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.
Shults T, Kownacki AA, Woods WE, Valentine R, Dougherty J, Tobin T.In horses given (rapid IV) methylphenidate (Ritalin, alpha-phenyl-2-piperidinacetic acid methyl ester; 0.70 mg/kg), plasma concentrations of the drug decreased rapidly at first, with an apparent alpha half-life of about 19 minutes, and then more slowly, with an apparent beta half-life of about 2.4 hours. These data were well fitted by a 2-compartment open model. In blood, about 40% of the methylphenidate present was in the plasma fraction, and of this, about 80% was plasma-protein bound. If given by subcutaneous or IM injection, plasma concentrations of methylphenidate peaked in about 1 hour a...
Dusek J, Munk Z.In a set of mares of English Thoroughbred horse of the Napajedla stock the gravidity length in the time period from 1880 to 1972 was evaluated. The variability of the gravidity length was evaluated in sets which were put together by combination of two age groups with a division of the studied time period into ten-year stages. Variance and sample means of the gravidity lengths in these sub-groups are significantly different in the period under study. In order to eliminate the action of non-genetic influences qualifying the variability of the gravidity length, and to increase the objectivity of ...
Pascoe JR, Ferraro GL, Cannon JH, Arthur RM, Wheat JD.Of 235 Thoroughbred racehorses examined with a flexible fiberoptic endoscope within 2 hours of racing to determine the frequency of exercise-induced pulmonary hemorrhage (EIPH), 103 (43.8%) had various degrees of hemorrhage in the tracheal lumen. Two of these horses (0.8%) subsequently had blood flow from the nostrils. Blood seemed to originate from the lung. Statistical analysis of frequency data for 191 horses which finished in 1st, 2nd, and 3rd places did not show any relationship between EIPH and horse's age, sex, or finishing position. However, a trend toward an increased frequency of EIP...
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...
Gunn HM.A modification of the histochemical reaction to demonstrate myosin adenosine triphosphatase activity in skeletal (striated) muscle was used to define the density of capillaries in transverse sections of 3 muscles (semitendinosus, diaphragm, and pectoralis transversus) of horses and dogs. Thoroughbred horses and Greyhound dogs, breeds noted for their speed in running, were compared with other members of their respective species. Thoroughbred cross horses were grouped with non-Thoroughbreds for comparison with Thoroughbreds. The area of muscle supplied by a capillary was remarkably similar in mu...
Irwin DH, Howell DW.An easy diagnostic technique for recognising fibrotic myopathy and scarring in the caudal popliteal area is described. A simplified corrective surgical technique is offered and discussed briefly. Some aspects of haematomas are reviewed.
Munk Z, Dusek J.The fertility problems were studied in the herd of the English Thoroughbred horse on the Napajedla stud farm. Breeding records for the period from 1880 to 1972 were used as the starting data. The survey comprised 32 stallions. The relationship between fertility and the number of matings was calculated by the chi 2 quantity. The calculated values are highly variable. However, it is generally seen in most of the stallions that the number of matings per heat (i. e. one or several matings) had no significant influence on the pregnancy of mares and on the fertility values of the stallions. A higher...
Littlejohn A, Bowles F.Radiometer Blood Micro-system 2 was used in studies designed to, (a) compare the mean blood gas and acid-base values of 38 normal horses and 20 horses with chronic obstructive pulmonary disease (COPD), (b) determine the means and standard deviations of blood gas and acid-base values of Thoroughbred horses in training, and (c) investigate the relationships between clinical data, blood gas values, intracardiac and pulmonary arterial pressures in subjects with COPD. There were significant differences between the mean values for partial pressure of arterial oxygen (PaO2), arterial carbon dioxide (...
