Equine veterinary journal. Supplement.
Discontinued
Publisher:
Equine Veterinary Journal, Ltd. Hobokken, NJ : Wiley (2009)
Frequency: Irregular
Country: United States
Language: English
Author(s):
British Equine Veterinary Association.
Start Year:1983 - 2013
ISSN:
Impact Factor
2.2
2022
| NLM ID: | 9614088 |
| (DNLM): | SR0062474(s) |
| (OCoLC): | 10429490 |
| Classification: | W1 EQ968 |
Route of carbohydrate administration affects early post exercise muscle glycogen storage in horses. No studies in horses have examined the effect of route of carbohydrate (glucose) administration on the rate of muscle glycogen storage following glycogen-depleting exercise. Objective: Glucose delivery from the gastrointestinal tract limits the rate of muscle glycogen storage following glycogen-depleting exercise. Methods: In a crossover design, 7 fit horses completed treadmill exercise (EX) on 3 occasions to deplete muscle glycogen by approximately 50%. After EX horses received: 1) i.v. glucose infusion (IV; 0.5 g/kg bwt/h for 6 h), 2) oral glucose boluses (OR; 1 g/kg bwt at 0, 2 and 4 h post...
Plasma concentrations of myeloperoxidase in endurance and 3-day event horses after a competition. In man, exercise of any type has been shown to induce neutrophil degranulation and respiratory burst activity, as well as an increase in plasma myeloperoxidase (MPO), a specific enzyme of neutrophil azurophilic granules with a strong oxidative activity. Until now, it is not known whether this is the same in horses. Objective: To study whether degranulation of blood neutrophils may be induced by exercise by measuring the total concentration of MPO and assess the possible influence of type of competition on this exercise-induced adjustment. Methods: Blood was sampled before, and 30 min after, th...
Racing speeds of quarter horses, thoroughbreds and Arabians. While Quarter Horses are recognised as the fastest breed of horse, direct comparisons to race times with other breeds can be misleading. Quarter Horse races begin when the starting gates open. Thoroughbred and Arabian races begin a short distance from the gates after horses have started running. This study compared speeds of these breeds as they accelerate from the starting gates and during the middle and end of races. Objective: To compare racing speeds of the 3 breeds, and to compare speeds during various segments of the races. Methods: Video tapes of races were obtained from a local track. ...
Endurance exercise is associated with increased plasma cardiac troponin I in horses. Information is lacking regarding the influence of long distance exercise on the systemic concentration of cardiac troponin I (cTnI) in horses. Objective: To determine if the concentration of cTnI in horses competing in 80 and 160 km endurance races increases with exercise duration and if cTnI concentrations can be correlated with performance data. Methods: Blood samples for the measurement of cTnI and 3 min electrocardiogram recordings were obtained from horses prior to, during and after completion of 80 and 160 km endurance races at 3 ride sites during the 2004 and 2005 American Endurance Rid...
Cardiac arrhythmias during and after treadmill exercise in poorly performing thoroughbred racehorses. The prevalence and severity of cardiac arrhythmias during exercise in athletic horses presented for poor performance is not well described. Objective: To describe prevalence and severity of ventricular and supraventricular arrhythmias immediately before, during and immediately after standardised incremental treadmill exercise tests (IET) to fatigue in Thoroughbred horses during investigation of poor performance. Methods: The electrocardiograms (ECG) of 88 Thoroughbred racehorses, judged to be free of significant heart disease or arrhythmia at rest, were used. A modified base-apex ECG was recor...
Movement between the equine ilium and sacrum: in vivo and in vitro studies. Sacroiliac disease (SID) is an important cause of loss of performance in horses, yet little is known about the biomechanics of movement of the sacroiliac joint (SIJ). Objective: (a) To document the presence of equine SIJ motion by measuring the change in cross-sectional area (CSA) of the dorsal portion of the dorsal sacroiliac ligament (DSIL) during application of manual forces to the pelvis, and to ascertain if this varied between horses with SID and normal horses; (b) To determine the amount and direction of motion available at the equine SIJ using 3-D orientation sensors, and how motion is ...
Effects of oral electrolyte supplementation on endurance horses competing in 80 km rides. There is no evidence that use of oral electrolyte pastes enhances performance in competing endurance horses. Objective: To ascertain whether oral administration of a high dose (HD) of sodium chloride (NaCl) and potassium chloride (KCl) to endurance horses would differentially increase water intake, attenuate bodyweight (bwt) loss and improve performance when compared to a low dose (LD). Methods: A randomised, blinded, crossover study was conducted on 8 horses participating in two 80 km rides (same course, 28 days apart). Thirty minutes before and at 40 km of the first ride 4, horses received o...
