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.
Brito G, Damián JP, Suárez G, Ruprechter G, Trigo P.RHU is the oldest endurance sport in Uruguay. However, despite 80 years of racing, there are no studies to characterize this type of competition, explore rates and causes of death, and identify the associated risk factors. The aim was to characterize the Raid Hipico Uruguayo (RHU) competencies according to the distance (short (SR, 60 km) vs. long (LR, 80-115 km)), the causes of deaths, and the associated risk factors. The study population comprised horses ( = 16,856) that participated in RHU rides from 2007 to 2018. LR were more frequent than SR ( < 0.001). The average speed of winners was ...
Flash ML, Shrestha K, Stevenson MA, Gilkerson JR.The social licence of the Australian thoroughbred (TB) industry relies on the general public's perception of how they manage the animal in their care. Methods: This study examines the horse, race and activity records for the 37,704 horses racing and training in Australia from 1 August 2017 to 31 July 2018. Three-quarters (75%, n = 28,184) of TBs started in one of the 180, 933 race starts that occurred during the 2017-2018 Australian racing season. Results: Horses participating in the 2017-2018 Australian racing season had a median age of 4 years, with geldings more likely to be aged 5 ye...
Timms M, Botteon A, Manos C, Griffin J, Levina V, Steel R.Gonadotropin-releasing hormone (GnRH) and its synthetic analogues are considered banned substances by the racing industry. GnRH is used as a pharmaceutical to regulate the female oestrous cycle, but the hormone is also thought to increase the production of testosterone in male animals. Using liquid chromatography in conjunction with high-resolution mass spectrometry (LC-HRMS) and data-independent acquisition (DIA), a method is presented for the detection of intact and truncated peptides of GnRH and its analogues down to the low picogram level in equine urine. The study of the catabolism of GnR...
Karatt TK, Muhammed Ajeebsanu M, Karakka Kal AK, Subhahar MB, Sathiq MA, Laya S.The formation of mass adducts is common during electrospray ionization mass spectrometry (ESI-MS). However, the mechanism that leads to adduct formation is poorly understood and difficult to control. Multiplication of mass adducts at once will adversely impact the sensitivity of mass analysis and cause misinterpretation of the level of detection. Prior studies on selective androgen receptor modulators (SARMs) revealed an immense mass adduct formation in both positive and negative ESI modes. Methods: In this study, additives in the mobile phases are investigated as a potential means of controll...
Wong KS, Cheung HW, Szeto CWL, Tsang CYN, Wan TSM, Ho ENM.Illicit administration of transgene into horses is a form of gene doping that has been a key concern in equine sports. The large number of potential performance-enhancing transgenes has demanded a cost-effective and reliable detection method. Multiplex qPCR is a relevant technique, but the cross-talking between fluorophores and high background noise limits the method sensitivity and specificity. This study reports a simpler multiplexing approach by using the same fluorophore for four hydrolysis probes each targeting one of the four transgenes: human growth hormone, insulin-like growth factor 1...
Grzędzicka J, Dąbrowska I, Malin K, Witkowska-Piłaszewicz O.Increased training loads in both human and equine athletes are generally implemented to improve their physical performance. These loads are tolerated only within appropriate training periodization with regard to recovery time. Otherwise, training overload causes failure in the systemic adaptation, which at first leads to overreaching, and progressively to overtraining syndrome (OTS). Exercise endocrinology, and anabolic/catabolic balance as an indicator of athlete performance status and OTS has continued to attract attention. In human medicine, changes in testosterone and cortisol levels, as w...
Sugiyama F, Takahashi Y, Nomura M, Ebisuda Y, Mukai K, Yoshida T.We investigated the risk factors for epistaxis in Japanese flat races over a 20-year period. The veterinary records of horses identified as having epistaxis by endoscopy on the race day, and the official racing records of all flat races from April to September between 2001 and 2020, were reviewed. The racecourses (n = 10), surface type, surface condition, race class, race distance, race year, sex, age, two training centers, ambient temperature, and body weight on race days were assessed using multivariable logistic regression (p < 0.05). Of 475,709 race starts, 616 (1.30 cases per 1000 starts;...
