Performance horses are equines specifically trained and conditioned for activities that require a high level of athleticism, such as racing, dressage, show jumping, and eventing. These horses undergo specialized training regimens to enhance their physical capabilities, including speed, endurance, agility, and strength. The management of performance horses often involves tailored nutrition plans, regular veterinary care, and specific conditioning programs to optimize their performance and minimize the risk of injury. This topic covers peer-reviewed research studies and scholarly articles that explore the physiology, training methodologies, health management, and performance outcomes of these horses in various competitive disciplines.
Tobin T, Harkins JD, Sams RA.Proper veterinary care of horses requires that horses in training have access to modern therapeutic medication. However, the sensitivity of equine drug testing now allows for detection of pharmacologically insignificant concentrations of many therapeutic medications. In 1995, the Association of Racing Commissioners International (ARCI) resolved that members 'address trace level detection so as not to lead to disciplinary action based on pharmacologically insignificant traces of these substances'. The rationale behind this approach is to prevent overly-sensitive testing from inhibiting the prop...
Dallap BL, Bramlage LR, Embertson RM.The purpose of this study was to evaluate screw fixation with cortical drilling as a surgical treatment for dorsal cortical stress fractures of MCIII in the Thoroughbred racehorse. Details of age, sex, limb affected, fracture assessment, and post operative recommendations were obtained from medical records and radiographs. Fracture healing was assessed radiographically at the time of screw removal. Performance evaluation was determined from race records obtained from The Jockey Club Information System, Lexington, Kentucky. Fifty-six Thoroughbred racehorses were treated surgically for stress fr...
Gottlieb-Vedi M, Essén-Gustavsson B, Thornell LE, Lindholm A.The aim of this study was to determine whether the metabolic response and ultrastructure of muscle differed when horses performed intense exercise at different ambient temperatures. Four Standardbred geldings performed treadmill exercise, including an intensive trot of 2600 m on two different occasions, either at a high ambient temperature of 35 degrees C or at a temperature of 20 degrees C. The horses had a warm-up period of 23.5 min of submaximal exercise, followed by 2 h of box rest before the intensive exercise. Muscle biopsy data of adenine nucleotides, creatine phosphate, lactate and gly...
Woodie JB, Ruggles AJ, Bertone AL, Hardy J, Schneider RK.To determine whether fracture fragment dimensions, suspensory ligament damage, and racing status at the time of injury were associated with outcome in Standardbred horses with apical fracture of the proximal sesamoid bone. Methods: Retrospective study. Methods: 43 Standardbred racehorses. Methods: Medical records, racing records, and radiographs were reviewed, and ultrasonographic findings were scored. Measurements of the fractured portion of the proximal sesamoid bone were made. Results: Seventy-four percent (32/43) of horses were pacers, and 26% (11/43) were trotters. Statistical differences...
Spiess BM, Nyikos S, Stummer E, Sahin A, Naegeli H.To determine concentrations of dexamethasone in serum and urine of horses treated repeatedly with a topically administered ophthalmic dexamethasone preparation. Methods: 4 clinically normal horses (2 mares, 2 geldings). Methods: 0.1% dexamethasone ophthalmic ointment was administered to the left eye of each horse every 5 to 9 hours for 8 consecutive days, yielding an estimated cumulative dexamethasone dose of 6.4 microg/kg of body weight. Serum and urine samples were obtained before the first dexamethasone treatment, on days 4 and 8 of treatment, and 24, 48, and 96 hours after cessation of tre...
Warren LK, Lawrence LM, Thompson KN.Because exercise fatigue has been associated with the accumulation of lactic acid, factors that influence lactate metabolism during exercise can potentially enhance performance. The objective of this study was to examine the effects of supplemental betaine on eight mature Thoroughbred horses before and after 8 wk of conditioning. The effects of betaine were tested in two cross-over design experiments, allowing each horse to receive both the control and betaine treatments at each fitness level. Ingestion of 80 mg of betaine/kg of BW for 14 d before exercise testing did not alter plasma lactate,...
Martin BB, Klide AM.The diagnosis of back pain is often a diagnosis of exclusion of other problems in the face of poor performance. It requires careful observation, thought, an open mind, and experience. The signs of back pain can be extremely variable and range from subtle to obvious. Obvious forelimb or hind limb lameness is not usually a sign of back pain. The most common differential diagnosis may be back pain secondary to degenerative joint disease of the hocks, fetlocks, or stifle. These diseases can mimic signs of back pain including lack of impulsion, shortening of the stride length, and change in the str...
