Horse racing is a competitive equestrian sport involving horses ridden by jockeys over set distances, often on flat tracks or over obstacles. It is characterized by a variety of race types, including thoroughbred, harness, and steeplechase, each with distinct rules and traditions. The sport emphasizes speed, stamina, and strategy, with races typically categorized by distance, surface type, and horse age or breed. Horse racing plays a significant role in the equine industry, influencing breeding, training, and veterinary care practices. This page compiles peer-reviewed research studies and scholarly articles that explore the physiological demands, training methodologies, and health considerations associated with horse racing.
Hiraga A, Sugano S.After publication of the epic report on equine exercise physiology by Matsuba and Shimamura in 1933, papers on exercise physiology of the racehorse in Japan began appearing in scientific journals and increased in number. In 1944, respiration during exercise at a walk, trot, and canter was measured by recording expiratory sounds with a microphone attached near the nostril. Respiratory frequency during cantering was synchronized with stride frequency, and expiratory sounds were found to occur during the stance phase of the trailing forelimb. Development of a radiotelemetry system in 1964 for ele...
Mizobe F, Okada J, Shinzaki Y, Nomura M, Kato T, Yamada K, Spriet M.Desmitis of the oblique distal sesamoidean ligaments (ODSL) is caused by hyperextension of the metacarpophalangeal/metatarsophalangeal joint and has been described as a significant cause of lameness in racehorses. In this study, three Thoroughbred racehorses (age range: 3-6 years) were diagnosed with desmitis of the forelimb ODSL using standing low-field magnetic resonance imaging (sMRI). Radiography and ultrasonography were inconclusive with regard to a definitive diagnosis. For all horses, the sMRI characteristics included increased signal intensity within the medial ODSL on T1-weighted grad...
Léguillette R, Steinmann M, Bond SL, Stanton B.Poor performance is often suspected to be associated with EIPH in barrel racing horses; however, there are no published reports of EIPH for this discipline. The prevalence of EIPH in barrel racing horses is also unknown. Objective: This study was performed to determine the prevalence of EIPH and signs of airway inflammation in barrel racing horses under normal racing conditions in Alberta. Methods: About 170 barrel racing horses. Methods: Observational cross-sectional study. Tracheobronchoscopic examinations were performed at least 30 minutes postrace. Video recordings were scored off-site ind...
Tanner J, Rogers C, Bolwell C, Cogger N, Gee E, Mcllwraith W.The objective was to describe the incidence of failure to finish a race in flat-racing Thoroughbreds in New Zealand as these are summary indicators of falls, injuries and poor performance. Retrospective data on six complete flat racing seasons (n = 188,615 race starts) of all Thoroughbred flat race starts from 1 August 2005 to 31 July 2011 were obtained. The incidence of failure to finish events and binomial exact 95% confidence intervals were calculated per 1000 horse starts. The association between horse-, rider- and race-level variables with the outcomes failure to finish, pulled-up/fell an...
Russell JW, Russell TM, Vasey JR, Hall MS.To evaluate a treatment protocol whereby superficial digital flexor (SDF) tendonitis in Thoroughbred and Standardbred racehorses was treated with autologous bone marrow aspirate (ABMA) obtained from the sternebrae. This treatment was combined with desmotomy of the accessory ligament of the SDF tendon (DAL-SDFT) in selected cases. Medical records of 105 horses treated using the reported protocol were reviewed. Signalment, history and details of treatment were recorded. Racing records were reviewed and performance recorded. Of Thoroughbreds, 82 per cent had one or more starts within the follow-u...
Graham R, McManus P.Changing social values and new technologies have contributed to increasing media attention and debate about the acceptable use of animals in sport. This paper focuses on the use of the whip in thoroughbred horse racing. Those who defend its use argue it is a necessary tool needed for safety, correction and encouragement, and that it does not cause the horse any pain. For those who oppose its use, it is an instrument of cruelty. Media framing is employed to unpack the discourses played out in print and social media in the UK (2011) and Australia (2009) during key periods of the whip debate foll...
