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.
Johnstone IB, Crane S.The incidence and nature of coagulation abnormalities in horses presented with colic and the possible prognostic value of these abnormalities was investigated. A coagulogram was performed on each of 24 adult Thoroughbred or Standardbred horses. A coagulogram consisted of measurements of eight parameters; platelet count, plasma fibrinogen, plasma antithrombin III (AT), partial thromboplastin time (PTT), prothrombin time (PT), thrombin clotting time (TCT), soluble fibrin monomer (SFM) and fibrin-fibrinogen degradation products (FDP). Retrospective determination of the cause of the colic and outc...
Allen BV.Results of blood counts have been analysed in three-year-old racehorses in training comprising 77 colt stayers, 27 colt sprinters, 61 filly stayers and 35 filly sprinters. The distributions of haemoglobin, erythrocyte count and haematocrit were significantly higher in colt stayers compared to the other three groups. In fillies these values were also significantly higher in stayers compared to sprinters. The erythrocyte count was significantly higher in filly stayers compared to colt sprinters but there were no significant differences between haemoglobin or haematocrit values in these groups. N...
Palmer SE.The prevalence of carpal fractures was determined for 211 thoroughbred and 75 standardbred racehorses. Statistically significant differences were found in the location of fractures between the 2 breeds. In the thoroughbred and standardbred groups, total fractures (460) were distributed nearly equally between the left (224) and right (236) carpi. The most common site of fracture in the thoroughbred group was the distal aspect of the radiocarpal bone (112), whereas the most common site of fracture in standardbred horses was the proximal surface of the third carpal bone (61). Slab fractures were ...
Hillidge CJ.Idiopathic left-sided laryngeal paralysis was present in 14 of 169 horses on a thoroughbred horse farm (8.3 per cent). In nine animals, it was evident only after exercise and arytenoid abduction and adduction were normal at rest. Asynchronous movement of the arytenoid cartilages was observed in 94 horses at rest (55.6 per cent), 86 of which were considered to be normal after exercise. Conversely, synchronous movement of the arytenoids was noted when at rest in six of the 14 animals diagnosed as having laryngeal hemiplegia after exercise. An abnormal inspiratory noise during exercise was detect...
Burrell MH, Mackintosh ME, Taylor CE.Streptococcus pneumoniae was isolated from nasopharyngeal swabs and tracheal washings taken from Thoroughbred horses in training at three of four separate stables that were sampled during investigations into respiratory disease. The growth of Strep pneumoniae in culture was enhanced by an environment enriched with carbon dioxide. In one stable, five of 15 horses that were sampled repeatedly were found to carry the organism for at least four months. There was an apparent association between lower respiratory tract inflammatory disease and heavy growths (10(6) to 10(8) colony forming units/ml) p...
Speirs VC, Anderson GA, Bourke JM.The efficacy of treating carpal lesions by arthrotomy was evaluated in 210 Thoroughbred racehorses, using survival analysis to compare their racing performances and earnings with those of 840 control horses. The treated horses were significantly inferior with respect to races contested, and wins plus places (P less than 0.001) and races won (P less than 0.01). There was no difference with respect to earnings (P less than 0.1); after adjusting for other factors, arthritis, site of fracture and presence of a displaced chip had no effect on racing performance in horses with a single-site lesion i...
Greene HJ, O'Connor JP.A 16-year old thoroughbred mare was presented with dysphagia and food being ejected from the mouth and nostrils. Clinical signs were exhibited for three weeks before it was euthanased on humanitarian grounds. Post mortem examination revealed a soft haemangioma measuring 7 cm X 5 cm suspended from the roof of the medial compartment of the left guttural pouch.
Lyons ET, Tolliver SC, Drudge JH, Swerczek TW, Crowe MW.Examination of the ligamentum nuchae for Onchocerca spp was completed in 523 Thoroughbreds (1 to 29 years old) at necropsy in Kentucky during a 13-month period (1984 to 1985). Onchocerca spp were found in 306 (59%) of the horses. Frequencies of this parasite were 3%, 17%, 40%, 43%, and 42% in 1-, 2-, 3-, 4-, and 5-year-old horses, respectively. For 6- to 29-year-old horses, frequency varied from 71% to 100%, except for 26-year-old horses (50%); 87% of the 304 horses examined in the 6- to 29-year-old age groups was infected. The suspensory ligaments and flexor tendons from fetlocks (thoracic li...
