Thoroughbreds are a breed of horse known for their agility, speed, and spirit, often associated with horse racing and equestrian sports. Originating from crossbreeding native English mares with imported Arabian, Barb, and Turkoman stallions, Thoroughbreds have a well-documented pedigree that traces back to the late 17th and early 18th centuries. This breed is characterized by a refined head, deep chest, and long legs, contributing to their athletic capabilities. Thoroughbreds are primarily bred for their performance in racing but are also utilized in other equestrian disciplines. This page compiles peer-reviewed research studies and scholarly articles that explore the genetics, physiology, and performance characteristics of Thoroughbreds, as well as their management and welfare in various equine activities.
Ortved KF, Cheetham J, Mitchell LM, Ducharme NG.Caudal descent of the larynx has been proposed to be associated with intermittent dorsal displacement of the soft palate (DDSP) as it leads to a loss of the seal between the epiglottis and soft palate but further investigation of this theory is required. Objective: To evaluate laryngohyoid position of horses with persistent DDSP in comparison to horses with intermittent DDSP and evaluate the outcome of treatment. Objective: Horses with persistent DDSP have a different laryngohyoid position compared to those with intermittent DDSP. Horses with persistent DDSP can be returned successfully to rac...
Hirota K, Kakoi H, Gawahara H, Hasegawa T, Tozaki T.We characterized the SNP 53 JPN System for parentage verification during horse registry. The SNP 53 JPN System was constructed using 53 highly polymorphic single nucleotide polymorphisms (SNPs), which were amplified and genotyped with 2 multiplex assays. The SNP 53 JPN System showed good resolution for 95 unrelated thoroughbreds, and the exclusion probability (PE01) for each SNP ranged from 11.5 to 23.0%, resulting in a total PE01 value of 99.996%. These results indicate that the SNP 53 JPN System is useful for parentage testing of thoroughbreds. Of the 53 SNPs, 8 SNPs could be used to exclude...
Michelotto PV, Muehlmann LA, Zanatta AL, Bieberbach EW, Fernandes LC, Nishiyama A.Inflammatory airway disease (IAD) is prevalent in young racehorses during training, being the 2nd most commonly diagnosed ailment interrupting training of 2-year-old Thoroughbred racehorses. Objective: That stabling and exercise cause oxidative stress, release of platelet-activating factor (PAF) and inflammation in airways of Thoroughbred colts. Methods: Colts in breeding farms (NC, n = 45), stabled for 30 days (EC, n = 40), and race trained (EX, n = 34). Methods: Cytological profile and parameters of bronchoalveolar lavage fluid (BALF) related to oxidative stress, bioactivity of the proinflam...
Doughty A, Cross N, Robins A, Phillips CJ.There are ethical concerns regarding the loss of horses from various equine industries and their corresponding slaughter. However, to date, no empirical evidence regarding the extent of this loss, nor of the condition of horses involved, exists within Australia. Objective: To determine the approximate ages, brand type and condition of feet of horses relinquished to an export abattoir in Australia. Methods: Data were collected from 340 horses processed at an Australian abattoir from November 2007-January 2008. Foot abnormalities, injuries and hoof indicators of overgrown and untrimmed hooves we...
Rijkenhuizen AB, Sinclair D, Jahn W.Aortoiliac thrombosis (AIT) is a progressive vascular disease characterised by an exercise-induced hindlimb lameness. After developing a surgical technique, a follow-up study was required. Objective: To assess the surgical results of a surgical thrombectomy in horses with AIT, a chronic arterial occlusive disease of the aorta and its caudal arteries. Methods: Seventeen cases showed the typical signs of AIT and diagnosis was confirmed by Doppler-ultrasonography. Average age of the horses was 12 years. Seven stallions, 6 mares and 4 geldings were included. Results: The thrombus was located in th...
Bartholomew S, Owens SD, Ferraro GL, Carrade DD, Lara DJ, Librach FA, Borjesson DL, Galuppo LD.Stem cells derived from umbilical cord tissue (UCT) and umbilical cord blood (UCB) in human subjects and horses can be obtained in a minimally invasive fashion with successful propagation of mesenchymal stem cells (MSCs). Currently there are no detailed protocols documenting a procedure to harvest UCB and UCT safely for equine stem cell propagation. Objective: UCB and UCT could be collected without harm to mare or foal. Objective: To develop a standard and safe method for UCB and UCT collection, and prospectively to compare foal and mare health between groups of animals where tissue was and wa...
