Standardbred horses are a breed known for their performance in harness racing, characterized by their ability to trot or pace at high speeds. This breed is distinguished by its well-muscled build, strong legs, and calm temperament. Standardbreds are primarily used in racing but are also versatile in other equestrian activities, including riding and driving. Their genetic lineage can be traced back to the late 18th century, with the establishment of the breed registry in the United States. This page compiles peer-reviewed research studies and scholarly articles that explore the genetics, physiology, and performance characteristics of Standardbred horses, as well as their management and health considerations in various equine disciplines.
Doll CU, Bohner M, Berner D, Buettner K, Horstmeier C, Winter K, Burk J.Low-field magnetic resonance imaging (MRI) has gained increasing importance to monitor equine tendon lesions. Comparing results between studies and cases is hampered, because image analysis approaches vary strongly. This study aimed to improve reliability, comparability and time efficiency of quantitative MRI image analysis. Unassigned: Induced tendon lesions were studied over a 24-week period with 10 follow-up MRI examinations. Signal intensities (SIs) of tendons, tendon lesions, cortical bone and background, as well as lesion cross-sectional areas (CSAs) were measured. Lesion SI standardisat...
Roxon C, Slack J, Bender S, Burns H, Turner R.A 12-year-old Standardbred stallion presented with a 5-month history of a growing mass in the left testis as well as an overall decrease in left testicular size. Palpation and ultrasonography of the left testis revealed a firm, hypoechoic, clearly delineated soft tissue mass in the craniolateral portion of the testis that measured 2.5 × 2.3 × 1.9 cm. Two smaller, hypoechoic regions also were visible ultrasonographically in the left testis, suggesting the presence of multifocal/multicentric neoplasia. The affected testis was very small (testicular volume of 40.3 cm). The right testis was ...
Bertuglia A, Pallante M, Pillon G, Valle D, Pagliara E, Riccio B.This case series describes an alternative surgical technique to obtain reattachment of osteochondritis dissecans (OCD) lesions in the lateral trochlear ridge of the femur (LTRF) as well as the clinical and radiological outcome of treated cases. Four Standardbred yearlings (6 lesions in total) underwent surgical fixation of large OCD defects in the LTRF under arthroscopic guidance. Reattachment of the OCD lesions was obtained using 3.0/3.7 mm headless bio-compression and absorbable poly-l-lactic acid (PLLA) screws, inserted perpendicularly to the cartilage surface through the lesion. All horse...
Timmerman I, Macaire C, Hanne-Poujade S, Bertoni L, Martin P, Marin F, Chateau H.Repeatability and reproducibility of any measuring system must be evaluated to assess possible limitations for its use. The objective of this study was to establish the repeatability and the inter-operator reproducibility of a sensors-based system (EQUISYM®) for quantifying gait asymmetries in horses.. Seven wireless IMUs were placed on the head, the withers, the pelvis, and the 4 cannon bones on three horses, by four different operators, four times on each horse, which led to a total of 48 repetitions randomly assigned. Data were collected along three consecutive days and analysed to calcula...
Lo Feudo CM, Stucchi L, Conturba B, Stancari G, Zucca E, Ferrucci F.Equine Gastric Ulcer Syndrome (EGUS) is a highly prevalent disorder in horses, which can be classified, based on the localization of the lesions, as Equine Squamous Gastric Disease (ESGD) or Equine Glandular Gastric Disease (EGGD). Although EGUS is recognized as a common cause of poor performance in racehorses, objective investigations about its relation with athletic capacity are lacking. Therefore, the present retrospective study aims to evaluate the associations between EGUS severity and some fitness parameters measured during an incremental treadmill test in Standardbred racehorses in trai...
Mild-moderate equine asthma (MEA) is a common respiratory disorder among racehorses, characterized by lower airway inflammation. Although it is generally agreed that MEA causes poor performance, contrasting results have been reported about the effects of tracheal mucus and the leukocyte populations of the bronchoalveolar lavage (BAL) on performance. This study aims to investigate the associations between airway inflammation and fitness parameters measured during an incremental treadmill test on Standardbred racehorses. For this purpose, the clinical records of 116 Standardbreds subjected to a ...
Gibson MJ, Legg KA, Gee EK, Rogers CW.After establishing a baseline of stipendiary stewards' reporting using the paper-based system in the 2015/16 and 2016/17 seasons of harness racing, it is important to examine if the implementation of an online system has altered frequency and descriptors used for clinical outcomes. The objective of this study was to describe the race level injury and reporting outcomes, and horse- and race-level variables associated with the rate of the reporting of these outcomes during the 2019/20 and2020/21 harness racing seasons in New Zealand. The introduction of the online system was associated with few ...