Matsui K, Sugano S, Amada A.Changes of the heart rate and ECG to twitching were examined using 5 Thoroughbred foals at various ages and their mares. The effect of the heart rate decrease to twitching was significantly greater in the foals than in the mares. The decreased heart rate in the foals continued during and after the twitching. Changes of the T wave in the A-B lead ECG shown as enhancement of the negative ingredient of the T wave were observed both in the foals and in the mares, accompanied by a decrease in the heart rate during and/or after the twitching. Two out of the five foals showed second-degree A-V block ...
Valentine BA, Ross CE, Bump JL, Eng VM.Intramuscular hemangiosarcoma resulting in severe anemia and thrombocytopenia was diagnosed in a 3-year-old Thoroughbred filly. Necropsy revealed multiple tumors within skeletal muscles and multiple pulmonary metastases.
Lyons ET, Tolliver SC, Drudge JH, Swerczek TW, Crowe MW.From Mar 1, 1984, to Feb 28, 1985, both eyes from 189 one- to four-year-old Thoroughbreds (88 males, 90 females, and 11 geldings) in Kentucky were examined at necropsy for eyeworms. Thelazia lacrymalis was recovered from 45% of 1-year-old horses, 26% of 2-year-old horses, 45% of 3-year-old horses, and 50% of 4-year-old horses; overall, 43% of 1- to 4-year old horses were infected. Prevalence of eyeworms in horses in the present study was comparable with that in horses of similar ages examined at necropsy in Kentucky in 2 previous studies (1975 to 1976 and in 1979), except for the lower percent...
Gregory MW, Longstaff JA, Giles CJ.Ciliates resembling Polymorphella ampulla (Dogiel, 1929) were found in large numbers in the crypts and lamina propria of the caecum and colon of a one-year-old Thoroughbred gelding that had shown recurring bouts of chronic diarrhoea and weight loss over a 5-month period. A heavy burden of helminths, mainly cyathostomes (trichonemes) was present at post-mortem examination and no significant bacterial pathogens were recovered. It was considered that the Polymorphella (which is normally a commensal organism) had in this case assumed a secondary pathogenic role.
Kaminski M, de Andres Cara DF.Genetic variants at eight blood loci were analysed, disclosing in Andalusian breed six rare markers: variants J of transferrin, H of esterase, D and S of Xk, M and W of prealbumin. Two of these, TfJ and PrM appear as characteristic markers of Andalusian breed. Allelic frequencies showed minor differences between Spanish (300 horses) and Lusitanian (100 horses) populations. Comparison was established with historically related breeds, Thoroughbreds or Connemara, and with Arab horses because of a presumed relationship. No visible similarities in genetic profiles were found with two former breeds,...
Kalinskiĭ MI, Kamenetskaia OV, Skorik LG, Tishchenko GN.The paper deals with possibility to regulate in a proper direction the acid-base state in race horse blood administering carbostimulin at rest and under physical exercises. The preparation is shown to favour an increase in alkaline blood reserves in race hours at rest and to prevent acidotic changes caused by physical exercises. The results obtained show a promising use of carbostimulin for the directed correction of the acid-base state of blood in race horses aimed at increasing the efficiency of the training process.
Bowling AT.Preliminary evidence for the fifth autosomal linkage group in the horse, comprised of the loci for a red cell alloantigen (U) and serum protease inhibitor (Pi), was demonstrated by means of paternal half-sib groups in thoroughbred, standardbred and Arabian breeds. Recombination frequency in males was estimated to be 0.125 +/- 0.019.