Noble P, Singer ER, Jeffery NS.Sagittal fractures of the first phalanx are a common, potentially catastrophic injury in racehorses. These fractures are often linked to an acute, one time, biomechanical event; however, recent evidence implies that chronic exposure to stress can lead to the accumulation of bony changes that affect the structural integrity of the bone and increase the likelihood of fracture. The aim of the study was to compare variations of two common metrics of bone adaptation - subchondral bone density and thickness across the proximal articular surface of the first phalanx in Thoroughbred horses that (1) ra...
O'Reilly J, Cheng HL, Poon ET.Weight-making practices have been shown to impair musculoskeletal and physiological function of jockeys. This study investigated the "in-race" heart rate (HR) responses and hydration status during competitive racing, as well as selected physiological and lifestyle parameters of professional jockeys based in Hong Kong. "In-race" HR responses and early morning hydration status of 20 male jockeys were examined in hot and moderate climactic occasions. Additionally, bone mineral density (BMD), dietary intake and lifestyle choices were assessed. Osteopenia was observed in the calcanei of jockeys (le...
Symons JE, Hawkins DA, Fyhrie DP, Upadhyaya SK, Stover SM.Race surface mechanics contribute to musculoskeletal injury in racehorses. These mechanics affect ground reaction forces applied to the hoof, and thus limb motions during stance that can contribute to musculoskeletal pathologies. Race surface design has been largely empirical within the industry, with little uniform consensus for injury prevention and performance. Furthermore, race surface installations are too expensive to install experimentally. The objective of this research was to develop and evaluate an integrated racehorse limb and race surface computational model. Combined forward/inver...
Kane-Smyth J, Barnett TP, Mark O'Leary J, Dixon PM.To describe a novel surgical technique for correcting postoperative ventral glottic stenosis (cicatrix or web formation) and the outcome in 2 Thoroughbred racehorses. Methods: Retrospective case report. Methods: Thoroughbreds diagnosed with ventral glottic stenosis (n=2). Methods: Horses presenting with iatrogenic ventral glottic stenosis and resultant exercise intolerance and abnormal exercise-related noise were anesthetized and a midline sagittal skin incision was made over the ventral larynx and between the sternohyoideus muscles overlying the cricothyroid notch. The cricothyroid ligament, ...
Negro Rama S, Valera M, Membrillo A, Gómez MD, Solé M, Menendez-Buxadera A, Anaya G, Molina A.The association of five candidate genes with sporting performance in young and adult Spanish Trotter horses (STHs) was performed according to a previous selection based on quantitative analysis of the trait time per kilometre (TPK). A total of 334 516 records of TPK from 5958 STHs were used to estimate the estimated breeding values (EBVs) at different age groups (young and adults horses) throughout the range of distances (1600-2700 m) using a bicharacter random regression model. The heritability estimated by distance ranged from 0.16 to 0.40, with a different range for the two age groups. Co...
Barker WH, Wright IM.A technique for minimally invasive repair of slab fractures of the third tarsal bone has not previously been reported. Results of third tarsal bone slab fracture repair in Thoroughbred racehorses are lacking. Objective: To report the outcomes of repair of uniplanar frontal slab factures of the third tarsal bone using a single 3.5 mm cortex screw in lag fashion. Methods: Retrospective case series. Methods: Case records of horses that had undergone this procedure were reviewed. Results: Seventeen horses underwent surgery. Eighteen percent of cases had wedge shaped third tarsal bones. A point mid...
Salz RO, Ahern BJ, Boston R, Begg LM.To determine the variation of tracheal mucus scores, tracheal blood scores and transendoscopic tracheal wash (TW) cytology in a population of Thoroughbred (TB) racehorses and assess their association with racing performance. Methods: A total of 220 endoscopic examinations were performed and TWs obtained from 155 TB racehorses. Samples were collected 60-120 min following gallop work. Tracheal mucus score, tracheal blood score and TW cytology were analysed and their association with racing performance assessed. Results: Of the total examinations and samples, 194 from 135 horses fitted the criter...
Waller CC, Cawley AT, Suann CJ, Ma P, McLeod MD.Furazadrol ([1',2']isoxazolo[4',5':2,3]-5α-androstan-17β-ol) is a designer anabolic androgenic steroid that is readily available via the internet. It contains an isoxazole fused to the steroid A-ring which offers metabolic stability and noteworthy anabolic activity raising concerns over the potential for abuse of this compound in equine sports. The metabolism of furazadrol was studied by in vivo and in vitro methods for the first time. Urinary furazadrol 17-sulfate and furazadrol 17-glucuronide metabolites were detected in vivo after a controlled administration and compared with syntheticall...
