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.
Toscan G, Cezar AS, Pereira RC, Silva GB, Sangioni LA, Oliveira LS, Vogel FS.Several formulations of macrocyclic lactones (abamectin, ivermectin, moxidectin), including ivermectin combined with pyrantel (tetrahydropyrimidine) and ivermectin combined with praziquantel (pyrazinoisoquinolin derivative), were tested regarding their efficacy to control gastrointestinal nematodes of horses on a stud farm in southern Brazil. In addition, we tested a pharmaceutically produced generic paste containing ivermectin 4%. Similar formulations of avermectins had different efficacies measured by reduction of EPG. Levels of efficacy of the tested drugs varied against Strongylus edentatu...
Warmuth V, Eriksson A, Bower MA, Barker G, Barrett E, Hanks BK, Li S, Lomitashvili D, Ochir-Goryaeva M, Sizonov GV, Soyonov V, Manica A.Despite decades of research across multiple disciplines, the early history of horse domestication remains poorly understood. On the basis of current evidence from archaeology, mitochondrial DNA, and Y-chromosomal sequencing, a number of different domestication scenarios have been proposed, ranging from the spread of domestic horses out of a restricted primary area of domestication to the domestication of numerous distinct wild horse populations. In this paper, we reconstruct both the population genetic structure of the extinct wild progenitor of domestic horses, Equus ferus, and the origin and...
Starke SD, Willems E, Head M, May SA, Pfau T.Flexion tests are a common tool during the prepurchase and clinical lameness examination, yet studies quantifying the effect of flexion, apart from distal forelimb flexion in sound horses, are sparse. Objective: To investigate the effect of proximal hindlimb flexion on perceivable and measurable changes in movement symmetry in horses with objective movement symmetry falling within the margins of 'sound'. Methods: Thirteen horses, selected based on objective movement symmetry, were instrumented with inertial sensors on left and right tuber coxae and over the os sacrum. Vertical movement symmetr...
Schwarzwald CC, Kedo M, Birkmann K, Hamlin RL.To investigate the relationship of heart rate (HR) and ECG time intervals to body weight (BWT) in healthy horses and ponies. We hypothesized that HR and ECG time intervals are related to BWT. Methods: 250 healthy horses of >30 breeds; 5.5 (1-30) y [median (range)]; 479 (46-1018) kg. Methods: Prospective study. Standard base-apex ECGs were recorded while the horses were standing quietly in a box stall. Mean HR over 15 s was calculated and RR interval, PQ interval, QRS duration, and QT interval were measured by a single observer.QT was corrected for differences in heart rate using Fridericia'...
Degueurce C.The first veterinary school in the world was created in Lyon in 1761 by an equerry, Claude Bourgelat (1712-1779), a man renowned for his skill in horsemanship and horse medicine, a man fully able to understand the issues of his time. Aware of the scope of the physiocratic movement and of the need to improve the health of farm animals, he was able to understand the expectations of Henri-Léonard Bertin, Minister of King Louis XV, in proposing the creation of an establishment, breaking with traditional farriery. The creation of the Veterinary School of Lyon would mark a milestone: the considerat...
Daly K, Al-Rammahi M, Arora DK, Moran AW, Proudman CJ, Ninomiya Y, Shirazi-Beechey SP.The heteromeric sweet taste receptor T1R2-T1R3 is expressed on the luminal membrane of certain populations of enteroendocrine cells. Sensing of sugars and other sweet compounds by this receptor activates a pathway in enteroendocrine cells, resulting in secretion of a number of gut hormones, including glucagon-like peptide 2 (GLP-2). This subsequently leads to upregulation in the expression of intestinal Na(+)/glucose cotransporter, SGLT1, and increased intestinal glucose absorption. On the basis of the current information available on the horse genome sequence, it has been proposed that the ge...
Graper M, Fischer AT.Practicing at a referral center makes one aware of the necessity for consistent clear communication with the referring veterinarians. The referring veterinarian is ultimately the primary client of the referral center and should be respected as such. Once the necessary care has been provided, the client and horse should be returned to the care of the referring veterinarian. It is important that the referring veterinarian stay involved in the case and communicate if they wish for more or less contact with the referral center.