Holmes JR, Henigan M, Williams RB, Witherington DH.The paper describes five cases of atrial fibrillation detected after racing. In four of them, the arrhythmia disappeared spontaneously within 24 h and they were regarded as paroxysmal in type. In the fifth case, which won its race, the arrhythmia persisted for at least 45 h after racing. It was therefore regarded as an example of persistent atrial fibrillation. It was then treated with quinidine sulphate which restored sinus rhythm. It would seem that paroxysmal atrial fibrillation may be a cause of sudden decrease in racing performance.
Cymbaluk NF, Bristol FM, Christensen DA.Plasma ceruloplasmin activities and plasma Cu and Zn concentrations were determined in 215 clinically normal equids of various ages and breeds. Newborn foals, regardless of breed, were hypocupremic, compared with adolescent and mature horses. The mean plasma Cu concentration of newborn Standardbred-Thoroughbred (STD-TB) foals was 2.9 mumol/L, which was about one-sixth of plasma Cu concentrations of mature horses. Newborn draft-cross foals had higher (4.6 mumol/L) plasma Cu concentrations than did newborn STD-TB foals, but plasma Cu content was only one-fifth of the dams' concentrations. Draft-...
Hodgson DR, Rose RJ, Dimauro J, Allen JR.Biopsy samples were obtained from the middle gluteal muscle of 10 Thoroughbred horses undergoing a commercial race-training program. Samples were obtained before the program began and again after 6 and 12 weeks of training. All horses had raced at least once by the 12th week of training. Serial sections of muscle were examined histochemically for myosin adenosinetriphosphatase after either acid (pH 4.3 and 4.6) or alkaline (pH 10.3) preincubation, and then muscle fibers were identified as types I, IIA, IIB, or IIC. The oxidative capacity of individual fibers was assessed, using the reduced nic...
Meredith D, Elser AH, Wolf B, Soma LR, Donawick WJ, Lazary S.Frequencies of equine leukocyte antigen distribution were determined by complement-mediated cytotoxicity testing among populations of Thoroughbred and Standardbred horses, including animals affected with equine sarcoid and laminitis. A highly significant association is described between the presence or history of sarcoid lesions in Thoroughbreds and the expression of the major histocompatibility complex (MHC)-encoded antigens, W3 and B1. No association was found between antigenic expression frequencies and laminitis in either breed. These findings suggest that a strong relationship exists betw...
De Waal A, Littlejohn A, Potgieter GM, Van der Berg J, Minnaar PI, Smith A.An apparatus was designed to collect four consecutive blood samples from exercising horses. The collection of each sample was controlled by valves activated by radiotelemetry signals transmitted by an observer. Using the device, venous blood samples were collected from ten thoroughbred racehorses before, during and after a 400 m training gallop. Blood glucose increased markedly post-exercise. Both phosphorus and potassium concentrations increased during exercise, decreased post-exercise and recovered to pre-exercise levels within 120 minutes. The system was modified to collect anaerobic sample...
Gelberg HB, Zachary JF, Everitt JI, Jensen RC, Smetzer DL.We reviewed case records, necropsy reports, and histologic sections from 25 Thoroughbred racehorses that died suddenly at 3 Chicago racetracks. These were young horses ranging in age from 2 to 5 years. There were more females (n = 16) than males (n = 9), and the incidence of death increased slightly in the spring and summer. Twenty-one of the 25 horses died while racing or training. Only 8 of the 25 horses (32%) had lesions sufficient to account for the death. In 6 of those 8 cases, death was caused by massive thoracic or abdominal hemorrhage. The site or nature of the vascular defect in these...
Sweeney CR, Beech J, Roby KA.Of tracheobronchial aspirates from 50 clinically healthy Thoroughbred racehorses, 4 (8%) had aerobic bacteria with recognized pathogenicity, 12 (24%) contained transient bacterial isolates, and 37 (74%) had no bacterial growth. Of tracheobronchial aspirates from 36 pastured, nonracing racehorses, 3 (8%) had bacteria with recognized pathogenicity, 23 (64%) contained transient bacteria, and 10 (28%) had no bacterial growth. Anaerobes were not isolated from 12 of 12 pastured horses. Transient bacteria were isolated more often in the pastured horses.
