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.
Blackmore DJ, Campbell C, Dant C, Holden JE, Kent JE.The activity of glutathione peroxidase (GSH-Px) was measured in the erythrocytes of 600 Thoroughbred horses in training; the selenium concentrations in whole blood and serum was measured in over 80 of these Thoroughbreds. A quadratic relationship was demonstrated between erythrocyte GSH-Px and whole blood or serum selenium concentration. There was no significant difference in the activity of aspartate aminotransferase, creatine kinase, or gamma-glutamyl transferase in the serum of Thoroughbreds with high erythrocyte GSH-Px activity (more than 25 u/ml) when compared with those with low erythroc...
Nimmo MA, Snow DH.To ascertain the effects of sprint and endurance exercise on the time course of skeletal muscle mitochondrial changes, an ultrastructural study was conducted on four Thoroughbred horses. Skeletal muscle biopsies were taken at various intervals during and after the exercise. Transient mitochondrial alterations of varying degrees were observed following both types of exercise and were considered to be related to the development of fatigue. The degree of distortion of mitochondrial structure is considered not to represent the in vivo condition but the state of responsiveness to the fixation mediu...
Osterhoff DR, le Grange L, Robinson M.Genetically controlled markers are ideal for the identification of individual animals, and throughout the world laboratories have been established whose chief function is to provide a blood-typing service for animals including horses. In order to achieve the aim of improved recording of foals almost all South African sires at stud were tested and their blood type identification completed. The genetic markers included in this survey were 14 blood group factors, transferrin, plasma esterase, haemoglobin, carbonic anhydrase, 6-phosphogluconate dehydrogenase, phosphoglucomutase and phosphohexose i...
Roberts MC, Kelly WR.A four-year-old thoroughbred was presented with clinical manifestations of purpura haemorrhagica. Evidence of renal involvement consistent with glomerulopathy and nephrotic syndrome, characterised by heavy proteinuria and azotaemia, became apparent and may have been exacerbated by diuretic therapy. Autopsy revealed membrano- and mesangial proliferative glomerulonephritis and chronic pleuritis. Circulating immune complexes may have been responsible for the renal diseases and the purpura.
Hanák J, Zert Z.The ECG characters were studied in two sires (Manrico and Infernal) and their 26-membered set of progeny as well as in one mare (Victoire) and her five daughters. The confer of some ECG characters from the sire's side as well as from the mare's side to the offspring was demonstrated. The consistency of some ECG characters was particularly obvious in externally dominant Manrico sire and his offspring as well as in the breeding mare and her five daughters (inclination of the electric cardiac axis, intrinsicoid deflexion lag, P wave shape, deep S in the 3rd connection).
Kovár J.The possibility of using the test for pulse-rate response to gradated load in the evaluation of the endurance component of horse performance (in other words, response to the degree of horse adaptation to load) is discussed in detail. A mathematic-statistical analysis of regression coefficients is performed in the equations of the dependence of pulse rate on speed obtained in 278 three years old horses in the period following the termination of the basic training (145 Bohemian Warm-Blooded horses, 115 Kladrub Black horses and 18 English Half-Breds). A ten-score scale is calculated on the basis ...
Burns PJ, Jawad MJ, Edmundson A, Cahill C, Boucher JK, Wilson EA, Douglas RH.Stallions on two Central Kentucky farms (9/farm) were studied during the 1980 breeding season. On one farm stallions were exposed to an increased photoperiod (16 h light/day) from 1 December 1979; on the second farm the stallions were maintained in an ambient photoperiod. On the basis of matings per conception (total mating/mares in foal) stallions on each farm were assigned to a high fertility (1 . 9-2 . 4 matings per conception, N = 4) or low fertility (2 . 6-5 . 6 matings per conception, N = 5) group. Exposure of stallions to increased photoperiod significantly increased serum concentration...
