The parasympathetic nervous system in horses is a component of the autonomic nervous system responsible for regulating rest and digest functions. It influences various physiological processes, including heart rate, digestion, and respiratory rate, by promoting a state of relaxation and energy conservation. The system operates primarily through neurotransmitters such as acetylcholine, which facilitate communication between nerves and target organs. Understanding the parasympathetic nervous system's role in equine physiology can provide insights into stress responses, recovery, and overall well-being. This section compiles peer-reviewed research studies and scholarly articles that explore the function, regulation, and impact of the parasympathetic nervous system in horses.
Wonghanchao T, Sanigavatee K, Poochipakorn C, Huangsaksri O, Yalong M, Poungpuk K, Thanaudom K, Lertsakkongkul P, Lappolpaibul K, Deethong N, Chanda M.Cooling down is essential for horse recovery before veterinary inspection during an endurance ride. As salt potentially decreases water temperature, we tested whether adding salt to the water used to cool horses could aid their recovery. Twelve healthy Arabian horses participating in a novice endurance ride were divided evenly into two groups. Heart rate variability (HRV) variables, including time and frequency domains, non-linear results, and autonomic nervous system indices, were determined before recovery and at 1-min intervals for 9 min during recovery using either cold or cold-saline wa...
Poochipakorn C, Wonghanchao T, Huangsaksri O, Sanigavatee K, Joongpan W, Tongsangiam P, Charoenchanikran P, Chanda M.During an African horse sickness (AHS) outbreak, horses were able to exercise daily in a net-covered arena, yet the physiological responses to exercise in a netted arena was unknown. In a cross-over study design, eight horses performed a 39-minute aerobic exercise in conventional (CA) and vector-protected arenas (VPA). Horses were slower in some gaits and covered less distance in the VPA arena (P < .01). Cortisol release, hematology, and heart rate variability (HRV) were also examined. An interaction between the riding arena and time was observed in hematocrit (P = .0013), hemoglobin (P = ...
Delivery is not easily predictable in horses and the consequences of dystocia can be serious for both the mare and foal. An induction protocol with low doses of oxytocin has been reported as a safe procedure. This study investigates the effect of induced delivery on at-term mares' sympathetic-vagal balance. Fourteen mares were included and divided into two groups, one subjected to spontaneous delivery (SD), and one to induced delivery (ID). In both groups, an ECG was recorded using an elastic belt with integrated smart textile electrodes. The recording started before the delivery (Basal), cont...
García-Gómez A, Guerrero-Barona E, García-Peña I, Rodríguez-Jiménez M, Moreno-Manso JM.To examine the effect of equine-assisted therapeutic interventions on users' heart rate variability, using this said variability as an objective biological variable related to stress levels. Methods: A systematic review has been carried out using the methodology suggested in the PRISMA declaration following systematic searches in academic databases. Results: 432 registers were initially identified; however, in the screening and suitability process, nine papers were included in the review. With one exception, all of them reported that equine-assisted therapeutic activities had a favourable effe...
Baldwin AL, Chea I.This study explored whether aromatherapy increases the parasympathetic component (root mean square of successive differences [RMSSD]) of heart rate variability (HRV) in horses. Horses are highly sensitive, easily stressed, have an acute sense of smell, and have been shown to benefit from aromatherapy. The protocol, performed on eight dressage horses, followed a crossover design with an experimental treatment of humidified essential oil (lavender, Lavandula angustifolia) and a control treatment of humidified air. Heart rate variability was recorded for 7 minutes before, during, and immediately...
Ohtani N, Kitagawa K, Mikami K, Kitawaki K, Akiyama J, Fuchikami M, Uchiyama H, Ohta M.There are many obvious health benefits to riding, including developing a strong core and legs, but there are also many less obvious benefits, such as increased confidence and introspection. Few studies have addressed the effects of horseback riding on children and the mechanisms underlying how riding affects humans. We examined the effects of horseback riding on the ability to distinguish Go/No-go tasks and solve arithmetic problems in children. Methods: The subjects were 34 boys and 72 girls, aged 10-12 years old, which were divided into three groups (horse riding, walking, and resting). Th...
Matsuura A, Maruta H, Iwatake T, Kumagai T, Nakanowatari T, Hodate K.The aim of this study was to determine whether autonomic nervous activity of a rider with no disability was altered by one practical and applicable horse trekking (HT) exercise. Changes in autonomic nervous activity were analyzed by heart rate variability (HRV). Twenty-three participants with no disability rode horses along a predetermined HT course at trotting and walking for 60 min. HRV was sampled at 60 min before and immediately, following 60 min, and 120 min after HT. As a control, the same measurements were performed for 22 age-matched participants during their rest. Only in the ...
Nagel C, Erber R, Ille N, von Lewinski M, Aurich J, Möstl E, Aurich C.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)...
