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.
Mazan MR.A 30-year-old Morgan-Quarter Horse gelding with hyperadrenocorticism was referred for treatment of a full-thickness tear of the retroperitoneal portion of the rectum. In older horses, the caudal end of the peritoneal space may be farther cranial than is commonly thought. Thus, there is a greater chance that full-thickness rectal tears will involve the retroperitoneal, rather than the peritoneal, portion of the rectum. This horse had a quick recovery and good outcome, despite underlying hyperadrenocorticism that would be expected to impair healing. Although relatively little is known about mana...
Patterson-Kane JC, Wilson AM, Firth EC, Parry DA, Goodship AE.This study was undertaken to test the hypothesis that collagen fibrils, the submicroscopic units of strength in tendon, would hypertrophy in response to a specific defined training programme. Fibril diameters were measured in central and peripheral regions of superficial digital flexor tendon (SDFT) samples from five 18-month-old horses which underwent a subsequent 18 month training programme and 6 age- and sex-matched controls. Central region fibrils from the trained horses had a mass-average diameter (MAD) of 105.3 nm, which was significantly lower (P < 0.01) than that of 131.7 nm for the...
Pearce SG, Firth EC, Grace ND, Fennessy PF.To evaluate standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal laparoscopically-guided, liver biopsy under general anaesthesia in foals, as techniques for obtaining tissue for assessment of copper status. The techniques were evaluated with respect to ease of use and effect on the animal. Methods: Twenty of 24 Thoroughbred mares and 21 of their foals were biopsied. The animals were part of a larger study of the effect of copper supplementation on copper status and the prevalence of developmental orthopaedic disease. Livers were also collected from...
Bentz BG, Granstrom DE, Stamper S.To determine seroprevalence of Sarcocystis neurona-specific antibodies in a population of horses residing in Chester County, Pa. Methods: Prevalence survey. Methods: 117 serum samples from selected members of a population of 580 Thoroughbred horses. Methods: Serum was analyzed for antibodies to Sarcocystic neurona, using a western blot. Information regarding age, sex, and housing of horse was obtained by questionnaire. Data were analyzed, using multivariable logistic regression. Results: Seroprevalence was 45.3% (95% CI, 36.3 to 54.3%). A relationship was not found between seroprevalence and s...
Todhunter RJ, Fubini SL, Freeman KP, Lust G.To determine whether keratan sulfate concentrations in plasma or synovial fluid from clinically normal horses were different from concentrations in horses with joint disease and whether concentrations varied with type of joint disease. Methods: Case-control study. Methods: 67 clinically normal horses, 10 clinically normal foals, and 160 horses with joint disease. Methods: ELISA was used to measure keratan sulfate concentrations. Results: Mean plasma keratan sulfate concentration (mean +/- SEM, 580 +/- 124 ng/ml) in foals peaked at 10 weeks of age. Mean plasma keratan sulfate concentration in c...
Okumura M, Asano M, Fujinaga T.The optimum pH for the measurement of serum p-phenylenediamine oxidase (Ox) activity was given (pH 6.6), and the relationship between serum ceruloplasmin (Cp) concentration and its Ox activity was established in healthy adult horses. In adult horses, serum antigenic Cp concentrations were measured by the single radial immunodiffusion (SRID) method with the affinity-purified antibody to equine plasma Cp and compared with its Ox activity. Efficient co-relation between Cp concentration and Ox activity in the sera (r = 0.93) and its Ox/Cp ratio were given. These results might contribute to the cal...
Wood SC, Fedde MR.Splenic contraction in racing horses increases the hematocrit (hct), thereby increasing blood viscosity. We tested as to whether racing also affects the elastic properties of blood. Mares and geldings were studied for thus purpose. After racing, there was: (i) an increased erythrocyte count independent of gender and race distance (0.32 to 1.7 km): (ii) an increased mean erythrocyte volume in both sexes; (iii) an increased heterogeneity of RBC size in both sexes; (iv) an increased plasma fibrinogen concentration and erythrocyte sedimentation rate in both sexes; and (v) an increased elastic yiel...
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...