O'Brien TR, Hornof WJ, Meagher DM.Subchondral lesions were identified in the distal palmar region of the third metacarpus in 21 fetlock joints of 15 Thoroughbred horses. The lesions were more commonly identified on the lateromedial and flexed lateral projection, with the flexed lateral projection permitting optimal visualization of the lesion. Lesions appeared as poorly marginated, radiolucent defects and were located at the level of the base of the proximal sesamoid bones. The shape and distribution of the radiolucent defects were: crescent, 4; flattened, 4; shallow concavity, 5; deep concavity, 3; oval, 3; and circular, 2. S...
Garma-Aviña A, Valli VE, Lumsden JH.Four cases of equine congenital cutaneous papillomatosis were found during a review of 555 cutaneous tumours received at the pathology department, Ontario Veterinary College, during a 10-year period. A fifth case received after that period was also included. Two of the tumours were found in Thoroughbreds, one in a Standardbred, one in an Arabian and in one case the breed was not specified. The anatomical locations were the rib cage, head, hind leg and 2 on the forehead.
Guttormsen SA, Weitkamp LR.Polymorphism of equine erythrocyte malic enzyme is detactable on starch gel electrophoresis. The frequency of ME1S was 0.06 in 667 Standardbred and 0.09 in 85 Thoroughbred horses. No genetically determined electrophoretic variation in soluble malate dehydrogenase was detected.
The Journal of heredityJanuary 1, 1981
Volume 72, Issue 1 65-66 doi: 10.1093/oxfordjournals.jhered.a109433
Dring LA, Hintz HF, Van Vleck LD.Average gestation periods for bay, chestnut, dark bay, gray, and black Thoroughbred mares were compared. A total of 1359 gestation periods were used. A linear model including factors for age of mare, sex of foal, month and year of breeding, and sire effects was used in the analysis. Dam and sire coat-color combinations were also investigated in a similar manner. No significant differences in gestation length could be attributed to coat color of the mare of to dam and sire coat-color combinations. Heritability of gestation length was estimated to be 0.38. The results of this study strongly sugg...
Love DN, Rose RJ, Martin IC, Bailey M.Amoxycillin trihydrate was administered orally to 6 foals at dose rates of 13 mg/kg (low), 20 mg/kg (medium) and 30 mg/kg (high) and serum concentrations determined at intervals up to 8 h. Therapeutic serum levels of 1 microgram/ml persisted for 268 mins at a dose rate of 13 mg/kg, for 339 mins at 20 mg/kg and for 381 mins at 30 mg/kg. A 2 micrograms/ml serum level persisted for 198 mins at a dose rate of 13 mg/kg, for 268 mins at 20 mg/kg and for 311 mins at 30 mg/kg. To determine the spectra of its antibacterial activity, the minimum inhibitory concentrations of amoxycillin against 8 genera ...
Campbell MD, Bellamy JE, Searcy GP.The microhematocrit heat-precipitation methods of Millar et al (1971) and Schalm et al (1975) were compared with the reference clottable protein method of Ratnoff and Menzie (1951) in the measurement of plasma fibrinogen concentration in horses. The millar et al method was more precise and accurate and showed better positive correlation with the reference method than did the Schalm et al method. There was no significant difference in the plasma fibrinogen concentration between healthy Thoroughbreds and healthy horses of other breeds. Horses with bacterial pneumonia and abscesses had significan...
Irwin DH.Thirty seven intra-articular injections, each 2 ml sodium hyaluronate were made into 21 arthritic joints in 15 racing Thoroughbreds and one part-bred polo pony. One joint failed to improve at all, 16 became sound with one injection, 4 became sound with 2 injections, and 11 joints showed various degrees of response. Eleven of 14 horses became sound for flat racing. Discussion relates to the technique of using sodium hyaluronate, some clinical and pathological aspects of traumatic arthritis, joint lubrication and a brief review of some properties of sodium hyaluronate which have a bearing on art...
Irwin DH, Howell DW.The clinical and laboratory findings of illness in a 2-year-old Thoroughbred filly are described. The treatment employed, including unilateral nephrectomy, and the macro- and microscopic findings in the diseases kidney are presented and this rare case is discussed briefly.
