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.
Hodges AA, Harrison AG, Wathes CM.The heights of 89 horses were measured at the withers before and after half a furlong of trotting exercise. The mean (+/- sd) height increase after exercise was 1.75 +/- 0.86 cm and the horses returned to their resting height within seven minutes. There was no linear relationship between gain in height and pre-exercise height.
Kalinskiĭ MI, Kamenetskaia OV, Skorik LG, Tishchenko GN.The paper deals with possibility to regulate in a proper direction the acid-base state in race horse blood administering carbostimulin at rest and under physical exercises. The preparation is shown to favour an increase in alkaline blood reserves in race hours at rest and to prevent acidotic changes caused by physical exercises. The results obtained show a promising use of carbostimulin for the directed correction of the acid-base state of blood in race horses aimed at increasing the efficiency of the training process.
Dalin G, Jeffcott LB.Gait analysis can play an important role in exercise physiology, racetrack ergonomics, lameness prophylaxis, and assessment of performance potential in racehorses. This article concentrates on the methods used for gait analysis and considers some basic data on the different gaits of the horse.
Lovell DK.Through the study of equine exercise physiology, one can learn more about what happens to the body of the performance horse during all forms of exercise. Better understanding of skeletal, joint, tendon, and ligament adaptations to loading and stress may allow adjustments to be made in training techniques to reduce the incidence of injury. The information obtained from exercise research may also facilitate the investigation of questions such as the following: What makes one horse perform better than another? How can one bring out the optimal performance in each horse? How can one tell when a ho...
Rose RJ, Allen JR.Hematology has been widely used in attempts to provide information about disease states, performance problems, and fitness in performance horses. However, owing to factors such as the temperament of the horse and time of collection and feeding, considerable variation in the hemograms can be found. This article reviews some of the hematologic responses to exercise and training.
Robinson NE.The primary function of the equine respiratory system is the exchange of oxygen and carbon dioxide at a rate that is matched to metabolism. Gas exchange requires ventilation, distribution of gas within the lung, perfusion of blood through pulmonary capillaries, matching of ventilation and blood flow, diffusion of gases between air and blood, and transport of gases to and from the muscles. In this article, the author reviews what is known about each of these processes in the resting and exercising horse.
Physick-Sheard PW.The quality of the overall response to exercise in the horse is very similar to that seen in man and laboratory animals; differences are mainly quantitative and persist when relative body weight is taken into account. The apparently greater flow capacity of the equine muscle bed during maximal whole-body exercise implicates the extent of central circulatory adaptations as the limiting factor in performance but implies a role for increase in arteriolar capacitance/muscle capillarity as an appropriate response to intense endurance training. The blood oxygen-carrying capacity of the horse is ofte...
Soma LR, Laster L, Oppenlander F, Barr-Alderfer V.In 3 groups of horses with exercise-induced pulmonary hemorrhage (EIPH), comparisons of racing times and finishing positions were made between the 5 races before the horses were given furosemide and 5 races after furosemide administration. The horses were grouped according to 3 methods used to diagnose EIPH: group 1, observation of hemorrhage at the nostrils within 1 hour after a workout or race; group 2, observation of pulmonary hemorrhage only by endoscopic examination after a race or workout; and group 3, observation of hemorrhage at the nostrils during a race or immediately after a race. G...
Vaughan LC, Edwards GB, Gerring EL.Implants of carbon fibre, made by plaiting a tow of 10,000 filaments of Grafil type HT-S, were used to treat strains and ruptures of digital flexor tendons in 46 horses. The relevant clinical data, the techniques employed and an analysis of the results are described. Apart from two horses in which the implant was extruded and had to be removed, there were minimal untoward consequences of the surgery. Of the 34 horses with acute or chronic tendinitis, 14 returned to racing, seven were used as hunters and seven as hacks. Among the former group, seven suffered a further strain while racing but th...
Kamerling SG, DeQuick DJ, Weckman TJ, Tobin T.The dose-related effects of intravenously administered fentanyl (0.010, 0.005, 0.0025 mg/kg) and saline were studied in mature performance horses using a rigorous experimental protocol. Fentanyl produced a dose-related prolongation of the skin twitch reflex latency but did not increase the hoof withdrawal reflex latency. Dose related increases in stepping frequency, cardiac and respiratory rats were observed following fentanyl, while changes in rectal temperature and pupil area were not. These data indicate that fentanyl, a prototypic mu-agonist, produces a syndrome characterized by analgesia,...