Ramzan PH, Palmer L.Musculoskeletal injury is the most common cause of lost training days in the young Thoroughbred horse in flat race training. To date, there has been little investigation of the regional patterns of injury frequently observed by clinicians in racehorse practice. The present study was conducted to determine incidence of musculoskeletal injuries in Thoroughbreds in training in Newmarket, United Kingdom. Veterinary records for all horses resident in three large (>100 horse) training yards were assessed for occurrence of significant musculoskeletal injury. A total of 248 injuries were recorded in 2...
Hill EW, Gu J, Eivers SS, Fonseca RG, McGivney BA, Govindarajan P, Orr N, Katz LM, MacHugh DE.Variants of the MSTN gene encoding myostatin are associated with muscle hypertrophy phenotypes in a range of mammalian species, most notably cattle, dogs, mice, and humans. Using a sample of registered Thoroughbred horses (n = 148), we have identified a novel MSTN sequence polymorphism that is strongly associated (g.66493737C>T, P = 4.85x10(-8)) with best race distance among elite racehorses (n = 79). This observation was independently validated (P = 1.91x10(-6)) in a resampled group of Thoroughbreds (n = 62) and in a cohort of Thoroughbreds (n = 37, P = 0.0047) produced by the same trainer...
Naito Y, Sasaki N, Matsui A, Nambo Y, Inokuma H, Yamada H.The concentrations of branched-chain amino acids (BCAA; valine, leucine, isoleucine) were determined in plasma of 7 healthy thoroughbred mares and their foals from birth (0 week) to 24 weeks of age, using automated high-performance liquid chromatography. In foals, the concentrations of plasma valine were significantly high (p<0.05) at 16, 20 and 24 weeks. The concentrations of plasma leucine were significantly high (p<0.05) at 1 and 3 weeks. The concentrations of plasma isoleucine were significantly high (p<0.05) from 1 to 24 weeks. In mares, the concentrations of plasma valine were s...
Cleary OB, Trumble TN, Merritt KA, Brown MP.To investigate the effects of exercise and osteochondral injury on concentrations of carboxy-terminal telopeptide fragments of type II collagen (CTX-II) in synovial fluid (SF) and serum of Thoroughbred racehorses and to compare findings with radiographic and arthroscopic scores of joint injury severity. Methods: 78 Thoroughbreds with (n = 38) and without (40) osteochondral injury. Methods: Serum and metacarpophalangeal or carpal joint SF samples were collected from noninjured horses before and at the end of 5 to 6 months of race training (pre- and postexercise samples, respectively) and from h...
Galvin N, Corley K.A retrospective study was carried out to investigate the causes of disease and death in a population of foals in Ireland during their first 12 months post partum. Foaling and veterinary records from 343 foals on four farms born between January 1, 2004 and May 30, 2008 were reviewed. Among 343 foals, 22 did not survive to 12 months of age. Over the five-year period, the incidence of stillbirth was 1.5% (5/343), mortality 5% (17/338) and overall morbidity was 88.5% (299/338). Morbidity was calculated to include all new conditions brought to the attention of the attending veterinary surgeon, no m...
Matsuda K, Qiu Y, Furuse T, Kawamura Y, Yokoyama D, Kato A, Taniyama H.This report documents an unusual case of congenital foregut cyst with dysphagia and stridor in a Thoroughbred foal. Histologically, the bilocular cyst, near the junction of larynx and trachea, had an epithelial lining of bronchogenic and esophageal origin. Concomitant malformation of the laryngeal muscles and cartilage resulted in a combination of anomalies that have not been reported in the human or veterinary literature.
McGivney BA, Eivers SS, MacHugh DE, MacLeod JN, O'Gorman GM, Park SD, Katz LM, Hill EW.Selection for exercise-adapted phenotypes in the Thoroughbred racehorse has provided a valuable model system to understand molecular responses to exercise in skeletal muscle. Exercise stimulates immediate early molecular responses as well as delayed responses during recovery, resulting in a return to homeostasis and enabling long term adaptation. Global mRNA expression during the immediate-response period has not previously been reported in skeletal muscle following exercise in any species. Also, global gene expression changes in equine skeletal muscle following exercise have not been reported...
Barakzai SZ, Boden LA, Dixon PM.To (1) assess the degree of arytenoid cartilage abduction lost after laryngoplasty (LP) in Thoroughbred National Hunt racehorses and (2) to correlate postoperative racing performance with degree of arytenoid abduction after LP. Methods: Case series. Methods: National Hunt Thoroughbred racehorses (n=68). Methods: Grade of postoperative arytenoid abduction for National Hunt racehorses that had LP with ventriculocordectomy was assessed at 1 day, 6 days, and 6 weeks after LP. Race records were analyzed to ascertain if there was correlation between the degree of arytenoid cartilage abduction and va...