Rose RJ, Rossdale PD, Leadon DP.Six spontaneously delivered foals, 8 Thoroughbred foals induced at term with fluprostenol and 17 Pony foals induced prematurely with fluprostenol and oxytocin at a gestational age of 270 to 330 days were studied to determine PO2, PCO2, pH, base excess and HCO3 values in arterial blood between birth and 7 days of age. The Pony foals were subdivided into those that survived greater than 24 h (N = 9) and less than 9 h (N = 8). Blood gas and acid base values in the term-induced foals were similar to those in spontaneously delivered foals. The induced premature foals surviving greater than 24 h had...
Simpson DJ, Greenwood RE, Ricketts SW, Rossdale PD, Sanderson M, Allen WR.In 1981 a trial was conducted on 6 Newmarket Thoroughbred stud farms into the use of real-time ultrasound echography (scanning) as an aid to the early diagnosis of pregnancy in the mare. The procedure was found to be practicable and interpretation of the findings was relatively straightforward. Pregnancy was positively diagnosed from as early as 14 days after ovulation and a number of twin pregnancies were recognized, some in which the conceptuses were situated in separate horns of the uterus but an almost equal number in which the conceptuses were together in the same horn. It was concluded t...
Pascoe PJ.A 16 year old Thoroughbred mare was presented to the Ontario Veterinary College because of an acute episode of colic. An exploratory laparotomy was performed and a neurofibroma was identified and successfully removed from the small colon. The clinical and pathological features of this case are discussed.
Jeffcott LB, Kold SE.The clinical and radiological characteristics of stifle lameness in 86 horses are described. The majority of these cases had been lame for some weeks before referral. The most frequent diagnoses made were osteochondrosis dissecans (13 per cent) and subchondral bone cyst (38 per cent). Both of these conditions were seen principally in Thoroughbreds at or before the onset of training. The other bone lesions encountered were osteoarthritis (3 per cent), fractures (4 per cent) and "epiphysitis" (1 per cent). The commonest soft tissue condition was an atypical or partial upward fixation of the pate...
Medeiros LF, Medeiros LO, Berciano Sanjurjo MA.1. The metabolism in the erythrocytes of thoroughbred horses in a sequential study from umbilical cord to the 1st month was investigated. 2. Emphasis was put on hemolytic period at which: (a). PFK, GSH-Px and GSH play a significant role. (b). There is a lower glucose consumption determined by a decreased activity in several enzymatic steps. (c). Singularly high concentrations of 2-3DPG and ATP were detected. 3. It has been suggested that the metabolic adjustments were achieved by an increased activity of the hexose monophosphate shunt, G-3PD and AK.
Lindsay WA, McMartin RB, McClure JR.Five cases of fracture of the third tarsal bone in racehorses are reported. A method of surgical correction employing a cortical bone screw is described in 2 cases. Healing of the fractures was followed radiographically. Surgical repair permitted both horses to return to competition. The 3 cases treated conservatively suffered a prolonged healing time and excessive new bone formation. They were unable to return to training due to persistent lameness.
van Niekerk CH, Morgenthal JC.The depressing effect on plasma progestagen levels of pregnant mares subjected to specific stressful conditions such as severe pain, infectious diseases, emotional disturbances and exogenous corticosteroids are described. It is concluded that the detrimental effect of stress, evident from its negative influence on plasma progestagen concentrations, could play a major role in the occurrence of pregnancy failure in the Thoroughbred mare.
Jeffcott LB, Kold SE.Thirty-three cases with subchondral bone cysts in the stifle are reported. The condition was most commonly seen in young Thoroughbreds and produced intermittent lameness of varying degree. Radiographically distinct areas of radiolucency were found in the distal femur or proximal tibia adjacent to the femorotibial joint. Lesions were usually unilateral but 5 horses had cysts in both stifles. The cases could be divided into 2 distinct groups. Horses in Group A (28 cases) had a large circular or dome-shaped cyst in the medial femoral condyle with a distinct communication with the femorotibial joi...
