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.
Kerr CL, Keating SCJ, Arroyo LG, Viel L.Neonatal foals may require prolonged sedation to permit ventilatory support in the first few days of life. The objective of this study was to evaluate and compare the cardiopulmonary effects and clinical recovery characteristics of 2 sedative/analgesia protocols in healthy foals receiving assisted ventilation. Foals were randomized to receive dexmedetomidine, butorphanol, and propofol (DBP) or midazolam, butorphanol, and propofol (MBP) during a 24-hour period. Infusion rates of dexmedetomidine, midazolam, and propofol were adjusted and propofol boluses administered according to set protocols t...
Jenny JCA, Hopster K, Hurcombe SD.To compare the accuracy and precision of cardiac output (CO) measurements derived from 4 thermodilution protocols that used different injectate temperatures and volumes in healthy adult horses. Methods: 8 healthy adult horses. Methods: Horses were anesthetized and instrumented with Swan-Ganz catheters. The CO was derived from each of 4 thermodilution protocols (IV injection of physiologic saline [0.9% NaCl] solution chilled to < 5 °C at volumes of 1 mL/15 kg of body weight [protocol A; control], 1 mL/25 kg [protocol B], and 1 mL/35 kg [protocol C] or maintained at 17 °C at a volume of 1 m...
Baldwin AL, Rector BK, Alden AC.Assisted living is a fast-growing living option for seniors who require residence-based activities for maintaining mental and physical health. Guided equine interactions may benefit seniors, so an on-site equine program was started at Hacienda at the River senior living community. For research purposes, twenty-four residents and associates, aged fifty-five or over, consented to physiological measurements before, during and after four guided sessions of stroking one of three horses for 10 min over 4-6 weeks. Heart rate variability (HRV) was measured simultaneously in humans and horses during in...
Stachurska A, Wiśniewska A, Kędzierski W, Różańska-Boczula M, Janczarek I.Horses in a herd develop and maintain a dominance hierarchy between all individuals. There are many situations in riding facilities and studs in which horses have to be separated out of a group. The aim of the study was to determine the rate of behaviours, level of locomotor activity and cardiac activity variables in a herd of horses during a short social separation of individuals differently ranked in the dominance hierarchy. Twelve adult Arabian mares were involved. A behavioural test had been performed before the main experiment to determine the rank order of the mares in this social herd. ...
O' Brien C, Pegg J.This observational study aimed to elucidate the effects of RWST on the cardiovascular and musculoskeletal systems of horses and concurrently determine whether RWST limits distal limb temperature increases previously reported during gallop training on land. A group of 15 clinically sound international event horses were recruited, and heart rate (HR), speed (km/h) and thermal images of the distal limb were analysed at set intervals during RWST training. Intervals of RWST produced a total mean HR value of 65.18 ± 3.76%, which is within the parameters for increased aerobic stamina. Mean HR increa...
Nuchprayoon N, Ritruechai P, Watchararat K, Limroongruengrat W, Wongtawan T, Arya N.Hippotherapy in patients with neuromuscular dysfunction creates high focal pressure on the pony's back due to bareback riding and an asymmetrical riding position. This study aimed to investigate the acute effect of asymmetrical bareback riding on the pony's spinal kinematics, blood lactate, serum creatine kinase, heart rate, and temperament score. Eight ponies were selected, and they were walked on a treadmill for 45 min on each experimental day, including warm-up (5 min), weight-loading by mannequin (30 min), and cool-down (10 min) sessions. During the weight-loading session, three different ...
Verdegaal EJMM, Howarth GS, McWhorter TJ, Boshuizen B, Franklin SH, Vidal Moreno de Vega C, Jonas SE, Folwell LE, Delesalle CJG.Establishing proper policies regarding the recognition and prevention of equine heat stress becomes increasingly important, especially in the face of global warming. To assist this, a detailed view of the variability of equine thermoregulation during field exercise and recovery is essential. 13 endurance horses and 12 trotter horses were equipped with continuous monitoring devices [gastrointestinal (GI) pill, heartrate (HR) monitor, and global positioning system] and monitored under cool weather conditions during four endurance rides over a total of 80 km (40 km loops) and intense trotter trac...