Loughridge AB, Hess AM, Parkin TD, Kawcak CE.Changes in subchondral bone density, induced by the repetitive cyclical loading of exercise, may potentiate fatigue damage and the risk of fracture. Objective: To use computed tomography (CT) to characterise bone density patterns at the articular surface of the third metacarpal bone in racehorses with and without lateral condylar fractures. Methods: Case control METHODS: Computed tomographic images of the distal articulating surface of the third metacarpal bone were obtained from Thoroughbred racehorses subjected to euthanasia in the UK. Third metacarpal bones were divided into 3 groups based ...
Takahashi Y, Akai M, Murase H, Nambo Y.The objective of the present study was to verify the seasonal luteal activity of racehorses in training in Japan from March to August. We allocated 102 horses into a luteal activity group and non-luteal activity group. The luteal activity group included horses with serum progesterone levels that were consistently >1 ng/ml and changed by ± 1 ng/ml. In contrast, the progesterone levels of the non-luteal activity group were consistently <1 ng/ml. In late spring (from May 1 to June 30) and summer (from July 1 to August 31), the percentage of horses in the luteal activity group was significa...
Mori M, Ichibangase T, Yamashita S, Kijima-Suda I, Kawahara M, Imai K.In the doping tests currently used in horse racing, prohibited substances or their metabolites are usually directly detected in urine or blood samples. However, despite their lasting pharmaceutical effects, some prohibited substances are rapidly eliminated from horse urine and blood, making them difficult to detect. Therefore, new indirect biomarkers for doping, such as plasma proteins that are increased by the prohibited substances, have recently attracted much attention. Here, a fluorogenic derivatization-liquid chromatography-tandem mass spectrometry (FD-LC-MS/MS) method was adopted for hor...
Dong HJ, Ho H, Hwang H, Kim Y, Han J, Lee I, Cho S.Equine gastric ulcer syndrome is one of the most frequently reported diseases in thoroughbred racehorses. Although several risk factors for the development of gastric ulcers have been widely studied, investigation of microbiological factors has been limited. In this study, the presence of Helicobacter spp. and the gastric microbial communities of thoroughbred racehorses having mild to severe gastric ulcers were investigated. Although Helicobacter spp. were not detected using culture and PCR techniques from 52 gastric biopsies and 52 fecal samples, the genomic sequences of H. pylori and H. ganm...
Chen JW, Uboh CE, Robinson MA, Jiang Z, Soma LR.To evaluate plasma interleukin 6 (IL-6) concentration in Standardbred racehorses by means of a novel ELISA following validation of the assay for use with equine plasma samples. Methods: Plasma samples obtained from 25 Thoroughbreds for use in assay validation and from 319 Standardbred racehorses at rest 2 to 2.5 hours prior to warm-up and racing. Methods: A sandwich ELISA was developed with equine anti-IL-6 polyclonal antibody and the biotin-streptavidin chemical interaction to enhance sensitivity. The assay was validated for specificity, sensitivity, precision, and accuracy by use of both rec...
Kinobe RT.Cobalt is an essential trace element for many vital physiological functions. Cobalt is also known to stabilise hypoxia-inducible transcription factors leading to increased expression of erythropoietin which activates production of red blood cells. This implies that cobalt can be used to enhance aerobic performance in racing horses. If this becomes a pervasive practice, the welfare of racing animals would be at risk because cobalt is associated with cardiovascular, haematological, thyroid gland and reproductive toxicity as observed in laboratory animals and humans. It is expected that similar e...
Arfuso F, Giannetto C, Giudice E, Fazio F, Piccione G.The effect of exercise on platelet aggregation, albumin and nonesterified fatty acids (NEFAs) values and the correlation among these parameters were evaluated in ten clinically healthy and regularly trained Thoroughbred horses. All horses were subjected to two simulated races. Blood samples were collected by jugular venipuncture before and after the first simulated race (T0PRE and T0POST), every 7 days at rest condition for a month (T1R-T2R-T3R), and before and after the second simulated race (T4PRE and T4POST) in order to assess platelet aggregation, albumin and nonesterified fatty acids (NEF...
