REASONS FOR PERFORMING STUDY AND OBJECTIVE: To review the prevalence of single and complex forms of dynamic airway obstructions within a large group of Thoroughbred horses in training referred for investigation of poor performance. METHODS: Video-endoscopic recordings of the upper respiratory tract made during a standardised treadmill exercise test of ...

OBJECTIVE: To determine concentrations of proglycogen (PG), macroglycogen (MG), glucose, and glucose-6-phosphate (G-6-P) in skeletal muscle of horses with polysaccharide storage myopathy (PSSM) before and after performing light submaximal exercise. ANIMALS: 6 horses with PSSM and 4 control horses. PROCEDURES: Horses with PSSM completed repeated intervals of 2 minutes of ...

REASONS FOR PERFORMING STUDY: The reliability of diagnoses of obstructive conditions of the upper respiratory tract (URT) based on examinations performed at rest vs. at exercise is controversial. OBJECTIVE: To compare diagnosis of URT by endoscopy at rest with that achieved during high-speed treadmill exercise (HSTE). HYPOTHESIS: Endoscopy of URT ...

We have recently demonstrated in a Phase I/II study that combination chemotherapy with docetaxel (TXT) and S-1 is active against metastatic gastric carcinomas. To elucidate the mechanisms underlying the synergistic effects of these drugs, both the growth inhibitory effects and the expression profiles of enzymes involved in fluorouracil (5-FU) metabolism ...

REASONS FOR PERFORMING STUDY: 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 ...

REASONS FOR PERFORMING STUDY: Running ability of Thoroughbred racehorses is correlated with maximal oxygen uptake, and the velocity at maximal oxygen uptake is highly correlated with the velocity at maximal heart rate (VHRmax). OBJECTIVE: To investigate the relationship between VHRmax and racing performance, expressed as 'peak dollars earned per race ...

REASON FOR PERFORMING STUDY: Trot is a symmetric gait and asymmetry might appear or increase during endurance rides due to lameness, pain or excessive fatigue. HYPOTHESIS: To assess whether trot asymmetry increases during endurance competitions, whether it is possible to discriminate between horses with different performance and also its possible ...

REASONS FOR PERFORMING STUDY: 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% ...

REASON FOR PERFORMING STUDY: The relationship between fatigue and stride and/or muscle stiffness requires further study. OBJECTIVE: To measure stride parameters in horses undergoing fatigue associated with running at submaximal speeds both on a treadmill and in an endurance ride. HYPOTHESIS: Stride frequencies and estimates of hindlimb stiffness would be ...

REASONS FOR PERFORMING STUDY: Horses in training tend to become inappetant; however, the mechanism responsible for this training-induced inappetance is not known. HYPOTHESIS: 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 ...

REASONS FOR PERFORMING STUDY: It is recognised that the amount of psychological stress that an animal encounters determines the degree of response of the hypothalamic-pituitary-adrenal (HPA) axis. In human athletes, the added emotive stress of competition is an important element in the adrenal response. The aim of this study was ...

REASONS FOR PERFORMING STUDY: 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 ...

REASONS FOR PERFORMING STUDY: In human and animal clinical practice, multi-frequency bioelectrical impedance analysis (MF-BIA) is increasingly used as a diagnostic tool to assess hydration of intra-and extracellular fluid compartments. Accurate determination of changes in hydration status within individuals over time has remained problematic due to the requirement for complete ...

REASONS FOR PERFORMING STUDY: Recombinant human erythropoietin (rhuEPO) causes an increase in red blood cell production and aerobic capacity in other species; however, data are lacking on effects in the horse. HYPOTHESIS: This study tested the hypothesis that rhuEPO administration would alter red cell volume (RCV), aerobic capacity (VO2max) and ...

REASONS FOR PERFORMING STUDY: Little is known in quantitative terms about the influence of different head-neck positions (HNPs) on the loading pattern of the locomotor apparatus. Therefore it is difficult to predict whether a specific riding technique is beneficial for the horse or if it may increase the risk for ...

REASONS FOR PERFORMING STUDY: Thoroughbred racehorses often experience interruptions to their training. Identifying the effects of these changes and how they alter athletic performance might provide an insight on to how to prevent these changes from occurring. HYPOTHESIS: Training and detraining young Thoroughbreds alters their aerobic capacities with correlated changes ...