Miller AB, Harris PA, Barker VD, Adams AA.Long-distance transport is associated with stress-related changes in equine immune function, and shipping-associated illnesses are often reported. Horses are frequently transported short distances, yet the effects of short-term transport on immune function remain largely unknown. Twelve horses, aged 15-30 yr, were assigned to either the control (n = 6) or treatment (n = 6) groups; treatment horses received a daily antioxidant supplement 3 weeks before and after transport. All horses were transported for approximately 1.5-2 hr on Day 0. Blood was collected via jugular venipuncture at 15-min pre...
Scherrer NM, Hopster K.To study the surgical, anesthetic and recovery qualities of horses receiving either a neuromuscular blocking agent (atracurium) or intravenous lidocaine (treatment groups A and L, respectively). Methods: A total of thirty horses presented for ocular surgery were used in this study. Methods: Horses were randomly assigned to receive either atracurium (group A) or a lidocaine constant rate infusion (group L). Surgical quality was graded on a scale from 1 (excellent)-5 (poor). While anesthetized, the heart rate, oxygen saturation and mean arterial blood pressure, and end-expiratory carbon dioxide ...
The incidence of significant arrhythmias in sport horses and knowledge about their exact influence on athletic performance need to be clarified. The aims of the present study are to report the prevalence of cardiac arrhythmias during maximal treadmill exercise in poorly performing Standardbreds, and to investigate the possible relationship of demographic, cardiac and performance indices on premature complexes (PCs). Electrocardiographic Holter recordings before, during and after treadmill exercise testing of 158 poorly performing Standardbreds were analyzed retrospectively. Fifty horses did no...
D' Fonseca NMM, Beukers M, Wijnberg ID, Navas de Solis C, de Ruijter-Villani M, van Doorn DA, Stout TAE, Roelfsema E.Changes in cardiovascular parameters, including blood pressure (BP) and cardiac anatomical dimensions, are an inconsistent feature of the equine metabolic syndrome. The order in which these changes arise is unknown. Objective: Determine the order in which EMS-associated changes in cardiovascular parameters arise. Methods: Twenty Shetland pony mares. Methods: High-energy (HE) diet mares were fed 200% of net energy requirements for 1 (n = 3) or 2 (n = 7) consecutive diet-years, with 17 weeks of hay-only between years. Noninvasive BP measurements and echocardiograms were performed during bo...
Hopster K, Hurcombe SDA.Bioreactance is the continuous analysis of transthoracic voltage variation in response to an applied high frequency transthoracic current and was recently introduced for non-invasive cardiac output measurement (NICOM). We evaluated NICOM compared to thermodilution (TD) in adult horses. Six healthy horses were used for this prospective, blinded, experimental study. Cardiac output (CO) measurements were performed simultaneously using TD and the bioreactance method. Different cardiac output scenarios were established using xylazine (0.5 mg/kg IV) and dobutamine (1.5-3 mcg/kg/min). Statistical ana...
Vitale V, Vezzosi T, Tognetti R, Fraschetti C, Sgorbini M.Recently, the use of smartphone ECG devices has been reported in humans and animals. Nevertheless, as the electrodes of these devices are inseparable, they can create only a precordial reading in veterinary species. Thus, although the smartphone ECG devices are considered valuable as a screening tool for the detection of some common arrhythmias, they are not always a reliable method for the measurement of the duration of the electrical deflections. The objectives of this study were to evaluate the feasibility of a novel smartphone ECG device, to report the readings obtained recorded simultaneo...
Kritchevsky J, Olave C, Tinkler S, Tropf M, Ivester K, Forsythe L, Couetil L.The use of thyroid supplement is pervasive in athletic horses although its effects on measures of performance are not known. Objective: One purpose of this study was to determine whether supra-physiologic doses of levothyroxine affect the velocities at which blood lactate was greater than 4 mmol/L (VLa4 ) and heart rate was over 150 (V150 ) and 200 (V200 ) beats per minute respectively. Additionally, a survey of post-race blood samples was also conducted to determine whether high thyroxine concentrations were common in racehorses. Methods: A randomised, crossover, trial was performed in six h...
Filippo PAD, Duarte BR, Albernaz AP, Quirino CR.The objective of this study was to evaluate the effect of feed restriction on some physical and blood parameters in horses kept outdoors under natural conditions. Twenty horses were deprived of food for 48 h. They were closely monitored and examined, and blood samples were taken at the beginning (0) of the experiment and 6, 12, 18, 24, 30, 36, 42 and 48 hours afterward. During the experimental period, the control group (12 animals) had free access to water and hay, while the restricted group had free access to water only. Data were submitted to two-way analysis of variance with repeated measur...