Kingston JK, Geor RJ, McCutcheon LJ.To compare dew-point hygrometry, direct sweat collection, and measurement of body water loss as methods for determination of sweating rate (SR) in exercising horses. Methods: 6 exercise-trained Thoroughbreds. Methods: SR was measured in 6 horses exercising at 40% of the speed that elicited maximum oxygen consumption for 45 km, with a 15-minute rest at the end of each 15-km phase. Each horse completed 2 exercise trials. Dew-point hygrometry, as a method of local SR determination, was validated in vitro by measurement of rate of evaporative water loss. During exercise, local SR was determined ev...
Martin RB, Gibson VA, Stover SM, Gibeling JC, Griffin LV.Fatigue or stress fractures are an important clinical problem in humans as well as racehorses. An important question in this context is, when a bone experiences fatigue damage during extreme use, how much is it weakened compared to its original state? Since there are very limited data on this question and stress fractures are common in racehorses, we sought to determine the effect of fatigue loading on the monotonic strength of equine cortical bone. Beams were machined from the dorsal, medial and lateral cortices of the third metacarpal bones of six thoroughbred racehorses. Beams from left and...
Sellon DC, Levine JF, Palmer K, Millikin E, Grindem C, Covington P.The records of horses presented to the Veterinary Teaching Hospital of North Carolina State University College of Veterinary Medicine between January 1, 1989 and April 30, 1994 were evaluated to determine risk factors associated with thrombocytosis. Of the 2,346 horses for which a CBC was performed, 24 (1.0%) had a platelet count > 400,000/microL. Demographic, diagnostic, physical examination, and clinicopathologic variables from these cases were compared with a reference population consisting of 189 horses with a normal platelet count presenting during the same period. Infectious/ inflamma...
Patterson-Kane JC, Parry DA, Birch HL, Goodship AE, Firth EC.The superficial digital flexor tendon is the most commonly injured tendon in the racing Thoroughbred. Despite the clinical significance of this structure, only limited data exist regarding normal age-related morphology of the tensile units, the collagen fibrils. The age at which these collagen fibrils become mature in composition and structure may be of importance. Consequently, the association of age and collagen fibril crosslink composition, diameter distribution and crimp morphology in the superficial and deep digital flexor tendons of Thoroughbreds up to and including three years of age ha...
Smith JM, Meyers KM, Barbee DD, Schott H, Bayly WM.To determine whether plasma von Willebrand factor (vWf) concentration changes in horses during and after treadmill exercise. Methods: 5 mature, fit Thoroughbreds. Methods: A blood sampling catheter was placed in the right jugular vein. A warm-up period was followed by a 3-minute rest period. Horses were galloped at racing pace until fatigued (about 2 minutes). Blood samples were collected prior to warm-up, during the postwarm-up rest period, 1 minute into the run, at cessation of the run, and 5 to 120 minutes after cessation of the run. vWf activity was measured by ELISA and corrected for plas...
Mills PC, Ng JC, Auer DE.The effect of inflammation on the disposition of phenylbutazone (PBZ) was investigated in Thoroughbred horses. An initial study (n = 5) in which PBZ (8.8 mg/kg) was injected intravenously twice, 5 weeks apart, suggested that the administration of PBZ would not affect the plasma kinetics of a subsequent dose. Two other groups of horses were given PBZ at either 8.8 mg/kg (n = 5) or 4.4 mg/kg (n = 4). Soft tissue inflammation was then induced by the injection of Freud's adjuvant and the administration of PBZ was repeated at a dose level equivalent to, but five weeks later than, the initial dose. ...
Martin GS, Strand E, Kearney MT.To develop a statistical model to evaluate the influence of specific parameters on racing performance in Thoroughbreds. Methods: Survey. Methods: Racing records of Thoroughbreds performing in Louisiana from 1981 to 1985. Methods: Race results for 20 randomly selected days from 5 racetracks during 5 years were analyzed, using regression analysis. Results: The most influential parameter was distance raced. There were significant differences in racing performance among horses at different tracks. At the tracks examined, fast racing surfaces resulted in significantly faster finish times than good ...