Holtby AR, McGivney BA, Browne JA, Katz LM, Murphy KJ, Hill EW.Thoroughbred horses are bred for competitive racing and undergo intense training regimes. The maintenance of physical soundness and desirable behavioural characteristics are critical to the longevity of a racing career. Horses intended for Flat racing generally enter training as yearlings and undergo introductory training prior to exercise conditioning for racing. This period requires rapid adjustment to a novel environment. As a prey animal, a horse's 'fight-or-flight' response is highly adapted, in which a well-understood component of this response, the hypothalamic-pituitary-axis, is activa...
Carstensen H, Nissen SD, Saljic A, Hesselkilde EM, van Hunnik A, Hohl M, Sattler SM, Fløgstad C, Hopster-Iversen C, Verheule S, Böhm M, Schotten U....Atrial fibrillation (AF) is more prevalent in athletes, and currently, the mechanisms are not fully understood. Atrial fibrillation inducibility and stability was investigated in trained and untrained Standardbred racehorses. The horses underwent echocardiography for evaluation of atrial size. High-density mapping during AF was performed, and the presence of structural remodeling, as well as the expression of inflammatory and pro-inflammatory markers in the atria, was studied. Atrial fibrillation sustained significantly longer after tachypacing in the trained horses, whereas no difference in A...
Maxwell L, McCarrel TM, Hay S, Cole C.The antifibrinolytic agent aminocaproic acid (ACA) is occasionally used prior to episodes of intense training in racehorses suffering from exercise-induced pulmonary hemorrhage. Although a previous study indicated that the drug is cleared rapidly in horses, some racetrack practitioners claim that recent adverse analytical findings for ACA in postrace samples were from ACA administrations 5-7 days before the race. The purpose of this study was to re-examine the pharmacokinetics of ACA in horses to address this apparent conundrum. Eight exercise-conditioned thoroughbred horses were administere...
Trigg LE, Lyons S, Mullan S.The development of exertional heat illness (EHI) is a health, welfare and performance concern for racehorses. However, there has been limited multivariable assessment of the possible risk factors for EHI in racehorses, despite such information being vital for regulators to effectively manage the condition. Consequently, this study aimed to identify the risk factors associated with the occurrence of EHI in Thoroughbred racehorses and assess the ability of the risk factor model to predict the occurrence of EHI in racehorses to assist in early identification. Runners at British racecourses record...
Keen B, Cawley A, Reedy B, Noble G, Loy J, Fu S.The use of catechol-O-methyltransferase inhibitors may mask doping agents, primarily levodopa, administered to racehorses and prolong the stimulating effects of dopaminergic compounds such as dopamine. It is known that 3-methoxytyramine is a metabolite of dopamine and 3-methoxytyrosine is a metabolite of levodopa thus these compounds are proposed to be potential biomarkers of interest. Previous research established a urinary threshold of 4,000 ng/mL for 3-methoxytyramine to monitor misuse of dopaminergic agents. However, there is no equivalent biomarker in plasma. To address this deficiency a...
Hill EW, McGivney BA, MacHugh DE.The proportion of the genome containing runs of homozygosity (ROH) affects production traits in livestock populations. In European and Australasian Thoroughbreds inbreeding, quantified using ROH (F ), is associated with the probability of ever racing. Here, we measured F using 333 K SNP genotypes from 768 Thoroughbred horses born in North America to evaluate the effect of inbreeding on racing traits in that region. Among North American horses, F was not associated (p = 0.518) with the probability of ever racing but was significantly associated with the number of race starts (p = 0.002). ...
Noordwijk KJ, Chen L, Ruspi BD, Schurer S, Papa B, Fasanello DC, McDonough SP, Palmer SE, Porter IR, Basran PS, Donnelly E, Reesink HL.Proximal sesamoid bone (PSB) fracture is the leading cause of fatal musculoskeletal injury in Thoroughbred racehorses in Hong Kong and the US. Efforts are underway to investigate diagnostic modalities that could help identify racehorses at increased risk of fracture; however, features associated with PSB fracture risk are still poorly understood. The objectives of this study were to (1) investigate third metacarpal (MC3) and PSB density and mineral content using dual-energy X-ray absorptiometry (DXA), computed tomography (CT), Raman spectroscopy, and ash fraction measurements, and (2) investig...