Barakzai SZ, Boden LA, Dixon PM.To evaluate the effect of laryngoplasty (LP) on race performance in longer distance (National Hunt) Thoroughbred racehorses. Methods: Case-control study. Methods: National Hunt Thoroughbred racehorses (n=71) and race-matched controls (n=126). Methods: Race records for National Hunt racehorses that had LP and ventriculocordectomy were analyzed and racing performance was compared with race-matched controls. Results: Sixty-three of 71 cases were matched with controls. Postoperatively, 78% of cases raced, 47% improved their individual performance and cases were as likely to start in 1 or 3 races a...
Tabar-Rodriguez JJ, Cruz AM, Monteith G, Gordon K, Hurtig MB.OBJECTIVE-To use quantitative ultrasonography to evaluate the association between the speed of sound (SOS) at 9 sites in the third metacarpal bone (MCIII) of racing Thoroughbreds with workload accumulation and the effect that MCIII failure has on this association. ANIMALS-Sixty-two 2- and 3-year-old Thoroughbreds in racing condition. PROCEDURES-Cumulative work index (CWI) was used to calculate total workload (CWI(total)) and also 3 independent CWIs for the various gaits (ie, trot [CWI(trot)], gallop [CWI(gallop)], and race [CWI(race)]) used during training and racing. Speed of sound was monito...
Schuh EM, Friedman MS, Carrade DD, Li J, Heeke D, Oyserman SM, Galuppo LD, Lara DJ, Walker NJ, Ferraro GL, Owens SD, Borjesson DL.OBJECTIVE-To optimize the isolation and culture of mesenchymal stem cells (MSCs) from umbilical-cord blood (UCB), identify variables that predicted successful MSC isolation, and determine whether shipping, processing, and cryopreservation altered MSC viability, recovery rates, and expansion kinetics. SAMPLE POPULATION-UCB samples from 79 Thoroughbred and Quarter Horse mares. PROCEDURES-UCB samples were processed to reduce volume and remove RBCs. Nucleated cells (NCs) were cryopreserved or grown in various culture conditions to optimize MSC monolayer expansion and proliferation. Donor and UCB-s...
Jung BY, Lee KW, Ha TY.Leptospirosis is a zoonotic disease of global importance, and has a worldwide distribution. The present study aimed to determine leptospiral seroprevalence in clinically healthy racing horses from all three racecourses in Korea. Serum samples from 1,226 racing horses were examined using a microscopic agglutination test to detect the presence of antibodies against 18 Leptospira serovars. Of the tested samples, 307 (25.0%) were found to be positive. The distribution of seroprevalence differed significantly by racecourse (P=0.004); the Jeju course had the highest incidence (31.1%), followed by th...
Wilsher S, Lefranc AC, Allen WR.Fillies completely devoid of endometrial glands (uterine gland knockout; UGKO) would make ideal experimental models in which to study the role of endometrial histotroph in embryogenesis and early fetal development in the mare. Objective: Administration of a synthetic progestagen plus oestrogen to newborn filly foals and, thereafter, at regular intervals to age 6 months, would permanently suppress endometrial gland development. Methods: Nine half-sister Thoroughbred filly foals were treated, in 3 groups, with: A) the weakly active progestagen, norgestomet, administered from birth to age 6 month...
Kakoi H, Tozaki T, Nagata S, Gawahara H, Kijima-Suda I.In order to develop a genotyping method that can be used in the registration procedure for Thoroughbreds, we developed a method for simultaneously genotyping multiple coat colour genes on the basis of single nucleotide polymorphism typing by using the SNaPshot(TM) technique. This method enabled precise and reasonable detection of causal mutations; it was effective for genotyping of MC1R, ASIP, and SLC45A2 at the Extension (E), Agouti (A), Cream dilution (C) loci, and the possibility of identification of rare variants of MC1R, EDNRB and KIT at the E, Overo (O) and Sabino 1 (SB1) loci, respectiv...
Moreau P, Lavoie JP.To evaluate effects of thrombophlebitis of 1 or both jugular veins on athletic performance of horses. Methods: Retrospective case series. Methods: 91 horses with jugular vein thrombophlebitis. Methods: Medical records of horses with jugular vein thrombophlebitis examined between 1988 and 2005 were reviewed for signalment, history, clinical signs, diagnosis, and treatment. Performance was evaluated in 2 ways. A questionnaire was used to obtain a subjective assessment from the owner or trainer of the horse's performance after thrombophlebitis, compared with the performance before thrombophlebiti...