Young LE, Blissitt KJ, Bartram DH, Clutton RE, Molony V, Jones RS.In order to determine if transoesophageal Doppler echocardiography could be used to estimate cardiac output in anaesthetized horses, we have compared the technique with estimations of cardiac output by thermodilution in eight healthy adult thoroughbreds. Measurements of aortic blood flow velocity were made by high pulse repetition frequency (HPRF) and continuous wave (CW) Doppler echocardiography from a 3.5-MHz transoesophageal probe. Cardiac output was increased during the study by administration of dobutamine, providing a range of cardiac output measurements by thermodilution from 15.0 to 64...
Enbergs H, Karp HP, Schönherr U.The present study was aimed to determine the contents of calcium, inorganic phosphate, parathormon, 25-OH-D3 and the activity of alkaline phosphatase in the plasma of one- and two-years-old thoroughbred horses. Data were obtained monthly from 44 one-year-old thoroughbred of 4 different studs from May during grazing-season and from October during stable-, resp. training-season up to april of the following year. Calcium, inorganic phosphate and the activity of alkaline phosphatase were measured with a photometric method and the concentration of PTH and 25-OH-D3 were determined with a radioimmuno...
Whittem T, Firth EC, Hodge H, Turner K.This study examined the pharmacokinetics of steady-state phenylbutazone and single bolus intravenous gentamicin when administered together in the horse. The trial design was completed as a cross-over with seven thoroughbred horses. In the first phase each horse received 2.2 mg/kg gentamicin intravenously. After a 2-week washout, each horse received 4.4 mg/kg phenylbutazone intravenously every 24 h for 5 days. On the fourth day each horse received gentamicin as before. Plasma was harvested for gentamicin concentration determination by fluorescence polarization immunoassay and for phenylbutazone...
Hillyer MH, Innes JF, Patteson MW, Barr AR.Discospondylitis, of presumed bacterial origin, was diagnosed in an adult thoroughbred racehorse. The clinical signs were vague and associated with abnormal mobility of the neck and forelimbs. Clinical pathology showed only a non-specific inflammatory response. A scintigraphic examination revealed the site of the lesion and the diagnosis was confirmed by the identification of radiographic changes affecting two thoracic vertebrae. A prolonged course of antimicrobial agents produced a complete recovery and the horse returned to full athletic use.
Bahmani MK, Nowrouzian I, Nakaya T, Nakamura Y, Hagiwara K, Takahashi H, Rad MA, Ikuta K.Borna disease virus (BDV) naturally infects horses and sheep and induces progressive poliomeningoencephalomyelitis. Here, BDV recombinant proteins of the first open reading frame (ORF-I; coding for p40 nucleoprotein) and the second ORF-II (coding for p24 polymerase cofactor) were immunoblotted with plasma derived from 72 healthy (28 Arabic, 17 thoroughbred and 27 cross-bred) race horses at Tehran in Iran to detect anti-BDV antibodies. In addition, their peripheral blood mononuclear cells (PBMCs) were also examined for BDV RNA by a nested reverse transcriptase-polymerase chain reaction (RT-PCR)...
Mawdsley A, Kelly EP, Smith FH, Brophy PO.A linear assessment trait evaluation system is proposed to allow quantitative description of the static conformation of the horse. Measurements were made on 27 selected traits. The system was tested initially for repeatability of measurements on 4 horses. Twenty-one of the selected traits were satisfactory and 6 proved unsatisfactory in terms of reproducibility. A population of 101, superior 2- and 3-year-old Thoroughbreds and 19 premium Thoroughbred stallions were similarly assessed. More than 65% of the traits exhibited large (CV > 10%) phenotypic variation within the sampled population. ...
Estberg L, Stover SM, Gardner IA, Drake CM, Johnson B, Ardans A.To investigate the relation between several racing speed history characteristics and risk of fatal skeletal injury (FSI) in racing Thoroughbreds. Methods: 64 Thoroughbreds euthanatized during a 9-month period in 1991 at a California racemeet because of a catastrophic fracture incurred while racing (cases), identified retrospectively. For each race in which an FSI occurred, 1 control horse was randomly selected from the noncatastrophically injured participants. Methods: Racing and officially timed workout histories were obtained for each horse. Several history characteristics were calculated to...