REASONS FOR PERFORMING STUDY: A large percentage of performance horses develop gastric ulcers and many of those horses are treated with omeprazole. Unfortunately, no data have been published on the effects of the drug on markers of performance in animals without ulcers. HYPOTHESIS: Omeprazole would alter markers of aerobic and ...

REASON FOR PERFORMING STUDY: 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 ...

REASONS FOR PERFORMING STUDY: 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 ...

To determine (1) if the cricothyroid muscle had respiratory-related electromyographic (EMG) activity that increased with respiratory effort and (2) if bilateral cricothyroid myotomy resulted in vocal fold instability and collapse in exercising horses. Experimental. Seven (3 EMG; 4 cricothyroid myotomy) Standardbred horses. Three horses exercised on a treadmill at speeds ...

REASON FOR PERFORMING STUDY: Information is lacking regarding the influence of long distance exercise on the systemic concentration of cardiac troponin I (cTnI) in horses. Objectives: To determine if the concentration of cTnI in horses competing in 80 and 160 km endurance races increases with exercise duration and if cTnI ...

REASONS FOR PERFORMING STUDY: Glucose regulation is critical for health and exercise performance. OBJECTIVES: 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 ...

REASONS FOR PERFORMING STUDY: During high intensity exercise, the very high pulmonary artery pressure (Ppa) experienced by Thoroughbred horses is considered a major factor in the aetiology of exercise-induced pulmonary haemorrhage (EIPH). Recently, endothelin-1 (ET-1), a potent vasoconstrictive hormone, has been found to increase Ppa in horses at rest via ...

REASONS FOR PERFORMING STUDY: There is limited understanding of the uric acid response to endurance races. OBJECTIVES: 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 ...

REASON FOR PERFORMING STUDY: Limited information exists about the physiological changes and clinical problems that occur in elite horses competing in high-speed 160 km endurance races. OBJECTIVES: To provide initial data describing changes in physiological and laboratory measurements in horses competing in a high-speed, 160 km endurance race under temperate ...

REASONS FOR PERFORMING STUDY: Heart rate (HR) recovery immediately after exercise is controlled by autonomic functions and the time constant (T) calculated from HR recovery is thought to be an index of parasympathetic activity in man. OBJECTIVES: To investigate whether it is possible to evaluate autonomic function using the time ...

REASONS FOR PERFORMING STUDY: One cause of overstrain injury to the superficial digital flexor tendon (SDFT) in horses is the force loaded on the SDFT during repeated running. Therefore, decreasing this force may reduce SDFT injury. It has been reported that strain on the SDFT decreases with a toe-wedge shoe. ...

REASONS FOR PERFORMING STUDY: 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 ...

REASONS FOR PERFORMING STUDY: Maximally exercising horses achieve mean pulmonary artery pressures (Ppa(mean)) that exceed the minimum threshold (75 mmHg) estimated for pulmonary capillary rupture and exercise-induced pulmonary haemorrhage (EIPH). EIPH is not expected to occur during moderate submaximal exercise (i.e. 40-60% VO2max) since Ppa(mean) remains well below this threshold. ...

REASONS FOR PERFORMING STUDY: 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. OBJECTIVES: To evaluate the ...

REASONS FOR PERFORMING STUDY: A close relationship between limb and respiratory rhythms has been shown in clinically healthy galloping horses due to mechanical constraints in the thoracic region. This synchronisation leads to a 1/1 ratio between stride frequency (SF) and respiratory frequency (RF) during galloping. Very little is known about ...

REASONS FOR PERFORMING STUDY: Adrenergic activity accompanies intense exercise and mediates physiological and metabolic responses to exercise. Guanabenz, an antihypertensive drug marketed for human usage, depresses brain vasomotor and cardioaccelerator centres, blocks peripherally adrenergic neurons and is reportedly used as a calming agent in horses but little is known of ...

REASONS FOR PERFORMING STUDY: Hyperhydration, prior to prolonged moderate-intensity exercise simulating the 2nd day of a 3-day equestrian event (E3DEC), may induce arterial hypoxaemia detrimental to performance. OBJECTIVES: Because moderate-intensity exercise does not induce arterial hypoxaemia in healthy horses, the effects of pre-exercise hypervolaemia on arterial oxygenation were examined during ...

REASONS FOR PERFORMING STUDY: To study the possible long-term effect of improved glucose tolerance in horses after long-term training, as the impact of exercise training on glucose metabolism is still unclear in the equine species. It is not known whether there is a direct long-term effect of training or if ...