Hanák J, Jagos P.In 246 horses of the English Thoroughbred breed of several age categories, divided into four test populations, the influence was studied of age and training on the pulse rate and time intervals of ECG (PQ, QRS, QT and QTc). It was found that with the increasing age and training action slowed down gradually. Duration of the atrioventricular path (PQ) is prolonged, time of ventricular activation (QRS) and time of the electrical systole (QT) including its value corrected according to the actual pulse rate (QTC). In this way the origin of the so called sports electrocardiogram in trained race hors...
Hintz RL.Criteria used to measure performance, environmental factors that influence performance and estimates of heritability are needed to estimate genetic differences. Published heritability estimates of various measures of performance in the horse are summarized. The average heritability estimates of pulling ability and cutting ability are .25 and .04, respectively. Heritability estimates are .18, .19 and .17 for log of earnings from jumping, 3-day event and dressage performance, respectively. Heritability estimates of performance rates, log of earnings, earnings, handicap weight, best handicap weig...
Littlejohn A, Bowles F.Pressure curves obtained by cardiac catheterization of the pulmonary artery, right ventricle and right atrium of 9 horses and ponies with chronic obstructive pulmonary disease (COPD) were compared with those similarly recorded from 6 clinically normal control subjects. The mean pulmonary peak systolic, pulmonary minimum diastolic and ventricular peak systolic pressures of the COPD subjects were significantly higher (P less than 0,01) than the corresponding mean pressures of the clinically normal control subjects. The mean pressure calculated from pressure curves obtained from 8 Thoroughbreds i...
Stull CL, Albert WW.The percentages of three muscle fiber types in the biceps femoris and triceps brachii were determined in five breeds of horses: Belgians, Standardbreds, Thoroughbreds, Quarter Horses and Welsh ponies. Biopsies were taken from the two muscles from each of four 2-year-old untrained fillies of each breed. Percentages of red, white and intermediate fiber types were determined from tissues stained for succinic dehydrogenase activity. Intermediate fibers were the most numerous for all breeds. The difference between red and white fibers varied significantly with breed. Thoroughbreds had the highest p...
Barth AD, Barber SM, McKenzie NT.A two month old Thoroughbred filly was presented with signs of depression, grinding of the teeth, frothing of the mouth and abdominal pain. These signs had persisted for two weeks despite treatment with mineral oil, dioctyl sodium sulfosuccinate, meperidine and antibiotics. A variety of diagnostic tests were done, the only abnormal finding was a stress leukon. On exploratory laparotomy the stomach was dilated with fluid and gas and the pyloric canal was constricted. Pyloroplasty resulted in correction of the condition. The etiological possibilities are discussed. This is believed to be the fir...
Greenwood RE, Simson AR.An outbreak of ataxia and paralysis on a Thoroughbred studfarm is reported. The cause of the disease was attributed to equid herpesvirus (EHV1) infection which stemmed from a single 10-month abortion on the studfarm. Stallions, mares and foals were all affected but the most serious clinical signs occurred in the mares. there were 35 out of 39 mares, 2 out of 4 stallions and 5 out of 39 foals which exhibited signs of ataxia. Nine mares became recumbent and died or were euthanased. Treatment with betamethasone and antibiotics was given. The outbreak was contained to one area of the stud apart fr...
Jenvey C, Caraguel C, Howarth GB, Riley CB.Prior to the start of endogenous production of immunoglobulins (Igs), absorption of maternal Igs is important to protect against pathogens in the early neonatal period. It is possible that mare- or foal-associated factors may influence neonatal IgA concentrations. Objective: The temporal relationships among serum and milk IgA concentrations in Thoroughbred mare-foal pairs were explored to determine if periparturient mare- and foal-associated factors contribute to the prediction of foal serum IgA concentrations. Methods: Blood and milk samples as well as complete veterinary records, were collec...