Ungemach FR.Doping in performance horses is defined as the "illegal application of any substance, except normal diet, that might modify the natural and present capacities of the horse at the time of the race." The prohibition of doping is mainly based on the protection of animals. Doping can be performed with various aims: "doping to win" can be regarded as the classical method by mobilization of overphysiological capacities. Such positive doping may be classified as an acute form using psychomotoric stimulants, as a chronic form using anabolic hormones, and as a paradoxical form using small doses of neur...
Anderson GF, Landsheft B.Performance horses should be thoroughly examined before sale to detect any defects that could render them unsuitable for the purchaser's intended use. With the horse in its stall, the eyes, nasolacrimal puncta, external ear canals and mouth are examined, the rectal temperature measured and the heart, lungs, trachea and sinuses auscultated. Moving the horse out of the stall, the head, parotid glands, mandibular lymph nodes, larynx, neck muscles, jugular veins and cervical vertebrae are inspected. The scapula, point of the shoulder, withers, tuber sacrale and point of the hip are palpated, after...
Essén-Gustavsson B, Karlström K, Lindholm A.Venous blood samples and middle gluteal muscle biopsies were obtained from 21 horses taking part in 100 km or 50 km endurance rides. Group A consisted of seven horses competing over 100 km (four horses completed the ride). Group B consisted of the six horses that were among the 10 best over 50 km while the other eight horses of Group C completed 50 km at a slower speed. Blood lactate, glycerol and creatine kinase increased in all groups while aspartate aminotransferase levels were higher only in Group A. No changes was found in blood glucose in Groups B and C while horses in Group A had lower ...
Leach DH, Ormrod K, Clayton HM.An investigation was made of the stride characteristics of horses jumping 2 obstacles during a Grand Prix competition. One obstacle was a picket fence and rail 1.3 m high (fence 2), and the other was a coop and rail 1.52 m high (fence 11). Thirteen distance and 22 timing measurements of 17 horses were extracted from high-speed films, using computer-aided analysis. These data were used to compare takeoff and landing of the lead and nonlead legs, the thoracic limbs and pelvic limbs, and fence 2 and fence 11. Paired t-tests were used to compare means and a stepwise regression analysis was done fo...
Smith JE, Moore K, Cipriano JE, Morris PG.Occasionally, horses are given large amounts of iron to improve performance. Although iron deficiency could limit erythrocyte production and other functions related to nonhematological tissues, it probably only occurs in blood loss. We have developed an enzyme immunoassay for ferritin in equine sera and evaluated its relationship to iron stored in liver and spleen. Serum ferritin correlated significantly (P less than 0.0001) with the concentration of nonheme iron in the liver and spleen. It increased following iron therapy and decreased after phlebotomy. We conclude that serum ferritin provide...
Hodgson DR, Rose RJ, Allen JR, Dimauro J.Muscle biopsy samples were collected from the left middle gluteal muscle of horses participating in competitive barrier trials. Twelve horses were biopsied the day before and within 30 minutes of completion of an 800 m barrier trial. A further six horses were sampled the day before, and within 30 minutes of, completion of a 1200 m barrier trial. Serial muscle sections were examined histochemically for myosin adenosine triphosphatase activity after acid preincubation, to demonstrate type I, IIA and IIB fibres. The glycogen content in the individual fibres was assessed using the periodic acid Sc...
Straub R, Isler R, Gysin J.The incremental three work loads test as a basis test, and the one work load test, in which one measures the heart rate and the serum lactic acid concentration, lead to the performance index values V4 and V150. These values are of great practical importance in judging the performance capacity, the ability to be trained, the trainings effectivity, and determining the optimal work load for interval training.