REASONS FOR PERFORMING STUDY: Although valvular regurgitation is diagnosed frequently by colour Doppler echocardiography in racehorses at rest, there is currently no information about the effect of exercise on valvular regurgitation. OBJECTIVES: To investigate the effect of light exercise on valvular regurgitation in a population of trotters. METHODS: Standardbred trotters ...

REASONS FOR PERFORMING STUDY: 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 ...

REASON FOR PERFORMING STUDY: There is no good method for measuring net anaerobic power in exercising horses to allow accurate estimates of total metabolic power. HYPOTHESIS: The increase in VO2max when breathing hyperoxic (HO) gas should be accompanied by a stoichiometrically equal (in terms of ATP turnover, i.e. energy equivalents) ...

REASONS FOR PERFORMING STUDY: There is limited published work on the effect of training using intensive and short intervals of exercise to condition horses for racing. Objectives: To examine the effect of conditioning horses 1, 2 or 3 x a week using 2 short fast exercise intervals on blood lactate ...

REASON FOR PERFORMING STUDY: Dynamic pharyngeal collapse (PC) is a condition seen in racehorses that can be career-ending. OBJECTIVES: 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 ...

REASONS FOR PERFORMING STUDY: Horses develop high pulmonary pressures during exercise, which force fluid out of pulmonary capillaries. Specific airway diseases in horses, especially those associated with hypoxaemia, hypercapnoea and acidosis may influence pulmonary haemodynamics and pulmonary interstitial fluid equilibrium. OBJECTIVES: This study was designed to determine fluid flux (J(V-A) ...

Prerace administration of frusemide to horses has been linked with a significant improvement in racing performance, but the basis for this improvement is unclear. To test whether improved performance with prerace administration of frusemide is due to the drug's diuresis-induced weight loss rather than its apparent alleviation of exercise-induced pulmonary ...

REASONS FOR PERFORMING STUDY: The prevalence and severity of cardiac arrhythmias during exercise in athletic horses presented for poor performance is not well described. OBJECTIVES: 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 ...

BACKGROUND: Alterations in the appearance and function of gastrointestinal mucosa are common after strenuous exercise. However, the duration of exercise required to alter the gastrointestinal mucosa has not been reported. HYPOTHESIS: We used 42 sled dogs to test the hypothesis that the magnitude of exercise-induced gastrointestinal mucosal dysfunction is related ...

OBJECTIVE: To assess whether reported alterations in metabolism of cartilage matrix in young (0 to 24 months old) horses with osteochondritis dissecans (OCD) may also be found in older (24 to 48 months old) horses with clinical signs of OCD and to investigate the role of eicosanoids in initiating these ...

OBJECTIVE: To measure alterations in lameness severity that occur following use of extracorporeal shock wave therapy (ESWT) in horses with naturally occurring unilateral forelimb lameness. DESIGN: Nonrandomized clinical trial. ANIMALS: 9 horses with unilateral forelimb lameness. PROCEDURES: Force platform gait analysis was performed prior to administration of any treatments (baseline) ...

REASONS FOR PERFORMING STUDY: The presence of abnormal respiratory sounds is commonly associated with obstructions of the upper respiratory tract. In order to establish their clinical significance measurements are required of both normal and abnormal respiratory sounds produced by horses exercising over-ground. OBJECTIVES: To determine whether high quality recordings of ...

Neurotensin is produced mainly in the N cells of the ileum and has a role in appetite regulation; levels are decreased in obese subjects and increase after bariatric surgery. Mature neurotensin is very unstable, with a short half-life. The objective of this study was to compare baseline and postoperative levels ...

BACKGROUND & AIMS: Continuous nasogastric infusion is commonly used to deliver enteral feed but current methods used to assess tolerance based on aspiration and measurement of gastric residual volume have been criticised. Electric impedance tomography (EIT) measures gastric emptying by monitoring changes in epigastric impedance when a meal progressively empties ...

Dehydration and the associated impairment of cardiovascular and thermoregulatory function comprise major veterinary problems in horses performing prolonged exercise, particularly under hot and humid conditions. For these reasons, there is considerable interest in using pre-exercise hyperhydration to help maintain blood volume in the face of the excessive fluid loss associated ...

Previous studies have shown that sildenafil inhibits the esophageal motility in both humans and animals. The aim of this study was to investigate the effects of sildenafil on intestinal myoelectrical activity and motility. The study was composed of 2 experiments and performed in 7 healthy female dogs with a duodenal ...