Topic:Heart Rate
Heart rate in horses is a physiological parameter that reflects the number of heartbeats per minute. It is an important indicator of cardiovascular function and can be influenced by factors such as exercise, stress, excitement, and health status. Monitoring heart rate provides valuable insights into the horse's physical condition and can aid in assessing fitness levels or detecting potential health issues. In equine practice, heart rate is often measured using stethoscopes, heart rate monitors, or electrocardiograms. This page compiles peer-reviewed research studies and scholarly articles that explore the determinants, measurement techniques, and implications of heart rate variations in equine health and performance.
[Stress parameters and behaviour of horses in walkers with and without the use of electricity]. In order to investigate stress responses of horses in walkers with and without electricity, 12 horses were trained during 3 weeks in a horse walker with and without the use of electricity (3.7 kV). To evaluate the stress response, cortisol levels in the blood were measured, the heart rate was monitored using the Polar® system and the behaviour was evaluated. Neither the cortisol levels nor the heart rates showed any relevant statistically significant difference between horses moved in the horse walker with or without the use of electricity. The highest cortisol levels and heart rates were rec...
Recovery from desflurane anesthesia in horses with and without post-anesthetic xylazine. The objective of this study was to compare recovery from desflurane anesthesia in horses with or without post-anesthetic xylazine. Six adult horses were anesthetized on 2 occasions, 14 d apart using a prospective, randomized crossover design. Horses were sedated with xylazine, induced to lateral recumbency with ketamine and diazepam, and anesthesia was maintained with desflurane. One of 2 treatments was administered intravenously at the end of anesthesia: xylazine [0.2 mg/kg body weight (BW)] or an equivalent volume of saline. Recovery parameters were recorded and assessed by 2 blinded observe...
Cardiopulmonary effects of an infusion of remifentanil or morphine in horses anesthetized with isoflurane and dexmedetomidine. To examine the cardiopulmonary effects of infusions of remifentanil or morphine, and their influence on recovery of horses anesthetized with isoflurane and dexmedetomidine. Methods: Randomized crossover study with 7-day rest periods. Methods: Six adult horses (507 ± 61 kg). Methods: After the horses were sedated with xylazine, anaesthesia was induced with ketamine and diazepam, and maintained with isoflurane. After approximately 60 minutes, a dexmedetomidine infusion was started (0.25 μg kg(-1) then 1.0 μg(-1) kg(-1) hour(-1) ) in combination with either saline (group S), morphine (0.15 mg ...
Parturition in horses is dominated by parasympathetic activity of the autonomous nervous system. External and internal stressors prolong parturition in different species. At parturition, sympathoadrenal activation should be avoided because an increased sympathetic tone may cause uterine atonia via β2-receptors. We hypothesized that at physiological parturition, horses are under parasympathetic dominance, and stress-response mechanisms are not activated during delivery of the foal. To evaluate stress responses, heart rate, heart rate variability, catecholamines, and cortisol were analyzed in mares (n = 17) throughout foaling. Heart rate decreased from 2 hours before (51 ± 1 beats/minute)...
Recommendations for management of equine athletes with cardiovascular abnormalities. Murmurs and arrhythmias are commonly detected in equine athletes. Assessing the relevance of these cardiovascular abnormalities in the performance horse can be challenging. Determining the impact of a cardiovascular disorder on performance, life expectancy, horse and rider or driver safety relative to the owner's future expectations is paramount. A comprehensive assessment of the cardiovascular abnormality detected is essential to determine its severity and achieve these aims. This consensus statement presents a general approach to the assessment of cardiovascular abnormalities, followed by a ...
Hyoscine-N-butylbromide premedication on cardiovascular variables of horses sedated with medetomidine. To evaluate the effects of intravenous (IV) or intramuscular (IM) hyoscine premedication on physiologic variables following IV administration of medetomidine in horses. Methods: Randomized, crossover experimental study. Methods: Eight healthy crossbred horses weighing 330 ± 39 kg and aged 7 ± 4 years. Methods: Baseline measurements of heart rate (HR), cardiac index (CI), respiratory rate, systemic vascular resistance (SVR), percentage of patients with second degree atrioventricular (2(o) AV) block, mean arterial pressure (MAP), pH, and arterial partial pressures of carbon dioxide (PaCO2 ) an...
Analgesic and gastrointestinal effects of epidural morphine in horses after laparoscopic cryptorchidectomy under general anesthesia. To evaluate the hypothesis that epidural morphine (0.1 mg kg(-1) ) decreases pain in horses after laparoscopic surgery without adversely affecting gastrointestinal (GI) motility. Methods: Randomized clinical trial. Methods: Eighteen horses undergoing laparoscopic cryptorchidectomy under general anesthesia. Methods: Horses were randomly assigned to receive either epidural morphine (0.1 mg kg(-1) ) or no epidural before the start of surgery. Pain behaviors were assessed during the first two post-operative days using a numerical rating scale. Barium-filled spheres were administered through a naso...