You Y, Proctor RM, Haughan J, Missanelli JR, Robinson MA.Fentanyl, a powerful synthetic mu opioid receptor agonist, is banned in equine sports by the Association of Racing Commissioners International and the Fédération Équestre Internationale. The presence of fentanyl in equine blood has been confirmed during routine post-race screening for doping substances in the authors' laboratory. While fentanyl can be detected and confirmed in blood, it is rapidly metabolized, and screening for the metabolite N-[1-(2-phenethy-4-piperidinyl)] maloanilinic acid (PMA) in equine urine is expected to allow for a longer detection time. In this study, a quantitati...
Gibson MJ, Legg KA, Gee EK, Rogers CW.Race day fatalities as a consequence of catastrophic musculoskeletal injury and cardiac failure are both a welfare concern and provide a challenge for the social perceptions of equine welfare within the racing industry. To reduce race day fatalities, the risk factors under New Zealand racing conditions need to be identified. The aim of this study was to examine race and horse-level risk factors for fatalities in New Zealand Thoroughbred flat racing using retrospective race day data from the 2011/12-2021/22 racing seasons. Horse and race-level factors associated with a suspected cardiac failure...
Stallones L, McManus P, McGreevy P.As society debates the use of animals in sport, entertainment, and leisure, there is an increasing focus on the welfare, social, and ecological impacts of such activities on the animals, human participants, people close to them, and the physical environment. This article introduces the "Enhanced One Welfare Framework" to reveal significant costs and benefits associated with Thoroughbred breeding and racing globally. In addition, relative to calls to ban horseracing and similar activities as part of sustainability approaches that focus chiefly on animals, the "Enhanced One Welfare Framework" is...
Melly V, Ortved KF, Manzi TJ, Richardson DW, Stefanovski D, Wulster KB.Increasing accessibility and advancements in computed tomographic (CT) imaging improve understanding of the contributors to poor performance in the Thoroughbred racehorse. Objective: To characterise an unreported site of tarsal subchondral bone injury (SBI) in Thoroughbred racehorses. Methods: Retrospective, cross-sectional analytical study. Methods: Tarsal CT scans of 108 horses were reviewed for evidence of SBI in the dorsodistolateral calcaneus (DDLC). Signalment, including age, breed, sex, and discipline of horses, was recorded. The association of DDLC SBI with Thoroughbred racehorse compa...
Legg KA, Gee EK, Breheny M, Gibson MJ, Rogers CW.The Thoroughbred racing industry faces new and competing pressures to operate within a modern, changing society. Three major moderators drive the focus and productivity of the industry worldwide: economic sustainability, horse biology and social licence to operate. This review proposes that despite the apparent homogeneity in the structure of racing across jurisdictions due to international regulation of the sport, there are significant differences within each jurisdiction in each of the three moderators. This creates challenges for the comparison of injury risk factors for racehorses within t...
Shaffer SK, Stover SM, Fyhrie DP.Focal bone lesions are often found prior to clinically relevant stress-fractures. Lesions are characterized by low bone volume fraction, low mineral density, and high levels of microdamage and are hypothesized to develop when bone tissue cannot sufficiently respond to damaging loading. It is difficult to determine how exercise drives the formation of these lesions because bone responds to mechanical loading and repairs damage. In this study, we derive steady-state rate constants for a compartment model of bone turnover using morphometric data from fractured and non-fractured racehorse proximal...
Salz RO, Elliott CRB, Zuffa T, Bennet ED, Ahern BJ.Overstrain of the superficial digital flexor tendon (SDFT) is a common Thoroughbred racehorse limb injury requiring treatment. Objective: To determine whether treatment of SDFT lesions in flat Thoroughbred racehorses with autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) or allogenic adipose-derived mesenchymal stem cells (A-MSCs) is associated with improved likelihood of returning to racing, when compared to racehorses managed with a controlled exercise rehabilitation program (CERP) alone. Methods: Retrospective cohort study combining clinical treatment records with race records...