Christensen JM, Blythe LL, Craig AM.Phenylbutazone was administered to six Thoroughbred horses in a cross-over study in which the horses received cimetidine pretreatment or no cimetidine pretreatment. Blood samples were collected at various times for 48 h after phenylbutazone administration and the plasma was analysed for phenylbutazone. Cimetidine pretreatment elevated phenylbutazone plasma concentrations during the first 8 h after phenylbutazone administration. The absorption rate, maximum phenylbutazone plasma concentrations and AUC were significantly greater with cimetidine pretreatment. The half-life of phenylbutazone did n...
Matsui K.Fetal electrocardiogram in a twin pregnancy of a Thoroughbred horse was recorded. Two colts were born alive at 340 days of gestation. One was healthy but the other was growth-retarded. Both fetal heart rates decreased similarly with gestational age, but the discrepancy was noted from 4 days before parturition. The higher heart rate seemed to be obtained from the growth-retarded colt. Maternal heart rate increased gradually with the advancement of gestational period and then increased prominently during the last 2 weeks before parturition.
Dewes HF, Lowe MD.Events leading to the deaths of two fillies at pasture are described. Pasture hay containing the flowering stages of Senecio jacobea (ragwort) had been fed three to four months earlier. Paddocks were subdivided with posts and rails treated with copper chrome arsenate. Six horses on the property chewed rails spasmodically. Both fillies presented with haemoglobinurea. Values in liver of 83 mg Cu kg and kidney 35 mg Cu kg wet weight and serum 1.4 mg Cu/l together with histophathology of seneciosis support a sequence of ragwort poisoning followed by copper accumulation in liver and kidney terminat...
Pascoe JR, McCabe AE, Franti CE, Arthur RM.The repeatability of endoscopic observations of exercise-induced pulmonary hemorrhage (EIPH) and the efficacy of furosemide as a prophylactic treatment of horses with EIPH were studied in Thoroughbred race horses after consecutive breezes (at or near maximum speed, approx 16 m/s). Of 56 horses examined greater than or equal to 2 times, 21 (38%) had identical EIPH scores, whereas 26 (46%) and 9 (16%) had scores that differed by greater than or equal to 1 grade. In 56 nontreated horses, there was good agreement between 2 consecutive observations (K = 0.59, Z = 4.54, P less than 0.001). Similar c...
Clothier J, Hinch G, Brown W, Small A.Clear definitions of 'normal' equine gestation length (GL) are elusive, with GL being subject to a considerable number of internal and external variables that have confounded interpretation and estimation of GL for over 50 years. Consequently, the mean GL of 340 days first established by Rossdale in 1967 for Thoroughbred horses in northern Europe continues to be the benchmark value referenced by veterinarians, breeders and researchers worldwide. Application of a 95% confidence limit to reported GL range values indicates a possible connection between geographic location and GL. Improved kno...
De Auer , Ng JC, Seawright AA.The copper and zinc concentrations in the blood of stabled thoroughbred horses and in Australian Stock Horses mares at pasture, either late pregnant or lactating were determined by an atomic absorption spectroscopic method. The plasma concentration of the trace elements in these apparently normal horses were generally below the "normal" range. The plasma copper, caeruloplasmin copper, whole blood copper and plasma zinc concentrations in the stabled thoroughbreds were 0.76 +/- 0.19 micrograms/ml (n = 82), 0.56 +/- 0.14 micrograms/ml (n = 83), 0.75 +/- 0.18 micrograms/ml (n = 82) and 0.47 +/- 0....
Nath LC, Forbes G, Elliott AD, Tomren V, Ryan A, Franklin SH.AliveCor is a smartphone electrocardiography device (iECG) providing automated heart rate (HR) and rhythm determination. Atrial fibrillation (AF) in horses often is paroxysmal and rapid ECG acquisition is needed for diagnostic confirmation. iECGs were collected post-race from 15 horses with AF and 64 horses in sinus rhythm (SR). Results of manual assessment were compared to 3 commercial algorithms for HR and rhythm. Agreement between manually derived HR (HRM ) and HR derived by the AliveECG Vet (HRVET ) and Kardia version-1 (KV1 HR) and Kardia advanced (KADV HR) algorithms was quantified by th...