Eivers SS, McGivney BA, Fonseca RG, MacHugh DE, Menson K, Park SD, Rivero JL, Taylor CT, Katz LM, Hill EW.Intense selection for elite racing performance in the Thoroughbred horse (Equus caballus) has resulted in a number of adaptive physiological phenotypes relevant to exercise; however, the underlying molecular mechanisms responsible for these characteristics are not well understood. Adaptive changes in mRNA expression in equine skeletal muscle were investigated by real-time qRT-PCR for a panel of candidate exercise-response genes following a standardized incremental-step treadmill exercise test in eight untrained Thoroughbred horses. Biopsy samples were obtained from the gluteus medius before, i...
Minami Y, Yamano S, Kawai M, Hiraga A, Miyata H.To find a new parameter indicating muscle fitness in Thoroughbred horses, we examined time-dependent recovery of glycogen content and sarcoplasmic reticulum (SR) Ca(2+)-ATPase activity of skeletal muscle after intensive treadmill running. Two repeated 50-sec running sessions (13 m/sec) were performed on a flat treadmill (approximately 90%VO2max). Muscle samples of the middle gluteal muscle were taken before exercise (pre) and 1 min, 20 min, 60 min, and 24 hr after exercise. Muscle fiber type composition was determined in the pre muscle samples by immunohistochemical staining with monoclonal an...
Voigt A, Saulez MN, Donnellan CM.The medical records of 2 Thoroughbred horses that developed headshaking after blunt trauma to the occipital region are reviewed. The history, signalment, clinical signs, diagnostic methods, diagnosis and treatment were recorded in each case. Both horses displayed headshaking, while one horse repeatedly lifted its upper lip and pawed excessively at the ground. In both horses, diagnostic imaging of the occipital region revealed avulsion fragments of the nuchal crest and a nuchal desmitis in association with hyperfibrinogenaemia. The presence of an avulsion fragment of the nuchal crest with assoc...
Boyle AG, Sweeney CR, Kristula M, Boston R, Smith G.To identify factors associated with an increased likelihood that horses would have a serum Streptococcus equi SeM-specific antibody titer > or = 1:1,600. Methods: Cross-sectional study. Methods: 188 healthy client-owned horses. Methods: A single serum sample from each horse was tested for SeM-specific antibody titer with an ELISA. Multivariate logistic regression was used to identify factors associated with having a titer > or = 1:1,600. Results: Age, breed, and vaccination status were significantly associated with the likelihood of having a titer > or = 1:1,600. The odds of having a ...
Saulez MN, Gummow B.Endoscopic examinations were performed on 1005 thoroughbred racehorses in South Africa a mean (sd) 24 (12.3) minutes after racing, to determine the prevalence of pharyngeal, laryngeal and tracheal disorders, and to determine the relationship of these disorders with performance (number of wins and placed finishes). Overall, there was a low prevalence of grade 2 and 3 laryngeal function (LF) (2.2 per cent), grade 4 LF (0.6 per cent), epiglottic entrapment (1.3 per cent), subepiglottic cyst (0.2 per cent) and epiglottic deformity (0.6 per cent), while a higher prevalence of grade 2 to 4 pharyngea...
Ryu SH, Koo HC, Park YK, Kim JM, Jung WK, Davis WC, Park YH, Lee CW.Equine respiratory disease is a common cause of poor performance and training interruptions. The higher incidence rate of infectious upper respiratory disease (IURD) in thoroughbred racehorses at the Seoul Race Park coincided with the frequent stabling season, shorter stabling periods, and younger ages in this study. Incidence rates were also correlated with significantly lower proportions of cells expressing MHC class II-, CD2 antigen-, CD4+- or CD8+-T lymphocyte-, and B lymphocyte in IURD patients compared with healthy control groups in the summer and fall and in 2-and-3-year-old groups. The...
Ramzan PH.Fractures involving the fetlock region are encountered commonly in Thoroughbred racehorses. Condylar fractures of the distal metacarpus/metatarsus and mid-sagittal fractures of the proximal phalanx account for the majority of fetlock injuries during both racing and training and clinical features, management and outcome of these injuries have been well described. Transverse fractures of the distal diaphysis of the third metacarpus, however, are seldom observed and have received little attention in the literature. This paper describes clinical and radiological findings associated with 6 cases en...