Trigo P, Muñoz A, Castejón F, Riber C, Hassel DM.We describe a fatal case, in which a horse suffered a fall and as a consequence, rib fractures. Diagnosis was made postmortem and the horse died without showing clear signs of respiratory dysfunction. The retrospective reports of injuries can be important to reduce these traumatic events and to avoid fatalities. Nous décrivons un cas mortel, chez un cheval ayant subi une chute qui a causé des fractures des côtes. Un diagnostic a été posé à l’autopsie et le cheval est mort sans avoir montré de symptômes évidents de troubles respiratoires. Les rapports rétrospectifs de blessures pe...
Williams GL, Thorson JF, Prezotto LD, Velez IC, Cardoso RC, Amstalden M.Reproductive seasonality in the mare is characterized by a marked decline in adenohypophyseal synthesis and secretion of LH beginning near the autumnal equinox. Thus, ovarian cycles have ceased in most mares by the time of the winter solstice. Endogenous reproductive rhythms in seasonal species are entrained or synchronized as a result of periodic environmental cues. In the horse, this cue is primarily day length. Hence, supplemental lighting schemes have been used managerially for decades to modify the annual timing of reproduction in the mare. Although a full characterization of the cellular...
Lescun TB, Baird DK, Oliver LJ, Adams SB, Hawkins JF, Moore GE.To determine the extent to which a hydroxyapatite coating promotes pin stability in the third metacarpal bone during transfixation casting in horses. Methods: 14 adult horses. Methods: 7 horses each were assigned to either an uncoated or hydroxyapatite-coated pin group. Three transcortical pins were placed in the third metacarpal bone of each horse and incorporated into a cast for 8 weeks. Insertion and extraction torque were measured, and torque reduction was calculated. Radiography was performed at 0, 4, and 8 weeks. Lameness evaluation was performed at 2, 4, 6, and 8 weeks. Bacteriologic cu...
Henderson IS, Brama P, Osborne M, Beltman ME.Deslorelin acetate implants, recently licensed in Ireland and the UK for ovulation induction in mares, have been associated with prolonged interovulatory intervals in USA studies, leading to the practice of removing implants postovulation. Trial data in Australia indicate a less pronounced effect on interovulatory intervals, suggesting possible geographical variation. Objectives of the current study were to assess the effect of deslorelin implants, with and without removal on oestrous cycle length in Irish- and UK-based Thoroughbred broodmares. Data were collected retrospectively from 88 oestr...
Johnson AL, Sweeney RW, McAdams SC, Whitlock RH.Clostridium botulinum type B is estimated to cause more than 85% of cases of equine botulism in the United States, as well as many outbreaks in cattle. In this study, a quantitative real-time polymerase chain reaction for detection of the neurotoxin gene of C. botulinum type B was compared to the mouse bioassay using 45 positive and 43 negative samples of equine, bovine or associated environmental origin. The sensitivity of the qPCR assay was 96%, whereas the sensitivity of the mouse bioassay was 84%. The specificity of the qPCR assay was 95% and the specificity of the mouse bioassay was 100%....
Steckler D, Naidoo V, Gerber D, Kähn W.To determine the intercyclic effect of oxytocin and carbetocin on equine myometrial tissue, the effect of the drugs was evaluated through pharmacokinetic and pharmacodynamic studies. The complete pharmacokinetic profile for oxytocin was unknown and had to be established. To do so, 25 IU of oxytocin were administered intravenously to six cycling mares and blood samples were collected before and 2, 4, 8, and 15 min after administration. The half-life of oxytocin was determined to be 5.89 min, the clearance rate 11.67 L/min, mean residence time (MRT) 7.78 min. The effective plasma concentration w...
Fayrer-Hosken R, Stanley A, Hill N, Heusner G, Christian M, De La Fuente R, Baumann C, Jones L.The cellular effects of tall fescue grass-associated toxic ergot alkaloids on stallion sperm and colt testicular tissue were evaluated. This was a continuation of an initial experiment where the effects of toxic ergot alkaloids on the stallion spermiogram were investigated. The only spermiogram parameter in exposed stallions that was affected by the toxic ergot alkaloids was a decreased gel-free volume of the ejaculate. This study examined the effect of toxic ergot alkaloids on chilling and freezing of the stallion sperm cells. The effect of toxic ergot alkaloids on chilled extended sperm cell...