Sasaki N, Nishi Y, Fujiwara Y, Takeyama T, Kumagai H, Senarathna S, Ushiya S, Tokuyama T, Tokuyama T, Tokuyama T, Mii T, Ayaki S, Matsuno K....Gastric ulcers cause appetite loss, poor body condition, and colic in horses. This study investigated the protective effect of a rice fermented extract on the gastric mucosa in 17 healthy Thoroughbreds. For one month, horses in the rice fermented extract (nine horses) and control (eight horses) groups were orally administered a rice fermented extract (100%; 0.2 ml/kg, SID) and tap water (0.2 ml/kg), respectively. Gastric endoscopic images were obtained before and one month after rice fermented extract administration. The gastric ulcer score was lower after administration (median, 1; maximum, 2...
Ferrari M, Pfau T, Wilson AM, Weller R.The influence of training on stride parameters is controversial and to date there is no information on how training influences stride parameters during high-speed locomotion in the field. Objective: To determine the influence of training on stride variables during high-speed locomotion in Thoroughbred racehorses. Methods: Speed, stride frequency, stance and protraction times were quantified in 8 Thoroughbreds with foot mounted accelerometers and GPS sensors during their first week of canter after the summer break and 6 months into training. Results: At a speed of 11 m/s, stride frequency was (...
de Mira MC, Ragle CA, Gablehouse KB, Tucker RL.A 3-year-old Thoroughbred mare was evaluated because of abnormal upper respiratory tract sounds (that had become apparent during race training) of 3 to 4 months' duration. Results: On initial physical evaluation, there were no abnormal findings. During trotting, an abnormal upper airway expiratory sound was audible. Endoscopic examination revealed a small mass protruding into the right ventral nasal meatus. Radiographic images of the skull revealed no abnormal findings. Computed tomography of the head revealed an abnormal structure in the same location as the mass that was observed during endo...
Hill EW, Fonseca RG, McGivney BA, Gu J, MacHugh DE, Katz LM.Sequence variation at the equine myostatin gene (MSTN) locus has previously been shown to have a singular genomic influence on optimum race distance in Thoroughbred racehorses. Myostatin, encoded by the MSTN gene, is a member of the TGF-β superfamily that regulates skeletal muscle development in a range of mammalian species including the horse. In the Thoroughbred, the C-allele at the g.66493737C/T SNP has been found at significantly higher frequency in subgroups of the population that are suited to fast, short distance, sprint races and also influences body composition phenotypes. We investi...
Carmalt JL, Wilson DG.To report arthroscopic debridement and lavage of a septic temporomandibular joint (TMJ) in a horse. Methods: Clinical case report. Methods: A 12-year-old Thoroughbred mare. Methods: Arthroscopic investigation of the dorsal joint pouch of the right TMJ was made through a stab incision into the dorsocaudal compartment. Mechanized resection of synovium and fibrinous debris combined with copious lavage, and intra-articular and systemic antibiotic administration was used to treat the septic TMJ. Results: Arthroscopic debridement and lavage of the TMJ, in combination with intra-articular and systemi...
Ousey JC, Kölling M, Kindahl H, Allen WR.The foal requires an active hypothalamo-pituitary-adrenal (HPA) axis for organ maturation and post natal survival. Prenatal administration of synthetic glucocorticoids may provide an effective method for inducing fetal maturation safely in the mare. Objective: To determine whether dexamethasone administered to late pregnant mares: 1) will induce fetal maturation and precocious delivery; 2) is safe to use and 3) to identify endocrine responses in the mare and foal. Methods: Pregnant Thoroughbred mares received either 100 mg dexamethasone i.m. (treated n = 5) or 50 ml saline i.m. (control n = 5)...
Zielińska P, Soroko-Dubrovina M, Dudek K, Ruzhanova-Gospodinova IS.The reason for undertaking this study was to investigate soft tissue response to high-intensity laser therapy (HILT) by measuring changes in skin surface temperature and longissimus dorsi muscle tone in the thoracolumbar back area in Thoroughbreds with back pain and diagnosed with and without Kissing Spines Syndrome (KSS). Thoroughbreds aged 3-4 years with clinically presented back pain underwent a radiological examination (to assess a lack or presence of KSS) and longissimus dorsi muscle palpation (to assess muscle tone and pain degree). The subjects were divided into two groups, those with K...