Prevalence of polysaccharide storage myopathy in horses with neuromuscular disorders. Controversy exists as to the prevalence of polysaccharide storage myopathy (PSSM) in breeds of horses and its impact on performance. Objective: To determine 1) the prevalence of PSSM in horses that presented with a neuromuscular disorder, as well as breed, sex and age distributions and clinical signs 2) effect of diagnostic criteria on prevalence, breed distribution and age of horses diagnosed with PSSM. Methods: Fresh frozen biopsies (n = 1426) submitted to the Neuromuscular Diagnostic Laboratory at the University of Minnesota were searched to identify horses diagnosed with PSSM. Horses with ...
Videoendoscopic evaluation of the upper respiratory tract in 93 sport horses during exercise testing on a high-speed treadmill. Videoendoscopy of the upper respiratory tract (URT) during high-speed treadmill exercise has proved to be invaluable in the assessment of URT dysfunction in racehorses. However, very little information exists regarding dynamic airway collapse in other sport horses used in nonracing equestrian disciplines. Objective: To evaluate the videoendoscopic findings at rest and during exercise in a mixed population of sport horses referred for investigation of poor athletic performance and/or abnormal respiratory noise. Methods: Videoendoscopy of the upper airway was performed at rest and during high-sp...
Oxygen consumption (VO2) during trotting on a 10% decline. Although there have been reports of oxygen consumption measurements of horses running on the level and incline, there are no measurements during decline locomotion. This may be due, in part, to the potential for muscle damage produced by eccentric contractions. In man, running on a 10% decline, VO2 decreased by 35% and stride frequency (SF) decreased by 3% when compared to level locomotion. Objective: The rate of O2 consumption and SF would be decreased in horses on a 10% decline when compared to the level. Methods: Six horses (average 467 +/- 68 kg) were acclimated to trotting on the level an...
Cold air-induced late-phase bronchoconstriction in horses. Inspired air is warmed to body temperature and fully humidified by the upper airway mucosa under normal resting conditions. This conditioning process may not be completed by the upper airways during conditions of increased minute ventilation or when the inspired air is unusually cold, resulting in cooling and desiccation of lower respiratory surfaces. Excess heat and water loss from intrapulmonary airways is believed to be the provocative stimulus for exercise-induced bronchoconstriction (occurring immediately after exercise) and associated late phase airway obstruction (occurring a few hours ...
Exercise and pharmacological stress echocardiography in healthy horses. Stress echocardiography could be a useful diagnostic test in horses suspected to suffer from exercise-induced myocardial dysfunction as a cause of exercise intolerance. Objective: To evaluate the effect of treadmill exercise and pharmacological stress test on left ventricular echocardiographic parameters. Methods: Echocardiography was performed in 2 groups of 5 healthy horses, either immediately after a near-maximal treadmill exercise (Group EXE) or during a pharmacological challenge (Group DOB) consisting of 35 microg/kg atropine, followed by incremental dobutamine infusion rates of 2-6 micro...
Interval exercise alters feed intake as well as leptin and ghrelin concentrations in standardbred mares. Horses in training tend to become inappetant; however, the mechanism responsible for this training-induced inappetance is not known. Objective: Training and/or ulcers alter the feed intake (FI) and hormonal and/or biochemical (active ghrelin, leptin, glucose, insulin and cortisol) responses to acute high intensity exercise. Methods: Eight Standardbred mares underwent 3 interval exercise tests (IET) and 3 parallel control tests (CON) before (IET1) and after 8 weeks of training (IET2) and after treatment for gastric ulcers (IET3). Plasma samples were taken before (0 min), during (last 10 sec of ...
Thyroid hormone responses to endurance exercise. Limited information exists about changes in circulating thyroid hormone concentrations during prolonged endurance exercise in horses. Objective: To examine the effects of prolonged exercise on serum iodothyronine concentrations in horses performing endurance exercise of varying distances. Methods: Serum concentrations of iodothyronines were measured in horses before and after completion of 40, 56, 80 and 160 km endurance rides (Study 1); daily during a 5 day, 424 km endurance ride (Study 2); and before and for 72 h after completion of a treadmill exercise test simulating a 60 km endurance ride...
Glucose dynamics during exercise: dietary energy sources affect minimal model parameters in trained Arabian geldings during endurance exercise. Glucose regulation is critical for health and exercise performance. Objective: To quantify the effects of exercise and diet on insulin sensitivity (SI), glucose effectiveness (Sg), acute insulin response to glucose (AIRg) and disposition index (DI) in horses. Methods: This study applied the minimal model of glucose and insulin dynamics to exercise-trained Arabian geldings during rest or constant moderate-intensity exercise after 8 weeks adaptation to feeds high in sugar and starch (SS, n = 6) or fat and fibre (FF, n = 6). Horses underwent 2 frequently sampled i.v. glucose tolerance tests (FSIG...