Pusterla N, Mapes S, Akana N, Barnett C, MacKenzie C, Gaughan E, Craig B, Chappell D, Vaala W.The objective of the present case-control study was to determine prevalence factors associated with the detection of equine herpesvirus type 1 (EHV-1) by quantitative PCR (qPCR) in horses presented to veterinarians with clinical signs related to an upper respiratory tract infection and/or acute onset of neurological disease from March 2008 to December 2014. Nasal secretions and whole blood from 4228 equids with acute onset of fever, respiratory signs and/or neurological deficits were tested by qPCR for EHV-1. Categorical analyses were performed to determine the association between observations...
Do KT, Cho HW, Badrinath N, Park JW, Choi JY, Chung YH, Lee HK, Song KD, Cho BW.Since ancient days, domestic horses have been closely associated with human civilization. Today, horse racing is an important industry. Various genes involved in energy production and muscle contraction are differentially regulated during a race. Among them, creatine kinase (CK) is well known for its regulation of energy preservation in animal cells. CK is an iso-enzyme, encoded by different genes and expressed in skeletal muscle, heart, brain and leucocytes. We confirmed that the expression of CK-M significantly increased in the blood after a 30 minute exercise period, while no considerable c...
Schweizer C, Ramseyer A, Gerber V, Christen G, Burger D, Wohlfender FD.Racetrack injuries are of welfare concern and the prevention of injuries is an important goal in many racing jurisdictions. Over the years this has led to more detailed recording of clinical events on racecourses. However, risk factor analyses of clinical events at race meetings have not been previously reported for Switzerland. Objective: To identify discipline-specific factors that influence the occurrence of clinical events during race meetings with the ultimate aim of improving the monitoring and safety of racetracks in Switzerland and optimising racehorse welfare. Methods: Retrospective s...
Brard S, Ricard A.An A/C mutation responsible for the ability to pace in horses was recently discovered in the gene. It has also been proven that allele C has a negative effect on trotters' performances. However, in French trotters (FT), the frequency of allele A is only 77% due to an unexpected positive effect of allele C in late-career FT performances. Here we set out to ascertain whether the genotype at SNP (linked to ) should be used to compute EBV for FT. We used the genotypes of 630 horses, with 41,711 SNP retained. The pedigree comprised 5,699 horses. Qualification status (trotters need to complete a 2,0...
Yamazaki M, Kusano K, Ishibashi T, Kiuchi M, Koyama K.Upon intensive, exhaustive exercise, exercise-induced reactive oxygen species may exceed the antioxidant defence threshold, consequently resulting in muscular damage or late-onset chronic inflammation. Recently, the therapeutic antioxidant and anti-inflammatory effects of molecular hydrogen (H2) for human rheumatoid arthritis have been demonstrated. However, it is also important to clarify the effects of administrating H2 in large animals other than humans, as H2 is thought to reach the target organ by passive diffusion upon delivery from the blood flow, indicating that the distance from the a...
Ruse K, Davison A, Bridle K.Thoroughbred jump racing sits in the spotlight of contemporary welfare and ethical debates about horse racing. In Australia, jump racing comprises hurdle and steeplechase races and has ceased in all but two states, Victoria and South Australia. This paper documents the size, geography, composition, and dynamics of Australian jump racing for the 2012, 2013, and 2014 seasons with a focus on debate about risks to horses. We found that the majority of Australian jump racing is regional, based in Victoria, and involves a small group of experienced trainers and jockeys. Australian jump horses are on...
Smith LJ, Marr CM, Payne RJ, Stoneham SJ, Reid SW.Septic arthritis is a serious problem in the neonate, with a poor prognosis being reported for recovery. The impact of neonatal septic arthritis on the likelihood that Thoroughbred (TB) foals will start on a racecourse is not known. Objective: The development of septic arthritis in a TB foal significantly reduces the likelihood that it will race when compared to foals from the same dam. Methods: Medical records of 69 foals treated for septic arthritis were reviewed. The dam's foaling records were reviewed and lifetime racing records were then retrieved for both the affected foals and at least ...