Parry BW, McCarthy MA, Anderson GA, Gay CC.The influence of occlusive bladder width on blood pressure, measured indirectly using a doppler ultrasound technique at the middle coccygeal artery, was studied in 6 anesthetized horses. The relationship was investigated on tails with and without hair, and the optimum bladder width (BW)/tail girth (TG) ratio was determined for systolic pressure (SP) and diastolic pressure (DP), with the data grouped as unclipped tails (TT-1), clipped tails (TT-2), and both unclipped and clipped tails collectively (TTB). The optimum BW/TG ratios for SP and DP were 0.296 and 0.866 for TT-1, 0.376 and 1.156 for T...
Fowden AL, Ellis L, Rossdale PD.Plasma concentrations of insulin and glucose were measured in Pony and Thoroughbred foals at birth and at intervals thereafter for up to 7 days. The plasma concentrations of insulin in foals of both breeds at birth were 11.2 +/- 2.5 microU/ml (N = 6) and 13.5 +/- 1.5 microU/ml (N = 16) respectively. These values were similar to those obtained for foals in utero but were significantly less than those in adult animals. There was little variation in the plasma concentrations of insulin and glucose during the first 2 h of life and both concentrations tended to rise in the next 24-48 h. Although th...
Pascoe RR.A total of 2187 Thoroughbred and Standardbred mares was examined over a 4-year period to determine the location of the fetus at 42 days, the location of the previous fetus as determined by examination 5-15 days after foaling, and pregnancy location the next season. Maiden mares showed 44 and 56% of pregnancies in the left and right horns respectively. No transuterine migration was observed in 139 maiden mares examined after their first foal. Lactating mares showed 62% implantations and full-term pregnancies on one side of the uterus with the next season's pregnancy being in the opposite uterin...
Ott EA, Asquith RL, Feaster JP.Forty-six Thoroughbred and Quarter Horse yearlings were used in two experiments designed to determine the amount of lysine in the concentrate necessary to promote maximum growth when fed the Coastal bermudagrass (Cynodon dactylon) hay provided at 1% body weight (BW)/day. In the first experiment, a 196-day trial, supplemental protein sources and analyses of the concentrates compared were: (1) soybean meal (SBM; 15.4% crude protein, .70% lysine); (2) SBM + .2% lysine (15.7% crude protein, .81% lysine), and (3) brewers dried grains + .2% lysine (15.9% crude protein, .59% lysine). Concentrate inta...
Waldron-Mease E, Klein LV, Rosenberg H, Leitch M.Malignant hyperthermia developed in a 4-year-old Thoroughbred horse following 3 hours and 15 minutes of halothane anesthesia, with supplementary succinylcholine. Clinical signs included fever, sweating, hyperventilation, tachycardia, and decreased blood pressure followed by a rapid increase in blood pressure. Biochemical aberrations included hypocalcemia, hyperkalemia, hyperphosphatemia, myoglobinuria, and high creatine phosphokinase and ornithine carbamyl transferase activities. Treatment consisted initially of surface cooling with cold water, alcohol and ice, IV administration of cooled bala...
George LW, Tanner ML, Roberson EL, Burke TM.A 6-year-old Thoroughbred gelding was examined because of respiratory disease that developed after it was placed on pasture occupied by a donkey. Clinical signs in the gelding included a harsh, dry paroxysmal cough and increased expiratory effort. Eosinophils were seen in smears of mucus aspirated from the trachea and the bronchi. Immature, 5th-stage Dictyocaulus arnfieldi was identified in the tracheal mucus. The cough and other clinical signs were not diminished by corticosteroid therapy or by the administration of bronchodilators. Treatment with 10-fold therapeutic dosages of thiabendazole ...
Lyons ET, Drudge JH, Swerczek TW, Crowe MW, Tolliver SC.At necropsy of 49 Thoroughbreds from farms with generally good parasite control programs in central Kentucky, examination was specifically made for presence of Strongylus vulgaris in all of the horses and of Parascaris equorum in 21 of them. None of the deaths of the horses was caused by infections of internal parasites. Visceral arteries were examined for specimens of S vulgaris and lesions related to migrating stages of this parasite. Contents of the small intestines were examined for P equorum. Specimens of S vulgaris were recovered from 19 (39%) horses, and arterial lesions were observed i...