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...
Farinelli F, de Rezende ASC, Fonseca MG, Lana ÂMQ, Leme FOP, Klein BON, Silva RHP, de Abreu AP, Damazio MJ, Melo MM.The Horse Agribusiness Complex is an important activity in the Brazilian agricultural sector. Mangalarga Marchador (MM) is the most numerous breed of horses in Brazil and its temperament and gait characteristics (4-beat stepping gait) allow for the constant growth of the breed and the performance of vs. equestrian activities. The training management currently adopted with MM horses is based on empiricism, and scientific support is necessary to improve the well-being of horses in competitions and maintain the physical integrity of these athletes. Therefore, this study aimed to verify the effect...
Mansour C, Mocci R, Santangelo B, Sredensek J, Chaaya R, Allaouchiche B, Bonnet-Garin JM, Boselli E, Junot S.The parasympathetic tone activity (PTA) index is based on heart rate variability and has been developed recently in animals to assess their relative parasympathetic tone. This study aimed to evaluate PTA index in anaesthetized horses with different health conditions and the performance of PTA variations (∆PTA) to predict changes in mean arterial pressure (MAP). Thirty-nine client-horses were anaesthetized for elective or colic surgery and divided into "Elective" and "Colic" groups. During anaesthesia, dobutamine was administered as treatment of hypotension (MAP <60 mmHg). In both groups, no...
Roşu O, Melega I, Evans AL, Arnemo JM, Küker S.Feral horses are immobilized for a variety of reasons including population control via contraceptives. Although opioid combinations have been successfully used for immobilization of feral horses, there is a need for combinations using drugs that are more readily available and present less of a human health hazard. We evaluated the chemical immobilization with physiological measurements and blood gas analyses of 91 free-ranging feral horses () remotely immobilized with a combination of 30 mg medetomidine and 775 mg ketamine in a single disposable 6 ml dart. During immobilization, heart rate, re...
Reed RA, Epstein KL, Bramski JH, Diehl KA, Ryan CA.To determine the effect of xylazine on intracranial pressure (ICP) in standing compared to isoflurane-anesthetized horses. Methods: Prospective, crossover study design. Methods: University Teaching Hospital. Methods: Six adult horses donated to the University. Horses were determined to be healthy via physical examination, complete blood count, and neurological evaluation. Methods: Horses were anesthetized, maintained on isoflurane in oxygen in left lateral recumbency, and ventilated to normocapnia. Horses were instrumented for intraparenchymal measurement of ICP, invasive blood pressure, pulse...
Jansson A, Gunnarsson VÞ, Ringmark S, Ragnarsson S, Söderroos D, Ásgeirsson E, Jóhannsdóttir TR, Liedberg C, Stefánsdóttir GJ.This study examined the effect of altered body weight (BW) and body fat content on exercise performance and recovery. Nine horses were divided into two groups, and changes in BW and fat content were induced by feeding a high (HA) or restricted (RA) energy allowance for 36 days in a cross-over design. In the last week of each treatment, BW and body condition score (BCS) were recorded, body fat percentage was estimated using ultrasound, and a standardized incremental treadmill exercise test (SET) and competition-like field test were performed (scored by judges blinded to treatments). Blood samp...
Cabrera AMZ, Soto MJC, Aranzales JRM, Valencia NMC, Gutiérrez MPA.Information on performance indices in Paso horses is scarce. Field exercise tests are necessary to recreate the exertion that occurs during training and competition. To describe blood lactate concentrations and heart rates of untrained Colombian Paso horses (CPHs) in response to a field exercise test. A 30-minutes-long standardized field exercise test was carried out on 11 untrained adult CPHs of both sexes. Blood lactate concentration (BLConc) and heart rate (HR) were measured before, during each step of the test, and at recovery. The BLConc and HR were used to calculate the HR at which a BLC...
Lee KE, Kim JG, Lee H, Kim BS.This study aimed to investigate whether breed, sex, and age affected temperament differently (more or less neophobic) in mature horses during a novel object test. The study included Jeju crossbred (n = 12, age = 9.42 ± 4.57 y), Thoroughbred (n = 15, age = 10.73 ± 3.09 y), and Warmblood horses (n = 12, age = 13.08 ± 3.55 y) with the females (n = 22, age = 11.36 ± 4.24 y) and geldings (n = 17, age = 10.65 ± 3.66 y). Jeju crossbreds (Jeju horse × Thoroughbred) are valuable considering their popular usage in Korea, but limited studies have explored temperament of Jeju crossbred horses. A tra...