Caron JP, Kaneene JB, Miller R.To determine the patterns of use and perceived efficacy of polysulfated glycosaminoglycan (PSGAG) for the treatment of degenerative joint disease in horses. Methods: Cross-sectional mail survey. Methods: 1,522 equine practitioners. Methods: Information was obtained on frequency and route of administration of PSGAG for the treatment of each of 4 forms of degenerative joint disease, the efficacy of PSGAG, and its efficacy compared with that of sodium hyaluronate. Data were analyzed by nonparametric and multivariate regression methods. Results: Response rate was 40.5%. Of practitioners responding...
Ishida N, Hasegawa T, Oyunsuren T, Mukoyama H.The mitochondrial DNA sequence of cytochrome b gene in a Thoroughbred horse was determined. By comparing DNA sequences between the Thoroughbred and published sequence data (two horses and one Grevyi zebra), polymerase chain reaction (PCR) primers were designed for amplification of a 590 bp DNA fragment in the cytochrome b gene, and PCR-restriction fragment length polymorphism (RFLP) analysis was studied in 140 horses of six breeds using three restriction enzymes (AciI, BamHI, RsaI). Two morphs were found using each of the three enzymes. By combining three enzymes morphs, the 140 horses examine...
Rivero JL, Talmadge RJ, Edgerton VR.The histochemical myofibrillar ATPase (mATPase) method is used routinely for identification of equine skeletal muscle fiber types, but important problems have been observed with the subdivision of fast fiber population when using this method. To verify the use of this qualitative method, a number of equine muscle biopsies were analyzed with a combination of histochemical, immunohistochemical, electrophoretic, and morphometric techniques. The influence of training on these interrelations was also evaluated. Methods: Five young (2-3 years old) thoroughbred horses were intensively trained for 8 m...
Maia MPM, Weber SH, Bastos LFC, Michelotto PV.This study aimed to investigate the prevalence of juvenile osteochondral conditions (JOCCs) in yearling Thoroughbred (TB) racehorses in Southern Brazil, as well as to examine the same animals studied as weanlings by Bastos et al. (2017) and compare the radiographic findings for the two ages. Radiographs of 76 male and female TB yearlings from Paraná State, Southern Brazil, were investigated. The proximal interphalangeal, metacarpophalangeal/metatarsophalangeal (MC/MT), tarsal, and femorotibial (FT) joints were evaluated using 24 radiographic projections. The evaluation consisted of a severit...
Arai T, Washizu T, Hamada S, Sako T, Takagi S, Yashiki K, Motoyoshi S.D-Glucose transport and cytosolic enzyme activities were measured in erythrocytes from 2-year-old thoroughbreds under continuous training exercise (race horses) and compared with those from untrained horses of various ages (sires, mares and untrained 2-year-old thoroughbreds). The activities of the glucose transport and glycolytic enzymes, hexokinase and pyruvate kinase, in the race horses' erythrocytes were elevated to 2-3.5 times above those of untrained horses. There were no significant differences in plasma glucose, triglyceride or IRI concentrations between the horses in training and untr...
Minamijima Y, Tozaki T, Kuroda T, Urayama S, Nomura M, Yamamoto K.Equine colitis is a diarrhoeal disease caused by inflammation of the large bowel and can potentially be life-threatening due to its rapid progression. Pathogenesis is multifactorial and pathophysiology is highly complicated, therefore, reliable diagnostic biomarkers are needed in the veterinary field. Objective: Serum is one of the most commonly used diagnostic tools in equine clinical investigation. To discover diagnostic or prognostic protein markers for colitis in horse serum, comprehensive and comparative proteomic analysis was conducted using liquid chromatography-tandem mass spectrometry...