Vitale V, Vezzosi T, Di Franco C, Briganti A, Tognetti R, Conte G, Bucchioni E, Sgorbini M.For the echocardiographic examination horses should not be sedated unless absolutely necessary because this alters cardiac dimensions and indices of function. However, some horses do not tolerate the echocardiographic procedure and require sedation to conduct the examination safely and obtain good quality images. The objective of this study was to evaluate whether the concurrent infusion of dobutamine in horses sedated with romifidine counteracts the cardiovascular changes observed with sedation alone. Twelve healthy untrained Standardbred mares were used. Three echocardiographic examinations ...
Buchalski FM, Rankins EM, Malinowski K, McKeever KH.The purpose of this study was to examine the effects of an external nasal strip on thermoregulation during submaximal exercise in Standardbred horses. While several studies have been conducted to determine the effects of the external nasal strip on airway resistance, exercise induced pulmonary hemorrhage, gas exchange, and time to fatigue in maximally exercising horses, the effects of the nasal strip on equine thermoregulation have not yet been examined. It was hypothesized that the application of an external nasal strip would alter central venous temperature (T), skin temperature (T), and exe...
Valberg SJ, Velez-Irizarry D, Williams ZJ, Henry ML, Iglewski H, Herrick K, Fenger C.Certain Standardbred racehorses develop recurrent exertional rhabdomyolysis (RER-STD) for unknown reasons. We compared gluteal muscle histopathology and gene/protein expression between Standardbreds with a history of, but not currently experiencing rhabdomyolysis (N = 9), and race-trained controls (N = 7). Eight RER-STD had a few mature fibers with small internalized myonuclei, one out of nine had histologic evidence of regeneration and zero out of nine degeneration. However, RER-STD versus controls had 791/13,531 differentially expressed genes (DEG). The top three gene ontology (GO) enriched ...
Egenvall A, Byström A, Pökelmann M, Connysson M, Kienapfel-Henseleit K, Karlsteen M, McGreevy P, Hartmann E.Horseracing is under public scrutiny with increasing demands to safeguard horse welfare. It is accepted that, as a result of bit pressure and/or equipment, mouth lesions accompany many types of horse use, including racing. However, there are currently no data available on the range of bit pressures in driven trotters. Our aim was to investigate whether rein tension (RT, proxy for bit pressures) differs among gaits, between tempo within gait, between horses and drivers, and between left/right reins. Standardbreds (n = 9), driven by experienced drivers (n = 11), performed exercise tests on a rac...
Burns JJ, MacMillan KM, John EE.Atrial fibrillation (AF) is the most clinically relevant cardiac arrhythmia identified in the Standardbred racehorse. However, there is limited literature regarding athletic ability in Standardbred racehorses following AF conversion. To investigate this issue, the objectives of this review were to: i) determine the success rate in using quinidine sulphate to treat AF in a population of hospitalized equine patients in Atlantic Canada between January 2008 and December 2019; and ii) measure return to athletic ability (using racetrack earnings and top-3 finishes) following cardioversion with quini...
Nocera I, Puccinelli C, Sgorbini M, Bagnoli E, Citi S.In adult horses, specific ultrasound (US) features and reference values have been reported for the appearance of the joint cartilage and thickness according to the type of joint, such as femoropatellar and tarsocrural. The US appearance of the fetlock has been described in several diseases. The present research evaluates the US features of the metacarpal/tarsal-phalangeal joints in healthy racehorses according to age and breed, since no information is available in the literature. Seventy-one fetlocks in 28 healthy horses (15/28 thoroughbreds and 13/28 standardbreds) were assessed. The horses w...
Lean NE, Zedler ST, Van Eps AW, Engiles JB, Ford M, Stefanovski D, Walsh DM, Pollitt CC.Surgical stabilisation of the distal phalanx (DP) is a potential therapeutic strategy for severe acute laminitis. Objective: To evaluate the effects of locking compression plate (LCP) fixation of the DP to the dorsal hoof wall. Methods: Ex vivo and in vivo experiments. Methods: A T-shaped LCP was applied to one limb per pair in six pairs of cadaver forelimbs subjected to a combination of thermally induced lamellar failure and vertical load to simulate severe acute laminitis. Standard radiographic measurements were used to compare DP displacement. The LCP was then applied to one forefoot in 12 ...