Soares JH, Brosnan RJ, Fukushima FB, Hodges J, Liu H.Anesthetic blood solubility predicts pharmacokinetics for inhaled agents and is essential for determination of blood anesthetic concentrations from end-tidal gas concentrations using Henry's Law. Though used to model anesthetic effects in humans, there are limited interspecies solubility comparisons that include modern haloethers. This study aimed to measure hematocrit-adjusted blood:gas anesthetic partition coefficients (λ B:G) for desflurane, sevoflurane, isoflurane, and methoxyflurane in humans and animals. Methods: Whole blood was collected from 20 rats, 8 horses, and 4 each of cats, catt...
Votion DM, Gnaiger E, Lemieux H, Mouithys-Mickalad A, Serteyn D.Within the animal kingdom, horses are among the most powerful aerobic athletic mammals. Determination of muscle respiratory capacity and control improves our knowledge of mitochondrial physiology in horses and high aerobic performance in general. Results: We applied high-resolution respirometry and multiple substrate-uncoupler-inhibitor titration protocols to study mitochondrial physiology in small (1.0-2.5 mg) permeabilized muscle fibres sampled from triceps brachii of healthy horses. Oxidative phosphorylation (OXPHOS) capacity (pmol O(2) • s(-1) • mg(-1) wet weight) with combined Complex...
Dymock DC, Pauwels FE.To describe key morphological attributes of the third metacarpal bone (Mc3) of horses and to determine whether or not the symmetry of the Mc3 varied significantly between limbs of the same horse. Methods: Ten pairs of metacarpi were collected from slaughter facilities. The age and breed of the horses were recorded. Fixed points and axes that could be easily reproduced between bones were identified on high-quality photographic images of each bone. Using image analysis, three angles were measured. Angle gamma measured the rotation around the long axis of the diaphysis of Mc3, angle delta the ang...
Hockenhull J, Creighton E.UK leisure horses are owned primarily for riding. Ridden behaviour problems may compromise the use of the horse in this role and lead to harsh redress or relinquishment of the horse. Despite the consequences of these problems little is known about their prevalence or the working lives of UK leisure horses. Objective: To generate data on the work undertaken by leisure horses, the equipment and training practices used with them and prevalence of ridden behaviour problems. Methods: An internet survey was used to generate horse-level data from a convenience sample of leisure horse carers. Responde...
Kozai K, Hojo T, Takahashi M, Acosta TJ, Nambo Y, Okuda K.Although circulating progesterone (P₄) levels tend to change with the season, little is known about the seasonal changes of P₄ synthesis-related proteins in the corpus luteum (CL) of mares. To examine these changes, seventy-four ovaries containing a CL were collected from Anglo-Norman mares at a local abattoir in Kumamoto, Japan (~N32°), five times during one year. The stages of the CLs were classified as early, mid and regressed by macroscopic observation of the CL and follicles. The mid CL, which had the highest P₄ concentration, was used to evaluate the seasonal changes in P₄ synth...
Lampe JF, Andre J.This study has shown that domestic horses are capable of cross-modal recognition of familiar humans. It was demonstrated that horses are able to discriminate between the voices of a familiar and an unfamiliar human without seeing or smelling them at the same moment. Conversely, they were able to discriminate the same persons when only exposed to their visual and olfactory cues, without being stimulated by their voices. A cross-modal expectancy violation setup was employed; subjects were exposed both to trials with incongruent auditory and visual/olfactory identity cues and trials with congruen...
Hauswirth R, Haase B, Blatter M, Brooks SA, Burger D, Drögemüller C, Gerber V, Henke D, Janda J, Jude R, Magdesian KG, Matthews JM, Poncet PA....During fetal development neural-crest-derived melanoblasts migrate across the entire body surface and differentiate into melanocytes, the pigment-producing cells. Alterations in this precisely regulated process can lead to white spotting patterns. White spotting patterns in horses are a complex trait with a large phenotypic variance ranging from minimal white markings up to completely white horses. The "splashed white" pattern is primarily characterized by an extremely large blaze, often accompanied by extended white markings at the distal limbs and blue eyes. Some, but not all, splashed white...