Lindsay WA, Horney FD.During a 6-year period, carpal arthrotomies were performed on 89 horses with carpal fractures. Fifty-two percent of the fractures involved the left forelimb; the 3rd carpal bone was most often involved (42%), followed by the radial carpal bone (30%). The effect of surgery on the performance of a subgroup of 48 thoroughbreds was evaluated by comparing the number of starts, level of racing (claiming value), and earnings for the 12 months of racing preceding and following arthrotomy. The data indicated that carpal arthrotomy in the Thoroughbred carries with it a favorable prognosis inasmuch as 80...
Haynes PF.Persistent dorsal displacement of the soft palate was diagnosed in 2 Thoroughbred horses examined because of decreased exercise tolerance and a respiratory noise during strenuous exercise. The persistent dorsal displacement of the soft palate was caused by an epiglottis that was approximately 2/3 normal size, and thus was incapable of maintaining the soft palate in a normal subepiglottic position. Contrast pharyngography suggested a primary epiglottic abnormality. Visual assessment of the lesion was accomplished by exploratory ventral laryngotomy and endoscopy of the oropharynx per os. Surgica...
Dhar AK, Thompson MS, Paradis MR, Alcivar-Warren A.To determine the complementary DNA (cDNA) sequence of interleukin-1 receptor antagonist (IL-1ra) in horses and compare messenger RNA (mRNA) expression of IL-1ra among horses of various breeds. Methods: Blood samples from neonatal and adult horses examined for a variety of diseases. Methods: A polymerase chain reaction procedure was used to amplify a 220 base pair (bp) portion of the genomic DNA. The upstream and downstream regions of the cDNA sequence were determined by means of 5' and 3' rapid amplification of cDNA ends (RACE) procedures. Northern blot hybridization was used to examine steady...
Whisenant KD, Ruggles AJ, Stefanovski D, Woodie JB, Hopper SA, Embertson RM.Haematogenous septic arthritis is a major cause of morbidity and mortality in foals. Previous research has demonstrated a variable prognosis for athletic performance in foals diagnosed with septic arthritis. Objective: To determine the racing prognosis for Thoroughbred foals, 6 months of age or less with single septic joint of presumed haematogenous origin without recognised systemic sepsis or other serious comorbidity compared with a group of maternal sibling controls. Methods: Retrospective cohort study. Methods: Data were collected from Rood and Riddle Equine Hospital in-patient records fro...
Within the veterinary world, data regarding the surgical management of hypospadias is lacking. Reports within equines have documented resective phallectomy procedures rather than urethral reconstruction. This case report documents the first ever urethroplasty for an equine hypospadias, performed by a consultant paediatric surgeon. The urethroplasty was achieved by applying the same surgical principles mastered from paediatric urology to a horse. The indication for surgery was contact dermatitis of the hind-leg, which impaired the thoroughbred foal's racing potential. Methods: A single stage ur...
Muñoz L, Sepúlveda-Calderón P, Villaguala-Pacheco C, Aqueveque CL.The aim of this research was to assess the copro-prevalence of Fasciola hepatica in owned Chilean breed horses (Equus caballus) residing in the province of Concepción, Chile. The study was carried out throughout October 2017. Samples were taken from all (100%) Chilean breed horse (124 specimens; 45 females and 79 males, aged between 7 months and 24 years old) from the Concepción province. A rectal stool sample was obtained from each animal. This was analyzed using the Army Medical School method (AMS III) technique to detect F. hepatica eggs. Information about the horse's age, sex, previous f...
Galuppo LD, Simpson EL, Greenman SL, Dowd JP, Ferraro GL, Meagher DM.To report clinical evaluation of headless compression screws for repair of metacarpal/metatarsal (MC/MT3) condylar fractures in horses. Methods: Retrospective case study. Methods: Racing Thoroughbreds (n=16) with nondisplaced lateral condylar fractures of MC/MT 3. Methods: Medical records (1999-2004) of horses with nondisplaced longitudinal fractures of the lateral condyle of MC/MT3 were reviewed. Pre-operative variables retrieved were: patient age, gender, limb involvement, injury occurrence, fracture length, and width, evidence of palmar comminution and degenerative joint disease, number of ...