Contalbrigo L, Borgi M, De Santis M, Collacchi B, Tuozzi A, Toson M, Redaelli V, Odore R, Vercelli C, Stefani A, Luzi F, Valle E, Cirulli F.Equine-assisted interventions (EAIs) are well-known complementary practices combining physical activity with emotional/cognitive stimulation. They are especially suited for children with autism spectrum disorders (ASD) who need a high degree of physical and psychological enrichment. Even though EAIs have become a common practice, stress responses in horses interacting with individuals that can manifest inappropriate behaviours, such as ASD children, have not been thoroughly investigated. Our multicentre study aimed to investigate behavioural and physiological indices of stress in horses involv...
Contreras-Aguilar MD, Cerón JJ, Muñoz A, Ayala I.Salivary biomarkers could be useful to evaluate stress, fitness level, and skeletal muscle damage associated to exercise in horses in an easy and non-painful way. Therefore, this study aims to evaluate if cortisol in saliva (sCor), salivary alpha-amylase (sAMY) and butyrylcholinesterase (sBChE) and lactate (sLA) and creatine kinase (sCK) in saliva of horses can show changes during a standardized exercise test, and if they are related to heart rate variability (HRV) parameters related to sympathetic and parasympathetic tone, fitness level or skeletal muscle damage. For this purpose, ten enduran...
Bessonnat A, Vanore M.Evaluate the effect of repeated doses of topical 1% cyclopentolate hydrochloride alone and in combination with topical 2.5% phenylephrine on pupil diameter (PD), tear production (STT-1), intraocular pressure (IOP), digestive function (gut motility and feces production), and heart rate (HR). Methods: Six healthy mares. Methods: In a prospective, randomized, controlled, and crossover design study, the left eye of six healthy mares was administered 0.2 mL of cyclopentolate alone and in combination with 0.2 mL of phenylephrine. The drugs were administered 3 times a day for 1 day, twice a day fo...
Bukhari SSUH, McElligott AG, Parkes RSV.There are approximately 112 million working equids in developing countries, many of which are associated with brick kilns. Brick kilns and overloading are associated with welfare problems in working equids. Understanding equids' abilities and influencing factors are important for both effective performance and welfare. Traditionally, measurement of the amount of 'bone' was used, and more recently, gait symmetry has been identified as a potential marker for loading capacity. Assessment of stride parameters and gait kinematics provides insights into adaptations to loading and may help determine ...
McGill S, Coleman B, Hayes M.Cooling out horses is a common practice after intense exercise. Typical cooling procedures include both walking and drenching (often with scraping). The cool out is performed to ensure the horses physiologic responses returned to a baseline range as quickly as possible. The use of water in cool out provides the greatest potential for removing heat from the animals. However, adding air velocities that can increase evaporation rates from the horses can potentially increase the rate of cool out; thereby reducing the time until the horses' physiologic measurements return to baseline. This study me...
Ricci-Bonot C, Romero T, Nicol C, Mills D.Social buffering occurs when the presence of one animal attenuates another's stress response during a stressful event and/or helps the subject to recover more quickly after a stressful event. Inconsistent previous results might reflect previously unrecognised contextual influences, such as the nature of the stimulus presented or social factors. We addressed these issues in a two-part study of horses paired with familiar (16 subjects) or unfamiliar (16 subjects) companions. Each subject performed 4 tests in a counterbalanced order: novel object test (static ball)-alone or with companion; and um...
O'Reilly C, Zoller J, Sigler D, Vogelsang M, Sawyer J, Fluckey J.Despite the fact that horseback riding is a popular sport, there is little information available on horseback riding as a physical activity. The objective of this experiment was to quantify energy expenditure of participants (n=20) during three riding tests: a 45min walk-trot-canter ride (WTC), a reining pattern ride and a cutting simulation ride while wearing a telemetric gas analyzer. Total energy expenditure (tEE), mean and peak metabolic equivalents of task (MET), heart rate (HR), respiratory frequency (RF), relative oxygen consumption (relVO2), and respiratory exchange ratio (RER) were as...