Frusemide results in an extracellular to intracellular fluid shift in horses. Frusemide (Lasix) is commonly used diuretic in horse racing and equine clinical practice. While pharmacology, pharmacodynamics, renal and haematological effects of frusemide have been studied in horses, its effects on the distribution of fluid within the horse remain unknown. Objective: To quantify the effects of frusemide on extracellular and intracellular fluid shifts. Methods: Horses were infused with 1 mg/kg body mass (n = 7) or 2 mg/kg (n = 9) i.v. frusemide. Total body water (TBW), extracellular fluid volume (ECFV) and plasma volume (PV) were measured using D2O, NaSCN and Evans blue dilu...
Effect of amino acid and glucose administration following exercise on the turnover of muscle protein in the hindlimb femoral region of thoroughbreds. In man, muscle protein synthesis is accelerated by administering amino acids (AA) and glucose (Glu), because increased availability of amino acids and increased insulin secretion, is known to have a protein anabolic effect. However, in the horse, the effect on muscle hypertrophy of such nutrition management following exercise is unknown. Objective: To determine the effect of AA and Glu administration following exercise on muscle protein turnover in horses. We hypothesise that administration of AA and Glu after exercise effects muscle hypertrophy in horses, as already shown in man and other ani...
Recruitment pattern of muscle fibre type during flat and sloped treadmill running in thoroughbred horses. There is little information about the muscle fibre recruitment pattern during sloped and flat track running in Thoroughbred horses. Objective: To examine the glycogen depletion pattern of each muscle fibre type during running on a flat and sloped treadmill. Methods: Thirteen Thoroughbred horses (3-9 years old) were used. They were initially subjected to incremental exercise tests on a treadmill at 10 and 0% inclines in each horse to determine running speed at 90 and 60% VO2max. Needle biopsy samples were obtained from the middle gluteal muscle immediately after the running at 90% VO2max for 4 ...
Correlations between exercising arterial blood gas values, tracheal wash findings and upper respiratory tract abnormalities in horses presented for poor performance. There are limited data on the correlations between arterial blood gas (ABG) values, tracheal wash (TW) cytology and upper respiratory tract (URT) abnormalities. Objective: To identify horses with abnormal exercising ABG, and compare the proportions of horses with abnormal ABG and TW cytology, mucus or URT dysfunction with those with normal ABG results and abnormal TW cytology, mucus or URT dysfunction. Methods: Medical records of 813 horses presenting to the treadmill facility that had a complete treadmill examination, including ABG analysis, TW and URT endoscopy were selected. Diagnoses, ABG ...
Measurements of fitness in thoroughbred racehorses using field studies of heart rate and velocity with a global positioning system. Field based studies of changes in fitness are difficult to conduct in galloping Thoroughbreds. Measurements of heart rate (HR) and real time velocity with a global positioning system (GPS) could provide a method for routine field studies of fitness. Objective: To investigate measurements of fitness in the field without using multiple, standardised steps of increasing velocity in the exercise test. Methods: Twelve healthy 3- to 5-year-old Thoroughbreds were used in the study of reliability, and twelve 2-year-old Thoroughbreds in the investigation of the effect of training. Five second averages ...
Heart rate responses during acclimation of horses to water treadmill exercise. The use of water treadmill exercise in horses is popular, although little is known about the physiological responses to this form of exercise. No information exists regarding the time taken to acclimate to water treadmill exercise compared to that of high-speed treadmill exercise, for both physiological and biomechanical parameters. Objective: To determine heart rate responses during acclimation to water treadmill exercise with and without sedation on first time exposure. Methods: All horses were exercised on a water treadmill at the walk for 15 min once a day for 4 days. Fourteen horses (mean...
Effects of a pre-moistened multilayered breathable fabric in promoting heat loss during recovery after exercise under hot conditions. Horses generate considerable internal heat burdens when exercising. Although common practice for a trainer or groom to place a wet blanket or towel on the dorsum of a hot horse post exercise, there are no data supporting the efficacy of this cooling method. Objective: To test the hypothesis that a pre-moistened blanket designed with a multilayered breathable fabric would enhance heat loss in horses post exercise. Methods: Eight treadmill-trained horses performed a standardised exercise test (SET) weekly for 3 weeks, with 3 different recovery treatments administered randomly. Pulmonary artery t...