Church ML, Norman JC.The main objective was to record electroretinogram (ERG) parameters of normal thoroughbred mares using the HMsERG, a mini-Ganzfeld electroretinographic unit, and a contact lens electrode. The second objective was to determine whether IV detomidine hydrochloride at 0.015 mg/kg is consistently an effective choice for sedation of horses undergoing this ERG protocol. Methods: The study population consisted of 30 normal thoroughbred mares. ERG data were harvested using a protocol that included three different light intensities (10, 3000, and 10,000 mcd s/m(2)) and a 30-Hz flicker at 3000 mcd s/m(2)...
Caron JP.Laparoscopic techniques for veterinary surgery are growing in popularity for the same reason the use of minimally invasive procedures has increased tremendously in human surgery. Compared with open surgery, the benefits of laparoscopic surgery include smaller incisions, reduced postoperative morbidity and pain, shorter hospitalization, a more rapid return to normal activities, and, in some instances, superior access. Laparoscopic surgery is different from open surgery in equipment/instrumentation and psychomotor skills. This first article in a series on equine laparoscopic surgery introduces t...
Smyth PA, Rifkin RE, Jackson RL, Hanson RR.The naturally occurring structure of articular cartilage has proven to be an effective means for the facilitation of motion and load support in equine and other animal joints. For this reason, cartilage has been extensively studied for many years. Although the roughness of cartilage has been determined from atomic force microscopy (AFM) and other methods in multiple studies, a comparison of roughness to joint function has not be completed. It is hypothesized that various joint types with different motions and regimes of lubrication have altered demands on the articular surface that may affect ...
Moraes EA, Matos WC, Graham JK, Ferrari WD.This study was to compare the effect of adding cholesterol or cholestanol loaded cyclodextrins in stallion sperm prior to cryopreservation to optimize sperm cryosurvival. Ejaculates from each of eight stallions were diluted to 120 million cells in a S-MEDIUM diluent. The diluted sperm were sub-divided into three treatments: no additive (control); 0.75mg of cyclodextrin pre-loaded with cholesterol (CLC)/120 million sperm (positive control); 1.5mg CLC/120 million sperm; 0.75mg of cyclodextrin pre-loaded with cholestanol (CnLC)/120 million sperm; and 1.5mg CnLC/120 million sperm. To set the exper...
Ing NH, Forrest DW, Love CC, Varner DD.Stallions are unique among livestock in that, like men, they commonly receive medical treatment for subfertility. In both species, about 15% of individuals have normal semen parameters but are subfertile, indicating a need for novel analyses of spermatozoa function. One procedure for improving fertilizing capability of stallions and men is isolation of dense spermatozoa from an ejaculate for use in artificial insemination. In the current study, dense and less dense spermatozoa were purified by density gradient centrifugation from individual ejaculates from seven reproductively normal adult sta...
Stover SM.Racehorses are susceptible to bone fractures when damage from repetitive, high-magnitude loads incurred during training and racing exceed concurrent damage removal and replacement, resulting in transient periods of focal osteoporosis and bone weakening. Clinically, these events correspond to cortical stress fractures and subchondral bone stress remodeling. Evidence of these preexisting lesions include periosteal callus, endosteal callus, and intracortical focal hyperemia for cortical stress fractures; and subchondral focal hyperemia located superficial to sclerotic compacted trabecular bone ti...
Morales JL, Manchado M, Vivo J, Galisteo AM, Agüera E, Miró F.Normal speed videography was used to determine the angular parameters of 28 Spanish Thoroughbreds at trot. Horses were divided into 3 groups: Group UT, comprising 9 animals (provided by the VII National Stud, Cordoba, Spain) which had undergone no specific training programme and which were hand led at the trot; Group T, formed by 19 horses considered to be highly bred and trained, and which were also hand led; and Group RT, comprising the same horses as the latter group but this time trotted by a rider. Each animal was filmed 6 times from the right-hand side, using a Hi8 (25 Hz) video camera. ...