Dewey EA, Maylin GA.The metabolism of propionylpromazine in the horse was studied. Although propionylpromazine is not currently approved or recommended for use in horses, it has been used illegally to alter their performance. Propionylpromazine hydrochloride was administered intramuscularly at clinical and subclinical doses. Three metabolites were detected in urine. The major metabolite was identified as 2-(1-hydroxypropyl) promazine sulfoxide. The detection of this metabolite in routine drug testing has been described.
van den Hoven R.Venous lactate concentrations were determined in standard-bred trotters following exercise of varying intensity to obtain a useful parameter in determining the working capacity of horses. After standard exercise, well-trained horses produced less lactate than did inadequately trained horses. During the post-exercise resting period, lactate disappeared faster from the blood in well-trained horses and young lightly trained horses than it did in poorly trained horses. Steady-state training resulted in lower lactate levels than those recorded after racing, whereas interval training resulted in the...
Warner A, Mayhew IG.Anhidrosis is loss of the ability to sweat. The problem is seen in horses kept in a hot humid climate, and it may cause severe impairment of thermoregulation in the equine athlete. British Thoroughbreds imported to her tropical colonies are the earliest recorded cases, and since then the syndrome has come to be described as one of Thoroughbreds, usually performance athletes, undergoing acclimatization to heat and humidity. A recent epidemiologic study of cases in Florida has shown, however, that many different breeds, and long time inhabitants of a hot climate, may be affected. Equine sweat gl...
Spurlock GH, Gabel AA.One-hundred and nine apical fractures of the proximal sesamoid bones were diagnosed in Standardbred racehorses at the Ohio State University Veterinary Hospital during a 5-year period ending December 1978. Lateral sesamoids of the hindlimbs accounted for 61 of the 109 fractures, which was a significantly (P less than 0.05) greater proportion than that for fractures in all other sesamoid bones. Two- and three-year-old horses accounted for 73 of the 109 apical sesamoid fractures. The remaining 36 apical sesamoid fractures were in horses 4 to 9 years old. The apical fragment was removed in 80 of t...
Tolley EA, Notter DR, Marlowe TJ.Repeatabilities (t) and heritabilities (h2) of racing time were estimated from data on 7,206 2- and 3-yr-old Standardbred pacers and trotters competing in 1-mile (1.6 km) charted races at six tracks between 1975 and 1978. A total of 38,487 records representing 2,387 sire progeny groups were divided into subsets by gait, age and track. Initially, the designation "class of race" was recognized as a subjective categorization that reflected nonrandom assignments of horses to races. After extensive investigation, we concluded that racing times should be adjusted by linear regression for the time of...
Revington M.Eight hundred and sixteen blood samples were collected from Thoroughbred racehorses at the race track, 1 to 3 h before racing, and subjected to routine haematological examination. Attempts were made to correlate the haemogram with subsequent performance. Races were classified according to age, class and distance, and performances were grouped according to distance from the winner. Intra- and interclass comparisons were made but no relationship emerged between racing performance and the haemogram. The haemograms of individual horses on different occasions were compared with subsequent performan...
McMiken DF.Although different physiological and behavioural attributes are needed for various types of equine competition, successful racing depends primarily on the animal's metabolic ability to convert chemical energy to mechanical energy--the function of muscle. Components of these energetic processes include the rate, efficiency and interaction of aerobic and anaerobic metabolism in muscle and the supply and utilisation of fuel. In anaerobic work like racing, fatigue processes may be largely regarded as a function of an intramuscular fuel (phosphogen) depletion, despite the fact that substrates are s...
Roberts MC.Vitamin B12 and folate concentrations were determined by radioimmunoassay in groups of horses in Queensland. Highest serum vitamin B12 levels were found in supplemented performance horses. These, together with pastured horses that included pregnant and lactating mares, had significantly greater serum folate activity than permanently stabled animals. The range of red cell folate concentrations was much narrower in horses in training than from any other group. Red cell folate may be a better indicator of a horse's folate status than the serum folate value. Vitamin B12 and folate concentrations w...
Bailey SR, Forbes G, Selvadurai N, McLarney K, Jones S, Steel CM.The administration of alkalinising agents including bicarbonate is of concern to racing authorities because resultant alkalosis may enhance performance and interfere with the detection of drugs in post-race urine. A threshold for total carbon dioxide (TCO ) of 36.0 mmol/L in plasma (with action limit of 37.0 mmol/L) has been set. Serial dosing of sodium bicarbonate has gained popularity in human athletes but has not been studied in horses previously. Sodium bicarbonate (200 g per horse) and 60 g of an electrolyte-vitamin complex was administered in 2-L water via nasogastric intubation to five ...