Malikides N, Hughes KJ, Hodgson JL.To determine whether percentages of neutrophils in tracheal aspirate (TA) samples collected from racehorses are increased after exercise and whether interpretation of results from TA samples taken before and after exercise agree. Methods: Case series of 40 young Thoroughbred and Standardbred racehorses in race training presented for evaluation of poor performance. Methods: TA samples were collected endoscopically from racehorses presented for poor performance 24 h before and 1 to 2 h after high speed treadmill exercise testing. Aliquots of the retrieved fluid were cytocentrifuged and smears we...
Wright IM, Minshall GJ.Although a well recognised clinical entity, only small numbers of osteochondromata on the caudal distal radius have previously been published and its occurrence in young racing Thoroughbreds has not previously been reported. Identification and management of associated lesions in the deep digital flexor tendon have received scant attention in the literature. Objective: Osteochondromata of the caudal distal radius occur commonly in young racing Thoroughbreds. They vary in size and location, sagittally and proximodistally, but the majority cause impingement damage to the deep digital flexor tendo...
Brownlow MA, Brotherhood JR.Exertional heat illness (EHI) is a syndrome that occurs when metabolic heat production from muscular contraction exceeds the rate at which it can be dissipated. Core body temperature rises to critical levels, causing hyperthermia and central nervous system dysfunction. Best practice for the prevention of EHI centres around early detection, rapid response and aggressive cooling. Advance planning enables risk mitigation measures. The more that is known about EHI in horses, the better prepared those in the positions of responsibility can be to anticipate events in which the risk of EHI may be ele...
Weese JS, Sabino C.Antimicrobials had been administered to 38/55 (69%) racing standardbred and Thoroughbred horses with poor performance, subsequently diagnosed with nonseptic inflammatory airway disease. Horses with cough were more commonly treated (P = 0.02). In almost all cases, no clinical signs suggested that bacterial infection was present. Inappropriate use of antimicrobials was common. Des antimicrobiens ont été administrés à 38/55 (69 %) chevaux standardbreds et chevaux pursang affichant une piètre performance, diagnostiqués par la suite avec une maladie inflammatoire aseptique des voies respirat...
Little CB, Ghosh P, Rose R.Articular cartilage degeneration in the middle carpal joint is a common problem in racing horses. This study evaluated the effect of exercise on the in-vitro synthesis of the large aggregating proteoglycans (aggrecan) and two small proteoglycans, biglycan and decorin, in articular cartilage taken from three weight bearing regions of the third carpal bone of horses which were subjected to moderate or strenuous exercise. Twelve Standardbred horses free from clinical and radiographic disease of the middle carpal joint were subjected to an 8 week moderate exercise program. The horses were then ran...
Cheung HW, Wong KS, Lin VYC, Farrington AF, Bond AJ, Wan TSM, Ho ENM.The concern about gene doping has remained high in horseracing and other equestrian competitions. Our laboratory has previously developed a duplex quantitative polymerase chain reaction (qPCR) assay capable of detecting in equine blood the human erythropoietin (hEPO) transgene and equine tubulin α 4a (TUBA4A) gene as an internal control the latter providing quality control over DNA extraction and qPCR. This study aimed to optimize the method for routine testing of regulatory samples. The use of an automated DNA extraction system has increased the sample throughput, consistency of DNA extracti...
Drum MG, Kawcak CE, Norrdin RW, Park RD, McIlwraith CW, Les CM.Comparison of subchondral bone density determined by quantitative computed tomography (CT) with gross and histopathologic changes have not been made in horses. The goal of this study was to determine if mean quantitative CT density and mean voxel standard deviation are associated with the presence and severity of osteochondral lesions in the palmar aspect of the distal third metacarpal bone in racing horses. Metacarpophalangeal joints from nine racehorses were imaged using CT and scored for gross damage. Four-millimeter-thick sagittal and 30 degrees palmar dorsal plane sections were cut, decal...
Harkins JD, Beadle RE, Kamerling SG.The running abilities of 25 Thoroughbred racehorses were measured at distances of 1200, 1600 and 20000 m. Various physiological variables were measured subsequently on the treadmill and correlated with running speed. There was a negative correlation for running speed with the velocity (VLa4) and work rate (WLa4) at which blood lactate reaches a steady-state concentration of 4 mmol/litre and a positive correlation with peak plasma lactate, suggesting that plasma lactate concentrations of faster horses rise more rapidly and to higher levels than do those of slower horses. The correlation between...