Soma LR, Stefonovski D, Robinson MA, Tsang DS, Haughan J, Boston RC.A retrospective study was conducted to establish the prerace venous acid-base and blood gas values of Standardbred horses at rest using big data analytics. Methods: Venous blood samples (73,382) were collected during seven racing seasons from 3 regional tracks in the Commonwealth of Pennsylvania. Horses were detained 2 hours prior to race time. Methods: A mixed-effects linear regression model was used for estimating the marginal model adjusted mean (marginal mean) for all major outcomes. The interaction between age and gender, track, and the interaction between month, treatment (furosemide), a...
Rankins EM, Salem K, Manso Filho HC, Malinowski K, McKeever KH.Clenbuterol (β agonist) is a commonly administered bronchodilator in race and performance horses. While long-term administration can alter exercise performance and muscle properties, little is known about its effects on these parameters following short-term administration. A single dose of clenbuterol (0.80 µg/kg) was expected to alter muscle activity of the extensor carpi radialis, semitendinosus, and longissimus dorsi during submaximal exercise. Eight mature Standardbred horses exercised for 2 minutes at 5 m/s on a high-speed treadmill following clenbuterol dosing (clenbuterol) or no dosin...
Barton AK, Troppenz A, Klaus D, Lindenberg I, Merle R, Gehlen H.There is contradictory evidence on the potential benefits of tongue ties on upper airway function and their efficacy in inhibiting intermittent dorsal displacement of the soft palate (DDSP) in racehorses. Objective: To test the hypothesis that tongue ties increase the pharyngeal diameter and decrease the occurrence of dynamic airway obstruction in racehorses. Methods: Prospective, crossover blinded clinical study. Methods: Data of 22 Thoroughbred and 8 Standardbred racehorses examined using overground endoscopy under full-intensity exercise on training racetracks with and without fixation of t...
Ekstrand C, Michanek P, Gehring R, Sundell A, Källse A, Hedeland M, Ström L.Atropine is an essential part of the treatment protocol for equine uveitis. Topical atropine administration has been associated with decreased intestinal motility and abdominal pain in horses. Experimental studies have indicated that frequent dosing is associated with a higher risk than dosing every 6 h. Unfortunately, no quantitative pharmacodynamic data for inhibition of the equine gut are published. Unassigned: Eight standardbred horses were assigned to receive either atropine or saline (control) to be infused over 30 min in a two-treatment cross-over design. Atropine concentrations in plas...
Ellero N, Lanci A, Baldassarro VA, Alastra G, Mariella J, Cescatti M, Giardino L, Castagnetti C.The importance of trophic factors, such as nerve growth factor (NGF), vascular endothelial growth factor (VEGF), and brain-derived neurotrophic factor (BDNF) during the perinatal period, is now emerging. Through their functional activities of neurogenesis and angiogenesis, they play a key role in the final maturation of the nervous and vascular systems. The present study aims to: (i) evaluate the NGF and VEGF levels obtained at parturition from the mare, foal and umbilical cord vein plasma, as well as in amniotic fluid; (ii) evaluate NGF and VEGF content in the plasma of healthy foals during t...
Burroughs DL, Lorch G, Guo Y, Hill K, Schroeder EL, Cole LK, Phelps MA.Mycophenolate mofetil (MMF) is the prodrug of mycophenolic acid (MPA) which acts as an immunosuppressive agent. During the biotransformation of MMF to MPA, additional metabolites including MPA phenol glucuronide (MPAG), MPA acyl glucuronide (AcMPAG) and MPA phenol glucoside (MPG) are formed. Objective: To define the noncompartmental pharmacokinetic (PK) parameters of three single doses of intravenous (i.v.) MMF and its downstream metabolites in healthy horses. Methods: Six healthy Standardbred mares. Methods: Generic MMF (Par Pharmaceuticals; Chestnut Ridge, NY, USA) was reconstituted and admi...
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...
Migliorisi A, Hart K, Vaughn S, Austin S, Aldridge B, Wilkins P.To describe ascorbic acid (AA) concentrations, plasma antioxidant capacity (PAC) and markers of oxidative stress, as measured by derivatives of reactive oxygen metabolites (dROMs), in healthy foals at birth and during the first month of life. Methods: Venous blood samples were collected from healthy Standardbred (n = 13) and Quarter Horse (n = 10) foals. Plasma AA, PAC, and dROMs were assessed at 3 to 12 hours, 3 days, and 1, 2, and 4 weeks of age. Methods: AA was measured via high-performance liquid chromatography. PAC and dROMs were measured with a free radical analytical system. Comparisons...