Wilson J, De Donato M, Appelbaum B, Garcia CT, Peters S.Overtraining syndrome (OTS) is the reduction in performance due to excess training and lack of proper recovery, which can lead to a chronic deprivation of energy and reduction in the repair of damage that can accumulate over time. Here, the effect of acute, intense physical exercise on the expression of innate and adaptive immune genes in 12 racing-bred American Quarter Horses, after resting for 3 days and immediately after intense exercise for 1.8 miles were compared. The expression of 84 genes related to innate and adaptive immune responses was analyzed. Significant variation among individua...
Mactaggart AG, Phillips CJC.We validated a Thoroughbred racehorse welfare index, developed initially from expert opinion, by relating it to horse behaviour recorded in a range of training stables and surveying trainers to investigate the environment and management systems for Thoroughbred racehorses. Relationships between the index scores and horse behaviour were observed. Then, an Australia-wide survey of racing industry stakeholders was conducted to identify which parameters are important for welfare in a training stable. Trainers performed well on horsemanship and health/disease aspects. Provisions for ventilation, tr...
Dirikolu L, Waller P, Malveaux K, Lucas CH, Lomnicka I, Pourciau A, Bennadji H, Liu CC.The TCO (total carbon dioxide) test is performed on the blood of racehorses as a means of combatting the practice of administering alkalizing agents. This study evaluated serum TCO concentrations and factors influencing concentration of TCO in Thoroughbred and Quarter Horses. The normality of data were evaluated with a Shapiro-Wilk test. Mann-Whitney tests and Kruskal-Wallis tests were used against different effects. When a fixed effect was detected, Dunn's post-hoc comparisons were performed. The median pre-race serum TCO concentration (32.20 mmol/L (interquartile range (IQR): 30.80-33.50)) w...
Harding C, Viljanto M, Habershon-Butcher J, Taylor P, Scarth J.YK-11 is a steroidal selective androgen receptor modulator, a compound class prohibited in both equine racing and human sports because of their potentially performance enhancing properties. YK-11 is easily accessible via internet-based supplement vendors making this compound a possible candidate for doping; however, its phases I and II metabolism has not yet been reported in the horse. The purpose of this study was to investigate the in vivo metabolites of YK-11 in urine and plasma following oral administration with three daily doses of 50 mg to two Thoroughbred horses. In vitro incubations ...
Adams VJ, LeBlanc N, Penell J.Next-generation sequencing (NGS) has been used to evaluate the effect of various interventions on the equine microbiome. The aim of this randomised blinded clinical trial was to determine if a prebiotic nutritional supplement would result in a change from baseline in the faecal microbiome composition of racing Thoroughbred horses in training being fed a high concentrate/grain-based diet to be more similar to that found in forage fed/pasture grazed horses. Thirty-two horses on one training yard were randomised to either receive the supplement or not. Faecal samples were collected at baseline, 6...
Tou K, Cawley A, Bowen C, Bishop DP, Fu S.The current approach to equine anti-doping is focused on the targeted detection of prohibited substances. However, as new substances are rapidly being developed, the need for complimentary methods for monitoring is crucial to ensure the integrity of the racing industry is upheld. Lipidomics is a growing field involved in the characterisation of lipids, their function and metabolism in a biological system. Different lipids have various biological effects throughout the equine system including platelet aggregation and inflammation. A certain class of lipids that are being reviewed are the eicosa...
Edwards VL, Loux S, Embertson R.Juvenile Thoroughbreds can be expensive to raise and train to race. Part of the economic return in these juveniles are the weanling, yearling and 2-year-old in training sales at which major surgeries must be declared. Objective: To determine if surgically corrected large colon displacements were associated with a reduction of sales price and racing performance. We hypothesised that the surgery would be associated with a reduced sales price but would not be associated with a reduction in race earnings or starts. Methods: Retrospective cohort study. Methods: The medical, sales and racing records...