Brama PA, Holopainen J, van Weeren PR, Firth EC, Helminen HJ, Hyttinen MM.There is ample evidence on topographical heterogeneity of the principal biochemical components of articular cartilage over the surface of the joint and the influence of loading thereon, but no information on depth-related zonal variation in horses. Objective: To study depth-related zonal variation in proteoglycan (PG) and collagen content in equine articular cartilage. Methods: Two techniques (safranin-O densitometry and Fourier transform infrared spectroscopy) were applied to sections of articular cartilage from the proximal phalangeal bone of the metacarpophalangeal joint of 18-month-old Tho...
Von Wittke P, Lindner A, Deegen E, Sommer H.In this study the effects of training history on the results of a standardized two-speed test in competing Thoroughbreds were investigated during a racing season. For nine Thoroughbreds, 1,755 training days were recorded. Within the observation period each horse completed a two-speed field test at intervals of 6-8 wk to determine its running velocity (v) eliciting blood lactate concentrations of 4 (v4) and 12 mmol/l (v12). Horses performed 29 two-speed tests. Changes of v4 and v12 in a horse between two consecutive tests were used to assess effects of training history variables calculated for ...
Neuschaefer A, Bracher V, Allen WR.The effect of treating lactating mares with the dopamine agonist bromocriptine was investigated. Seven pony and 4 Thoroughbred lactating mares were given a single intramuscular (i.m.) injection of 100 mg bromocriptine between Days 18 and 28 after foaling when the secretion rate of prolactin was elevated. Prolactin and luteinizing hormone (LH) concentrations were measured in serial peripheral plasma samples taken before and after the treatment and, in 5 of the pony mares, levels of these hormones were also measured in pituitary venous effluent obtained by cannulation of the cavernous sinus. In ...
Sasaki N, Mizuno Y, Yoshihara T.Electrogastrography (EGG), in which the electrical activity of the smooth muscular layer of the stomach is recorded percutaneously through the abdominal wall, has been applied in recent years to humans as a non-invasive method. In acute abdominal disease in horses, it is considered diagnostically useful to analyze digestive activity using EGG. Electrocecography (ECG) was examined to determine its effectiveness in evaluating equine digestive motility through comparison, after xylazine administration, between the results of the percutaneous ECG method and the results obtained using a strain-gaug...
Thompson K, McManus P, Stansall D, Wilson BJ, McGreevy PD.The idea that whip use is critical to thoroughbred racing integrity is culturally entrenched but lacks empirical support. To test the longstanding beliefs that whip use aids steering, reduces interference, increases safety and improves finishing times, we conducted a mixed-method analysis of 126 race reports produced by official stewards of the British Horseracing Authority, representing 1178 jockeys and their horses. We compared reports from 67 "Hands and Heels" races, where whips are held but not used (whipping-free, WF), with 59 reports from case-matched races where whipping was permitted (...
Walker WT, Kawcak CE, Hill AE.To characterize medial femoral condyle (MFC) morphometrics and subchondral bone density patterns in Thoroughbred racehorses and to determine whether these variables differ between left and right limbs. Methods: Stifle joints harvested from 6 Thoroughbred racehorses euthanized for reasons other than hind limb lameness. Methods: The distal portion of the left and right femurs of each cadaver was scanned via CT. Hounsfield units were converted to dipotassium phosphate equivalent densities through use of a phantom on each specimen. Medial femoral condyle width, length, height, and curvature; subch...
Harris RC, Foster CV.Treadmill exercise in Thoroughbred horses of 2 min duration and increasing intensity resulted in increased formation and accumulation of acetylcarnitine in the working middle gluteal muscle. At high work intensities a plateau in acetylcarnitine formation was reached corresponding to approximately 70% of the total carnitine pool (approx. 30 mmol.kg-1 dry muscle). Formation of acetylcarnitine was mirrored by an equal fall in the free carnitine content, which stabilised, at the highest work intensities, at around 8 mmol.kg-1 dry muscle. Acetylcarnitine and carnitine reached their point of maximum...
Fukuda T, Kikuchi M, Kurotaki T, Oyamada T, Yoshikawa H, Yoshikawa T.Atrophy of seminiferous tubules and interstitial fibrosis are frequently observed in aged horses. Samples from 8 male Thoroughbreds, age 4-24 years, were subjected to histological, electron microscopical and immunohistochemical examination and statistical analysis. There were statistically significant increases in collagen fibres in the lamina propria of seminiferous tubules and testicular interstitium in 3 horses age 23 and 24 years compared with 5 horses age 4-20 years (P<0.001). Lamina propria surrounding atrophic tubules was thickened by an increase in collagen type IV and elastic fibre...