Nardi S, Nuti M, Nocera I, Sgorbini M, Marmorini P, Barsotti G.This study assesses lacrimal secretion in healthy foals within 48 hours after birth and evaluates their variations in lacrimal secretion and menace response appearance during the first month of life. A total of 31 Standardbred foals were evaluated. Foals were housed with their dams in 4 × 4 m boxes throughout the study. A complete ophthalmic examination was performed for each animal enrolled in the study, including the foals' dams which were used as a control group to compare the lacrimal secretion of foals at birth with that of adult horses. In foals, the Schirmer Tear Test I (STT I) and m...
Hale JN, Hughes KJ, Hall S, Labens R.Autologous conditioned serum (ACS) is a commonly administered intra-articular treatment for the management of osteoarthritis in athletic horses. Objective: To investigate the influence of exercise on the concentration of cytokines in a non-commercial method of ACS production. Methods: Non-randomised cross over design. Methods: Whole blood was obtained from eight healthy Standardbred horses immediately prior to, 1 h and 24 h following a single bout of exhaustive exercise. Blood was processed using a non-commercial method of ACS production. Fluorescent microsphere immunoassay (FMIA) analysis ...
Lanci A, Perina F, Donadoni A, Castagnetti C, Mariella J.Dystocia as a prolonged stage II parturition (>30 min) was associated with a higher risk of complications. The hypothesis of the study was that any type of dystocia could affect the foal’s health, even when the stage II was <30 min. Clinical reports on 222 Standardbred mares and their foals hospitalized at the Veterinary Teaching Hospital of the University of Bologna from 2004 to 2020 were reviewed. Mares were divided into the Eutocia Group (165, eutocic delivery) and the Dystocia Group (57, dystocic delivery). The incidence of dystocia was 4.9%. Stage II was longer in the Dystocia Gro...
Lo Feudo CM, Stucchi L, Cavicchioli P, Stancari G, Conturba B, Zucca E, Ferrucci F.To evaluate the association between the severity of dynamic upper airway obstruction (DUAO) and selected fitness parameters in Standardbred racehorses measured by treadmill test. 191 Standardbred racehorses that underwent a standardized diagnostic protocol for poor performance evaluation between 2002 and 2021 at the Veterinary Teaching Hospital, University of Milan. Horses underwent a diagnostic protocol including clinical examination, lameness evaluation, laboratory analyses, ECG, resting upper airway endoscopy, metabolic incremental treadmill test, high-speed treadmill endoscopy, postexercis...
Mann S, Abuelo A, Stokol T, Wakshlag JJ, Bayly W, Reed S, Gandy J, Ramsay JD, Divers TJ.High serum γ-glutamyl-transferase (GGT) activity syndrome in racehorses has been associated with maladaption to exercise. Investigation of affected horses before and immediately after standard exercise may provide critical insight into the syndrome's pathophysiology. Objective: To investigate blood biomarker changes in actively competing racehorses with high GGT activity associated with an exercise challenge. Methods: Case-control study. Methods: High GGT case (age: 2-3 years) and normal GGT control (age: 2-7 years) pairs (3 Thoroughbred, 4 Standardbred pairs) at least 3 months into thei...
Weis R, Carstensen H, Sattler SM, Buhl R, Hesselkilde EM.During acute myocardial infarction (AMI), the ischemia and necrosis of the infarcted tissue result in local electrophysiological changes, which bring about deviations of the ST segment and T wave. In this case report, the aim was to investigate whether these changes could be detected with a 12-lead electrocardiogram (ECG) during acute occlusion of the coronary artery in a 15-year-old Standardbred mare (scheduled for euthanasia due to non-cardiac health problems). The left anterior descending (LAD) coronary artery was occluded using an angioplasty balloon catheter guided through the carotid art...
Nissen SD, Weis R, Krag-Andersen EK, Hesselkilde EM, Isaksen JL, Carstensen H, Kanters JK, Linz D, Sanders P, Hopster-Iversen C, Jespersen T....Long-term exercise induces cardiac remodeling that potentially influences the electrical properties of the heart. Objective: We assessed whether training alters cardiac conduction in Standardbred racehorses. Methods: Two hundred one trained and 52 untrained Standardbred horses. Methods: Cross-sectional study. Resting ECG recordings were analyzed to assess heart rate (HR) along with standard ECG parameters and for identification of atrial and ventricular arrhythmias. An electrophysiological study was performed in 13 horses assessing the effect of training on sinoatrial (SA) and atrioventricular...