Han H, McGivney BA, Allen L, Bai D, Corduff LR, Davaakhuu G, Davaasambuu J, Dorjgotov D, Hall TJ, Hemmings AJ, Holtby AR, Jambal T, Jargalsaikhan B....Selection for system-wide morphological, physiological, and metabolic adaptations has led to extreme athletic phenotypes among geographically diverse horse breeds. Here, we identify genes contributing to exercise adaptation in racehorses by applying genomics approaches for racing performance, an end-point athletic phenotype. Using an integrative genomics strategy to first combine population genomics results with skeletal muscle exercise and training transcriptomic data, followed by whole-genome resequencing of Asian horses, we identify protein-coding variants in genes of interest in galloping ...
Avella CS, Ely ER, Verheyen KL, Price JS, Wood JL, Smith RK.It is important to ascertain the prevalence of superficial digital flexor tendon (SDFT) injuries and to improve methods of predicting injury in National Hunt (NH) racehorses. Objective: To establish: 1) the prevalence of SDFT tendinopathy in NH horses; 2) whether routine ultrasonography can be used to predict SDFT injuries; 3) whether previous tendinopathy predisposes to reinjury; 4) a normal range for the SDFT cross-sectional area (CSA); and 5) the effects of gender, age, background (ex-flat or ex-store), limb, training and rest periods on SDFT CSA. Methods: Routine ultrasound assessment of t...
Perkins NR, Reid SW, Morris RS.To describe and enumerate conditions that interrupted training and racing in a population of Thoroughbred racehorses in New Zealand. Methods: A longitudinal study design was used to collect data on horses training under the care of 20 licensed racehorse trainers from venues in the mid to lower regions of the North Island between October 1997 and July 2000. Incidence rates were reported for first and second occurrences for different categories of musculoskeletal injury (MSI), and first occurrences of upper and lower respiratory tract disease, using training days as time-at-risk. The proportion ...
O'Meara B, Bladon B, Parkin TD, Fraser B, Lischer CJ.There is limited information regarding the number of races and the period for evaluation of outcome which is critical for assessment of SDF tendonitis treatments. Objective: To evaluate the re-injury rate and racing performance of Thoroughbred racehorses that sustain SDF tendonitis in relation to matched controls in terms of number of races post treatment and maximum racing performance ratings before and after injury. Methods: Clinical records and racing histories of 401 racehorses with a first occurrence of SDF tendonitis diagnosed by ultrasonography. Controls were of the same age, sex and we...
Turner M, McCrory P, Halley W.Professional horse racing is an exciting and demanding sport with high injury rates. Surprisingly few epidemiological studies have been published and no prospective studies have been reported. This paper reviews the literature and provides a detailed breakdown of injuries in Great Britain and the Republic of Ireland for 1992-2000. The introduction of protective equipment is discussed and evidence for its effectiveness put forward.
Boden LA, Anderson GA, Charles JA, Morgan KL, Morton JM, Parkin TD, Slocombe RF, Clarke AF.Determining the risk of fatality of Thoroughbred horses while racing is essential to assess the impact of intervention measures designed to minimise such fatalities. Objective: To measure the risk of racehorse fatality in jump and flat starts on racecourses in Victoria, Australia, over a 15 year period and to determine proportional mortality rates for specific causes of death. Methods: All fatalities of Thoroughbred horses that occurred during or within 24 h of a race were identified from a database. The risk of a start resulting in a racehorse fatality in all races and within flat and jump ra...
Buhl R, Ersbøll AK, Eriksen L, Koch J.To evaluate changes over time in echocardiographic measurements in young Standardbred racehorses undergoing training and racing and determine whether there was any relationship between cardiac dimensions and racing performance. Methods: Longitudinal observational study. Methods: 103 horses. Methods: 2-dimensional and M-mode echocardiography was performed 4 times at 6-month intervals. Results: Significant cardiac enlargement took place during the study period as indicated by increases in left ventricular internal diameter in diastole (LVIDd), estimated left ventricular muscle mass (LV mass), an...
Rosanowski SM, Chang YM, Stirk AJ, Verheyen KL.To date, no large scale studies have reported race-day events requiring veterinary attention in British Thoroughbreds racing on the flat. Quantifying and describing common injuries and health conditions affecting racehorses will enable targeted risk factor analysis aimed at reducing their occurrence. Objective: To describe the type and incidence of race-day veterinary events experienced by Thoroughbred racehorses participating in flat racing in the UK. Methods: Retrospective cohort study (2000 to 2013). Methods: Veterinary events recorded by race-day veterinarians were retrieved and linked to ...