Smith JJ, Embertson RM.To compare racing performance before and after sternothyroideus myotomy, staphylectomy, and oral caudal soft palate photothermoplasty in Thoroughbred racehorses with intermittent dorsal displacement of the soft palate (DDSP). Methods: Retrospective study. Methods: Thoroughbred racehorses (n=102) with DDSP. Methods: Retrieved data included signalment, primary complaint, and upper respiratory tract endoscopic finding. Lifetime race records were compared for earnings per start before and after surgery, days to 1st start, and races won postoperatively. Results: Comparing mean earnings per start fo...
Modesto RB, Rodgerson DH, Masciarelli AE, Spirito M.This retrospective study describes placement of distal radial transphyseal screws in Thoroughbred yearlings with carpal varus deformities while standing, and identifes short- and long-term complications following the procedure. Data gathered from 2009 to 2013 identified 8 yearlings that met the inclusion criteria. Horses were sedated intravenously and a single 4.5-mm cortical screw was placed in the distal lateral radial physis following application of local anesthetic and surgical preparation of a pre-placed hole. All horses were evaluated weekly after surgery and screw removal was performed ...
Kondo T, Mashimo Y, Sato F, Tsuzuki N, Yamada K.Thoroughbred horses appear to be particularly predisposed to cervical vertebral stenotic myelopathy (CVSM), also known as wobbler syndrome. We hypothesized that variations in the cervical vertebral volumes can affect the dynamic instability of the cervical vertebrae. This observational study aimed to clarify whether cervical vertebral volume could be considered as a contributing factor in CVSM in Thoroughbred horses. Computed tomography (CT) was used to investigate a total of 21 male Thoroughbred horses (age range, 217-1,002 days; mean, 542.3 days). The study population comprised 17 CVSM horse...
Ohmura H, Hiraga A, Takahashi T, Kai M, Jones JH.To determine prevalence of atrial fibrillation (AF) immediately after racing among racehorses that finished well behind the winners and examine potential risk factors for AF in these horses. Methods: Case-control study. Methods: 39,302 racehorses representing 404,090 race starts in races sanctioned by the Japan Racing Association between 1988 and 1997. Methods: Horses that finished > or = 4 (turf races) or 5 (dirt races) seconds behind the winner or that did not complete the race were examined for AF within 5 minutes after the race. Logistic regression and chi2 analyses were used to determine ...
Anderson JD, Tulleners EP, Johnston JK, Reeves MJ.The efficacy of sternothyrohyoideus myectomy (SM) and staphylectomy as treatments for intermittent dorsal displacement of the soft palate was evaluated in 209 racehorses (126 Thoroughbreds, 83 Standardbreds). The 2 most common complaints were respiratory tract noise (75% of horses) and exercise intolerance (51% of horses). Stopping, defined as the inability to finish the race at racing speed, was reported in 40% of the horses. Endoscopy at rest revealed evidence of abnormal epiglottic anatomy (hypoplasia or flaccidity) in 51% of the horses and abnormal soft palate function in 36% of the horses...
Panagiotopoulou O, Rankin JW, Gatesy SM, Hutchinson JR.Horse racing is a multi-billion-dollar industry that has raised welfare concerns due to injured and euthanized animals. Whilst the cause of musculoskeletal injuries that lead to horse morbidity and mortality is multifactorial, pre-existing pathologies, increased speeds and substrate of the racecourse are likely contributors to foot disease. Horse hooves have the ability to naturally deform during locomotion and dissipate locomotor stresses, yet farriery approaches are utilised to increase performance and protect hooves from wear. Previous studies have assessed the effect of different shoe desi...
Hardee GE, Tshabalala MA, Moore JN, Gokhales RD.Separate high performance liquid chromatographic methods were developed for thiabendazole (TBZ) and 5-hydroxy thiabendazole (5-OH-TBZ) determination in horse plasma using 1-methyl-2-phenyl benzimidazole (MPBZ) as an internal standard. In both methods TBZ and 5-OH-TBZ were extracted from plasma using organic solvents, injected on to a C-18 column, and eluents monitored by a fluorescence detector. However, mobile phase composition, extraction solvent as well as detector wavelength differed in the two methods. The linear range for TBZ was 0.02 to 0.77 microgram ml-1 while that for 5-OH-TBZ was 0....