Ronéus N, Essén-Gustavsson B, Lindholm A, Persson S.Blood samples from the jugular vein and muscle biopsies (gluteus medius) in 25 Standardbred trotters were obtained 5-10 min after racing. The biopsies were analysed for fibre type composition and enzymatic profile and blood samples for plasma lactate and ammonia concentrations. Muscle characteristics, plasma lactate and ammonia concentrations after racing were compared with each horse's individual performance index (IPI). The IPI is calculated annually from the individual horse's racing performance (% placing 1, 2 or 3, total annual earnings, average earning per start, and best racing record),...
Couroucé A.This review considers standardized exercise testing which is, routinely used for French Trotters in the field. Track testing provides a more limited range of measurements than treadmill testing, but has the advantage of being performed in the horse's natural environment. Various measurements such as heart rate during exercise and blood lactate concentration after exercise may be measured on the track and lead to the calculation of physiological variables such as V200 (velocity corresponding to a 200 bpm heart rate) and V4 (velocity corresponding to a 4 mmol/L blood lactate concentration). V4 i...
Lindinger MI.This paper reviews the limits to exercise imposed by increases in ambient, hypothalamic, and contracting skeletal muscle temperature in humans and horses. Like humans, horses frequently compete in hot environments, yet their high mass-specific rate of heat production and low mass-specific surface area for heat dissipation places them at a great disadvantage compared to humans. Exercise in hot conditions increases the rate of body heat storage and reduces the time required to reach a critical hypothalamic temperature that results in voluntary fatigue. This critical temperature appears to be ass...
Muñoz A, Santisteban R, Rubio MD, Agüera EI, Escribano BM, Castejón FM.The effects of two training programmes in 20 Andalusian and 12 Anglo-Arabian horses were evaluated by an increasing intensity work test at velocities of 4, 5, 6, 7 and 8 m sec(-1). Heart rate was monitored and blood samples were drawn at rest and after each velocity to analyse packed cell volume, haemoglobin concentration, plasma lactate and potassium levels. Furthermore, the programmes were video-taped and stride length, duration and frequency, stance (restraint and propulsion), swing phase durations and stride vertical component were measured. The training protocol of the Andalusian horses p...
More SJ.To develop a profile of the racing careers of Thoroughbred horses in south-eastern Queensland, and to examine factors that affect racing during the first years of racing. Methods: A longitudinal study using the racing records of a defined cohort of Thoroughbred horses that were born on or within 12 months following 1 August 1991. Data collection commenced in 1996 and will continue until all horses cease racing. In this paper two measures of performance were examined: race earnings during the first year of racing and cumulative proportion of horses still racing up to 2 years after their first s...
Barrey E.Over the last 30 years, the increase in interest in horses for racing and riding activities has stimulated scientific research in equine locomotion. This paper presents a review of the measurement methods and their applications used to assess equine locomotion. After describing gaits and velocity-related changes in stride variables, the current applications of gait analysis are presented. The economic consequences of lameness justifies the great effort now being put into lameness quantification and prevention. To improve breeding and reduce the costs of training, early performance evaluation t...
Muñoz A, Riber C, Santisteban R, Rubio MD, Agüera EI, Castejón FM.The cardiovascular and metabolic response to two cross-country events (CC*: preliminary level and CC*** advanced level) were analysed in 8 male eventing horses (4 Anglo-Hunter and 4 Anglo-Arabian). This study focused on the establishment of the main metabolic pathways involved in the muscle energy resynthesis during the competitions. Heart rate (HR) was recorded throughout the CC events. Jugular venous blood samples were withdrawn before the warm-up period, immediately after the competitions and at 5 and 10 min in the recuperation period. The following haematological parameters were studied: r...
Lucas JM, Ross MW, Richardson DW.A retrospective study of 176 Standardbred horses that had arthroscopic surgery for carpal chip fractures over a 7 year period was done in order to determine fracture location and post operative performance. Chip fractures of the proximal third carpal bone and the distal radiocarpal bone occurred with equal frequency (49.2 and 49.6% respectively), and chip fractures involving the antebrachiocarpal joint were rare. Trotters had significantly more third carpal bone lesions than radiocarpal bone lesions when compared to pacers (P = 0.0304). Seventy-four per cent of horses made at least one start f...