Glycaemic and insulinaemic response of quarter horses to concentrates high in fat and low in soluble carbohydrates. Quarter Horses are particularly susceptible to polysaccharide storage myopathy (PSSM). Nutritional therapy and possibly prophylaxis includes fat-supplemented diets whilst starch supply should be kept to a minimum. Objective: To investigate the glycaemic and insulinaemic response of clinically normal Quarter Horses to concentrates high in fat and low in starch. Methods: Twelve Quarter Horses were studied. The precondition for inclusion in the study population was that the horses had not shown clinical signs of myopathy. The Quarter Horses were fed according to a 4 x 4 Latin square design haylag...
Observations on respiratory flow strategies during and after intense treadmill exercise to fatigue in thoroughbred racehorses. Locomotor-respiratory coupled (LRC) breath types are a feature of galloping exercise in horses. Differences in breath type have been demonstrated during exercise in particular the 'big respiratory cycle' (BRC) and 'flow hesitation'. To investigate breath types during recovery and quantitatively investigate BRCs during exercise to understanding the mechanism driving BRCs. Objective: To investigate the occurrence of different breath types during and after intense treadmill exercise, and test the hypothesis that large breaths (BRCs) were a function of respiratory frequency. Methods: Six trained a...
MCT1 and CD147 gene polymorphisms in standardbred horses. Transport of lactate across membranes is facilitated by proton-monocarboxylate transporters (MCT). The most widely distributed isoform is MCT1, which needs an ancillary protein CD147. Studies on erythrocytes have shown that high activity of MCT1 is inherited as the dominant allele and that activity is regulated through CD147. Mutations of human MCT1 have been described that appear to impair lactate transport in muscles and cause exertional rhabdomyolysis. There are no reports of this potential relationship in the horse. Objective: To obtain sequences of equine MCT1 and CD147 to examine differe...
Prevalence of inflammatory airway disease in national hunt horses referred for investigation of poor athletic performance. Inflammatory airway disease (IAD) is thought to be an important cause of poor performance in young Thoroughbred racehorses. However, little study has been made of IAD in older National Hunt (NH) horses. Objective: To determine the prevalence of IAD in NH racehorses referred for investigation of poor athletic performance and identify some of the risk factors that may be associated with IAD in this group of horses. Methods: Tracheal mucus was graded, and tracheal wash (TW) and bronchoalveolar lavage (BAL) performed after treadmill exercise in 91 NH horses referred to the University of Bristol. C...
Optimal active recovery intensity in standardbreds after submaximal work. A retrospective study concerning spontaneous active recovery intensity, i.e. at a freely chosen speed, after a submaximal exercise in trotters showed that the mean intensity demanded by trainers corresponds to 40-50% of maximal heart rate (max HR; unpublished data). However, in human athletes, optimal active recovery intensity was found to be about 60-70% of max HR. Is the spontaneous recovery optimal after a submaximal exercise in trotters? Objective: To compare different recovery intensities and define the most efficient one. Methods: Thirty-seven trotters performed a standardised exercise t...
Dynamic pharyngeal collapse in racehorses. Dynamic pharyngeal collapse (PC) is a condition seen in racehorses that can be career-ending. Objective: To characterise and grade PC and describe the effects of PC on athletic performance. Methods: Medical records were reviewed for 828 horses, of which 49 (6%) records were identified as horses with a primary diagnosis of PC. Tapes of video-endoscopy of the pharynx during exercise were reviewed. Each video recording was assigned a grade (0-4) reflecting the degree of PC and a classification for severity of upper airway obstruction. Earnings per race prior to diagnosis of PC were compared to ea...
Double blind investigation of the effects of oral supplementation of combined glucosamine hydrochloride (GHCL) and chondroitin sulphate (CS) on stride characteristics of veteran horses. Oral chondroprotective supplements are commercially popular for veteran (and other athletic or arthritic) horses prone to joint degeneration, yet lack conclusive scientific support. Objective: To quantify the effects of an oral joint supplement (combination glucosamine hydrochloride (GHCL), chondroitin sulphate (CS) and N-acetyl-D-glucosamine) in vivo on stride parameters of veteran horses. Methods: Twenty veteran horses were randomly assigned to a treatment (n = 15) or placebo group (n = 5). Pre-treatment gait characteristics were recorded at trot using digital video footage (50 Hz). The rang...
Uric acid responses to endurance racing and relationships with performance, plasma biochemistry and metabolic alterations. There is limited understanding of the uric acid response to endurance races. Objective: To demonstrate uric acid increments and its relationship to diverse biochemical and performance parameters, in horses subjected to a prolonged effort, with and without presentation of metabolic alterations. Methods: Blood samples were taken from horses the day before, and 5-10 mins after, successfully finishing a 121 km (Assay 1, n = 24) or 164 km endurance race (Assay 2, n = 17), and from 19 animals eliminated by metabolic disorders during several endurance races (Assay 3). Plasma was obtained and determin...