Parkin TD, Clegg PD, French NP, Proudman CJ, Riggs CM, Singer ER, Webbon PM, Morgan KL.Considerable variation in the rates of equine fatality at different racecourses draws attention to probable risk factors at the level of course or race that might be partly responsible. Distal limb fractures are the most common cause of equine fatality on UK racecourses and identification of risk factors for such injuries and subsequent implementation of intervention strategies could significantly reduce the total number of racecourse fatalities. Objective: To identify race- and course-level risk factors for fatal distal limb fracture in Thoroughbreds on UK racecourses. Methods: A case-control...
Murray RC, Dyson SJ, Tranquille C, Adams V.Although anecdotal reports of increased orthopaedic injury risk in equine sports exist, there is little scientific evidence to support this. Objective: To test whether horses undertaking a single competitive sport have increased risk of specific injuries compared to those used for general purpose riding (GP); and whether injury type varies with sport category and performance level. Methods: Data from 1069 records of horses undergoing orthopaedic evaluation (1998-2003) and meeting inclusion criteria were reviewed. Sport category (GP, showjumping, dressage, eventing, racing), level (nonelite or ...
Butler PJ, Woakes AJ, Smale K, Roberts CA, Hillidge CJ, Snow DH, Marlin DJ.A new design of flowmeter is described and used in a comprehensive study of the respiratory and cardiovascular adjustments that occur during a standardised exercise test in Thoroughbred horses. The flowmeter system and associated lightweight, fibreglass mask (total mass, 0.7 kg) have a maximum dead space of 500 ml and negligible resistance to airflow. They have no systematic effect on blood gases and, together with a rapidly responding mass spectrometer, enable an accurate computation of gas exchange to be performed together with breath-by-breath determination of other respiratory variables. A...
Verheyen KL, Wood JL.Musculoskeletal injury is the major cause of days lost from training and wastage in Thoroughbred racehorses. Little scientific information is available on the majority of injuries occurring in training. Objective: To estimate the incidence of fractures in British racehorses in training and describe the occurrence of different fracture types and bones involved. Methods: Thirteen UK racehorse trainers participated in a prospective study, providing data on horses in their care for 2 years. Details on horses, their daily exercise and fracture occurrence were recorded. Results: A total of 1178 hors...
Gu J, MacHugh DE, McGivney BA, Park SD, Katz LM, Hill EW.The wild progenitors of the domestic horse were subject to natural selection for speed and stamina for millennia. Uniquely, this process has been augmented in Thoroughbreds, which have undergone at least 3 centuries of intense artificial selection for athletic phenotypes. While the phenotypic adaptations to exercise are well described, only a small number of the underlying genetic variants contributing to these phenotypes have been reported. Objective: A panel of candidate performance-related genes was examined for DNA sequence variation in Thoroughbreds and the association with racecourse per...
Rooney MF, Hill EW, Kelly VP, Porter RK.Thoroughbred horses are finely-tuned athletes with a high aerobic capacity relative to skeletal muscle mass, attributable to centuries of genetic selection for speed and stamina. Polymorphisms in the myostatin gene (MSTN), a pronounced inhibitor of skeletal muscle growth, have been shown to almost singularly account for gene-based race distance aptitude in racehorses. In Thoroughbreds, two MSTN polymorphisms, a single nucleotide variation in the first intron (SNP g.66493737C>T) and a non-coding transposable element within the promoter region (a 227 bp SINE insertion) are of particular inter...
Parkin TD.This article describes the development of epidemiologic analyses of racetrack injury in racehorses. The risk or rate of fatal and nonfatal injury in racing and training around the world is examined. The focus is on the importance of global collaboration and the identification of modifiable risk factors. In particular, exercise-related risk factors for injury are evaluated and the potential impact of interventions discussed.