Umar MA, Fukui S, Kawase K, Itami T, Yamashita K.Cardiovascular effects of total intravenous anesthesia using ketamine-medetomidine-propofol drug combination (KMP-TIVA) were determined in 5 Thoroughbred horses undergoing surgery. The horses were anesthetized with intravenous administration (IV) of ketamine (2.5 mg/kg) and midazolam (0.04 mg/kg) following premedication with medetomidne (5 µg/kg, IV) and artificially ventilated. Surgical anesthesia was maintained by controlling propofol infusion rate (initially 0.20 mg/kg/min following an IV loading dose of 0.5 mg/kg) and constant rate infusions of ketamine (1 mg/kg/hr) and medetomidine (1.25...
Manohar M, Goetz TE.To determine whether intravenous infusion of nitroglycerin would modify pulmonary arterial, capillary, or venous hypertension in strenuously exercising Thoroughbreds. Methods: 5 healthy Thoroughbred horses. Methods: Right atrial, right ventricular, and pulmonary vascular pressures were measured. Each horse was used in a control treatment (not medicated) and a nitroglycerin infusion (20 microg/kg of body weight/min) at rest and during exercise on a treadmill. Sequence of treatments was randomized for each horse, and treatments were separated by a 7-day interval. Galloping at 14.2 m/s on a 5% up...
Byrne KM, Davis WC, Holmes MA, Brassfield AL, McGuire TC.Two monoclonal antibodies (MAb), HB65A (IgG2a) and HB86A (IgGI), recognize a unique cell surface molecule on equine T-lymphocytes. The molecule, designated EqWC4, identified by these MAbs is present on a subpopulation of CD4+ equine lymphocytes (6.3-10.2% of Arabian lymphocytes CD4+ WC4+) and a smaller population of CD8+ lymphocytes (0.5% to 1.2% of Arabian lymphocytes CD8+ WC4+). EqWC4 is absent from B-lymphocytes, granulocytes, and macrophages. Both MAbs bound to a 46-kDa protein following immunoprecipitation reactions with lysates of surface labeled thymocytes. Immunoaffinity purification u...
Kuroda T, Nagata SI, Tamura N, Kinoshita Y, Niwa H, Mita H, Minami T, Fukuda K, Hobo S, Kuwano A.To determine plasma pharmacokinetics of metronidazole and imipenem following administration of a single dose PO (metronidazole, 15 mg/kg) or IV (imipenem, 10 mg/kg) in healthy Thoroughbreds and simulate pleural fluid concentrations following multiple dose administration every 8 hours. Methods: 4 healthy Thoroughbreds. Methods: Metronidazole and imipenem were administered, and samples of plasma and pleural fluid were collected at predetermined time points. Minimum concentrations of metronidazole and imipenem that inhibited growth of 90% of isolates (MIC90), including 22 clinical Bacteroides iso...
Denham J, Hulme A.Sodium bicarbonate administration in the hours prior to exercise has been used as a performance-enhancing substance in horses since the late 1980s. Although sodium bicarbonate administration to racehorses 24 hours before racing is a banned practice in most racing industries, whether or not it improves running performance in racehorses is currently unclear. The aim of this systematic review and meta-analysis was to establish whether or not acute sodium bicarbonate administration improves running performance in trained Standardbred and Thoroughbred horses. Seven randomized controlled trials, in...
Berry CR, Pool RR, Stover S, O'Brien TR, Koblik PD.The source of a previously described radiolucent crescent in the flexor cortex of the distal sesamoid (navicular) bone on the palmaro45 degrees proximal-palmarodistal oblique (Pa45 degrees Pr-PaDio) clinical radiographic projection was investigated in 48 forelimb navicular bones from 24 Thoroughbreds by use of high-detail radiography and x-ray computed tomography (CT). Twenty-five of these bones also were evaluated, using microradiography and histologic examinations. Of these 25 bones, 5 had been labeled in vivo with fluorochrome markers. Tetrachrome-stained 100-microns-thick nondecalcified se...
Huggons N.A Thoroughbred yearling was presented with neurological, radiographic, and myelographic abnormalities consistent with cervical vertebral stenotic myelopathy. Surgical correction was performed by using ventral cervical interbody fusion at 3 intervertebral spaces. The patient recovered uneventfully from surgery. The neurological status remained unchanged initially; however, significant improvement was noted 37 weeks postoperatively. Un Thoroughbred d’un an a été présenté avec des anomalies neurologiques, radiographiques et myélographiques compatibles avec une myélopathie sténosée des ...