White A, Reyes A, Godoy A, Martínez R.1. Packed cell volume (PCV), blood glucose, total plasma proteins (TPP) and plasma electrolytes, osmolality, cortisol and aldosterone alterations produced by transport and racing, were investigated in race horses. 2. Plasma cortisol, sodium and blood glucose, found after transport, were higher, while aldosterone was lower than control levels. 3. After racing, PCV, blood glucose, TPP and plasma cortisol, sodium and osmolality were higher than control, while chloride diminished and aldosterone returned to control values. 4. These results demonstrate that transport and racing are different kinds ...
Ferrari M, Pfau T, Wilson AM, Weller R.The influence of training on stride parameters is controversial and to date there is no information on how training influences stride parameters during high-speed locomotion in the field. Objective: To determine the influence of training on stride variables during high-speed locomotion in Thoroughbred racehorses. Methods: Speed, stride frequency, stance and protraction times were quantified in 8 Thoroughbreds with foot mounted accelerometers and GPS sensors during their first week of canter after the summer break and 6 months into training. Results: At a speed of 11 m/s, stride frequency was (...
Nieto JE, Spier S, Pipers FS, Stanley S, Aleman MR, Smith DC, Snyder JR.To compare effects of a commercially available omeprazole paste and a compounded omeprazole suspension on healing of gastric ulcers in Thoroughbred racehorses in active training. Methods: Randomized controlled trial. Methods: 32 horses with gastric ulcers. Methods: Horses were assigned to 2 groups on the basis of endoscopic gastric ulcer severity. Group-1 horses were treated with omeprazole suspension for 30 days and with omeprazole paste for an additional 30 days. Group-2 horses were treated with omeprazole paste for 30 days and omeprazole suspension for an additional 30 days. Serum omeprazol...
Mahaffey CA, Peterson ML, Thomason JJ, McIlwraith CW.Different horseshoe designs have been developed in an attempt to optimise footing for equine athletes. Horseshoe performance is assumed to be dependent on the surface and gait, but there are limited data on horseshoe performance on different surfaces, independent of gait variation. Objective: To quantify the dynamic loading for 3 aluminium racing shoe designs on Thoroughbred racetrack surface materials, using a biomechanical surface tester. Methods: A flat racing plate, a serrated V-Grip and a shoe with a 6 mm toe grab and 10 mm heel calks were tested on synthetic and dirt surfaces under t...
Orsini JA, Parsons CS, Capewell L, Smith G.This retrospective study investigated the factors associated with a poor outcome (death by euthanasia or from other causes) in horses treated for laminitis at a tertiary care hospital. Cases (n = 247) were defined as patients with laminitis that were euthanized or that died of other causes during hospitalization. Controls (n = 344) were patients with laminitis that survived to be discharged from the hospital. In the final multivariate analysis, the factors significantly associated with an increased risk for death and their respective odds ratios (OR) were as follows: Thoroughbred (OR = 1.57); ...
Colón JL, Bramlage LR, Hance SR, Embertson RM.The purpose of this study was to examine the longevity of postoperative careers and quality of performance of 461 Thoroughbred racehorses after arthroscopic removal of dorsoproximal first phalanx (P1) osteochondral fractures. Six hundred and 59 dorsoproximal P1 chip fractures were removed arthroscopically from 574 joints in 461 horses presented for lameness or decreased performance attributed to the chip fractures. Radiological and arthroscopic examination revealed an average of 1.43 fragment sites/horse, 1.15 fragment sites/joint and 1.25 affected joints/horse. Eighty-nine percent of the hors...
Laws EG, Richardson DW, Ross MW, Moyer W.A retrospective study of 114 Standardbred horses diagnosed with osteochondrosis (OC) of the cranial intermediate ridge of the distal tibia was carried out, and their subsequent race records were compared with 456 control horses. Each OC-affected horse was compared with 4 horses randomly selected from a list of horses matched to it by year of birth, sex and sire. The horses with OC were treated by arthroscopic removal of osteochondral fragments (N = 58) or managed conservatively (N = 56). The clinical presentation of these two groups was similar, although joint effusion was a more common presen...