Matsumura T, Mashiko R, Sato T, Itokawa K, Maekawa Y, Ogawa K, Isawa H, Yamamoto A, Mori S, Horita A, Ginnaga A, Miyatsu Y, Takahashi M, Taki H....The redback spider (Latrodectus hasseltii Thorell) reportedly invaded Japan in September 1995. To date, 84 redback spider bite cases have been reported; 7 of these cases employed the antivenom. Antivenom has been imported from Australia in the past, but because of restrictions on exportation it was evident that nearly all of the antivenom present in Japan would expire during 2014. In 2014, a plan was proposed to experimentally manufacture and stockpile a horse antiserum for ourselves, using redback spiders indigenous to Japan. A total of 11,403 female spiders were captured alive: 1,217 from th...
Ziadi A, Ozmaie S, Asghari A, Rajaei SM.This study aims to assess the effect of topical 0.5% apraclonidine on Intraocular pressure (IOP) in horses and compare the effects of timolol maleate 0.5% with 0.5% apraclonidine in the equine eye. Twenty healthy female thoroughbred horses were used. Horses were divided into two groups. Ten horses received single dose of 0.2 mL of 0.5% apraclonidine in one randomly selected eye and the contralateral eye received single dose of 0.2 mL of artificial tears. In the second group, 10 horses received single dose of 0.2 mL of 0.5% timolol maleate in one eye and the opposite eye received single dose of...
Knych HK, Stanley SD, Benson D, Arthur RM.Guaifenesin is an expectorant commonly used in performance horses to aid in the clearance of mucus from the airways. Guaifenesin is also a centrally acting skeletal muscle relaxant and as such is a prohibited drug with withdrawal necessary prior to competition. To the authors' knowledge, there are no reports in the literature describing single or multiple oral administrations of guaifenesin in the horse to determine a regulatory threshold and related withdrawal time. Therefore, the objective of the current study was to describe the pharmacokinetics of guaifenesin following oral administration ...
Pemberton AD, John HA, Ricketts SW, Rossdale PD, Scott AM.Failure to inhibit proteinases can lead to excessive tissue damage. The possibility that the severity of endometritis in Thoroughbred mares correlates with the haplotypes of plasma alpha 1-proteinase inhibitor (alpha 1-PI) expressed was investigated in two groups of mares. In mares with pyometritis before treatment, the frequency of the N haplotype, which is already high in the Thoroughbred population, was significantly increased when compared with that in a large published population. In mares with acute endometritis which persisted after treatment followed by sexual rest, the absence of S an...
Hudson BJ, Chicken C, Blishen A, Todhunter KH, Begg AP, Chan L, Karagiannis T, Raymond B, Bogema D, Adkins AR, O'Sullivan CB, O'Rourke BA....We describe three cases of osteoarticular infection (OAI) in young thoroughbred horses in which the causative organism was identified by MALDI-TOF as . The pattern of OAI resembled that reported with infection in humans. Analysis by 16S rRNA PCR enabled construction of a phylogenetic tree that placed the isolates closer to and , rather than . Average nucleotide identity (ANI) comparison between the new isolate and and however revealed low probability that the new isolate belonged to either of these species. This preliminary analysis suggests the organism isolated is a previously unrecognis...
Uboh CE, Soma LR, Rudy JA, Morgan E, Mengeringhausen K, Sams R.This study was undertaken to determine the applicability of plasma concentration of furosemide and specific gravity (SG) of urine in regulating the use of furosemide administered 4 hours prior to race time in Exercise-Induced Pulmonary Hemorrhage (EIPH) race horses. Nonbleeders (CTL) and certified bleeders (FUR) actively racing in Illinois (IL) and Pennsylvania (PA) were used in the study. Various doses (less than 250, 250, 300, 350, 400 and 500 mg) were administered either as a single intravenous (IV) dose or as a combination (IV-IM) of IV and intramuscular (IM) administrations 4 hours before...