McCashin FB, Gabel AA.Xylazine administered intramuscularly (IM) to horses at the dose level of 2 mg/kg was an effective sedative and preanesthetic for thiamylal sodium narcosis or thiamylal sodium and halothane anesthesia. Evaluation of response of cardiovascular, respiratory, and hepatic function did not indicate serious untoward effects, although cardiac and respiratory rate decreased, calculated vigor of left ventricular contraction decreased, calculated peripheral vascular resistance increased, and transient innocuous cardiac arrhythmias occurred. Effects of the anesthetics used on respiratory function (blood ...
McConachie E, Barton MH, Rapoport G, Giguère S.Cardiac output (CO) is not routinely measured in critically ill adult horses because of invasiveness of currently validated methods. Noninvasive CO monitoring would complement clinical assessment of hemodynamic status in adult horses. Objective: Volumetric methods for measuring CO will have better agreement with lithium dilution than Doppler-based methods. Methods: Eight healthy adult horses. Methods: Prospective study. CO was manipulated with continuous rate infusions of dobutamine and romifidine to achieve high and low CO states, respectively. At each level, CO was measured by lithium diluti...
Younes M, Robert C, Barrey E, Cottin F.Although cardiac recovery is an important criterion for ranking horses in endurance competitions, heart rate variability (HRV) has hardly ever been studied in the context of this equestrian discipline. In the present study, we sought to determine whether HRV is affected by parameters such as age, exercise duration and test site. Accordingly, HRV might be used to select endurance horses with the fastest cardiac recovery. The main objective of the present study was to determine the effects of age, exercise duration, and test site on HRV variables at rest and during exercise and recovery in young...
Schott HC, Marlin DJ, Geor RJ, Holbrook TC, Deaton CM, Vincent T, Dacre K, Schroter RC, Jose-Cunilleras E, Cornelisse CJ.Limited information exists about the physiological changes and clinical problems that occur in elite horses competing in high-speed 160 km endurance races. Objective: To provide initial data describing changes in physiological and laboratory measurements in horses competing in a high-speed, 160 km endurance race under temperate conditions and to compare data between horses that successfully completed the race and those that failed to finish. Methods: Body mass (BM) was measured, blood samples were collected, and veterinary examinations performed on horses before, during, and at the finish of a...
Thorbergson ZW, Nielsen SG, Beaulieu RJ, Doyle RE.Riding is considered to be an arousing activity for horses. It has been suggested that wither scratching may be a more useful tool for relaxation compared with the common practice of neck patting. In the current study, 18 horses were exposed to 3 treatments, including control or no interaction, neck patting, and wither scratching, for 1 min each following a short obstacle course. Heart rate, heart rate variability, and a variety of behaviors were measured in the horses. Wither scratching produced a significantly longer duration of relaxed-type behaviors. Wither scratching could be a useful to...
Buhl R, Ersbøll AK, Larsen NH, Eriksen L, Koch J.To evaluate by echo- and electrocardiography the cardiac effects of sedation with detomidine hydrochloride, romifidine hydrochloride or acepromazine maleate in horses. Methods: An experimental study using a cross-over design without randomization. Methods: Eight clinically normal Standardbred trotters. Methods: Echocardiographic examinations (two-dimensional, guided M-mode and colour Doppler) were recorded on five different days. Heart rate (HR) and standard limb lead electrocardiograms were also obtained. Subsequently, horses were sedated with detomidine (0.01 mg kg(-1)), romifidine (0.04 mg ...
The incidence of significant arrhythmias in sport horses and knowledge about their exact influence on athletic performance need to be clarified. The aims of the present study are to report the prevalence of cardiac arrhythmias during maximal treadmill exercise in poorly performing Standardbreds, and to investigate the possible relationship of demographic, cardiac and performance indices on premature complexes (PCs). Electrocardiographic Holter recordings before, during and after treadmill exercise testing of 158 poorly performing Standardbreds were analyzed retrospectively. Fifty horses did no...
Muir WW, Skarda RT, Milne DW.An evaluation and comparison of thermodilution technique with dye dilution technique was made in the computation of cardiac output in 39 conscious adult horses (av body wt, 450 kg). Estimation of cardiac output by thermodilution was found to compare favorably with values obtained from dye dilution when a volume of 30 to 40 ml at a temperature of 0 C was used. Difficulties in obtaining accurate thermodilution curves in the horse seem predominantly associated with errors in mixing and observation.