Effect of body position on intra-abdominal pressures and abdominal perfusion pressures measured at three sites in horses anesthetized with short-term total intravenous anesthesia. To assess effects of body position on direct measurements of intra-abdominal pressure (IAP) and abdominal perfusion pressure (APP) in horses anesthetized with total intravenous anesthesia (TIVA). Methods: 9 healthy adult horses. Methods: Instrumentation in unsedated standing horses involved insertion of an arterial catheter for blood pressure measurements and 3 intraperitoneal cannulas (left flank, right flank, and ventral abdomen) for IAP measurements. Baseline values were measured for heart rate, respiratory rate, systolic arterial blood pressure, mean arterial blood pressure (MAP), diastoli...
N-butylscopolammonium bromide causes fewer side effects than atropine when assessing bronchoconstriction reversibility in horses with heaves. Bronchospasm results in airway obstruction in horses with heaves. Atropine is the most potent bronchodilator drug currently available for horses, but is associated with side effects that limit its use. Like atropine, N-butylscopolammonium bromide (NBB) is an anticholinergic agent with bronchodilatory properties. Objective: To compare the bronchodilating effects and side effects of atropine and NBB in horses with heaves. Methods: Cross-over experiment using horses with heaves. Methods: Eight horses with heaves were administered atropine and NBB, using a cross-over design. Heart rate, pupillary ...
Effects of hyperflexion on acute stress responses in ridden dressage horses. The effects of hyperflexion on the welfare of dressage horses have been debated. This study aimed to investigate acute stress responses of dressage horses ridden in three different Head-and-Neck-positions (HNPs). Fifteen dressage horses were ridden by their usual rider in a standardised 10-min dressage programme in either the competition frame (CF), hyperflexion ("Low-Deep-and-Round"; LDR) or a looser frame (LF) in a balanced order on three separate test days. Heart rate (HR), heart rate variability parameters (HRV), behaviour and rein tension were recorded during the test. Salivary cortisol c...
Characterization of a reversible lameness model in the horse. Characterization of a model of reversible foot lameness in the horse. Methods: Both forelimb hooves were fitted with a circumferential clamp. After three baseline measurements utilizing a force platform, one clamp was tightened to induce a grade 2.5/5 lameness and left in place for 120 hours. Serial heart rate and force platform measurements were obtained and the asymmetry index was calculated. After 120 hours, the clamp was released and force platform data recorded until the horse returned to soundness. The procedure was repeated for the opposite forelimb. The responses of treatment compared ...
The effect of different types of physical exercise on the behavioural and physiological parameters of standardbred horses housed in single stalls. The aim of this study was to investigate the impacts of three different physical exercises on the physiological and behavioural patterns of Standardbred trotters housed in single stalls. Twelve racing mares were observed twice during each different exercise: daily training (DT) consisted of forty minutes at slow trot (4-5 m/s) in a small track; maximal exercise (ME) consisted of 1600 m run at maximal velocity; race (R) was a real race of 1600 m. The mares were examined at rest in their stall (Time I), soon after the completion of the exercise (Time II), one hour (Time III), and two hours...
Physiological response to a breed evaluation field test in Icelandic horses. This study examined the response in terms of heart rate (HR), respiratory rate (RR), haematocrit (Htc), rectal temperature (RT), and some plasma variables in Icelandic horses of different sexes and ages performing the riding assessment in a breed evaluation field test (BEFT). The study was conducted in Iceland on 266 horses (180 mares and 86 stallions, divided into four age groups; 4, 5, 6 and ≥7 years old). RT and RR were recorded and blood samples were taken before the warm-up and after the riding assessment. Horse HR, velocity and distance were recorded during the warm-up, the riding asse...
Effect of different head-neck positions on physical and psychological stress parameters in the ridden horse. Different head-neck positions (HNPs) are used in equestrian sports and are regarded as desirable for training and competition by riders, judges and trainers. Even though some studies have been indicative of hyperflexion having negative effects on horses, this unnatural position is frequently used. In the present study, the influence of different HNPs on physical and psychological stress parameters in the ridden horse was investigated. Heart rate (HR), heart rate variability (HRV) and blood cortisol levels were measured in 18 horses. Low frequency (LF) and high frequency (HF) are power componen...
[Influence of atracurium on cardiovascular parameters in horses undergoing vitrectomy during general anaesthesia, and on recovery duration and quality]. In most ocular procedures, a central position of the eye is necessary. This can be achieved using a deep plane of anaesthesia, locoregional blocks or with neuromuscular blocking agents. The aim of this study was to evaluate the influence of atracurium on cardiovascular parameters, and on recovery quality and duration in horses. Methods: Thirty-four warmblood horses undergoing in total 50 vitrectomies were divided into two groups. Premedication, induction and maintenance were identical in all patients. After 20 minutes, horses of group A received atracurium (0.1 mg/kg) while in the control grou...