Maninchedda U, Lepage OM, Gangl M, Hilairet S, Remandet B, Meot F, Penarier G, Segard E, Cortez P, Jorgensen C, Steinberg R.The aim of this work was to develop an equine metacarpophalangeal joint model that induces osteoarthritis that is not primarily mediated by instability or inflammation. The study involved six Standardbred horses. Standardized cartilage surface damage or "grooves" were created arthroscopically on the distal dorsal aspect of the lateral and medial metacarpal condyles of a randomly chosen limb. The contralateral limb was sham operated. After 2 weeks of stall rest, horses were trotted 30 minutes every other day for 8 weeks, then evaluated for lameness and radiographed. Synovial fluid was analyzed ...
Buhl R, Ersbøll AK.To assess whether physical training induces cardiac hypertrophy and valvular regurgitation in maturing Standardbred trotters and to establish a prediction model for the size of the left ventricle. Methods: Longitudinal observational study. Methods: 53 Standardbred trotters. Methods: Each horse underwent 2-D, M-mode, and color flow Doppler echocardiography at 5.5 years of age; previously, each horse had been examined at 2, 2.5, 3, and 3.5 (time of maturity) years of age. Horses were or were not in training or racing for variable periods during the entire assessment period; data for a given hors...
Zink MC, Yager JA, Smart NL.Of 131 cases of Corynebacterium equi infection in horses submitted for necropsy to the Ontario Veterinary College or Veterinary Laboratory Services, OMAF, Guelph, Ontario from 1958 to 1984, 115 were diagnosed as suppurative pneumonia, and of these 55 had associated ulcerative enterocolitis. Only five animals had intestinal involvement without pulmonary lesions. The remaining 11 cases included arthritis/cellulitis, skin abscesses and submandibular lymphadenitis. While the lung, intestine and associated lymph nodes yielded C. equi most frequently, in 21% of cases C. equi was also cultured from p...
Lapointe JM, Vrins A, McCarvill E.Sixty Standardbred horses, aged 3 to 10 years, were examined endoscopically for exercise-induced pulmonary haemorrhage (EIPH) 1 h after racing, on at least 3 occasions. Racing time, finishing position and post exercise venous lactate concentrations were also recorded. Horses positive for tracheal blood on endoscopy were classified as having either grade 1 EIPH (one or a few spots of blood in the trachea), or grade 2 (stream of blood). Air temperature, relative humidity and air pollutant levels were recorded on each examination day. Of the 60 horses, 52 (87%) were EIPH-positive on at least one ...
Bailey SR, Adair HS, Reinemeyer CR, Morgan SJ, Brooks AC, Longhofer SL, Elliott J.The link between the fermentation of carbohydrate in the equine large intestine and the development of acute laminitis is poorly understood. Absorption of endotoxin (lipopolysaccharide; LPS) into the plasma has been observed in one experimental model of laminitis, but does not cause laminitis when administered alone. Thus, the potential role of endotoxin is unclear. Platelet activation has previously been demonstrated in the developmental stage of laminitis. Equine platelets are more sensitive than leukocytes to activation by endotoxin, and can be activated directly by LPS in the low pg/ml ran...
Nolen-Walston RD, Harris M, Agnew ME, Martin BB, Reef VB, Boston RC, Davidson EJ.To determine whether there are important differences relating to seasonality of signs or clinical features between subtypes of inflammatory airway disease (IAD) in horses caused by neutrophilic and eosinophilic-mastocytic inflammation having dissimilar etiopathologic pathways. Methods: Retrospective case series. Methods: 98 horses. Methods: Data were compiled from medical records of horses examined because of poor performance from 2004 through 2010. Horses underwent a standardized high-speed treadmill test, lameness evaluation, cardiac evaluation, and postexercise bronchoalveolar lavage (BAL)....
Stubbs NC, Hodges PW, Jeffcott LB, Cowin G, Hodgson DR, McGowan CM.Research in spinal biomechanics and functional anatomy has advanced back pain research in man. Yet, despite the performance limiting nature of back pain in horses, there are few data for the equine spine. Objective: To describe aspects of functional anatomy of the equine thoracolumbar and lumbosacral (LS) spine and potential effects on performance. Methods: The first study investigated variations in LS vertebral formula by post mortem examination of 120 horses. Midline vertebral transection was carried out on 65 Thoroughbred (TB), 24 Standardbred (SB) and 31 other breeds. The second study inve...
Cripps PJ, Eustace RA.Lateromedial radiographic projections were made from the feet of 25 normal horses and 3 angles and 3 distances were measured. From these, normal ranges of calculated variables were obtained. The width and length of each foot and the height of the horse at the withers was also measured. In view of its possible importance in clinical laminitis, particular attention was paid to 'founder' distance (D). This is the vertical distance between the proximal limit of the dorsal hoof wall and the proximal limit of the extensor process of the distal phalanx. There were significant differences between bree...