Lo Feudo CM, Stucchi L, Conturba B, Stancari G, Zucca E, Ferrucci F.Equine Gastric Ulcer Syndrome (EGUS) is a highly prevalent disorder in horses, which can be classified, based on the localization of the lesions, as Equine Squamous Gastric Disease (ESGD) or Equine Glandular Gastric Disease (EGGD). Although EGUS is recognized as a common cause of poor performance in racehorses, objective investigations about its relation with athletic capacity are lacking. Therefore, the present retrospective study aims to evaluate the associations between EGUS severity and some fitness parameters measured during an incremental treadmill test in Standardbred racehorses in trai...
Berg AL, Dörries R, Berg M.Borna disease virus (BDV) is a neurotropic agent with capacity to infect and cause neurological disease in a broad range of warmblooded hosts including horses, sheep, cattle, cats, and possibly also humans. The epidemiology of BDV is largely unknown. However, it is likely that subclinically infected animals may represent potential virus reservoirs. In two groups of Swedish racing horses, one clinically healthy and one consisting of horses with diffuse neurological signs, the BDV seroprevalence was 24.5% and 57.7%, respectively. BDV RNA was detected in peripheral blood mononuclear cells in 8 ou...
Crispe EJ, Lester GD.Exercise-induced pulmonary hemorrhage (EIPH) occurs commonly in horses undergoing strenuous exercise. Reported risk factors include racing in cold temperatures and wearing of bar shoes. In horses with documented moderate to severe EIPH, increasing the interval between races and adopting a negative race pace strategy may reduce the severity of EIPH in subsequent races. EIPH seems to have an impact on performance only when moderate to severe. This occurs in a small number of starters, approximately 6%. EIPH often is erratic in severity from race to race, although across a population it is weakly...
Peel JA, Peel MB, Davies HM.The economic impact of soundness problems in racehorses is very high and low hoof angle at the toe has been associated with a lack of soundness. However, it is not clear what environmental and management factors might contribute to a low hoof angle. Objective: To investigate the hypothesis that the hooves of racehorses become flatter when in gallop training, as well as to determine factors contributing to this trend. Methods: Weekly hoof measurements were taken with a hoof gauge from 45 Thoroughbred racehorses; 4 Thoroughbred show horses kept in consistent conditions and shod by the same farri...
Gramkow HL, Evans DL.Running ability of Thoroughbred racehorses is correlated with maximal oxygen uptake, and the velocity at maximal oxygen uptake is highly correlated with the velocity at maximal heart rate (VHRmax). Objective: To investigate the relationship between VHRmax and racing performance, expressed as 'peak dollars earned per race start'. Methods: Heart rate (HR) and velocity were recorded in 25 Thoroughbred racehorses during trotting and subsequent fast gallops in the field at velocities of 15-16 m/sec. Velocity was recorded by a global positioning system (GPS). Maximal HR (HRmax) and maximal velocity ...
Beisser AL, McClure S, Wang C, Soring K, Garrison R, Peckham B.To determine the incidence of and compare the types of catastrophic musculoskeletal injuries (CMIs) sustained in Thoroughbreds and Quarter Horses during racing at 3 Midwestern racetracks from 2000 to 2006. Methods: Retrospective cohort study. Methods: 139 Thoroughbred and 50 Quarter Horse racehorses euthanized because of CMIs. Methods: Veterinary officials from 3 Midwestern racing jurisdictions provided injury reports for Thoroughbreds and Quarter Horses that sustained CMIs (which required euthanasia) and the total number of race starts for each year. The number of CMIs/1,000 starts was determ...
Page AE, Adam E, Arthur R, Barker V, Franklin F, Friedman R, Grande T, Hardy M, Howard B, Partridge E, Rutledge M, Scollay M, Stewart JC, Vale A....The ability to identify horses at risk for catastrophic injuries continues to be a pressing issue for the racing industry, especially given recent events in North America. Objective: Since most catastrophic injuries occur in areas of existing pathology and this pathology is likely to elicit an inflammatory response, it was hypothesised that analysis of messenger RNA (mRNA) expression would detect significant changes in select genes in horses at risk for a catastrophic injury. Methods: Prospective cohort study. Methods: Five racing jurisdictions across the United States participated in this stu...