Arterial oxygen tension and pulmonary ventilation in horses placed in the Anderson Sling suspension system after a period of lateral recumbency and anaesthetised with constant rate infusions of romifidine and ketamine. Some controversy exists over whether or not horses' recovery and cardiopulmonary function are affected by suspension in slings. Objective: To measure arterial oxygen tension and pulmonary ventilation in anaesthetised horses placed in a standing position in an Anderson Sling (AS) after a period of right lateral recumbency (RLR). Methods: Randomised crossover experimental study. Methods: Six Standardbred horses were anaesthetised twice. Catheters were inserted into the right jugular vein and the left carotid artery. After premedication with romifidine, anaesthesia was induced with diazepam and k...
Efficacy of intramuscular meperidine hydrochloride versus placebo in experimental foot lameness in horses. There are no peer reviewed, blinded controlled studies regarding the skeletal analgesic efficacy of intramuscularly administered meperidine in horses. Objective: Using an adjustable heart bar shoe model of equine foot pain, the objective of this study was to test the hypothesis that meperidine (pethidine) administered intramuscularly would prove more efficacious in alleviating lameness than a saline placebo. Methods: Crossover pharmacodynamic experiment. Methods: Eight healthy adult Thoroughbred horses randomly underwent weekly i.m. treatments 1 h after lameness induction: saline placebo (1â...
[The effectiveness of romifidine on myocardial function in horses with and without heart disease, evaluated with M-mode echocardiography and PW-tissue Doppler imaging]. The aim of this study was to evaluate to what extent the myocardial function in horses (measured by PW-tissue Doppler = PW-TDI) is affected during a sedation with romifidine (0.04 mg/kg, i. v.), particularly in case of an accompanying heart disease. Based on an echo- and electrocardiographic examination, a total of 45 horses was subdivided into group 1 (no heart disease), group 2 (heart disease without increased heart dimensions) and group 3 (heart disease with increased heart dimensions). Heart rate (HF), M-mode- (FS%) and TDI-measurements were performed before and after the application of ro...
Reduced-size microchips for identification of horses: response to implantation and readability during a six-month period. In this study, readability of reduced-size microchips in horses and the response to implantation were analysed. It was hypothesised that small microchips can be implanted stress-free but are less readable than larger microchips. Adult mares (n=40) were implanted with a reduced-size microchip (10.9×1.6 mm) at the left side of the neck (size of conventional microchips 11.4×2.2 mm). Microchips were identified with three different scanners (A, B, C) immediately, and at 6, 12 and 28 weeks after implantation. Twelve out of the 40 mares were submitted to microchip implantation and control treatment...
Effects of three antagonists on selected pharmacodynamic effects of sublingually administered detomidine in the horse. To describe the effects of alpha2 -adrenergic receptor antagonists on the pharmacodynamics of sublingual (SL) detomidine in the horse. Methods: Randomized crossover design. Methods: Nine healthy adult horses with an average age of 7.6 ± 6.5 years. Methods: Four treatment groups were studied: 1) 0.04 mg kg(-1) detomidine SL; 2) 0.04 mg kg(-1) detomidine SL followed 1 hour later by 0.075 mg kg(-1) yohimbine intravenously (IV); 3) 0.04 mg kg(-1) detomidine SL followed 1 hour later by 4 mg kg(-1) tolazoline IV; and 4) 0.04 mg kg(-1) detomidine SL followed 1 hour later by 0.12 m...
[Comparison of different electrocardiographic techniques for the detection of arrhythmias in horses]. The aim of the study was to extend the range of the electrocardiographic examination in horses, evaluating the practicability of special electrocardiographic techniques (exercise- and Holter-ECG) and comparing these with more common techniques (resting-ECG) in equine medicine. Methods: Electrocardiographic examination (resting-ECG for 1 minute, exercise-ECG and Holter-ECG) was performed in 20 horses without any clinical or echocardiographic findings and in 80 patients with abnormal findings (valvular regurgitation and/or atrial fibrillation). Results: In comparison with the resting-ECG, the ex...
Effects of dexmedetomidine and xylazine on cardiovascular function during total intravenous anaesthesia with midazolam and ketamine and recovery quality and duration in horses. To compare cardiovascular effects and recovery quality and duration of total intravenous anaesthesia (TIVA) with xylazine-ketamine-midazolam or dexmedetomidine-ketamine-midazolam. Methods: Prospective, randomized experimental cross-over trial. Methods: Eight adult warmblood horses. Methods: After sedation with acepromazine and either xylazine [0.5 mg kg(-1) , intravenously (IV)] or dexmedetomidine (3.5 μg kg(-1) IV) anaesthesia was induced with ketamine and midazolam and maintained with a constant rate infusion (CRI) of xylazine (1 mg kg(-1)  hour(-1) ) [XKM] or dexmedetomidine (7 μg...