Parkin TD, Clegg PD, French NP, Proudman CJ, Riggs CM, Singer ER, Webbon PM, Morgan KL.Lateral condylar fractures of the third metacarpus/metatarsus are the most common cause of equine fatality on UK racecourses. Identification of risk factors for such injuries and the subsequent implementation of intervention strategies could significantly reduce the total number of racecourse fatalities. Objective: To identify horse-, race- and course-level risk factors for fatal lateral condylar fracture in Thoroughbreds on UK racecourses. Methods: Case-control study designs were used. Case horses were defined as those that were subjected to euthanasia having sustained an irreparable lateral ...
Witkowska-Piłaszewicz O, Maśko M, Domino M, Winnicka A.In horse racing the most acceptable way to objectively evaluate adaptation to increased exertion is to measure lactate blood concentration. However, this may be stressful for the horse, therefore, a simple, noninvasive procedure to monitor race progress is desirable. Forty Thoroughbreds attended race training, with blood samples collected at rest, immediately after, and 30 min after exercise. The lactate concentration was determined 60 s after blood collection using an Accusport. Thermal imaging of the neck and trunk areas was performed following international veterinary standards from a dista...
Tozaki T, Sato F, Hill EW, Miyake T, Endo Y, Kakoi H, Gawahara H, Hirota K, Nakano Y, Nambo Y, Kurosawa M.Myostatin is a member of the transforming growth factor-β family with a key role in inhibition of muscle growth by negative regulation of both myoblast proliferation and differentiation. Recently, a genomic region on ECA18, which includes the MSTN gene, was identified as a candidate region influencing racing performance in Thoroughbreds. In this study, four SNPs on ECA18, g.65809482T>C, g.65868604G>T, g.66493737C>T, and g.66539967A>G, were genotyped in 91 Thoroughbred horses-in-training to evaluate the association between genotype and body composition traits, including body weight...
Elton D, Bryant N.Despite the availability of vaccines, equine influenza virus (EIV) continues to pose a threat to the racing industry. The virus spreads rapidly in unprotected populations and large scale outbreaks, such as those in South Africa in 2003 and Australia in 2007, can cost billions of pounds. Like other influenza viruses, EIV undergoes antigenic variation, enabling it to evade antibodies generated against previous infection or vaccination. The UK has an active surveillance programme to monitor antigenic drift and participates in an international collaboration with other countries in Europe, Japan an...
Andrews FM, Sifferman RL, Bernard W, Hughes FE, Holste JE, Daurio CP, Alva R, Cox JL.Equine gastric ulcer syndrome (EGUS) is very common among performance horses, with a reported prevalence of approximately 90% in racehorses, and also > 50% in foals. Omeprazole, an acid pump inhibitor 5 times more potent than ranitidine, has been used with great success to treat EGUS. This multicentre study of Thoroughbred racehorses with endoscopically verified gastric ulcers was designed to demonstrate the efficacy of an equine oral paste formulation of omeprazole in the treatment and prevention of recurrence of EGUS. Of the 100 horses entered into the study, 25 were sham-dosed for the full ...
Evans DL, Harris RC, Snow DH.At 2 and 5 mins after an 800-m gallop, venous blood was collected from 26 Thoroughbred racehorses for measurement of blood lactate concentration, packed cell volume (PCV) and haemoglobin concentration. In addition, 14 racehorses were given a strenuous submaximal treadmill exercise test. Heart rates during and after exercise at 10 m/sec on a treadmill inclined at 5 degrees were recorded. Blood samples at 2 and 5 mins after exercise were used to measure PCV, blood and plasma lactate and ammonia concentrations. Results of each exercise test were compared with the retrospective performance of hors...
Lam KH, Parkin TD, Riggs CM, Morgan KL.This study was part of a programme to optimise the longevity and maximise the health and welfare of the Thoroughbred racehorses in Hong Kong. Injuries to the superficial digital flexor (SDF) tendon are the most common veterinary reason for premature retirement in this population. Objective: To describe the frequency and pattern of retirements associated with SDF tendon injuries in Thoroughbred racehorses and to compare the characteristics of these horses with those that retired for other reasons. Methods: A retrospective analysis of retirement records documented in the Hong Kong Jockey Club cl...