Chiaradia E, Gaiti A, Terracina L, Avellini L.Physical exercise induces a reduction of immune defences and an imbalance of red-ox status. In this study plasma levels of cysteine and homocysteine (Hcy) were determined in horses before and after submaximal treadmill exercise as well as the effect on horse lymphocyte proliferation. The exercise induced a significant increase in plasma Hcy levels, which remained high both after the 20 min recovery period and after 2 h of rest. Moreover, a reduction of lymphocyte responsiveness to the proliferative stimulus induced by Concanavalin A was observed. The effects of different Hcy concentrations on ...
Ungemach FR.Doping in performance horses is defined as the "illegal application of any substance, except normal diet, that might modify the natural and present capacities of the horse at the time of the race." The prohibition of doping is mainly based on the protection of animals. Doping can be performed with various aims: "doping to win" can be regarded as the classical method by mobilization of overphysiological capacities. Such positive doping may be classified as an acute form using psychomotoric stimulants, as a chronic form using anabolic hormones, and as a paradoxical form using small doses of neur...
Denny JE.Horses receiving a pelleted or cubed dietary supplementation with roughage, have serum inorganic phosphate (SIP) concentrations consistently below an accepted mean of 1,032 mmol l-1 or 3, 1 mg dl-1. Further, it has been reported that the best eight, two-year-old Irish Thoroughbred track performers of 51 horses tested over a 10 month period, had significantly lower SIP concentrations than the worst eight track performers. In an endeavour to assess any nutritive effect on SIP concentrations and also to assess any effect of SIP concentrations on track performance, metabolic blood profiles from 30...
Walmsley EA, Anderson GA, Adkins AR.Determine the long-term outcome for Thoroughbreds undergoing desmotomy of the accessory ligament of the deep digital flexor tendon (DAL-DDFT) for type 1 flexural deformity of the distal interphalangeal joint (DIPJ). Methods: Retrospective matched cohort study Methods: Medical records were retrieved over a 17-year period for Thoroughbreds that underwent DAL-DDFT for type 1 flexural deformity. Long-term outcome was determined by analysis of race records and comparison with maternal siblings. Comparisons between cases and controls included 2-year-old, 3-year-old and total career performance data....
Seeherman HJ, Morris E, O'Callaghan MW.Discovering the cause of poor performance in racehorses can often represent a considerable challenge eluding the more common diagnostic techniques available at the racetrack. Application of sports medicine techniques to these problem cases can aid in the diagnosis of poor performance. Central to the development of this capability has been the use of highspeed treadmills, allowing the racehorse to be evaluated in the controlled laboratory setting, at exercise intensities equivalent to those of racing. Video and cinematographic gait analysis can be used in the diagnosis of subtle lameness condit...
Knych HK, Stanley SD, Arthur RM, McKemie DS.Cetirizine is an antihistamine used in performance horses for the treatment of hypersensitivity reactions and as such a withdrawal time is necessary prior to competition. The objective of the current study was to describe the disposition and elimination of cetirizine following oral administration in order to provide additional serum concentration data upon which appropriate regulatory recommendations can be established. Nine exercised thoroughbred horses were administered 0.4 mg/kg of cetirizine orally BID for a total of five doses. Blood samples were collected immediately prior to drug admin...
Curi RA, Pereira GL, Alvarez MVN, Baldassini WA, Machado Neto OR, Chardulo LAL.The main objectives of this study were to identify and functionally classify SNPs and indels by exome sequencing of animals of the racing line of Quarter Horses. Based on the individual genomic estimated breeding values (GEBVs) for maximum speed index (SImax) obtained for 349 animals, two groups of 20 extreme animals were formed. Of these individuals, 20 animals with high GEBVs for SImax and 19 with low GEBVs for SImax had their exons and 5' and 3' UTRs sequenced. Considering SNPs and indels, 105 182 variants were identified in the expressed regions of the Quarter Horse genome. Of these, 72 ...