The influence of age on serum concentrations of cardiac troponin I: results in rats, monkeys, and commercial sera. Cardiac troponins serve as serum biomarkers of myocardial injury. The current study examined the influence of age on serum concentrations of cardiac troponin I (cTnI). An ultrasensitive immunoassay was used to monitor cTnI concentrations in Sprague-Dawley (SD) rats and Erythrocebus patas monkeys of different ages. The mean cTnI concentrations were highest in 10-day-old rats compared to 25-, 40-, and 80-day-old SD rats. Cardiomyocyte remodeling was apparent in hearts from 10-day-old SD rats as evident by hypercellularity, irregularly shaped nuclei, and moderate numbers of myocytes undergoing mi...
Cardiorespiratory and antinociceptive effects of two different doses of lidocaine administered to horses during a constant intravenous infusion of xylazine and ketamine. This study investigated the antinociceptive effects of a constant rate infusion (CRI) of lidocaine during xylazine and ketamine anesthesia in horses and aimed to correlate these effects with cardiorespiratory variables, bispectral index (BIS) and plasma lidocaine concentrations. Six adult crossbred mares weighing 320-400 kg were anesthetized on three different occasions. Sedation was performed with xylazine (0.75 mg/kg IV) and anesthetic induction with guaifenesin (75 mg/kg IV) and ketamine (2 mg/kg IV). Anesthesia was maintained with 37.5 μg/kg/min of xylazine and 87.5 μg/kg/min of ketamine...
Using eye temperature and heart rate for stress assessment in young horses competing in jumping competitions and its possible influence on sport performance. The aims of this study were, first, to evaluate eye temperature (ET) with infrared thermography and heart rate (HR) to measure stress in horses during show jumping competitions and their relationship with competition results, and second, to evaluate the influence of different extrinsic and intrinsic factors of the horse on the stress measurements analysed. One hundred and seventy-three Spanish Sport Horses were analysed for ET and HR, and these measurements were taken 3 h before the competition, just after and 3 h after it. Two interval measurements were also assessed for each parameter. Posit...
Prevalence and risk factors for cardiac diseases in a hospital-based population of 3,434 horses (1994-2011). Risk factors for cardiac diseases in horses have not been explored in a large population of animals. Objective: To describe risk factors for various cardiac diseases in a hospital-based population of horses. Methods: Files of 3,434 horses admitted at the Internal Medicine Department of the Liege Equine Teaching Hospital between 1994 and 2011 were reviewed and of those, 284 were categorized as having moderate-to-severe cardiac disease. Methods: Observational study. After calculating prevalence for each cardiac disease, we tested whether breed (chi-square test) or sex, age, body weight (BW), and...
Physiological parameters of endurance horses pre- compared to post-race, correlated with performance: a two race study from scandinavia. Few studies have investigated the physiological parameters of endurance horses in Scandinavia. Hence, this two race study has focused on the effects of endurance racing in terms of equine clinicopathological blood parameters, heart score, and fluid use. Race A involved 15 horses (120 km). Two pre- and one post-race blood samples were taken, body condition score was assessed in triplicate pre-race, and an ECG was used to determine heart score. Race B involved 16 horses (65-120 km). One pre- and two post-race blood samples were taken. For both races, horse data as well as fluid intake estima...
A prospective study on a cohort of horses and ponies selected for participation in the European Eventing Championship: reasons for withdrawal and predictive value of fitness tests. Eventing is generally recognized as a challenging equestrian discipline and wastage figures for this discipline are relatively high. There is a need for information that provides insight into the causes of wastage and withdrawal from competition, for animal welfare and economic reasons. The aim of the present investigation was to conduct a prospective study following the entire national selection of event horses (n = 20) and ponies (n = 9) in the Netherlands that prepared for the European Championship in 2010 (ponies) and 2011 (horses), noting causes of withdrawal and monitoring fitness using ...
Effects of intravenous administration of polymyxin B in neonatal foals with experimental endotoxemia. To evaluate the effect of IV administration of polymyxin B on clinical and serum biochemical variables in foals with experimental endotoxemia. Methods: Prospective experimental study. Methods: 14 healthy neonatal foals. Methods: Foals were randomly assigned to a treatment or control group and were administered a single dose of lipopolysaccharide (0.5 μg/kg [0.23 μg/lb]) IV over 30 minutes. The treatment group received polymyxin B (6,000 U/kg [2,727 U/lb], IV) immediately after completion of lipopolysaccharide infusion; the control group was administered an equal volume of saline (0.9% NaCl) ...