Henderson B, Bramlage LR, Koenig J, Monteith G.To assess the influence of humeral stress fracture location on the time to return to racing and postinjury performance of thoroughbred racehorses. Methods: Retrospective study (1992-2015). Methods: Thoroughbred racehorses (n = 131) that presented for lameness with the sole diagnosis of humeral stress fractures in the lame limb, as determined by scintigraphy or radiology. Methods: Sex, fracture site, age, starts, earnings, and average earnings per race were examined for differences in pre-stress and post-stress fracture diagnosis for the entire population as well as individual stress fracture l...
Wickens C, Arias Esquivel AM, Hendricks C, Heleski C.Several studies have indicated higher incidence of stereotypic behaviors (STBs) in Thoroughbreds. The aftercare of Off-the-Track Thoroughbreds (OTTBs) has received increased attention in the last decade; however, research on the impact of STBs on placement of OTTBs after their racing career is limited. Thoroughbred Aftercare Alliance (TAA) accredits centers throughout North America that work to rehome OTTBs in a safe, welfare-friendly manner. Although the authors have suspected that having an STB would make OTTBs more challenging to rehome, this hypothesis remains to be empirically tested. The...
Brown-Douglas CG, Firth EC, Parkinson TJ, Fennessy PF.To determine the responsiveness of the pituitary-gonadal axis of peri-pubertal colts to GnRH, buserelin (0.5, 1, 5, 10 and 40 microg) was given to 13 male Thoroughbred yearlings ( n=3-8 colts per dose). Jugular venous blood samples were taken at -10, 0, 10, 20, 30, 40, 60, 120 and 180 min relative to buserelin administration. Increases (P < 0.05) in LH concentrations occurred in colts that received 5, 10, or 40 microg buserelin, but not in those that received 0.5 or 1 microg. Peak LH concentrations and mean area under the curve were higher (P < 0.05) in colts receiving 40 microg busereli...
Shibahara T, Kuwano A, Ueno T, Anzai T, Kuwamoto Y, Sato H, Maeda T, Ishikawa Y, Kadota K.A 21-month-old Thoroughbred colt showed continuous diarrhea and developmental retardation for 7 months, and was thereafter subjected to euthanasia for necropsy and laboratory examinations. At necropsy, the cecal and colonic mucosae were diffusely rough and hyperemic. Histopathologically, the mucosa and submucosa were edematous and were infiltrated by numerous lymphocytes and macrophages. Meanwhile, three morphological types of Brachyspira antigen-containing spirochetes were found to be numerous in the crypts and in the mucus layer over the epithelium in the cecal and colonic lesions. They were...
Kuroda T, Minamijima Y, Niwa H, Mita H, Tamura N, Fukuda K, Kuwano A, Sato F.Cephalothin (CET) concentrations in body fluids (plasma, synovial fluid, pleural fluid, peritoneal fluid, and aqueous humor) and tissue samples (bone, lung, jejunum, hoof, and subcutaneous tissue) were investigated to consider the treatment of infectious diseases in horses. CET 22 mg/kg body weight was intravenously administered to 12 horses. Samples were collected from four different horses at 1, 3, and 5 hr after administration. The CET concentration in body fluids other than aqueous humor was maintained above the MIC90 values of Streptococcus zooepidemicus and Staphylococcus aureus until 5 ...
Pick M.Intensive strain of racing-horses during training and race is not an end in itself but should be understood from the social task to create exceptionally efficient horses. This roughness in sports obliges the responsible associations to issue rigorous regulations for the protection of horses. In this paper, some physical and psychical disorders of racing-horses are described. Improved keeping conditions as well as performance-adapted training methods will help to avoid defects. The aids being used during training and races are critically investigated on their effects according to the regulation...