Allen KJ, Franklin SH.Overground endoscopy is being performed with increasing frequency in the UK. A previous study has shown that the type of exercise test may affect the diagnosis of upper respiratory tract (URT) obstructions. The successful clinical application of overground endoscopy systems requires understanding of appropriate field exercise testing protocols. Objective: The aim of this study was to report the exercise test parameters used during overground endoscopy in UK Thoroughbred racehorses and to investigate potential effects of these on the diagnosis of URT obstructions. Methods: The exercise test par...
O' Brien C, Pegg J.This observational study aimed to elucidate the effects of RWST on the cardiovascular and musculoskeletal systems of horses and concurrently determine whether RWST limits distal limb temperature increases previously reported during gallop training on land. A group of 15 clinically sound international event horses were recruited, and heart rate (HR), speed (km/h) and thermal images of the distal limb were analysed at set intervals during RWST training. Intervals of RWST produced a total mean HR value of 65.18 ± 3.76%, which is within the parameters for increased aerobic stamina. Mean HR increa...
Machnik M, Gerlach M, Kietzmann M, Niedorf F, Thevis M, Schenk I, Guddat S, Düe M, Schänzer W.The anti-doping rules of national and international sport federations ban any use of tetrahydrogestrinone (THG) in human as well as in horse sports. Initiated by the THG doping scandals in human sports a method for the detection of 3-keto-4,9,11-triene steroids in horse blood and urine was developed. The method comprises the isolation of the analytes by a combination of solid phase and liquid-liquid extraction after hydrolysis and solvolysis of the steroid conjugates. The concentrations of THG in blood and urine samples were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS)...
Murphy DJ, Kö-Peternelj V, Aleri JW.Superficial digital flexor tendon (SDFT) injury is common in racehorses and a significant cause of lost training days and wastage in the industry. Objective: To compare the post-injury performance of Thoroughbred and Standardbred racehorses diagnosed with SDFT tendonitis treated with intralesional bone marrow and superior check desmotomy or managed conservatively and further to compare this performance with that of uninjured racehorses. Methods: Retrospective and case-controlled. Methods: Medical and race records of racehorses treated surgically or managed conservatively for SDFT tendonitis we...
Vergara-Hernandez FB, Nielsen BD, Robison CI, Fabus TA, Kompare JL, LeCompte Lazić RA, Colbath AC.The main factors influencing speed in athletes are stride length (SL) and stride rate (SR). However, conflict remains whether SL or SR is the key determinant of higher speeds. Quarter Horses (QH) generally reach higher speeds in their races than do Thoroughbreds (TB). However, the influence of SL and SR on this greater speed is unclear. Therefore, the main objective of this study was to compare SL and SR in QH and TB raced in short (sprint) and long (classic) distances. We hypothesized that QH have a higher SR in comparison to TB, and SR decreases as distance increases. Two race distances were...
Vonaparti A, Lyris E, Panderi I, Koupparis M, Georgakopoulos C.In equine sport, theobromine is prohibited with a threshold level of 2 microg mL(-1) in urine, hence doping control laboratories have to establish quantitative and qualitative methods for its determination. Two simple liquid chromatography/mass spectrometry (LC/MS) methods for the identification and quantification of theobromine were developed and validated using the same sample preparation procedure but different mass spectrometric systems: ion trap mass spectrometry (ITMS) and time-of-flight mass spectrometry (TOFMS). Particle-free diluted urine samples were directly injected into the LC/MS ...
Viljanto M, Cutler C, Taylor P, Habershon-Butcher J, Gray B.MK-0677 (ibutamoren) is an orally active non-peptide growth hormone secretagogue that binds to the ghrelin receptor stimulating the secretion of endogenous growth hormone. It is one of the most prevalent performance-enhancing compounds currently available online and is potentially subject to abuse both in human and equine sports. The aim of the current study was to investigate whether it could be detected in equine hair following oral administration of MK-0677 mesylate to a Thoroughbred racehorse. MK-0677 and its O-dealkylated metabolite were extracted using an existing method for prohibited s...
Kavazis AN, Kivipelto J, Choe HS, Colahan PT, Ott EA.The objective of this study was to investigate the effects of ribose supplementation on blood ammonia-N, plasma lactic acid, plasma glucose, volume of oxygen consumption (VO2), heart rate, and performance in Thoroughbred geldings performing a maximal treadmill standardized exercise test (SET). The hypothesis tested was that ribose supplementation would decrease ammonia-N and lactic acid accumulation during exercise, and improve performance. Eight Thoroughbred geldings were assigned randomly to one of two groups: glucose or ribose. The glucose group received 0.15 g glucose/kg of BW, and the rib...