Radovic L, Remer V, Krcal C, Rigler D, Brem G, Rayane A, Driss K, Benamar M, Machmoum M, Piro M, Krischke D, Butler-Wemken IV, Wallner B.In horses, demographic patterns are complex due to historical migrations and eventful breeding histories. Particularly puzzling is the ancestry of the North African horse, a founding horse breed, shaped by numerous influences throughout history. A genetic marker particularly suitable to investigate the paternal demographic history of populations is the non-recombining male-specific region of the Y chromosome (MSY). Using a recently established horse MSY haplotype (HT) topology and KASP™ genotyping, we illustrate MSY HT spectra of 119 Barb and Arab-Barb males, collected from the Maghreb regio...
Imaizumi K, Nakamura T, Kiryu K, Kanemaru T, Kaneko M.The aorta and extrapulmonary artery were examined pathologically in 33 thoroughbred racehorses ranging in age from 1 to 5 years. Many of the great vessels of these horses exhibited degenerative or sclerotic changes in the media with neither lipidosis nor deposits of cholesterol. The severe lesions were predominantly observed at the bifurcation of the pulmonary artery. The severity of the lesions in both the aorta and pulmonary artery appeared to be associated with the racing career of the racehorse rather than with increasing age. Histopathogenetically, the medial changes in the great vessels ...
Greco-Otto P, Bond S, Sides R, Bayly W, Leguillette R.Equine water treadmills (WT) were initially designed for rehabilitation of musculoskeletal injuries, but are also commonly used for conditioning sport horses, however the effects are not well documented. The purpose of this study was to test the effect of an 18-day WT conditioning programme on peak oxygen consumption (V̇O2peak). Nine unfit Thoroughbreds were used in a randomised controlled trial. Six horses worked daily for 18 days in stifle-height water (WT group), while 3 control horses worked without water (dry treadmill group (DT)). Preconditioning and postconditioning maximal exercise ra...
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...
Pinilla MJ, Tranquille CA, Blunden AS, Chang YM, Parkin TDH, Murray RC.A detailed histopathological study of the distal third metacarpal bone of Thoroughbred racehorses was undertaken to characterize lesions observed previously on magnetic resonance imaging (MRI). The bones were selected and grouped on the basis of MRI features. Representative sections in different planes were processed for histopathology. All lesions observed in the articular cartilage (AC) and subchondral bone (SCB) were recorded and graded with a scoring system, based partially on the Osteoarthritis Research Society International grading system. The scoring system included the severity of the ...
Lloyd DR, Rose RJ, Duffield AM, Suann CJ.The combination of large doses of sodium bicarbonate and the potent narcotic, etorphine, has reportedly been given to racehorses in attempts to improve their performance and also to "mask" the presence of etorphine in urine samples. The increased urinary output and pH associated with sodium bicarbonate (approximately 500 g) administration may reduce the urinary concentration of etorphine, making it more difficult to detect. Our experiment was designed to examine the effects of this combination. Six Thoroughbred horses were used in a latin-square design with three horse pairs and three treatmen...
Hernández-Avilés C, Castaneda C, Raudsepp T, Varner DD, Love CC.Acrosomal dysfunction has been considered as a cause of subfertility in males of different species, including stallions. A subset of subfertile stallions with acrosomal dysfunction is unique because they have normal sperm quality (motility, morphology, viability, and DNA quality). The current work aims to describe the clinical characteristics of subfertile stallions that were diagnosed with Impaired Acrosomal Exocytosis (IAE) by using two high throughput methods: flow cytometry and molecular genetic analysis, and to identify the prevalence of subfertility due to IAE in stallions evaluated at T...