Trumble TN, Scarbrough AB, Brown MP.To investigate the effects of exercise and osteochondral (OC) injury on type II collagen degradation products (collagenase cleavage neoepitope commercially known as C2C) in synovial fluid (SF) from Thoroughbred (TB) racehorses and to compare these results with radiographic and arthroscopic scores of severity of joint injury. Methods: Metacarpophalangeal/metatarsophalangeal (MCP/MTP) and carpal SF was obtained from (1) 20 normal rested horses, (2) the same horses after 5 to 6 months of race training, and (3) 27 horses with OC injury from racing. For group 3, radiographic and arthroscopic scores...
Peter VG, O'Keeffe TA, Smith LCR, Schweizer-Gorgas D. To investigate the racing performance of Thoroughbred horses with osseous cyst-like lesions (OCLLs) in the distal phalanx causing lameness and treated conservatively. To assess horses' ability to race and perform after radiographic identification of OCLL in the distal phalanx of Thoroughbred horses with lameness at the time of detection and undergoing conservative treatment. Retrospective case control study. The clinical database of one equine clinic was reviewed in a 10-year period for Thoroughbreds showing lameness localized to the foot and a radiographic diagnosis of OCLL in the distal ...
Schrurs C, Dubois G, Van Erck-Westergren E, Gardner DS.The racing industry is supported by a predominance of female stablehands and work riders, but few become professional jockeys. Female jockeys have recently had notable race success. No study has assessed whether the sex of the rider may subtly influence racehorse physiology to affect performance. Here, using a validated exercise tracking system (the 'Equimetre'™) that records many physiological parameters simultaneously, this study characterised racehorse cardiovascular (heart rate, heart rate recovery) and biomechanical (stride length and frequency) parameters at various exercise intensitie...
Davie AJ, Wen L, Cust ARE, Beavers R, Fyfe T, Zhou S.This study investigated the effects of six weeks of normobaric hypoxic training on transcriptional expression of the genes associated with mitochondrial and glycolytic activities in Thoroughbred horses. Eight horses were divided into two groups of four. They completed an identical incremental, moderate intensity training program, except that one group trained in a hypoxic chamber with 15% oxygen for 30 min on alternate days except Sundays (HT), while the other group trained in normal air (NC). Prior to and post training, heart rate and blood lactate were measured during an incremental treadm...
Nishita T, Matsushita H, Kai M.The location of carbonic anhydrase III (CA-III) in frozen sections of biopsies of Thoroughbred horse skeletal muscle was studied. Fibre types were determined by ATP-ase and succinate dehydrogenase staining. CA-III isozyme was detected using a peroxidase conjugated anti-CA-III antibody. CA-III was found to be localised in slow twitch oxidative fibres (ST), but was also present in fast twitch oxidative (FTH) fibres in small amounts. Fast twitch glycolytic (FT) fibres were stained lightly compared with control sections. The concentrations of CA-III in muscle and liver were 70 micrograms/mg protei...
Hansen M, Knorr C, Hall AJ, Broad TE, Brenig B.The solute carrier family 26, member 2 (SLC26A2) gene belongs to a family of multifunctional anion exchangers. Mutations in the human SLC26A2 gene are associated with autosomal recessively inherited chondrodysplasias. Hence, we postulate that the equine SLC26A2 could be a candidate gene for conformational traits in horses. An equine BAC clone harboring the SLC26A2 gene was isolated. The complete 142,625 bp insert sequence of this clone was determined by transposon sequencing. Together with the SLC26A2 gene the BAC clone contains four genes, i.e. the macrophage colony stimulating factor 1 recep...
Kwok WH, Ho EN, Lau MY, Leung GN, Wong AS, Wan TS.In recent years, there has been an ongoing focus for both human and equine doping control laboratories on developing detection methods to control the misuse of peptide therapeutics. Immunoaffinity purification is a common extraction method to isolate peptides from biological matrices and obtain sufficient detectability in subsequent instrumental analysis. However, monoclonal or polyclonal antibodies for immunoaffinity purification may not be commercially available, and even if available, such antibodies are usually very costly. In our study, a simple mixed-mode anion exchange solid-phase extra...
Anzai T, Nakanishi A, Wada R, Higuchi T, Hagiwara S, Takazawa M, Oobayashi K, Inoue T.For determination whether strangles has invaded the Hidaka district of Hokkaido, the main racehorse-breeding area of Japan, a epizootiological survey with bacterial isolation was carried out during the breeding season in 1995. Streptococcus equi subsp. equi, which is the causative agent of strangles, was isolated from two Thoroughbred horses with submandibular lymphadenitis. Isolates were identified by serological grouping, biochemical tests and analysis of cell surface proteins by Western immunoblotting. Through this survey, it revealed that S. equi subsp. equi has invaded the Hidaka district...