Pearson RA, Vall E.Use of animal power generally enables farmers in sub-Saharan Africa to increase agricultural production and improve the quality of life. Effective use of working animals depends on an understanding of the capabilities of the animals for work, their husbandry requirements and the factors which can influence their performance. These issues are reviewed in this paper in the context of the use of animal power in agriculture in sub-Saharan Africa. The type of animal used for work determines power available to the farmer. The performance of donkeys, horses and cattle have been compared in work tests...
Kotsiubenko AA.The indexes of standardized deviations by the measured characters (probits) are expedient to be used for distribution of horses according to classes M-, M0 and M+, under these conditions one can select individuals M0 for to rise their capacity for work and expressivity of the type of breed.
Aguilera-Tejero E, Garfia B, Estepa JC, López I, Mayer-Valor R, Rodríguez M.To determine effects of exercise on blood ionized calcium (Ca2+) and plasma parathyroid hormone (PTH) concentrations in horses and to compare the effects of exercise-induced and EDTA-induced hypocalcemia on PTH secretion. Methods: 17 horses entered in a show jumping competition and 5 horses given EDTA. Methods: Blood Ca2+ and plasma PTH concentrations were measured before and after exercise in the 17 horses entered in the jumping competition. In the other 5 horses, concentrations were measured during infusion of EDTA IV. Results: Exercise resulted in a significant decrease in blood Ca2+ concen...
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. ...
Bailey CJ, Reid SW, Hodgson DR, Bourke JM, Rose RJ.A retrospective case-control study was conducted to identify and quantify risk factors for serious musculoskeletal injury sustained at 4 Australian metropolitan racetracks. During the period of study (August 1988-July 1995) there were 196 cases from flat racing, 52 cases from hurdle racing and 53 cases from steeplechases. The incidences of fatal musculoskeletal injuries per start for flat, hurdle and steeple races were 0.06, 0.63 and 1.43% respectively. Logistic regression identified harder track surfaces, horses being older than age 3 years, one racecourse (Flemington) and jumping races as si...
Galisteo AM, Cano MR, Morales JL, Vivo J, Miró F.The influence of speed and height at the withers on some biokinematic stride parameters (linear, temporal and angular) was measured in 15 Spanish Thoroughbreds (Andalusian Purebred) trotted hand-led along a track; analysis was made of the correlation between speed and height at the withers and of some biokinematic parameters of equine locomotion. Both height at the withers and speed were positively and significantly correlated to the linear parameters examined. Temporal parameters did not reveal a significant correlation with the height at the withers. The correlations with the angular paramet...
Peham C, Licka T, Mayr A, Scheidl M, Girtler D.Treadmills are widely used in equine motion analysis. For the evaluation of the trot of a horse, a trotting speed with low variation between motion cycles is necessary to make the measurements reproducible. The aim of this study is to show how an individual 'optimum' trotting speed for lameness quantification can be determined. In this study, the stability of a horse's gait pattern was evaluated by calculating the standard deviation (S.D.) of motion-cycle speed (MCS). In trot, eighteen horses were analysed at several speeds. The measurements were taken with the ExpertVision System (Motion Anal...
Chiaradia E, Avellini L, Rueca F, Spaterna A, Porciello F, Antonioni MT, Gaiti A.Since it has been suggested that lipid peroxidation following free radical overproduction may be one of the causes of physical exercise-induced myopathies and hemolysis in horses, we looked for the possible relationships between these phenomena and muscle fiber damage. We use a homogeneous group of Maremmana stallions which, after a 3-month training period, underwent a series of physical exercises of increasing intensity. We determined the contents of malondialdehyde (MDA), one of the main lipid peroxidation end-products, and glutathione the substrate of one of the most important free radical ...
Biewener AA.The stresses acting in muscle-tendon units and ligaments of the forelimb and hindlimb of horses were determined over a range of speed and gait based on recordings of ground reaction forces and limb kinematics. Maximum stresses of 40-50 MPa were calculated to act in several of the principal forelimb (superficial digital flexor (SDF), deep digital flexor (DDF), ulnaris lateralis (UL) and flexor carpi ulnaris/radialis (FCU/R)) and hindlimb tendons (plantaris, DDF) at the fastest galloping speeds recorded (up to 7.4 m s-1). Smaller stresses were found for the gastrocnemius (GAST) tendon (30 MPa) a...
Southwood LL, Trotter GW, McIlwraith CW.To determine the outcome of horses after arthroscopic removal of abaxial fracture fragments of the proximal sesamoid bone and association of fracture grade with outcome. Methods: Retrospective study. Methods: 47 horses. Methods: Information obtained from dorsopalmar and dorsoplantar radiographic views of metacarpophalangeal and metatarsophalangeal joints was used to classify fractures as grade 1 ( 25 mm long) and type 1 (abaxial) and type 2 (apical-abaxial). Outcome was determined by whether the horse returned to its intended use, raced in the same class or higher (racehorses), or performed sa...
