Background: In humans and small animals, plasma ANP concentration is increased in heart disease and correlates with the severity of clinical signs and heart enlargement. Methods: Ten healthy horses (control) and 36 horses with HVR were evaluated by auscultation, electrocardiography, echocardiography, and determination of plasma ANP. Results: Control horses demonstrated mean plasma ANP concentration of 21+/-5.4 pg/mL. Of th...
Janicek JC, Carson WL, Wilson DA.The purpose of this investigation was to design and verify the capabilities of an in vitro loading-measurement system that mimics in vivo unconstrained three dimensional (3D) relative motion between long bone ends, applies uniform load components over the entire length of a test specimen, and measures 3D relative motion between test segment ends to directly determine test segment construct stiffness free of errors due to potting-fixture-test machine finite stiffness.Intact equine cadaveric radius bones, which were subsequently osteotomized/ostectomized and instrumented with bone plates were su...
Hamill D, Washington KA, White OR.The purpose of this single subject research study was to examine the effects of a once weekly, 10-week hippotherapy program for three children, ages 27-54 months, with cerebral palsy. Participants were rated as Level V on the Gross Motor Function Classification System. The Sitting Dimension of the Gross Motor Function Measure was used to establish a baseline of sitting abilities, and was administered every 2 weeks during intervention. The Sitting Assessment Scale and the Gross Motor Function Measure were administered before, after, and 4 weeks postintervention. Parental perceptions of the hipp...
Gregg AJ, Schenkel AR.Platelet endothelial cell adhesion molecule (PECAM, CD31) and vascular cell adhesion molecule-1 (VCAM-1, CD106) are essential for leukocyte emigration and diapedesis. PECAM is an essential histologic marker of endothelial cells; VCAM-1 is a prototype marker for endothelial cell activation. In this study, equine PECAM and VCAM mRNA were cloned and sequenced. Both genes are highly conserved amongst several species. This study also revealed conserved structural and regulatory motifs, emphasizing the importance of these genes' physiological roles in immunological responses.
Bogaert L, Martens A, Van Poucke M, Ducatelle R, De Cock H, Dewulf J, De Baere C, Peelman L, Gasthuys F.Bovine papillomavirus (BPV), the causative agent of papillomas in cattle, has been shown to play a major role in the pathogenesis of equine sarcoids in horses. BPV has also been detected occasionally in normal equine skin. In this study, presence and activity of BPV in normal skin and peripheral blood of 4 groups of horses were evaluated: sarcoid-affected horses, horses living in contact with sarcoid-affected horses, horses living in contact with papilloma-affected cattle and control horses. From each horse, 3 samples on 4 locations were collected: a swab of the intact skin surface and both a ...
Bigley RF, Gibeling JC, Stover SM, Hazelwood SJ, Fyhrie DP, Martin RB.Volume effects are a fundamental determinant of structural failure. A material exhibits a volume effect if its failure properties are dependent on the specimen volume. Many brittle ceramics exhibit volume effects due to loading a structure in the presence of "critical" flaws. The number of flaws, their locations, and the effect of stress field within the stressed volume play a role in determining the structure's failure properties. Since real materials are imperfect, structures composed of large volumes of material have higher probabilities of containing a flaw than do small volumes. Consequen...
Yu NH, Ho EN, Tang FP, Wan TS, Wong AS.A multi-target high-throughput liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for the detection of low ppt to low ppb levels of anabolic steroids, corticosteroids, anti-diabetics, and non-steroidal anti-inflammatory drugs (NSAIDs) in equine plasma was developed for the purpose of doping control. Plasma samples were first deproteinated by addition of trichloroacetic acid. Drugs were then extracted by solid-phase extraction (SPE) using Bond Elut Certify cartridges, and the extracts were analysed by a triple-quadrupole/linear ion trap LC-MS-MS instrument in positive electrospray...
Toribio RE.A number of viruses transmitted by biological vectors or through direct contact, air, or ingestion cause neurologic disease in equids. Of interest are viruses of the Togaviridae, Flaviviridae, Rhabdoviridae, Herpesviridae, Bornaviridae, and Bunyaviridae families. Many are classified as arboviruses because they use arthropod vectors, whereas others are transmitted directly via ingestion, inhalation, or integument damage. The goal of this article is to provide an overview on pathophysiologic and clinical aspects of arboviruses of equine importance, including alphaviruses (Togaviridae) and flaviv...
Siciliano PD.Little is known regarding nutrient requirements and feeding of geriatric horses, and more effort should be placed on this area of equine nutrition research. That which is known suggests that some geriatric horses may not have different requirements than other mature horses, whereas others affected by disease or poor dentition may have special nutritional needs. In general, rations for geriatric horses should be based on high-quality roughage supplemented with complementary minerals and vitamins. The need for additional energy aside from that provided by the forage can be supplied by adding ene...
Deane NJ, Davies AS.The most consistent published ideas on the function of the carpal joint of the horse concern the elasticity of the joint, and its limits to extension. Most of these are not well substantiated experimentally. Compression stress appears to be absorbed by the intercarpal ligaments as the carpal bones are separated by a wedge action during loading. Overextension is prevented by occlusion of dorsally located stop facets on the rows of carpal bones, and by the support of a stay apparatus.
Nuñez CM, Adelman JS, Rubenstein DI.Adoption of nongenetic offspring occurs in a variety of species but is rare in equids. We report a case of adoption by a free-ranging, feral mare Equus caballus and compare the maternal care received by her genetic offspring (born 1995) to that of her adopted offspring (born 1996) for the first 30 weeks of development. We compare five measures of care: (1) total time spent suckling, (2) mare aggression during suckling, (3) number of mare-terminated suckling bouts, (4) contact maintenance, and (5) mare-foal distance. For most behaviors, we detected no difference in the mare's treatment of the t...