Kaşikçi G, Horoz H, Alkan S, Düzgün O, Aktaş M.A modified surgical technique has been developed for repairing third-degree perineal lacerations in mares. Complications of the currently used methods include rectovaginal fistula formation, urine pooling, complete dehiscence of the repair, constipation, tenesmus and difficulty of performance in the practice. The modified method is simpler and more practical. This method was performed on eight Thoroughbred mares with third-degree perineal lacerations after delivery. The rectovestibular septum was reconstructed by three lines of sutures in a transverse direction in relation to the longitudinal ...
Rivas VN, Magdesian KG, Fagan S, Slovis NM, Luethy D, Javsicas LH, Caserto BG, Miller AD, Dahlgren AR, Peterson J, Hales EN, Peng S, Watson KD....Idiopathic hypocalcemia in Thoroughbred (TB) foals causes tetany and seizures and is invariably fatal. Based upon the similarity of this disease with human familial hypoparathyroidism and occurrence only in the TB breed, we conducted a genetic investigation on two affected TB foals. Familial hypoparathyroidism was identified, and pedigree analysis suggested an autosomal recessive (AR) mode of inheritance. We performed whole-genome sequencing of the two foals, their unaffected dams and four unaffected, unrelated TB horses. Both homozygosity mapping and an association analysis were used to prior...
Bolwell CF, Rosanowski SM, Scott I, Sells PD, Rogers CW.Against a global background of increasing anthelmintic resistance in parasites, little is known about the current parasite control strategies adopted within the equine industry in New Zealand. The aim of the study was to describe and compare the current parasite management and control practices used on Thoroughbred and Standardbred stud farms in New Zealand. An online questionnaire was used to collect data on the demographics of respondents, parasite control methods, grazing management, and use of faecal egg counts. Questions regarding parasite control strategy, how often horses were dewormed,...
Hillyer LL, Ridd Z, Fenwick S, Hincks P, Paine SW.While cobalt is an essential micronutrient for vitamin B synthesis in the horse, at supraphysiological concentrations, it has been shown to enhance performance in human subjects and rats, and there is evidence that its administration in high doses to horses poses a welfare threat. Animal sport regulators currently control cobalt abuse via international race day thresholds, but this work was initiated to explore means of potentially adding to application of those thresholds since cobalt may be present in physiological concentrations. Objective: To devise a scientific basis for differentiation b...
Panizzi L, Dittmer KE, Vignes M, Doucet JS, Gedye K, Waterland MR, Rogers CW, Sano H, McIlwraith CW, Riley CB.Biomarkers for osteoarthritis (OA) in horses have been extensively investigated, but translation into clinical use has been limited due to cost, limited sensitivity, and practicality. Identifying novel biomarkers that overcome these limitations could facilitate early diagnosis and therapy. This study aimed to compare the concentrations of synovial fluid (SF) and plasma cell-free DNA (cfDNA) over time in control horses with those with induced carpal OA. Following an established model, unilateral carpal OA was induced in 9 of 17 healthy Thoroughbred fillies, while the remainder were sham-operate...
Staniszewska M, Kowalik S, Sadok I, Kędzierski W.Catabolism of tryptophan (Trp) is modulated by physical activity and provides a pool of active compounds: Trp is considered a calmative agent, kynurenine (Kyn) and 3-hydroxykynurenine (3-HKyn) show neurotoxic effects, kynurenic acid (Kyna) and xanthurenic acid (XA) have neuroprotective properties like nicotinamide (NAm), while serotonin is the neurotransmitter. The study was conducted to investigate the dependence of exercise intensity, measured by plasma lactic acid (LA) concentration, on the level of Trp, its catabolites (serotonin, Kyn, 3-HKyn, Kyna and XA), and NAm in Thoroughbred horses. ...
Knych HK, Harrison LM, Casbeer HC, McKemie DS.Methylprednisolone acetate (MPA) is commonly administered to performance horses, and therefore, establishing appropriate withdrawal times prior to performance is critical. The objectives of this study were to describe the plasma pharmacokinetics of MPA and time-related urine and synovial fluid concentrations following intra-articular administration to sixteen racing fit adult Thoroughbred horses. Horses received a single intra-articular administration of MPA (100 mg). Blood, urine, and synovial fluid samples were collected prior to and at various times up to 77 days postdrug administration a...