Ohmuro K, Okada K, Satoh A, Murakami K, Satake S, Asahina M, Numakunai S, Ohshima K.A thoroughbred horse, gelding, gray color, aged 19 years old had cutaneous melanomas from the root to the middle of the tail, and throughout the connective tissues of the whole body. Histologically, the tumors were diagnosed as mature melanotic melanomas characteristically deposited with abundant melanin pigment. Examined with an electron microscope, melanosomes were electron opaque without internal structure (stage IV), or as mature granular and lamellar types. Most of them were fused with each other, and formed compound melanosomes, which was similar to internal melanin aggregates in shape. ...
Campos Schweitzer A, Mespoulhès-Rivière C, Möller D, Ducharme N, Genton M, Farfan M, Rossignol F.Selective laryngeal reinnervation using the first and second cervical nerve (C1C2) is a treatment option for recurrent laryngeal neuropathy that aims to restore the function of the cricoarytenoideus dorsalis (CAD) muscle. Despite the technique's satisfying success rate, it has several limitations. These triggered the search for another potential donor nerve that could reduce CAD muscle fatigue and shorten rehabilitation. The ventral branch of the spinal accessory nerve, providing motor innervation to the sternomandibularis (SM) muscle, was identified as a potentially well-adapted nerve. Object...
Soma LR, Uboh CE, Guan F, Moate P, Luo Y, Teleis D, Li R, Birks EK, Rudy JA, Tsang DS.The pharmacokinetics of clenbuterol (CLB) following a single intravenous (i.v.) and oral (p.o.) administration twice daily for 7 days were investigated in thoroughbred horses. The plasma concentrations of CLB following i.v. administration declined mono-exponentially with a median elimination half-life (t(1/2k)) of 9.2 h, area under the time-concentration curve (AUC) of 12.4 ng.h/mL, and a zero-time concentration of 1.04 ng/mL. Volume of distribution (V(d)) was 1616.0 mL/kg and plasma clearance (Cl) was 120.0 mL/h/kg. The terminal portion of the plasma curve following multiple p.o. administrati...
Soroko-Dubrovina M, Górniak W, Zielińska P, Górniak A, Čebulj-Kadunc N, Korczyński M.The aim of this study was to evaluate the effect of shiitake mushroom () supplementation on the hematology and biochemical blood parameters of young Thoroughbred racehorses. The study was conducted with 20 horses divided into two groups: the supplemented and the control group. The supplemented group was given 30 g of daily for four months. One blood sample was collected four times from each horse at four-week intervals. The hematology analysis in the supplemented group showed a higher level of monocytes at day 56 when compared to the control group ( = 0.000986). Biochemical analysis showed th...
Walmsley EA, Jackson M, Wells-Smith L, Whitton RC.Subchondral bone injury at the palmar/plantar aspect of the condyles of the third metacarpal/metatarsal bone (MC/MT3) commonly causes lameness and poor performance in racehorses. Injury occurs due to repetitive loading, the magnitude of which may be influenced by the position of the distal phalanx relative to the ground surface, i.e. the solar angle. The association of solar angle and injury at the palmar/plantar condyles of distal MC/MT3 therefore warrants investigation. Objective: Investigate the relationship between solar angle and radiopharmaceutical uptake at the palmar/plantar aspect of ...
Furness JB, Poole DP.The functioning of the gastrointestinal tract is under the control of the most extensive system of peripheral neurons in the body, the enteric nervous system, and the largest endocrine system of the body, the GEP endocrine system. The enteric nervous system in large mammals contains 500 million neurons, and the GEP endocrine system produces more than 30 hormones. Numerous enteric neuropathies affecting both humans and animals have been described and digestive disorders affect commercially important species, such as horses and cattle. The most severe enteric neuropathies (e.g., lethal white syn...
Gürelli G, Lyons ET, Kesbiç FI.Species composition and distribution of hindgut ciliates were investigated in the feces of 20 thoroughbred mares in Kentucky, USA. Thirty-three species and six morphotypes belonging to 21 genera were identified. The average density of hindgut ciliates in mares was 13.5 ± 13.7 × 104 cells ml-1, whereas mean number of ciliate species per host was 14.4 ± 5.3. Bundleia nana, B. elongata, B. piriformis, Blepharoconus hemiciliatus, Holophryoides ovalis, H. macrotricha, Blepharoprosthium polytrichum, Prorodonopsis coli, Paraisotrichopsis composita, Blepharocorys microcorys, and Ochoterenaia append...