Muir WW, Robertson JT.The visceral analgesic, cardiorespiratory, and behavioral effects induced by xylazine, butorphanol, meperidine, and pentazocine were determined in 9 adult horses with colic. Colic was produced by inflating a balloon in the horses' cecum. Heart rate, respiratory rate, mean arterial blood pressure, and cardiac output increased after cecal balloon inflation. Xylazine and butorphanol decreased the hemodynamic response to cecal balloon inflation. Meperidine and pentazocine had minimal effects on the cardiorespiratory changes induced by cecal balloon inflation. Xylazine produced the most pronounced ...
Purohit RC, Mysinger PW, Redding RW.A continuous series of electroencephalograms (EEG) was obtained from each of 6 mature horses which had been given xylazine and ketamine hydrochloride IV. Electrocardiograms and respiratory rates were also obtained. The EEG of the unsedated standing adult horse displayed a dominant fast activity in the range of 25-35 Hz, 5-30 microV superimposed over slower 1-4 Hz, 10-50 microV activity with occasional 10-14 Hz, 10-40 microV spindle-type activity. The xylazine-sedated horse displayed hypersynchronous EEG patterns, with the dominant activity being 1-3 Hz, 10-70 microV with overlying mixed freque...
Manohar M.Eight healthy adult grade ponies were studied at rest as well as during maximal exertion carried out with and without adenosine infusion (3 microM X kg-1 X min-1 into the pulmonary artery) on a treadmill to compare levels of blood flow in respiratory muscles with those in other vigorously working muscles and to ascertain whether there remained any unutilized vasodilator reserve in respiratory muscles of maximally exercising ponies. Radionuclide-labeled 15-micron-diam microspheres, injected into the left ventricle, were used to study tissue blood flows. During maximal exertion, there were incre...
Hargreaves BJ, Kronfeld DS, Naylor JR.Thermoregulation may limit exercise performance under hot and humid conditions. This study compared heart rate (HR), respiratory rate (RR), rectal temperature (Tr), packed cell volume (PCV) and total plasma protein concentration (TPP) during a submaximal incremental field exercise test under high vs. low ambient temperature and relative humidity. Ten horses were tested 3 times in summer (July) and 3 times in autumn (September). Heart rate was measured continuously, the other variables at rest and immediately after 4 min at 3.5, 4.5 and 7.0 m/s, separated by 3 min rest intervals, and after 5 an...
HOLT JP, RHODE EA, PEOPLES SA, KINES H.Studies of left ventricular volume and pressure have been carried out in the control state in four classes of intact anesthetized mammals (horses, cattle, swine, and dogs), body weights of which varied 54-fold. On the basis of these studies of both large and small hearts, extending over a wide range, a pattern of function for the left ventricle of all mammals has been described. Mathematical equations are given describing the interrelationships between left ventricular end-diastolic volume and end-systolic volume, stroke volume, cardiac output, stroke-work, heart rate, and total peripheral res...
Wiśniewska M, Janczarek I, Wilk I, Wnuk-Pawlak E.The aim of the study was to evaluate the effect of music therapy on changes in the level of parameters describing heart rate (HR) and heart rate variability (HRV) as excitability indicators in geriatric horses. The study involved 20 warmblood geriatric horses, aged 20 years or more. Animals were kept in two identical stables in one facility. Horses from stable No. 1 were considered the experimental group, whereas horses from stable No. 2 constituted a control group. The experiment consisted in playing relaxation new age music to the horses in the experimental group for 28 days use special so...
Sanchez LC, Elfenbein JR, Robertson SA.To evaluate effects of butorphanol, acepromazine, and N-butylscopolammonium bromide (NBB) on visceral and somatic nociception and duodenal motility in conscious, healthy horses. Methods: 6 adult horses. Methods: Visceral nociception was evaluated by use of colorectal distention (CRD) and duodenal distention (DD) threshold. Somatic nociception was evaluated via thermal threshold (TT). Nose-to-ground height, heart rate, and respiratory rate were also measured. Each horse received each treatment in randomized order; investigators were not aware of treatments. Butorphanol was administered IV as a ...