Ainsworth DM, Eicker SW, Yeagar AE, Sweeney CR, Viel L, Tesarowski D, Lavoie JP, Hoffman A, Paradis MR, Reed SM, Erb HN, Davidow E, Nalevanko M.To determine whether physical examination, laboratory, or radiographic abnormalities in foals with Rhodococcus equi infection were associated with survival, ability to race at least once after recovery, or, for foals that survived and went on to race, subsequent racing performance. Methods: Retrospective study. Methods: 49 Thoroughbreds and 66 Standardbreds admitted to 1 of 6 veterinary teaching hospitals between 1984 and 1992 in which R equi infection was positively diagnosed. Methods: Results of physical examination, laboratory testing, and thoracic radiography were reviewed. Indices of raci...
Goodwin WA, Keates HL, Pasloske K, Pearson M, Sauer B, Ranasinghe MG.To determine the pharmacokinetics and pharmacodynamics of the neurosteroidal anaesthetic, alfaxalone, in horses after a single intravenous (IV) injection of alfaxalone, following premedication with acepromazine, xylazine and guaiphenesin. Methods: Prospective experimental study. Methods: Ten (five male and five female), adult, healthy, Standardbred horses. Methods: Horses were premedicated with acepromazine (0.03 mg kg(-1) IV). Twenty minutes later they received xylazine (1 mg kg(-1) IV), then after 5 minutes, guaiphenesin (35 mg kg(-1) IV) followed immediately by IV induction of anaesthesia w...
Frippiat T, van Beckhoven C, Moyse E, Art T.Heart rate is evaluated in exercising horses to monitor the level of fitness to exercise, and it is usually acquired using heart rate monitors (HRM) or telemetric electrocardiograms (ECG). While HRM are commonly available and easy-to-use for horse's owners, ECG is a more expensive equipment requiring user's experience. Interest for heart rate variability (HRV) in horses is increasing for both research and clinical purposes. HRV is usually calculated from interbeat intervals (IBI) obtained by ECG. The aim of this study was to determine the accuracy of an HRM to detect IBI for the calculation of...
Kinnunen S, Hyyppä S, Lehmuskero A, Oksala N, Mäenpää P, Hänninen O, Atalay M.Strenuous exercise is a potent inducer of oxidative stress, which has been suggested to be associated with disturbances in muscle homeostasis, fatigue and injury. There is no comprehensive or uniform view of the antioxidant status in horses. We have previously shown that moderate exercise induces protein oxidation in trotters. The aim of this study was to measure the antioxidative capacity of the horse in relation to different antioxidant components and oxidative stress markers after a single bout of moderate exercise to elucidate the mechanisms of antioxidant protection in horses. Eight clini...
Doubli-Bounoua N, Richard EA, Léon A, Pitel PH, Pronost S, Fortier G.The potential involvement of viruses in inflammatory airway disease (IAD) was previously investigated through either serology or PCR from nasopharyngeal swabs (NS). The aims of this study were to determine the prevalence and incidence of viral genome detection by qPCR in the equine airways, and their association with respiratory clinical signs. Both NS and tracheal washes (TW) were collected monthly on 52 Standardbred racehorses at training, over 27 consecutive months (581 samples). Equid herpesviruses (EHV)-1, -4, -2 and -5, equine rhinitis virus-A and -B (ERBV), equine adenovirus-1 and -2, e...
Angelos J, Oppenheim Y, Rebhun W, Mohammed H, Antczak DF.The relationship between breed and the risk of developing sarcoid tumours or uveitis of unknown etiology was evaluated in a retrospective study of 16242 equine cases admitted between 1975 and 1987 to the New York State College of Veterinary Medicine Large Animal Hospital, and 3198 equine tissue samples sent to the New York State Veterinary Diagnostic Laboratory between 1977 and 1987. Of 120 sarcoid cases from the Large Animal Hospital, sarcoids were twice as likely to develop in Quarter Horses (odds ratio, OR = 1.8, P less than 0.05) relative to Thoroughbreds and less than half as likely to de...
Drevemo S, Dalin G, Fredricson I, Hjertén G.The movements of the individual limbs of 30 clinically sound Standardbred trotters were studied using high-speed cinematography. At a speed of 12 metres per second (m/sec; 1:23.6 min/km) the mean stride length was 545 cm and the mean duration of the stride was 455 milliseconds (msecs). The stance phase in the forelimbs was 100 msecs and 177 msecs in the hindlimbs. This difference was due to a longer restraint period in the hindlimbs and resulted in slightly shorter swing phases for the hindlimbs. The variations in any particular horse for stride length and for the duration of stride, stance, s...