Dzikiti TB, Bester L, Cilliers I, Carstens A, Stegmann GF, Hubert J.A 10-year-old Thoroughbred mare was presented for lameness of the left hindlimb as a result of an apical fracture of the lateral proximal sesamoid bone. The mare was ultimately euthanased after suffering catastrophic fractures of the 3rd and 4th metatarsal bones of the contra-lateral hindlimb during an uncoordinated attempt to rise during recovery from general anaesthesia after undergoing arthroscopic surgery. The case report focuses mostly on horse anaesthesia-related mortality, anaesthetic procedure in the horse, possible causes of fractures in horses during recovery and ways in which rate o...
Crowley J, Po E, Celi P, Muscatello G.Oxidative stress (OS) is most simply defined as an imbalance between oxidants and antioxidants. Oxidative stress has been suggested to play roles in various equine respiratory diseases and the significance of OS in the pathogenesis of Rhodococcus equi pneumonia is unknown. Objective: To measure and relate biomarkers of OS to lesions consistent with R. equi pneumonia. Methods: Case-control study. Methods: Various OS biomarkers were measured from blood and exhaled breath condensate (EBC) samples collected from 26 foals between 1 and 2 months of age (n = 12 cases and n = 14 controls) on 2 Thoro...
Gee EK, Firth EC, Morel PC, Fennessy PF, Grace ND, Mogg TD.To determine the influence of copper (Cu) supplementation by injection of mares in late gestation on the frequency and severity of osteochondrosis (OC) lesions in their foals at around 160 days of age. To determine if there was any influence of the concentration of Cu in the liver, growth rate, birthweight, weight at 160 days of age, fatness, sex, or year of birth of the foal on the frequency and severity of OC lesions. To determine the influence of dam's age, and sex and birthweight of the foal on the growth rate from birth to 160 days of age, and weight at 160 days of age. Methods: Thirty-th...
Osteochondrosis (OC) develops in growing horses due to disturbed differentiation and maturation of cartilage, particularly at the predilection sites of the fetlock, hock and stifle joints. Horses with osteochondrotic lesions are at a high risk of developing orthopaedic problems later in life. This article briefly reviews the published heritability estimates for OC and offers perspectives for selection in the horse industry. Heritabilities for OC in Warmblood and Standardbred horses have been estimated at 0.1-0.4 in animal threshold models. Whole genome scans using microsatellites have identifi...
Mohammed HO, Cummings JF, Divers TJ, Valentine B, de Lahunta A, Summers B, Farrow BR, Trembicki-Graves K, Mauskopf A.Equine motor neuron disease (EMND), a newly described neurodegenerative disease, bears a striking resemblance to progressive muscular atrophy (PMA) in humans. We present a comparison of the equine and human diseases and the results of a case-control study conducted to identify intrinsic factors associated with EMND. Cases included all horses with a confirmed diagnosis of EMND diagnosed in the United States since 1985 (32 cases). Controls included horses diagnosed with either cervical stenotic myelopathy, equine degenerative myeloencephalopathy, or protozoan myelitis at the Veterinary Teaching ...
Sullivan JJ, Turner PC, Self LC, Gutteridge HB, Bartlett DE.Reproductive efficiency was evaluated for 838 Quarter-horse mare-years on five farms and 939 Thoroughbred mare-years on seven farms over 4 years. The pregnancy rate from first service was 51% for Quarter-horse mares and 43% for Thoroughbred mares (P less than 0-05). The cumulative pregnancy rate after five services was 85% for Quarter-horse and 77% for Thoroughbred mares (P less than 0-05). First-service-period pregnancy rates were 44, 40 and 54% for maiden, barren and foaling mares, respectively. Cumulative pregnancy rates after five service-periods were 84, 74 and 84% for maiden, barren and ...