Da Costa Gómez TM, Radtke CL, Kalscheur VL, Swain CA, Scollay MC, Edwards RB, Santschi EM, Markel MD, Muir P.To determine whether bone microcracks are altered after application of focused and radial extracorporeal shock wave therapy (ESWT) to the equine distal limb. Methods: An ex vivo experimental model. Methods: A contralateral limb specimen was obtained from 11 Thoroughbred racehorses with a unilateral catastrophic injury. Distal limb specimens were also obtained from 5 non-racing horses. Methods: Three separate skin-covered bone segments were obtained from the mid-diaphysis of the metacarpus (MC3) or metatarsus (MT3). Focused (9,000 shockwaves, 0.15 mJ/mm2, 4 Hz) and radial (9,000 shockwaves, 0.1...
Olive J, Serraud N, Vila T, Germain JP.The metacarpal condyle has received extensive attention as a predominant site of overload arthropathy in racehorses. However, detailed descriptions of MRI lesion patterns for the metacarpophalangeal joint and comparisons between types of racing horses are currently lacking. Aims of this retrospective, cross-sectional study were to describe and compare standing low-field magnetic resonance findings in the metacarpophalangeal joints for groups of Standardbreds and Thoroughbreds using systematic semiquantitative scores. Data archives at the Clinique Vétérinaire Equine de Chantilly and Imavet we...
Bernard SL, Glenny RW, Erickson HH, Fedde MR, Polissar N, Basaraba RJ, Hlastala MP.We determined the spatial distribution of pulmonary blood flow at rest and during increasing levels of exercise (34, 59, and 90% of maximal oxygen consumption) in Thoroughbred racehorses (n = 4) using 15-microns fluorescent microspheres. After the horses were killed, the lungs were flushed free of blood, removed, air-dried at total lung capacity, and sliced into isogravitational planes, which were sampled in a systematic fashion for three-dimensional reconstruction. The fluorescence was measured for quantification of blood flow. Mean pulmonary blood flow heterogeneity (expressed as a coefficie...
Hill EW, Ryan DP, MacHugh DE.Variation at the myostatin (MSTN) gene locus has been shown to influence racing phenotypes in Thoroughbred horses, and in particular, early skeletal muscle development and the aptitude for racing at short distances. Specifically, a single nucleotide polymorphism (SNP) in the first intron of MSTN (g.66493737C/T) is highly predictive of best race distance among Flat racing Thoroughbreds: homozygous C/C horses are best suited to short distance races, heterozygous C/T horses are best suited to middle distance races, and homozygous T/T horses are best suited to longer distance races. Patent applica...
Hoffman CJ, Clark CK.Cervical vertebral malformation (CVM) is seen in young, rapidly growing horses, and is commonly associated with a poor prognosis for racing. Objective: To examine the records of a population of Thoroughbreds with a presumptive diagnosis of CVM and to determine which radiographic findings and neurologic exam findings have an effect on these horses achieving athletic function when managed conservatively. Methods: One hundred and three thoroughbreds presumptively diagnosed with CVM and treated conservatively between 2002 and 2010. Methods: Racing records were reviewed in this retrospective study ...
Morrice-West AV, Hitchens PL, Walmsley EA, Tasker K, Lim SL, Smith AD, Whitton RC.Fatigue life (FL) is the number of cycles of load sustained by a material before failure, and is dependent on the load magnitude. For athletes, 'cycles' translates to number of strides, with load proportional to speed. To improve previous investigations estimating workload from distance, we used speed (m/s, x) per stride collected using 5 Hz GPS/800 Hz accelerometer sensors as a proxy for limb load to investigate factors associated with FL in a Thoroughbred race start model over 25,234 race starts, using a combination of mathematical and regression modelling. Fore-limb vertical force (NKg) w...
Evans DL, Kiddell L, Smith CL.Inflammatory airway disease (IAD) is common in racehorses, and is a cause of wastage in the industry. IAD has been diagnosed by measurement of percent neutrophils (N%) in tracheal aspirates (TA). The aim of this study was to investigate whether spirometric indices of pulmonary function were correlated with N% in TAs. Limits to breathing were measured by analyses of relationships between relative times and relative respiratory gas flows during inspiration and expiration in individual breaths recorded after exercise. Horses with higher N% had significantly lower relative gas flows at the same re...