Bailly-Chouriberry L, Cormant F, Garcia P, Kind A, Popot MA, Bonnaire Y.Cobra venom (Naja kaouthia) contains a toxin called α-cobratoxin (α-Cbtx). This toxin is a natural protein containing 71 amino acids (MW 7821 Da) with a reported analgesic potency greater than morphine. In 2007, in USA, this substance was found in the barns of a thoroughbred trainer and since then till date, the lack of a detection of this molecule has remained a recurring problem for the horseracing industry worldwide. To solve this problem, the first method for the detection of α-cobratoxin in equine plasma has now been developed. Plasma sample (3 mL) was treated with ammonium sulfate at ...
Harris PA.The effect of feeding diets with low, adequate and high sodium contents on plasma aldosterone concentrations in horses and ponies was evaluated using human immunoassay kits. The effect of moderate to high intensity exercise of up to six minutes duration on plasma aldosterone concentrations in three thoroughbred horses was also investigated. On an adequate sodium diet plasma aldosterone concentrations increased to a peak around four hours after feeding. Little daily variation was found in the pre-feeding aldosterone concentrations over three days. Feeding additional salt resulted initially in n...
O'Neill HD, Bladon BM.Records of horses admitted to a veterinary surgery in the UK for lameness investigation during 2000 to 2008 were reviewed. Twenty-one horses were identified with both scintigraphic and radiological evidence of enostosis-like lesions (ELLs), in which 68 individual foci of increased radiopharmaceutical uptake were confirmed in 57 long bones. The presenting lameness was attributed to ELLs in 15 of 21 (71 per cent) horses; the remainder were thought to be incidental findings. Five horses were subjected to a repeat examination, four of which showed the occurrence of new lesions in the same or diffe...
Murphey ED, Schneider RK, Adams SB, Santschi EM, Stick JA, Ruggles AJ.To determine clinical features of horses with a slab fracture of the central or third tarsal bone and to report outcome of horses in which treatment did not include surgery. Methods: Retrospective study. Methods: 25 horses (14 Standardbreds, 6 Thoroughbreds, 5 Quarter Horses). Methods: Medical records of horses with a slab fracture of the central (n = 9) or third (16) tarsal bone were reviewed. Only horses for which treatment consisted of confinement to a stall were included in this study. Clinical features and radiographic findings were recorded and summarized. Outcome was determined for raci...
Freire R, Clegg HA, Buckley P, Friend MA, McGreevy PD.The effects of dietary supplements of virginiamycin on the behaviour and physiology of 17 thoroughbred geldings (five cribbers, six weavers and six control horses) were compared with the effects of a placebo over a period of 16 weeks. Virginiamycin had no effect on the horses' stereotypic behaviour, but it reduced their explorative behaviour, possibly owing to a reduction in feeding motivation. Virginiamycin increased the water intake of the cribbers and decreased the water intake of the control horses, but it was not possible to eliminate possible confounding factors for this effect. Virginia...
Mason DK, Watkins KL, McNie JT, Luk CM.In late November 1988 large numbers of thoroughbred horses in training in Hong Kong developed a transient pyrexia with, in some cases, the clinical signs of viral respiratory disease. Serial blood samples for haematological examination were taken from 10 of the horses which were stabled in six different blocks. They had developed a high temperature within three days of each other and subsequently seroconverted to equine herpes virus 1 (EHV1). The absolute monocyte count was more than 0.5 x 10(9)/litre in all 10 within the first five days, and nine of them had a high neutrophil/lymphocyte ratio...
Powell DM, Lawrence LM, Fitzgerald BP, Danielsen K, Parker A, Siciliano P, Crum A.The metabolic effects of short-term feed restriction and dietary calorie source were studied in horses receiving high-roughage or high-concentrate diets. Four Thoroughbred geldings were assigned to four treatment groups in a 4 x 4 Latin square experiment. The four treatments were 1) a nutritionally adequate high-roughage ration (70% roughage, 30% concentrate; AHR), 2) a nutritionally adequate high-concentrate ration (40% roughage, 60% concentrate; AHC), 3) 70% of the intake of the AHR diet (RHR), and 4) 70% of the intake of the AHC diet (RHC). Diets AHR and AHC were designed to meet the calori...