Schweizer C, Ramseyer A, Gerber V, Christen G, Burger D, Wohlfender FD.Racetrack injuries are of welfare concern and the prevention of injuries is an important goal in many racing jurisdictions. Over the years this has led to more detailed recording of clinical events on racecourses. However, risk factor analyses of clinical events at race meetings have not been previously reported for Switzerland. Objective: To identify discipline-specific factors that influence the occurrence of clinical events during race meetings with the ultimate aim of improving the monitoring and safety of racetracks in Switzerland and optimising racehorse welfare. Methods: Retrospective s...
Grubb TL, Constable PD, Benson GJ, Foreman JH, Olson WO, Thurmon JC, Tranquilli WJ, Davis LE.To determine the most repeatable method for evaluating right ventricular relaxation rate in horses and to determine and compare effects of isoflurane or halothane with and without the added influence of intravenously administered calcium gluconate on right ventricular relaxation rates in horses. Methods: 6 Thoroughbred horses from 2 to 4 years old. Methods: 6 models (2 for monoexponential decay with zero asymptote, 3 for monoexponential decay with variable asymptote, and 1 for biexponential decay) for determining right ventricular relaxation rate were assessed in conscious and anesthetized hor...
Melly V, Ortved KF, Manzi TJ, Richardson DW, Stefanovski D, Wulster KB.Increasing accessibility and advancements in computed tomographic (CT) imaging improve understanding of the contributors to poor performance in the Thoroughbred racehorse. Objective: To characterise an unreported site of tarsal subchondral bone injury (SBI) in Thoroughbred racehorses. Methods: Retrospective, cross-sectional analytical study. Methods: Tarsal CT scans of 108 horses were reviewed for evidence of SBI in the dorsodistolateral calcaneus (DDLC). Signalment, including age, breed, sex, and discipline of horses, was recorded. The association of DDLC SBI with Thoroughbred racehorse compa...
van Weeren PR, Denoix JM.Juvenile osteochondral conditions (JOCC) have a major impact on the equine industry and include many musculoskeletal disorders of the young horse, of which osteochondrosis (OC) is the most prominent. The Breeding, Osteochondral Status and Athletic Career (BOSAC) project is the first large, comprehensive, longitudinal field study on the subject conducted in three breeds of performance horses (Thoroughbreds, Standardbred Trotters and Warmbloods) that were monitored in their natural environment where they were reared under common field conditions. The BOSAC study used a radiographic protocol desi...
Lizarraga I, Panizzi L, Gieseg MA, Riley CB, Chambers JP.To evaluate thermal nociceptive thresholds (TNTs) before and after inducing a standardized radiocarpal bone osteochondral fracture (OCF) in horses. Methods: Prospective, controlled, randomized, masked study. Methods: A group of 10 Thoroughbred fillies aged 2 years. Methods: Skin temperature and TNTs were measured on the skin over the triceps brachii muscle in both the thoracic limbs before (week 0) and weekly (weeks 1-8) after unilateral arthroscopic induction of a radiocarpal OCF (n = 4) or sham surgery (n = 6) followed by a standardized exercise programme. The contralateral, non-operated t...
Soma LR, Uboh CE, You Y, Guan F, McDonnell S.Pennsylvania (PA) State Racing Commissions regulate the endogenous androgenic steroid, testosterone (TES), in racing intact males (RIM) by quantification of TES in post-race samples. Post-race plasma samples (2209) collected between March 2008 and November 2010 were analyzed for TES, nandrolone (NAN), and other anabolic steroids (ABS). Of the 2209 plasma samples, 2098 had quantifiable TES ≥ 25 pg/mL. Plasma (mean ± SD) concentrations of TES and NAN in RIM were 329.2 ± 266.4 and 96.0 ± 67.8 pg/mL, respectively. Only 64.6% of RIM had quantifiable concentration of NAN, and there was no relat...