Pre-clinical studies on human isolated bronchi have relevant translational value in human in vivo, conversely no investigation has been performed to assess whether data resulting from equine isolated airways can have any translational application in asthmatic horses. Thus, a meta-regression analysis via random-effect method was carried out to correlate the pharmacological characteristics of bronchodilators resulting from experiments performed in equine isolated bronchi with their impact on the lung function outcomes in asthmatic horses. Data on the potency of different bronchodilators were ext...
Wenker C, Hoby S, Steck BL, Ramsauer AS, Blatter S, Tobler K.Equine sarcoids (ES) were diagnosed in 12 Somali wild asses (SWA) () from 10 different institutions of the SWA European Endangered Species Programme from 1976 to 2019. Samples of surgically excised masses, biopsies, or necropsy samples were submitted for histologic and virologic analysis. In addition, tissue samples from one onager (), one kulan (), and two Hartmann's mountain zebras (HMZ) () were examined. Histology confirmed the diagnosis of ES exhibiting the typical microscopic features. Polymerase chain reaction detected bovine papillomavirus type 1 (BPV1) DNA in eight SWA samples and bovi...
Tuvshintulga B, Nugraha AB, Mizutani T, Liu M, Ishizaki T, Sivakumar T, Xuan X, Yokoyama N, Igarashi I.Theileria equi, an intraerythrocytic protozoan parasite, causes equine piroplasmosis, a disease which negatively impacts the global horse industry. Genetic manipulation is one of the research tools under development as a control method for protozoan parasites, but this technique needs to be established for T. equi. Herein, we report on the first development of a stable transgenic T. equi line expressing enhanced green fluorescent protein/blasticidin S deaminase (eGFP/BSD). To express the exogenous fusion gene in T. equi, regulatory regions of the elongation factor-1 alpha (ef-1α) gene were id...
Munsterman AS, Hanson RR.To develop a direct method for measuring intra-abdominal pressures in the standing horse, identify a reference interval for direct intra-abdominal pressures, compare these pressures to indirect intra-abdominal pressures measured from the bladder, and determine the optimal bladder infusion volume for indirect pressure measurement. Methods: Prospective, experimental study. Methods: A university-based equine research facility. Methods: Ten healthy adult horses, 5 males and 5 females. Methods: Direct intra-abdominal pressures were measured through an intraperitoneal cannula and zeroed at the heigh...
Czlonkowska M, Boyle MS, Allen WR.Fourteen horse embryos recovered non-surgically on Days 6-8 after ovulation (Day 0) were cooled slowly to - 35 degrees C (7 embryos) or - 40 degrees C (7 embryos) and stored in liquid nitrogen (- 196 degrees C) for 4-98 days. Surgical transfer of the thawed embryos to unmated recipient mares that had ovulated - 2 to + 1 days with respect to the embryo donors resulted initially in the establishment of 4 conceptuses. However, only one mare maintained her pregnancy to term.
Bartos L, Bartosová J, Starostová L.It has become accepted that the horse cannot see directly in front when the nose is lowered and must therefore rely on the rider. We tested the hypothesis that this conclusion would be correct only if the horse did not adjust the eyeball horizontal axis to changes of the head position. The results of the present study suggest that it is unlikely that horses have limited vision in relation to their head position when driven by the rider, and that the horse maintains the optimal horizontal eyeball position regardless of head position relative to the ground.
Mastellar SL, Moffet A, Harris PA, Urschel KL.Current equine threonine requirement estimates do not account for probable use of threonine to maintain gut health and mucin synthesis. The objective of this study was to determine if threonine supplementation (+Thr) would increase whole-body protein synthesis (WBPS) in weanling colts (Study 1) and adult mares (Study 2). Both studies used a crossover design, where each of six animals was studied twice while receiving the isonitrogenous diets. The basal diets contained lower threonine levels (Basal) than the threonine (+Thr) supplemented diets. Threonine intakes in mg/kg BW/day were as follows:...
Williams MR, Arnoczky SP, Pease AP, Stick JA.To determine the microvascular anatomy of the suspensory ligament of the forelimb of horses. Methods: 17 cadaveric forelimbs from 9 adult horses with no known history of forelimb lameness. Methods: The median artery of the forelimb was cannulated proximal to the antebrachiocarpal joint and injected with contrast medium for CT evaluation of the gross vasculature (n = 2) or India ink to evaluate the microvasculature (12). Routine histologic evaluation was performed on an additional 3 forelimbs to confirm the microvascular anatomy. Results: The vascular supply of the suspensory ligament of the fo...
King WA, Bezard J, Bousquet D, Palmer E, Betteridge KJ.Confusion exists as to whether the oocytes of the domestic horse are ovulated at the first meiotic metaphase (MI) or the second (MII). In this study eight oocytes were collected from the preovulatory follicles of 16 mares 36 h after human chorionic gonadotropin CG treatment. Six of the eight oocytes were judged to be at MII by the presence of the first polar body and this judgement was confirmed by semithin sectioning in one. Of the two that had no polar body, one was found to be at MII after fixation for chromosomal analysis and the meiotic stage of the other remained undetermined. Since all ...
Scott IS, Long SE.Meiotic preparations were made from testicular material obtained after surgical castration of eight stallions (Equus caballus) with normal spermatogenesis. The material was examined after conventional Giemsa staining and C-banding. C-banding demonstrated that the Y chromosome at diakinesis associated with the short arm of the X chromosome. In 315 cells at diplotene or diakinesis, 56 (17.7%) had univalents and 51 (16.1%) of these involved the sex chromosomes. The overall mean chiasma number was 54.4 +/- 1.8 SD, and the mean calculated nondisjunction (ND) frequency was 3.4%. These results are di...