Bailey J, Colahan P, Kubilis P, Pablo L.This study was designed to test the hypothesis that a specific beta 2 adrenergic receptor agonist, albuterol sulphate, when delivered by metered-dose inhaler (MDI) would affect the performance of Thoroughbred horses during incremental exercise testing. Six conditioned Thoroughbred horses were randomly assigned to one of 2 treatment groups: Group 1 horses received placebo and Group 2 received albuterol. Each horse received both treatments in a crossover design with a 3 week interval between trials. Horses inspired albuterol (900 micrograms) or placebo over a 5 min period followed by an incremen...
Edwards VL, Loux S, Embertson R.Juvenile Thoroughbreds can be expensive to raise and train to race. Part of the economic return in these juveniles are the weanling, yearling and 2-year-old in training sales at which major surgeries must be declared. Objective: To determine if surgically corrected large colon displacements were associated with a reduction of sales price and racing performance. We hypothesised that the surgery would be associated with a reduced sales price but would not be associated with a reduction in race earnings or starts. Methods: Retrospective cohort study. Methods: The medical, sales and racing records...
Cullinane A, Garvey M, Walsh C, Gibbons J, Creighton A.The association between poor performance and respiratory disease in Thoroughbred racehorses that do not have a structural abnormality of the respiratory tract, is often based on anecdotal evidence. The objective of this scoping review was to examine the scientific evidence for such associations. Publications were selected based on a search of three databases (PubMed, Scopus, and CAB Direct), in English and without date restriction, followed by a screening process to exclude non-relevant papers, duplicates, and reviews. This process identified 996 publications of which 20 were analysed using th...
Rumpler MJ, Kandala B, Vickroy TW, Hochhaus G, Sams RA.Glycopyrrolate (GLY) is an antimuscarinic agent that is used in humans and domestic animals primarily to reduce respiratory tract secretions during anesthesia and to reverse intra-operative bradycardia. Although GLY is used routinely in veterinary patients, there is limited information regarding its pharmacokinetic (PK) and pharmacodynamic (PD) properties in domestic animals, and an improved understanding of the plasma concentration-effect relationship in racehorses is warranted. To accomplish this, we characterize the pharmacokinetic-pharmacodynamic (PK-PD) actions of GLY during and after a 2...
Madelin TM, Clarke AF, Mair TS.Sera from 54 two- to three-year-old Thoroughbred horses from an English racing stable were examined for precipitins to antigen extracts prepared from 18 species of moulds (fungi and thermophilic actinomycetes) isolated from the same stable. Twenty-seven horses exhibited serum precipitins to one or more antigens; sixteen of the mould antigens elicited positive reactions in sera from one or more horses. Significantly more precipitins occurred in sera of those horses stabled in a barn than among those stabled in individual boxes. This indicated a possible association between type of housing, leve...
Owens SD, Johns JL, Walker NJ, Librach FA, Carrade DD, Tablin F, Borjesson DL.To evaluate N-hydroxysuccinimide (NHS)-biotin labeling of equine RBCs and determine posttransfusion survival of autologous equine RBCs stored in citrate phosphate dextrose adenine-1 (CPDA-1) for 0, 1, 14, and 28 days. Methods: 13 healthy adult Thoroughbreds. Methods: Serial dilutions of biotin and streptavidin-phycoerythrin (PE) were evaluated in vitro in blood collected from 3 horses. One horse was used to determine RBC distribution and recovery. Twelve horses were allocated to 4 groups for in vivo experiments in which blood was collected into CPDA-1. Blood was labeled with biotin and reinfus...