Johnston GCA, Ahern BJ, Woldeyohannes SM, Young AC.Equine advanced imaging research involving racehorse fetlock pathology commonly uses cadaver limbs and a freeze-thaw process. The presence of short tau inversion recovery (STIR) signal intensity in the distal third metacarpal/metatarsal bone is of particular interest and may be clinically relevant in the diagnosis of horses at risk of fracture. However, little is known about the effect of the freeze-thaw process on the MRI appearance of STIR hyperintensity in these bones. This study compares the low-field MRI appearance of the distal third metacarpal/metatarsal bone from cadaver limbs of Thoro...
Shin JA, Yang YH, Kim HS, Yun YM, Lee KK.The study was carried out to investigate the genetic polymorphism of the serum proteins of horses in Cheju. They were assigned to three groups; 45 Cheju native horses(CNH), 60 Cheju racing horses(CRH) and 60 Thoroughbreds(TB). We analyzed the phenotypes and gene frequencies of serum proteins which were albumin (Alb), vitamin-D binding protein(GC), esterase (ES), A1B glycoprotein(A1B) and transferrin(TF) loci using horizontal polyacrylamide gel electrophoresis (HPAGE). All of the loci, except A1B in TB, showed polymorphisms and different allelic and phenotypic frequencies in all three groups. E...
Sullivan M, Snow DH.The absorption of orally administered phenylbutazone (5 mg/kg) was studied in 10 thoroughbreds, eight ponies and four pony foals. Large variations in area under the curve (AUC) and peak plasma concentrations were found both within an animal and within groups of animals. Administration of phenylbutazone (5 mg/kg) following an overnight fast resulted in no difference among the three groups of animals with respect to AUC (0 to 24 hours), mean (+/- sd) values of which were 132 +/- 68, 107 +/- 48 and 98 +/- 6, respectively. Absorption characteristics of two oral phenylbutazone preparations (Equipal...
Hatzipanagiotou A, Lindner A, Sommer H.The distribution of LDH and CK isoenzymes in blood plasma of ten clinically sound Thoroughbreds with reasonable performance and without elevated clinico-chemical blood variables (reference group) was compared with 57 Thoroughbreds, which had histories of mild locomotor disturbances and/or poor performance and had elevated CK, LDH and/or AST activities (trial group). The trial group was subdivided according to the number of altered blood variables and in the groups with two as well as three altered blood variables also according to the extent of alteration of the total CK activity. The pattern ...
McCutcheon LJ, Geor RJ, Shen H.The objective of this study was to determine the effects of 10 consecutive days of moderate intensity training on 1) the concentration of middle gluteal muscle Na(+)-K(+)-ATPase as determined by vanadate-facilitated 3H[ouabain binding; and 2) plasma potassium regulation before, during and after exercise at 100% of the pre-training maximum rate of oxygen consumption (VO2max). Six mature, unfit Thoroughbred horses completed both incremental (for determination of VO2max) and high-intensity exercise protocols before (HI1) and after (HI2) training. There additional horses undertook no training or e...
Janicek JC, Rodgerson DH, Boone BL.A 20-year-old Thoroughbred mare was evaluated because of a 2-year history of infertility. The mare had normal estrous cycles and had been bred 7 times by different stallions. Ultrasonographic examination revealed a homogeneous hyperechoic intramural mass in the tip of the right uterine horn; the mass was also detected via hysteroscopy Unilateral ovariectomy and partial hysterectomy were performed by use of a hand-assisted laparoscopic technique. Leiomyoma was diagnosed via histologic examination of the mass. Unilateral ovariectomy and partial hysterectomy are recommended in mares with leiomyom...
Sallé G, Canlet C, Cortet J, Koch C, Malsa J, Reigner F, Riou M, Perrot N, Blanchard A, Mach N.The widespread failure of anthelmintic drugs against nematodes of veterinary interest requires novel control strategies. Selective treatment of the most susceptible individuals could reduce drug selection pressure but requires appropriate biomarkers of the intrinsic susceptibility potential. To date, this has been missing in livestock species. Here, we selected Welsh ponies with divergent intrinsic susceptibility (measured by their egg excretion levels) to cyathostomin infection and found that their divergence was sustained across a 10-year time window. Using this unique set of individuals, we...
Orme CE, Harris RC.The aim of the study was to develop a model for the pre-exercise elevation of plasma free fatty acids in the horse, with a view to its future use in investigations of fat metabolism during exercise. A comparison of the lipase releasing and anticoagulative effects of heparin and a related substance pentosan polysulphate was investigated. Furthermore, the ability of heparin and pentosan polysulphate to affect an increase in plasma free fatty acid concentration, when co-administered with-a triglyceride emulsion, was quantified. Doses of 0.39 and 1.3 mg kg-1 body wt of heparin and pentosan polysul...