Wong JKY, Kwok WH, Chan GHM, Choi TLS, Ho ENM, Jaubert M, Bailly-Chouriberry L, Bonnaire Y, Cawley A, Ming Williams H, Keledjian J, Brooks L....Acadesine, 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, commonly known as AICAR, is a naturally occurring adenosine monophosphate-activated protein kinase (AMPK) activator in many mammals, including humans and horses. AICAR has attracted considerable attention recently in the field of doping control because of a study showing the enhancement of endurance performance in unexercised or untrained mice, resulting in the term 'exercise pill'. Its use has been classified as gene doping by the World Anti-Doping Agency (WADA), and since it is endogenous, it may only be possible to control del...
Neil KM, Axon JE, Begg AP, Todhunter PG, Adams PL, Fine AE, Caron JP, Adkins AR.To determine the clinical characteristics, short-term outcome and future athletic performance of foals with septic osteomyelitis. Methods: Retrospective clinical study of 108 Thoroughbred foals with radiographic evidence of bone infection that were presented at the Scone Veterinary Hospital between August 1995 and December 2001. Medical records were reviewed and information concerning signalment, the clinical, laboratory and radiographic findings, treatment and outcome was obtained. Racing records were obtained and evaluated for surviving foals that had reached racing age. Results: Mean age of...
Dosi MCMC, McGorum BC, Kirton RD, Cillán-García E, Mellanby RJ, Keen JA, Hurst EA, Morgan RA.Vitamin D deficiency is common in humans and is increasingly linked to the pathogenesis of a multitude of diseases including obesity and metabolic syndrome. The biology of vitamin D in horses is poorly described; the relative contribution of the diet and skin synthesis to circulating concentrations is unclear and associations with the endocrine disease have not been explored. Objective: To determine the relationship between management, season and endocrine disease and vitamin D status in horses. Methods: Cross-sectional cohort study. Methods: Plasma concentrations of 25-hydroxyvitamin D2 (25(O...
Haywood L, Spike-Pierce DL, Barr B, Mathys D, Mollenkopf D.Incomplete ossification of the cuboidal bones of the carpus and tarsus in foals has the potential for significant consequences including chronic lameness and decreased athletic ability. Objective: To determine if the degree of ossification of the cuboidal bones is associated with gestational length and if the diagnosis of incomplete ossification is a predictor of performance in Thoroughbred racehorses. Methods: Retrospective cohort study. Methods: The medical records of Thoroughbred foals less than 90 days of age from 1994 to 2011 were examined and records containing tarsal radiographs identif...
Kai M, Hiraga A, Kubo K, Tokurik M.The purpose of this study was to determine whether there was any difference in the stride characteristics between cantering on a flat or inclined treadmill. Five 2-year-old Thoroughbred horses were cantered on a treadmill at 3 different velocities and at 3 different slopes. The sequence of speeds at each slope was chosen at random and 16 mm cinefilms at 300 frames/s were taken from a lateral view at a distance of 15 m from the treadmill to record the linear and temporal data. On the slope, stride length, stride duration, stance duration and swing duration did not change. However, midstep lengt...
Jager MC, Tomlinson JE, Henry CE, Fahey MJ, Van de Walle GR.Theiler's disease, a.k.a. equine serum hepatitis, is a devastating, highly fatal disease of horses. Equine parvovirus-hepatitis (EqPV-H) has been identified as the likely cause of this disease. While the incidence of Theiler's disease is low, the prevalence of EqPV-H DNA in horses is high, with up to 37% in some regions, suggesting that subclinical or persistent infection is common. To determine the prevalence and pathogenicity of EqPV-H infection at New York racetracks, DNA was extracted from archived formalin-fixed, paraffin-embedded liver tissues from racehorses submitted for necropsy to th...
Zekas LJ, Ramirez S, Brown MP.Left dorsal displacement of the large colon was diagnosed in a 3-year-old Thoroughbred gelding. Conservative treatment that included lunging after administration of phenylephrine and rolling while under general anesthesia was not successful. The displaced segment of colon was reduced surgically through a ventral midline incision, but displacement recurred 4 days after surgery. Ablation of the nephrosplenic space by suturing the nephrosplenic ligament to the splenic capsule was performed through the left flank. At followup 1 year after surgery, the horse had not had further signs of colic and h...