Minetti AE.By refining a previously published model, a simple equation for the estimation of the mechanical internal work during locomotion is presented. The only input variables are the progression speed, the stride frequency and the duty factor, i.e. the fraction of the stride duration at which a foot is in contact with the ground. The inclusion of this last variable, easily measurable, allows to obtain a single equation for both walking and running. The model predictions have been compared with the mechanical internal work experimentally obtained on humans in several conditions: speeds (range 0.8-3.3 ...
Trevorrow P.In this sensational case, it was alleged that after jinking unexpectedly and throwing its rider, racehorse Ile de Chypre, had been nobbled by an ultrasonic emitter concealed within a pair of binoculars. Ile de Chypre was 4-1 favourite at the King George V Handicap at Ascot on June 16, 1988 and a good distance away from the pack, a clear winner albeit for this alleged act of sensational intervention.
Staempfli S, Janett F, Burger D, Kuendig H, Haessig M, Thun R.In this study the effect of exercise (treadmill, riding) on scrotal surface temperature (SST) in the stallion with and without suspensory was evaluated. Our results show that SST was significantly influenced by exercise and suspensory the latter causing in general a rise in SST. Furthermore, from SST measurements in stallions exercised on treadmill and by riding, it is concluded that air circulation near the scrotum must be considered an important thermoregulatory factor.
Hjertén G, Drevemo S.The initial forelimb loading of a horse trotting at 3.7 ms-1 on a treadmill was studied by use of an instrumented shoe, accelerometers and high-speed cinematography. At the beginning of the stance phase the forelimb was loaded successively from the hoof. This is suggested to be an important factor for effective shock force absorbency in the extremities. Shearing forces may appear in the carpus before the onset of the longitudinal loading of the limb. These forces are proposed to depend on speed, locomotion pattern and the friction and hardness of the surface. It is suggested that shearing forc...
Dyke TM.Drugs of relevance to equine practice that modify the central nervous system (CNS) can be broadly classified as depressants or stimulants. The pharmacologic mechanisms of action, uses, and side effects of selected CNS depressant and stimulant drugs in horses are reviewed. Knowledge of the way these CNS-modifying drugs may affect performance is limited.
Kwok WH, Ho EN, Leung GN, Tang FP, Wan TS, Wong HN, Yeung JH.1-Testosterone (17β-hydroxy-5α-androst-1-en-3-one), a synthetic anabolic steroid, has been described as one of the most effective muscle-building supplements currently on the market. It has an anabolic potency of 200 as compared to 26 for testosterone. Apart from its abuse in human sports, it can also be a doping agent in racehorses. Metabolic studies on 1-testosterone have only been reported for human in the early seventies, whereas little is known about its metabolic fate in horses. This paper describes the studies of in vitro and in vivo metabolism of 1-testosterone in horses, with the ai...
Harland MM, Stewart AJ, Böse R.A comprehensive purchase examination is expected by American clients intent on importing a horse from a foreign country. American veterinarians may be involved in performing purchase examinations in foreign countries or, more often, interpreting findings from foreign veterinarians for their American clients. Exportation and importation requirements for horses and semen vary from country to country. Detailed knowledge of the requirements by all involved veterinarians is essential for efficient and successful international equine travel.
Andrews FM.Early aggressive medical therapy in horses with acute rhabdomyolysis is essential to prevent further muscle damage and secondary complications, such as laminitis and acute renal failure. A variety of pharmacologic agents may be helpful in the treatment of this condition but may have adverse affects if hydration status is not corrected first or concurrently with oral or intravenous fluids. Early aggressive therapy will help prevent irreversible muscle damage that could lead to poor performance in the future.
Cohen ND, Hu Z, Stanley SD, Wang N.Furosemide is frequently used to control or prevent exercise-induced pulmonary hemorrhage in performance horses. The bronchodilating agent clenbuterol is also commonly used as a treatment for inflammatory airway disease in performance horses. Use of both medications is regulated by many racing authorities. The effects of concomitant administration of furosemide and clenbuterol on the pharmacokinetics of clenbuterol have not been well characterized. A study was designed to evaluate the influence of furosemide on serum and urine concentrations of clenbuterol after oral administration of clenbute...