Bannai H, Takahashi Y, Ohmura H, Ebisuda Y, Mukai K, Kambayashi Y, Nemoto M, Tsujimura K, Ohta M, Raidal S, Padalino B.This study evaluated the effects of 12-hour transportation on immune responses to equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4). Possible replication of EHV-1 and EHV-4 was monitored by real-time PCR of nasal swabs and peripheral blood mononuclear cells (PBMCs), and changes in systemic and mucosal antibodies were investigated. Six healthy Thoroughbreds with transport experience were transported in commercial trucks, repeating the same three-hour route four times. Blood samples for cortisol measurement were taken before departure and every three hours. Nasal swabs, PBMCs, nasal wash and ...
Pagan JD, Hauss AA, Pagan EC, Simons JL, Waldridge BM.To assess the relationship between plasma and RBC fatty acid composition and incidence and severity of squamous gastric ulcers when altered by short-chain (SC) or long-chain (LC) polyunsaturated fatty acid (PUFA) supplementation. 13 fit Thoroughbred horses in training. Horses were evaluated by gastroscopy for squamous ulcer score, gastric pH, and blood fatty acid composition prior to supplementation (UNSUPP) and after 3 months of supplementation with a corn-flax oil blend of alpha-linolenic acid and linoleic acid (SC-PUFA) or a gamma-linolenic acid (GLA)-fish oil blend of GLA, eicosapentaenoic...
Berber N, Gaouar S, Leroy G, Kdidi S, Tabet Aouel N, Saïdi Mehtar N.In this study, genetic analyses of diversity and differentiation were performed on five horse breeds raised in Algeria (Barb, Arab-Barb, Arabian, Thoroughbred and French Trotter). All microsatellite markers were highly polymorphic in all the breeds. A total of 123 alleles from 14 microsatellite loci were detected in 201 horses. The average number of alleles per locus was the highest in the Arab-Barb horses (7.86) and lowest in the thoroughbred breed (5.71), whereas the observed and expected heterozygosities per breed ranged from 0.71 (Thoroughbred) to 0.752 (Barb) and 0.71 (Thoroughbred) to 0....
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...
Kondo T, Sato F, Tsuzuki N, Chen CJ, Yamada K.Computed tomographic myelography can be a useful tool for evaluating vertebral canal stenosis. However, an index of spinal cord compression is yet to be established. This observational descriptive study aimed to establish an index for spinal cord compression using computed tomography (CT). Twenty-three Thoroughbred horses (age, 155-717 days; weight, 205-523 kg) with suspected cervical vertebral malformation were subjected to computed tomographic myelography in dorsal recumbency using large-bore gantry CT to define the entire cervical vertebrae from C1 to C7. Subsequently, the height of the sp...
Knych HK, Weiner D, Steinmetz S, Flynn K, McKemie DS.Hydroxyzine is a first-generation antihistamine and cetirizine, a second-generation antihistamine and active metabolite of hydroxyzine. Hydroxyzine is commonly used in performance horses and as such its use in closely regulated; however, there are no published studies suitable for establishing appropriate regulatory recommendations. In the current study, 12 exercised Thoroughbred research horses received a single oral administration of 500 mg of hydroxyzine. Blood and urine samples were collected prior to and up to 96 hr postdrug administration and concentrations of hydroxyzine and cetirizin...
Yamasaki A, Omura T, Murata D, Kobayashi M, Sunaga T, Kusano K, Ueno Y, Kuramoto T, Hobo S, Misumi K.Synovium-derived mesenchymal stromal cells (SM-MSCs) from seven Thoroughbreds with naturally occurring intra-articular fracture proliferated to over ten million cells by the second passage. Using three experimental Thoroughbreds, columnar osteochondral defects were made arthroscopically at the bilateral distal radius. Five million allogenic SM-MSCs were implanted into the right defect, and another five million were injected into the right radio-carpal joint (implantation site). No SM-MSCs were implanted into the left defect or the same joint (control site). At 3 and 6 weeks after surgery, ten ...