Lowis TC, Hyland JH.This project surveys the reproductive performance of 154 foaling Thoroughbred mares on a commercial stud in southern Victoria. Of these, 96 were served on foal heat (FHS) and 58 were served at a subsequent prostaglandin-induced oestrus (PGS). The PGS group of mares performed more favourably in all aspects except the foaling-to-conception interval where there was a 9.4 day advantage to the FHS group. The first service conception rate in the FHS group was 47.9% compared with 55.2% in PGS mares. Second heat period conception rates were 46% vs 57.7% for FHS and PGS mares, respectively. Overall con...
Atwill ER, Mohammed HO, Dubovi E, Lopez J.A retrospective study was designed to determine the distribution of equine monocytic ehrlichiosis among the equine population in New York state, and to identify factors associated with risk of disease. Serum samples submitted to the diagnostic laboratory of the university during the period from January 1985 through December 1986 were examined for antibodies to Ehrlichia risticii, using the indirect fluorescent antibody technique. Factors evaluated included geographic origin and date of submission of the sample, and age, breed, and sex of the horse. Logistic regression analysis was used to iden...
Bayly WM, Slocombe RF, Weidner JP, Schott HC, Hodgson DR.The influences of facial airflow, exercise and wearing a facemask on gas exchange and upper airway (Pu), transpulmonary (PTP) and transdiaphragmatic (PTD) pressures were investigated in 6 horses performing an incremental exercise test on an inclined (10%) treadmill. The test consisted of a 2 min walk followed by two 2 min exercise bouts at intensities which produced 40% and 80% of maximal oxygen consumption. Horses performed the test 4 times, once for each of 4 protocols, which involved not wearing a facemask (A), wearing a mask with either no biased flow through it (B), with an expiratory bia...
Mita H, Tamura N, Fukuda K, Kuroda T, Kuwano A, Sato F.We aimed to investigate the recent incidence of carpal fractures and the risk factors for recurrent ipsilateral fractures after arthroscopic removal of clinically active unilateral carpal chip fracture fragments in Thoroughbred racehorses. The findings for horses managed under the Japan Racing Association that developed carpal bone fractures between 2014 and 2018 were retrospectively reviewed. The proportion of cases that developed a recurrent carpal fracture in the originally affected joint was calculated, and the risk factors for recurrent fractures were analysed. In total, 2858 carpal fract...
Holcombe SJ, Berney C, Cornelisse CJ, Derksen FJ, Robinson NE.To determine the effect of a commercially available nasal strip on airway mechanics in exercising horses. Methods: 6 horses (5 Standardbreds and 1 Thoroughbred). Methods: Horses exercised on a treadmill at speeds corresponding to 100 and 120% of maximal heart rate with and without application of a commercially available nasal strip. Concurrently, tracheal pressures, airflow, and heart rate were measured. Peak inspiratory and expiratory tracheal pressures, airflow, respiratory frequency, and tidal volume were recorded. Inspiratory and expiratory airway resistances were calculated by dividing pe...
Pearce SG, Firth EC, Grace ND, Fennessy PF.The effect of copper status on the evidence of bone and cartilage lesions was investigated in 21 Thoroughbred foals. The foals and their dams were grazed on pasture containing 4.4-8.6 mg Cu/kg dry matter (DM). Four treatment groups were created by randomly allocating mares and their foals to either copper supplemented (0.5 mg Cu/kg liveweight (LW)/day), or control (pasture only) groups. This experimental design allowed the effect of copper supplementation of mare and foal to be examined independently. Parameters of bone and cartilage development were assessed in the foals both in vivo, and at ...
Tong P, Ren M, Xu X, Song X, Zhang L, Kuang L, Xie J.Multiple novel circular replication-associated protein (Rep)-encoding single stranded (CRESS) DNA viruses have been extensively identified in the feces of humans and animals. Here, we first detected CRESS DNA virus (named Horse-CRESS DNA-like virus, HCLV) in two fecal samples from 10 imported thoroughbred (TB) horses in the customs quarantine station in North Xinjiang province, China. Additionally, we found that this virus was not detected in local breeds (LBs) (0/41) and was found only in imported TB horses (2/73). We obtained the whole-genome sequences of four viruses (HCLV ALSK-3-4, ALSK-13...