Hinrichs K, Cummings MR, Sertich PL, Kenney RM.Swab specimens for bacterial culture were obtained from the uterus, vagina, vestibule, and clitoral fossa of 48 mares that had normal reproductive tracts, no history of reproductive problems, and no inflammation on evaluation of endometrial biopsy. The mares were predominantly Thoroughbred and Standardbred. Swab specimens of the vagina were obtained through a sterile speculum; swab specimens of the uterus were obtained by use of a double-guarded, occluded culture instrument. Fifteen (31%) of the uterine swab specimens and 20 (42%) of the vaginal swab specimens yielded growth on aerobic culture...
Haga HA, Dolvik NI.To evaluate Fourier-transformed electroencephalographic (EEG) variables, mean arterial blood pressure (MAP) and pulse rate as nociceptive indicators in isoflurane-anaesthetized horses. Methods: Five standardbred and three Norwegian cold-blooded trotter stallions undergoing castration, aged 2-4 years, mass 378-538 kg. Methods: All horses received intravenous (IV) detomidine (10 microg kg(-1) IV) and butorphanol (0.01 mg kg(-1) IV). Additional detomidine (4 microg kg(-1) IV) was administered in the induction area. Anaesthesia was induced with ketamine (2.5 mg kg(-1) IV) and diazepam (40 microg k...
Back H, Ullman K, Treiberg Berndtsson L, Riihimäki M, Penell J, Ståhl K, Valarcher JF, Pringle J.The equine gamma herpesviruses 2 and 5 (EHV-2 and -5) have frequently been observed in the equine population and until recently presumed low to nonpathogenic. However, recent reports linking presence of equine gamma herpesviruses with clinical signs of mild to severe lung disease, suggest that the role of these viruses in respiratory disease and poor performance syndrome is still unclear. Moreover, baseline data regarding the temporal pattern of shedding of EHV-2 and EHV-5 within stables and within individual actively racing horses have been lacking. In a prospective longitudinal study, we fol...
Kinnunen S, Hyyppä S, Lappalainen J, Oksala N, Venojärvi M, Nakao C, Hänninen O, Sen CK, Atalay M.Acute exercise induces oxidative stress and heat shock protein (HSP) expression. Information on the protection of stress proteins against oxidant insult and muscle damage during moderate exercise is scanty. We aimed to show how a single bout of moderate exercise affects the markers of oxidative stress and heat shock factor-1 (HSF1; the transcriptional regulator of HSP synthesis), and HSP70, HSP90 and glucose-regulated protein (GRP75) expression in horses. Eight clinically normal and regularly trained standardbred trotters were treadmill-exercised for 45 min at moderate intensity. Blood samples...
Antczak DF, Bright SM, Remick LH, Bauman BE.A genetic system controlling lymphocyte alloantigens of the horse is described. Alloantisera to paternal histocompatibility antigens induced as a result of pregnancy in mares were used in an antibody-mediated complement-dependent microcytotoxicity assay to define 15 Equine Leukocyte Antigen (ELA) specificities using cluster analysis. In this study 369 sera were screened for alloantibody using lymphocytes from 10 randomly selected, unrelated horses. A high proportion (83%) of these sera were found to be positive for antibody to lymphocyte alloantigens. After initial cluster analysis, 120 of the...
Crabb BS, MacPherson CM, Reubel GH, Browning GF, Studdert MJ, Drummer HE.We describe a type-specific ELISA, which distinguishes antibody to equine herpesvirus 4 (EHV4; equine rhinopneumonitis) and EHV1 (equine abortion virus) thereby identifying horses that have been infected with either or both of these antigenically related viruses. The antigens used are parts of the EHV4 and EHV1 glycoprotein G (gG) homologues expressed in E. coli as fusion proteins [Crabb and Studdert, 1993: J Virol 67: 6332-6338). The expressed proteins comprise corresponding regions of the gG molecules that are highly divergent and encompass strong, typespecific epitopes. Plasma samples from ...
Celeste CJ, Deschesne K, Riley CB, Theoret CL.To map skin temperature kinetics, and by extension skin blood flow throughout normal or abnormal repair of full-thickness cutaneous wounds created on the horse body and limb, using infrared thermography. Methods: Experimental. Methods: Standardbreds (n = 6), aged 3-4 years. Methods: Three cutaneous wounds were created on the dorsolateral surface of each metacarpus and on the lateral thoracic wall. Thoracic skin wounds and those on 1 randomly chosen forelimb healed by second intention without a bandage, whereas contralateral limb wounds were bandaged to induce formation of exuberant granulation...