Chateau H, Degueurce C, Denoix JM.Understanding of the biomechanical effects of egg-bar shoes remains incomplete because kinematic studies are usually performed on hard tracks and with skin markers that do not measure the actual 3-dimensional (3D) movements of the 3 digital joints. Objective: To quantify the effects of egg-bar shoes on the 3D kinematics of the distal forelimb in horses walking on a sand track. Methods: Four healthy horses were equipped with ultrasonic markers fixed surgically to the 4 distal segments of the left forelimb. The 3D movements of these segments were recorded while the horses were walking on a sand ...
Vorstenbosch MA, Buchner HH, Savelberg HH, Schamhardt HC, Barneveld A.To study the role of head movements in lame horses. Methods: 11 Dutch Warmblood horses. Methods: A 2-segment 2-dimensional inverse dynamic model of trotting horses was developed: trunk and head/neck segment joined in a neck joint. Model input consisted of averaged segmental inertial properties and averaged kinematic data, taken from 11 horses, trotting on a treadmill (3.5 m/s) in 3 conditions of induced lameness: sound, mildly lame, and moderately lame. Dynamic and static effects were analyzed. Results: Dynamic effects were found to be considerably larger than static effects. In the moderately...
Campbell EH.Equine conditioning programmes are rarely driven by science. Indeed, the scientific literature on conditioning responses often refers to conventional technique rather than physiological driving parameters. This, alongside poor classification of conditioning protocols, has reduced the possibility of comparative data analysis. Recent interest into lactate-driven conditioning programmes has driven this review which provides a summary of equine protocols used to date and their responses. Key areas identified for further standardisation and/or investigation include (1) the treadmill acclimation pro...
Platt H, Whitwell KE.A form of generalized fat necrosis and steatitis occurs in pony and donkey foals. The clinical and pathological features of this disorder are described and its possible relationship to a similar condition in the Thoroughbred foal, and to yellow Fat Disease in other species, is discussed.
Haadem CS, Nødtvedt A, Farstad W, Thomassen R.Pregnancy rates with cooled equine semen can be unsatisfactory and show great variation. Information about first cycle pregnancy rates and pregnancy rates per cycle are often lacking from publicly available records. This retrospective cohort study was performed to evaluate the fertility of the Norwegian Coldblooded trotter. The aim of the study was to compare the breeding results after insemination with fresh, extended with those of cooled, shipped semen among Norwegian Coldblooded trotter mares. First cycle pregnancy rate was the main parameter used to measure fertility. Stud-books were colle...
Gibb Z, Morris LH, Maxwell WM, Grupen CG.The low efficiency of flow cytometric sex-sorting of stallion sperm has been attributed to the use of an opaque skim milk-based diluent during Hoechst 33342 (H33342) staining. Three experiments were conducted to formulate an optically clear stallion semen diluent for use during H33342 staining, and to determine whether a clear diluent improved resolution during sorting. For Experiment 1, sperm were incubated at 34 °C in each of five diluents containing either no protein, skim milk, 0.25% Cohn's Fraction V BSA, 0.5% BSA, or 1% BSA, following an 18 h storage (15 °C) period, or shortly after co...
Geiser DR.There are several beneficial physiologic and therapeutic effects of hyperbaric oxygen therapy (HBOT). The indications list for the use of HBOT in the horse has been developed through extrapolation from a review of human indications and from anecdotal clinical experiences. Hyperbaric therapy is a safe treatment option with very few side effects when administered properly.
Stewart GA.During the last three decades in Australia and New Zealand the heart score theory has been used in the cardiovascular assessment of racehorses in training (Steel 1957, 1963, 1966-67; Irvine 1964, 1966; Stewart and Steel 1970; Steel and Stewart 1972, 1974). In particular the heart score has been of value as one of several factors employed in assessing the potential of the horse for different types of racing. More recently, studies indicating the heritability of heart score and its possible sex-linkage (Steel et al 1977) have suggested its use also as one of several criteria for selection in rac...
Davies HM, Watson KM.The aims of this study were to test whether longer third metacarpal (MC3) bones had thicker dorsal cortices in a group of racehorses that were exercising at similar maximum speeds, and to establish if horses with larger differences in length between their right and left MC3 bones showed larger differences in the dorsal cortical thickness between the two limbs. Methods: An observational study. Methods: Forty Thoroughbred racehorses aged between 2 and 6 years and in training at racing speed at two racing stables were used. Two sets of radiographs of each left and right metacarpus of each horse w...