Almonte H, Schumacher J, Johnson CR, Berk JT, Bell RP.To the authors' knowledge, the effect of a combination of butorphanol tartrate and detomidine hydrochloride on the laryngeal function and symmetry of the arytenoid cartilages in young Thoroughbred horses has not been examined. Therefore, this study aimed to examine the effects of administration of butorphanol and detomidine on left-to-right rima glottidis ratio (L:R RGR), cross-sectional area of the rima glottidis (CSARG) and grade of laryngeal function of Thoroughbred yearlings examined endoscopically at rest. Forty-six Thoroughbred yearlings underwent laryngeal video endoscopy, at rest, befo...
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...
Legg KA, Colborne GR, Gee EK, Rogers CW.To evaluate the elastic modulus of various ligaments of the forelimbs of cadaveric horses. Methods: 408 ligaments from 37 forelimbs of 10 Thoroughbred cadavers and cadavers of 9 other horse breeds. Methods: Collateral ligaments and straight and oblique sesamoid ligaments were harvested from the proximal interphalangeal, metacarpophalangeal, carpal, and elbow joints of both forelimbs of all 19 horses. Ligament dimensions were measured, and the elastic modulus was determined by tensile testing the ligaments with a strain rate of 1 mm•s. Results: Elastic modulus of the ligaments differed signif...
Lepeule J, Bareille N, Valette JP, Seegers H, Jacquet S, Denoix JM, Robert C.Developmental orthopaedic disease (DOD) affects all breeds and is a common cause of pain and lameness for horses in sports. A thorough knowledge of between-breed variations for the prevalence of DOD, for its distribution among the various joints and for its severity at earlier stages in the disease process is needed in order to improve the relevance and the cost-effectiveness of DOD screening protocols. However, no prevalence study for DOD simultaneously performed on several breeds with similar farming systems and based on radiographic findings (RF) on quite a large number of joints and views,...
Sprayberry KA, Slovis NM.Pericarditis is a sporadic, but important cause of critical illness in horses of all ages. There is limited information on whether Thoroughbred horses that survive pericarditis are able to reach athletic potential. Objective: To determine how pericarditis affected horses that had the disease as young animals with regard to selling price in public sales and the ability to race successfully. Methods: Retrospective case series. Methods: Medical records were searched to identify pericarditis cases. Signalment and month of diagnosis were noted and Thoroughbreds with ultrasonographically confirmed p...
Nakamura Y, Nishi H, Katayama Y, Niwa H, Matsumura T, Anzai T, Ohtsu Y, Tsukano K, Shimizu N, Takai S.An eight-year-old thoroughbred mare with no previous history of illness aborted a fetus at 196 days of gestation, and its internal tissues were examined immunohistologically and bacteriologically. The placenta was not examined, but specimens of the intrauterine fluids and the dam's faeces were collected four days after the abortion and examined bacteriologically. No significant histological lesions were found in the fetus but the amnion and the umbilical cord were oedematous and had petechial haemorrhages. Rhodococcus equi was isolated in pure culture from the lung, heart and stomach contents ...
Young LE, Helwegen MM, Rogers K, Kearns L, Schreiber C, Wood JL.Exercise-induced pulmonary haemorrhage (EIPH) and tricuspid (TR) and mitral valve regurgitation (MR) are conditions with high prevalence in conditioned Thoroughbreds. Stress failure of pulmonary capillaries, leading to EIPH, is most likely when pulmonary vascular pressure is increased, and mitral regurgitation can result in pulmonary venous hypertension. Objective: There might be an association between MR and EIPH and the right ventricle (RV) of horses known to suffer repeated episodes of EIPH, as their hearts would be subject to higher pulmonary vascular pressures and cardiac output during tr...
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...