Walker NL, Patout AR, Cater M.Hereditary equine regional derma asthenia (HERDA), an autosomal-recessive trait, found in Quarter Horses, causes abnormal collagen structure. Owing to current breeding practices, 3.5% of registered quarter horses and 28.3% of the cow horse population are heterozygote carriers. Research demonstrated homozygote horses develop hyperextensible skin susceptible to injury and other abnormal tissues containing high fibrillar collagen content. No research exists determining the effects of the disease in heterozygote carriers. Currently, 30% of cutting sires are HERDA carriers, potentially increasing t...
Charman RE, Vasey JR.Carpal flexural deformities (CFD) are frequently encountered in the horse, with both congenital and acquired forms described. The success of surgical correction of CFD, both in terms of the ability to achieve a straight palmar carpal angle and the impact on future athletic performance, requires further investigation. Objective: To report the surgical management and outcome of treatment of flexural deformity of the carpus in 72 horses up to 12 months of age. Methods: Information was obtained from the medical records of horses surgically treated for CFD and through follow-up contact with owners....
Izzati MRNZ, Noraniza MA, Adamu L, Rasedee A.Endurance horses are usually eliminated from the race due to lameness, metabolic ailments or technical reasons. The purpose of the study was to determine the validity and reliability of the metabolic disorder index (MDI) in predicting metabolic eliminations in endurance horses during an endurance race. Fifty-four endurance horses competing on two local endurance tracks were involved in the study. Blood samples were collected a day prior to the event to determine packed cell volume (PCV), chloride (Cl), interleukin-6 (IL-6), creatine kinase (CK) and glutathione reductase (GR) concentrations fro...
Ramzan PHL, Wylie CE.Arthroscopy has been advocated as the treatment of choice for dorsal osteochondral chip fracture of the metacarpo/metatarsophalangeal (MCP/MTP) joint. However, there is no published research on racing performance outcomes of horses with this pathology managed nonsurgically. Objective: To compare racing career outcomes of Thoroughbred racehorses with nonsurgically (non-SX) or surgically (SX) managed MCP/MTP dorsal osteochondral chip fracture alongside a cohort of horses with no dorsal osteochondral chip fracture (unexposed). Methods: Retrospective cohort study conducted between 2006 and 2014. M...
Kingston JK, McCutcheon LJ, Geor RJ.To quantify total fluid loss in sweat of Thoroughbreds during >3 hours of low-intensity exercise in controlled conditions and to calculate and compare estimated ion losses in sweat, according to 3 methods. Methods: 6 exercise-trained Thoroughbreds. Methods: Fluid and ion losses in sweat were measured in 6 horses exercising at 40% of the speed that elicited maximum oxygen consumption for 45 km. Horses were given a 15-minute rest period at the end of three 15-km exercise phases. Horses completed 2 exercise trials. Ion losses in sweat were calculated, using measurements of local sweating rate and...
Kavazis AN, Sobota JS, Kivipelto J, Porter MB, Colahan PT, Ott EA.A diverse group of studies, which are equine exclusive, indicate that ribose administered to myocardial and skeletal muscle tissue stimulates ATP production and recovery. This study investigated the effects of ribose supplementation on blood and muscle metabolites and performance in Thoroughbred geldings performing a maximal treadmill standardised exercise test (SET). In Experiment 1, 6 conditioned Thoroughbred geldings performed a baseline SET and horses were assigned to one of 2 experimental treatment groups, placebo or ribose, based on VO2max. The placebo treatment group received 0.07 g glu...
Ellis KL, Seabaugh K, King MR.Local injection of corticosteroids is commonly performed in horses with sacroiliac (SI) region pain and/or dysfunction, ,and ultrasound findings of normal horses and those with SI pain have also been well described. However, no studies have been performed that have evaluated if ultrasound findings, injection technique, or medications injected affect prognosis for return to function. The objectives of the current study are to determine if findings on ultrasound, injection technique, or medications injected are predictive of return to function in horses with SI region pain and/or dysfunction. Me...