Morris DD, Fregin GF.Seventy-seven horses with atrial fibrillation (AF) were treated orally with quinidine sulfate (QS) at the University of Pennsylvania, School of Veterinary Medicine, Thirty-seven horses (48%) had adverse reactions to QS, the most common of which were nasal mucosal edema, anorexia, colic, and diarrhea. The mean highest daily QS dose was slightly greater in horses showing toxicity (P less than 0.1) and their conversion rate was less (P less than 0.05). A schedule of gradually increasing QS dose was time consuming, costly and not associated with fewer adverse reactions. Horses were compared by the...
Amory H, Votion DM, Fraipont A, Goachet AG, Robert C, Farnir F, Van Erck E.It is unknown whether or not exercise-induced cardiac fatigue (EICF), as demonstrated in human athletes performing long duration exercise, occurs in endurance horses. Objective: To examine the effects of a long distance endurance race on left ventricular systolic function in horses. Methods: Echocardiography was performed before, and after, a 2 or 3 star international endurance race (106-132 km) in 11 horses. Systolic (s) and diastolic (d) interventricular and left ventricular free wall thickness (IVS and LVFW, respectively), left ventricular, left atrial and aortic internal diameter (LVID, LA...
Ambrósio AM, Ida KK, Souto MT, Oshiro AH, Fantoni DT.To assess if positive end-expiratory pressure (PEEP) titration improves gas exchange and respiratory mechanics, without hemodynamic impairment in horses during anesthesia. Methods: Prospective, randomized study. Methods: Thirteen isoflurane-anesthetized healthy horses. Methods: After 60 minutes of anesthesia with spontaneous breathing, mechanical ventilation was initiated with an inspiratory-expiratory ratio of 1:2, PEEP of 5 cmH2O, tidal volume of 10-20 mL kg(-1) and respiratory rate adjusted to maintain normocapnia. Constant PEEP of 5 cmH2O was continued (control group; n = 6) or titrated (P...
Smith GW, Constable PD, Foreman JH, Eppley RM, Waggoner AL, Tumbleson ME, Haschek WM.To determine whether cardiovascular dysfunction is evident in horses with leukoencephalomalacia experimentally induced by administration of fumonisin B1. Methods: 11 healthy horses of various breeds (body weight, 252 to 367 kg). Methods: Horses were randomly assigned to 3 groups and administered fumonisin B1 daily. Horses received IV injections of 0 (control horses; n = 4), 0.01 (3), or 0.20 mg (4) of fumonisin B1/kg for 7 to 28 days. Horses were examined daily for evidence of neurologic disease. When neurologic signs consistent with leukoencephalomalacia were evident, horses were anesthetized...
Gehlen H, Faust MD, Grzeskowiak RM, Trachsel DS.Heart rate variability (HRV) is a noninvasive technique to detect changes in the autonomous nervous system. It has rarely been investigated in horses with colic. Therefore, the objective was to assess the evolution of HRV parameters and cortisol concentrations in horses with colic. The 43 horses included in this study were categorized into three groups according to the treatment (1, surgical; 2, conservative; 3, euthanized). The HRV and laboratory variables were measured at admission (T1), the day after admission (T2), and at discharge (T3) and compared between groups and over time with an ANO...
Eaton MD, Evans DL, Hodgson DR, Rose RJ.We examined the effect of treadmill speed and incline on O2 uptake (VO2), CO2 production, heart rate (HR), plasma lactate concentration, economy of locomotion, stride frequency, and stride length. A further aim was to examine the relationships between HR and VO2 and lactate and VO2 and whether these relationships vary with alterations in treadmill incline. The experiment was a latin square design, using five horses and five treadmill inclines (0, 2.5, 5.0, 7.5, and 10.0%). Fit Thoroughbred horses exercised for 4 min at 3 m/s at 0% slope, after which the treadmill was set to the allocated incli...
Larsson J, Pilborg PH, Johansen M, Christophersen MT, Holte A, Roepstorff L, Olsen LH, Harrison AP.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...
Klous L, Siegers E, van den Broek J, Folkerts M, Gerrett N, van Oldruitenborgh-Oosterbaan MS, Munsters C.In this study, we examined the effects of pre-cooling on thermophysiological responses in horses exercising in moderate environmental conditions (average wet bulb globe temperature: 18.5 ± 3.8 °C). Ten international eventing horses performed moderate intensity canter training on two separate days, and were either pre-cooled with cold-water rinsing (5-9 °C for 8 ± 3 min; cooling) or were not pre-cooled (control). We determined velocity (V), heart rate (HR), rectal temperature (T), shoulder and rump skin temperature (T and T), plasma lactate concentration (LA), gross sweat loss (GSL), and lo...