Kane AJ, Stover SM, Gardner IA, Case JT, Johnson BJ, O'Brien MJ, Read DH, Ardans AA.To develop a standard technique for evaluation of racehorse shoes, to assess homotypic variation (interlimb variation) in shoe characteristics, and to determine whether shoe characteristics varied with age and sex. Methods: Cross-sectional study. Methods: Thoroughbred racehorses (n = 201) that died or were euthanatized at California racetracks between August 1992 and July 1994. Methods: Shoe characteristics were measured on horses examined after death. Percentage of agreement was used to compare shoe characteristics between limbs (homotypic variation). Using chi 2 analysis, shoe characteristic...
Rainger JE, Evans DL, Hodgson DR, Rose RJ.The influence of training on blood lactate concentrations during treadmill exercise and a 40-minute inactive recovery period was examined in seven trained and seven detrained thoroughbred horses. Lactate concentrations were measured in venous blood collected at the end of each exercise state, and at intervals for 40 minutes afterwards. Measurements were made of maximum oxygen uptake (VO2max, ml kg-1 min-1), VLA4 (velocity at which blood lactate concentration was 4 mmol litre-1); LA8 (lactate concentration [mmol litre-1] during exercise at 8 m sec-1), peak lactate (highest lactate concentration...
Hoffman AM, Viel L, Juniper E, Prescott JF.Respiratory tract infections are prevalent in foals, yet the frequency with which the distal airways are affected in clinical episodes of respiratory tract disease has not been evaluated to our knowledge. The objective of the study was to determine the incidence of distal respiratory tract infection (DRTI) in foals on a sample of Thoroughbred breeding farms (n = 10) in Ontario. In a pilot study, clinical criteria commonly used to select foals for antimicrobial treatment (detection of abnormal lung sounds, plus nasal discharge, cough, fever, tachypnea, and/or lethargy) were found to segregate f...
Todd ET, Hamilton NA, Velie BD, Thomson PC.Horses produce only one foal from an eleven-month gestation period, making the maintenance of high reproductive rates essential. Genetic bottlenecks and inbreeding can increase the frequency of deleterious variants, resulting in reduced reproductive levels in a population. In this study we examined the influence of inbreeding levels on foaling rate, gestation length and secondary sex ratio in Australian Thoroughbred mares. We also investigated the genetic change in these traits throughout the history of the breed. Phenotypic data were obtained from 27,262 breeding records of Thoroughbred mares...
Nieto JE, Spier S, Pipers FS, Stanley S, Aleman MR, Smith DC, Snyder JR.To compare effects of a commercially available omeprazole paste and a compounded omeprazole suspension on healing of gastric ulcers in Thoroughbred racehorses in active training. Methods: Randomized controlled trial. Methods: 32 horses with gastric ulcers. Methods: Horses were assigned to 2 groups on the basis of endoscopic gastric ulcer severity. Group-1 horses were treated with omeprazole suspension for 30 days and with omeprazole paste for an additional 30 days. Group-2 horses were treated with omeprazole paste for 30 days and omeprazole suspension for an additional 30 days. Serum omeprazol...
Beste KJ, Ortved KF, Rossignol F, Ducharme NG.To describe the use of a silicone-covered laser guide and diode laser for surgical correction of epiglottic entrapment and report postoperative outcomes in horses with epiglottic entrapment. Methods: Retrospective case series. Methods: Thoroughbred and standardbred racehorses (n = 29) with epiglottic entrapment. Methods: A silicone-covered laser guide was placed endoscopically to direct the diode laser cutting action during transection of the entrapping subepiglottic membrane and to act as a physical barrier between the membrane and the epiglottic cartilage. Postoperative complications and tra...
Warner A, Mayhew IG.Anhidrosis is loss of the ability to sweat. The problem is seen in horses kept in a hot humid climate, and it may cause severe impairment of thermoregulation in the equine athlete. British Thoroughbreds imported to her tropical colonies are the earliest recorded cases, and since then the syndrome has come to be described as one of Thoroughbreds, usually performance athletes, undergoing acclimatization to heat and humidity. A recent epidemiologic study of cases in Florida has shown, however, that many different breeds, and long time inhabitants of a hot climate, may be affected. Equine sweat gl...