Tennent-Brown BS, Goetz TE, Manohar M, Hassan AS, Freeman DE, Bundy JS, Evans MR.Hyperhydration, prior to prolonged moderate-intensity exercise simulating the 2nd day of a 3-day equestrian event (E3DEC), may induce arterial hypoxaemia detrimental to performance. Objective: Because moderate-intensity exercise does not induce arterial hypoxaemia in healthy horses, the effects of pre-exercise hypervolaemia on arterial oxygenation were examined during a prolonged exercise protocol. Methods: Blood-gas studies were carried out on 7 healthy, exercise-trained Thoroughbred horses in control and hyperhydration experiments. The study conformed to a randomised crossover design. The se...
Treiber KH, Boston RC, Geor RJ, Hess TM, Harris PA, Kronfeld DS.Tools and criteria to evaluate and understand glucose metabolism are essential to optimise equine energy utilisation for exercise performance and reduced metabolic health risks. Objective: To re-evaluate models of glucose kinetics in the horse at rest and during endurance type exercise using a single injection technique and compartmental modelling. Methods: Twelve exercise trained Arabian geldings received a bolus of 100 µmol/kg bwt [6,6-(2) H]glucose i.v. while at rest and while running at ∼ 4 m/s on a treadmill. Tracer and tracee glucose curves from 4-150 min after the bolus dose (while t...
Moeller BC, Clifford A, Emery RT, Alarcio G, Favro G, Arthur RM.Zilpaterol is a β -adrenergic agonist and a repartitioning agent that has a high potential for abuse in equine performance athletes. Analysis of zilpaterol in hair is an alternative sampling matrix that extends detection time periods beyond those found in urine or blood samples. Our laboratory has been screening for zilpaterol in hair for many years and recently detected and confirmed its presence in official samples. Accordingly, a liquid chromatography-mass spectrometry method was developed and validated to detect and confirm zilpaterol in equine hair. Briefly, equine hair was decontaminate...
Kovár J, Kostelecká B.On the basis of test results, regarding the pulse rate response to the increased load, obtained from 278 three-year-old horses after finishing their elementary training (145 Bohemian warm-blooded horses, 115 Kladrub Black horses and 18 English half-bred horses), a method was worked for the evaluation of their performance. As an evaluating criterion a velocity (v170) was chosen which was obtained from an experimentally determined regression dependence of velocity on the pulse rate at 170 pulses per minute. A set of v170 data were statistically processed and on the basis of quantiles of normal d...
Knych HK, Stanley SD, McKemie DS, Steinmetz SJ.Romifidine is an alpha-2 adrenergic agonist used for sedation and analgesia in horses. As it is a prohibited substance, its purported use at low doses in performance horses necessitates further study. The primary goal of the study reported here was to describe the serum concentrations and pharmacokinetics of romifidine following low-dose administration immediately prior to exercise, utilizing a highly sensitive liquid chromatography-tandem mass spectrometry assay that is currently employed in many drug testing laboratories. An additional objective was to describe changes in heart rate and rhyt...
Bonnaire Y, Dehennin L, Plou P, Toutain PL.A pharmacological dose of a long-acting testosterone ester, testosterone hexahydrobenzoate, was administered intramuscularly to two mares. The time course for some characteristic metabolites in blood and urine was then studied using an analytical method based on gas chromatography-mass spectrometry associated with stable isotope dilution. Among the plasma analytes, testosterone glucuronide was found to be the most adequate indicator for the monitoring of exogenous testosterone up to 2 weeks postadministration if a threshold value of 200 ng/L was applied. In urine, the simultaneous measurement ...
Rumpler MJ, Sams RA, Colahan P.We describe a validated, rapid, sensitive, and specific UHPLC-MS/MS method to detect and quantify glycopyrrolate in 0.5 mL of horse urine. Further, we investigated the elimination of glycopyrrolate in urine after both intravenous and oral administration of clinically relevant doses to Thoroughbred horses. Quantification was performed by weighted, linear regression analysis using a deuterated analogue of glycopyrrolate as internal standard (IS). The method was characterized by a linear range of 5-2500 pg/mL, a lower limit of quantification of 5 pg/mL and a limit of detection of 1 pg/mL. The int...