Waran NK, Robertson V, Cí·¯ord D, Kokoszko A, Marlin DJ.The effects of transporting horses facing either forwards or backwards were compared by transporting six thoroughbred horses in pairs in a lorry on one journey facing in the direction of travel, and on another journey facing away from the direction of travel, over a standard one-hour route. Heart rate monitors were used to record their heart rate before, during and after the journey and the horses' behaviour was recorded by scan sampling each horse every other minute. The average heart rate was significantly lower (P < 0.05) when the horses were transported facing backwards, and they also t...
Manohar M.The present study was carried out 1) to compare blood flow in the costal and crural regions of the equine diaphragm during quiet breathing at rest and during graded exercise and 2) to determine the fraction of cardiac output needed to perfuse the diaphragm during near-maximal exercise. By the use of radionuclide-labeled 15-micron-diam microspheres injected into the left atrium, diaphragmatic and intercostal muscle blood flow was studied in 10 healthy ponies at rest and during three levels of exercise (moderate: 12 mph, heavy: 15 mph, and near-maximal: 19-20 mph) performed on a treadmill. At re...
Muñoz A, Riber C, Santisteban R, Rubio MD, Agüera EI, Castejón FM.The cardiovascular and metabolic response to two cross-country events (CC*: preliminary level and CC*** advanced level) were analysed in 8 male eventing horses (4 Anglo-Hunter and 4 Anglo-Arabian). This study focused on the establishment of the main metabolic pathways involved in the muscle energy resynthesis during the competitions. Heart rate (HR) was recorded throughout the CC events. Jugular venous blood samples were withdrawn before the warm-up period, immediately after the competitions and at 5 and 10 min in the recuperation period. The following haematological parameters were studied: r...
Nath LC, Elliott AD, Weir J, Curl P, Rosanowski SM, Franklin S.Atrial fibrillation (AF) impacts performance and horse and jockey safety. Understanding the outcomes of AF identified postrace will better inform regulatory policy. Objective: To investigate the outcomes after episodes of AF identified postrace and determine whether affected horses are at increased risk of additional episodes compared to the general racing population. Methods: Total of 4684 Thoroughbred racehorses. Methods: Race records for Thoroughbred horses racing in Hong Kong from 2007 to 2017 were reviewed. Horses that performed below expectation were examined by cardiac auscultation and ...
Younes M, Robert C, Cottin F, Barrey E.Nearly 50% of the horses participating in endurance events are eliminated at a veterinary examination (a vet gate). Detecting unfit horses before a health problem occurs and treatment is required is a challenge for veterinarians but is essential for improving equine welfare. We hypothesized that it would be possible to detect unfit horses earlier in the event by measuring heart rate recovery variables. Hence, the objective of the present study was to compute logistic regressions of heart rate, cardiac recovery time and average speed data recorded at the previous vet gate (n-1) and thus predict...
Goodrich LR, Nixon AJ, Fubini SL, Ducharme NG, Fortier LA, Warnick LD, Ludders JW.To determine whether preoperative epidural administration of morphine and detomidine would decrease postoperative lameness after bilateral stifle arthroscopy in horses. Methods: Prospective clinical controlled study. Methods: Eight adult horses that had bilateral arthroscopic procedures, including drilling of cartilage and subchondral bone within the femoropatellar joints. Methods: Horses were randomly separated into 2 groups. Preoperatively, 4 horses were administered a combination of epidural morphine (0.2 mg/kg) and detomidine (30 microg/kg), and 4 horses were administered an equivalent vol...
Potter JJ, MacFarlane PD, Love EJ, Tremaine H, Taylor PM, Murrell JC.To compare sedative and analgesic properties of buprenorphine or morphine for standing procedures combined with a detomidine continuous rate infusion (CRI). Methods: Blinded, prospective, randomized clinical pilot study. Methods: Ten horses presented for dental or sinus procedures. Methods: Horses received 0.02 mg kg(-1) acepromazine intravenously (IV), followed 30 minutes later by detomidine 10 μg kg(-1) IV. Five minutes later, buprenorphine 0.01 mg kg(-1) (n = 6) or morphine 0.1 mg kg(-1) (n = 4) was administered IV. Detomidine was administered by CRI (0.2 μg kg(-1) minute(-1)) and adjuste...