Anthenill LA, Stover SM, Gardner IA, Hill AE.To assess individual and combined associations of high-speed exercise and horseshoe characteristics with risk of forelimb proximal sesamoid bone fractures and proximal sesamoid bone midbody fractures in Thoroughbred racehorses. Methods: 269 deceased Thoroughbred racehorses. Methods: A case-control study design was used to compare 121 horses with a fracture of at least 1 of 4 forelimb proximal sesamoid bones (75 horses had a midbody fracture) and 148 horses without a forelimb proximal sesamoid bone fracture. Univariable and multivariable logistic regression analyses were used to evaluate potent...
Estberg L, Stover SM, Gardner IA, Johnson BJ, Case JT, Ardans A, Read DH, Anderson ML, Barr BC, Daft BM, Kinde H, Moore J, Stoltz J, Woods LW.To characterize and contrast data from Thoroughbreds that incurred a fatal musculoskeletal injury (FMI; injury resulting in death or euthanasia) during racing or training and data from all California race entrants during a 9-month period in 1991. Methods: Case-control study. Methods: Thoroughbreds that incurred a FMI during racing or training at a California race-meet and all California race entrants from January through June and October through December 1991. Methods: Age and sex were compared with chi 2 and Fisher's exact tests among horses fatally injured while racing and training. A log-li...
Pascoe JR, Ferraro GL, Cannon JH, Arthur RM, Wheat JD.Of 235 Thoroughbred racehorses examined with a flexible fiberoptic endoscope within 2 hours of racing to determine the frequency of exercise-induced pulmonary hemorrhage (EIPH), 103 (43.8%) had various degrees of hemorrhage in the tracheal lumen. Two of these horses (0.8%) subsequently had blood flow from the nostrils. Blood seemed to originate from the lung. Statistical analysis of frequency data for 191 horses which finished in 1st, 2nd, and 3rd places did not show any relationship between EIPH and horse's age, sex, or finishing position. However, a trend toward an increased frequency of EIP...
Couëtil LL, Denicola DB.The purpose of this study was to evaluate the relationship between bronchoalveolar lavage (BAL) cytology, arterial blood gases and plasma lactate concentration during a standardised treadmill test (STT) in racehorses with small-airway inflammation (SAI), or exercise-induced pulmonary haemorrhage (EIPH). Sixteen Thoroughbred and 20 Standardbred actively racing racehorses, were divided into a control group (n = 10), EIPH group (n = 13) and SAI group (n = 13). Each STT consisted of a 2 min trot at 4 m/s followed by 5 x 1 min, incremental speed steps (6, 8, 10, 11 and 12 m/s) at 10% incline for Th...
Norrdin RW, Kawcak CE, Capwell BA, McIlwraith CW.Gross examination of metacarpo-/metatarsophalangeal (fetlock) joints from racehorses revealed defects on the condylar surface that ranged from cartilage fibrillation and erosion to focal cartilage indentations and cavitation in subchondral bone characteristic of traumatic osteochondrosis. Because these lesions represented a spectrum of mechanically induced arthrosis in which microdamage is thought to play a role, a histologic study of sagittal sections was made to study the morphogenesis. Subchondral bone failure developed beneath a flattened section of the condyle where the margin of the sesa...
MacNamara B, Bauer S, Iafe J.Endoscopic examinations were performed on 965 Standardbred racehorses competing at Yonkers Raceway between June 16 and Aug 3, 1988, to demonstrate an association between exercise-induced pulmonary hemorrhage or chronic obstructive pulmonary disease and poor racing performance. Findings suggested that both exercise-induced pulmonary hemorrhage and chronic obstructive pulmonary disease adversely affect performance, whereas a combination of the 2 conditions more severely affects racing performance than do either of the conditions individually.
Pfau T, Witte TH, Wilson AM.During locomotion cyclical interchange between different forms of mechanical energy enhances economy; however, 100% efficiency cannot be achieved and ultimately some mechanical work must be performed de novo. There is a metabolic cost associated with fluctuations in mechanical energy, even in the most efficient animals. In this study we investigate the exchanges between different forms of mechanical energy involved in high-speed gallop locomotion in Thoroughbred race horses during over-ground locomotion using innovative, mobile data collection techniques. We use hoof-mounted accelerometers to ...