Moore BR, Krakowka S, Robertson JT, Cummins JM.Cytologic examination of bronchoalveolar lavage fluid (BALF), including phenotypic analysis of lymphocytes, was performed on 32 Standardbreds with poor race performance and endoscopic examination findings characteristic of inflammatory airway disease (IAD). Nucleated cell counts in BALF from IAD-affected horses were higher than those in control horses; the cytologic profile of BALF in affected horses included mixed inflammation, characterized by mild neutrophilia, lymphocytosis, and monocytosis. Eosinophil and mast cell counts were not higher in the IAD-affected group, compared with those in t...
McCoy AM, Beeson SK, Splan RK, Lykkjen S, Ralston SL, Mickelson JR, McCue ME.Osteochondrosis (OC), simply defined as a failure of endochondral ossification, is a complex disease with both genetic and environmental risk factors that is commonly diagnosed in young horses, as well as other domestic species. Although up to 50 % of the risk for developing OC is reportedly inherited, specific genes and alleles underlying risk are thus far completely unknown. Regions of the genome identified as associated with OC vary across studies in different populations of horses. In this study, we used a cohort of Standardbred horses from the U.S. (n = 182) specifically selected for...
Couroucé-Malblanc A, Pronost S, Fortier G, Corde R, Rossignol F.There are a variety of reasons for poor performance in racehorses. Exercise intolerance has often been associated with subclinical respiratory abnormalities, and diagnostic aids are therefore used to enhance clinical detection. Physiological variables can also be measured in order to evaluate the metabolic reponse to exercise. This study evaluated the relationship between physiological measurements and upper airway videoendoscopy during a standardised treadmill exercise test and bronchoalveolar lavage (BAL) cytology in control horses (good racing performance, n = 14) and poor performers (n = 2...
Rendle DI, Rutledge F, Hughes KJ, Heller J, Durham AE.Metformin is a potential therapeutic agent for the treatment of insulin resistance (IR). In laboratory animals, orally administered metformin reduces intestinal glucose absorption and may therefore affect insulinaemic responses to oral carbohydrate ingestion. Objective: To determine whether pretreatment with metformin reduces plasma glucose concentration and insulin responses following consumption of dextrose in horses. Methods: Therapeutic cross-over study. Methods: Seven healthy Standardbred and Thoroughbred geldings were subjected to an oral dextrose challenge test on 4 occasions: with and ...
Langlois B, Blouin C.Declarations of matings (535,746) and 308,549 consecutive declarations of birth from 1989 to 1999 were analysed by logistic regression in order to determine the effects of year, breed and age of parents on numerical productivity (the number of foals declared per mated mare per year). For the years 1994 to 1999, the status of the mare, type of mating and month of first mating, were also available. The effect of inbreeding and, for warm-blooded horses, the effect of the level of performances or the effect of the level of breeding value estimation were also analysed. The main results are the foll...
Cottin F, Barrey E, Lopes P, Billat V.Interval training is a commonly used training method for trotting horses. In addition, trainers are provided with efficient and inexpensive heart rate monitor devices for the management of training. Objective: Since the high frequency (HF) frequency peak (fHF) of heart rate variability (HRV) corresponds to the breathing frequency in combination with stride frequency during trotting, it is hypothesised that modifications of breathing and stride frequencies induced by repeated exercise could be detected from fHF. Methods: RR interval time series of 7 trotting horses were recorded during an inter...
Bischofberger AS, Dart CM, Horadagoda N, Perkins NR, Jeffcott LB, Little CB, Dart AJ.To investigate the effect of 66% Manuka honey gel on the concentrations of transforming growth factor (TGF)-β1 and TGF-β3, bacterial counts and histomorphology during healing of contaminated equine distal limb wounds. Methods: In this experimental study of 10 Standardbred horses, five full-thickness skin wounds (2 × 1.5 cm) were created on one metacarpus and six similar wounds were created on the contralateral metacarpus. Wounds were assigned to three groups: non-contaminated control wounds; contaminated control wounds; contaminated wounds treated daily with 1 mL Manuka honey gel to...
The attention of sports community toward probiotic supplementation as a way to promote exercise and training performance, together with good health, has increased in recent years. This has applied also to horses, with promising results. Here, for the first time, we tested a probiotic mix of several strains of live bacteria typically employed for humans to improve the training performance of Standardbred horses in athletic activity. To evaluate its effects on the horse performance, we measured lactate concentration in blood, a translational outcome largely employed for the purpose, combined wit...