Schwarz BC, Sallmutter T, Nell B.A 6-year-old 680-kg (1,496-lb) German Warmblood gelding was evaluated because of bilateral blepharospasm and head shaking. Results: Moderate blepharospasm was evident bilaterally, and both eyes had hyperemic and edematous conjunctivas and lusterless corneas. For each eye, the Schirmer tear test value was only 7 mm/min. The horse's nasal mucosa was dry. Abnormal behaviors included mild repetitive vertical movement of the head, snorting, and flehmen response (classic signs of head shaking). Touching the horse's nostrils and face revealed paresthesia and dysesthesia with slight nasolabial muscle ...
Hada T, Ohmura H, Mukai K, Eto D, Takahashi T, Hiraga A.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. Objective: To investigate whether it is possible to evaluate autonomic function using the time constant in horses. Methods: Five Thoroughbred horses were subjected to a standard exercise test. Following pre-medication with saline, atropine and/or propranolol, the horses ran for 2.5 min at a speed of 8 m/sec at a 10% incline and T was calculated from HR after the exercise. Secondly, 7 Thorough...
Kato T, Ohmura H, Hiraga A, Wada S, Kuwahara M, Tsubone H.To determine the effects of immersion in warm springwater (38 degrees to 40 degrees C) on autonomic nervous activity in horses. Methods: 10 male Thoroughbreds. Methods: Electrocardiograms were recorded from horses for 15 minutes during a warm springwater bath after being recorded for 15 minutes during stall rest. Variations in heart rate (HR) were evaluated from the power spectrum in terms of low frequency (LF, 0.01 to 0.07 Hz) power and high frequency (HF, 0.07 to 0.6 Hz) power as indices of autonomic nervous activity. Results: Mean (+/- SE) HR during stall rest and immersion in warm springwa...
Ohmura H, Hiraga A, Aida H, Kuwahara M, Tsubone H.To investigate the effects of repeated atropine injection on heart rate (HR) variability in resting Thoroughbred horses, two microg/ kg of atropine as parasympathetic nervous blockade was injected intravenously every 6 min to a total of 8 microg/kg after intravenous administration of 0.2 mg/kg of propranolol as sympathetic nervous blockade. We recorded electrocardiograms and obtained the HR, then evaluated variation in HR from the power spectrum in terms of low frequency (LF, 0.01-0.07 Hz) power and high frequency (HF, 0.07-0.6 Hz) power. Administration of atropine decreased parasympathetic ne...
Physick-Sheard PW, Marlin DJ, Thornhill R, Schroter RC.The pattern of variation in heart rate on a beat-to-beat basis contains information concerning sympathetic (SNS) and parasympathetic (PNS) contributions to autonomic nervous system (ANS) modulation of heart rate (HR). In the present study, heart period (RR interval) time series data were collected at rest and during 3 different treadmill exercise protocols from 6 Thoroughbred horses. Frequency and spectral power were determined in 3 frequency bands: very low (VLF) 0-0.01-0.07-< or = 0.5 cycles/beat. Indicators of sympathetic (SNSI = LO/HI) and parasympathetic (PNSI = HI/TOTAL) activity were...
Perkins JD, Bowen IM, Else RW, Marr CM, Mayhew IG.The parasympathetic terminal cardiac ganglia were examined in three normal horses and in five horses with grass sickness. Histopathological changes, consistent with those observed in other ganglia of horses with grass sickness, were identified in the terminal cardiac ganglia of the affected horses. A functional analysis of cardiac autonomic control by time domain analysis (TDA) of heart rate variability was applied to eight horses with grass sickness, and double-paired to 16 normal horses on the basis of their age, sex and breed, and the time of day at which the electrocardiographs were obtain...
Thayer JF, Hahn AW, Pearson MA, Sollers JJ, Johnson PJ, Loch WE.High heart rate variability (HRV) has been associated with more efficient autonomic control, allowing more responsivity and sensitivity to changing environmental demands. Previous results from spectral analysis of interbeat intervals of equine heart rate (HR) indicated increased HRV, reflecting more effective vagal control of the heart. This study focuses on characterizing equine HR and HRV during increasing then decreasing physical demand. A non-invasive ambulatory monitoring system continuously records HR and HRV as horses exercise on a high speed equine treadmill at increasing then decreasi...
Kuwahara M, Hashimoto S, Ishii K, Yagi Y, Hada T, Hiraga A, Kai M, Kubo K, Oki H, Tsubone H, Sugano S.We studied power spectral analysis of heart rate (HR) variability in the horse, with the hypothesis that the quantitative information provided by the spectral analysis of HR variability reflects the interaction between sympathetic and parasympathetic regulatory activities. For this purpose, electrocardiogram, blood pressure (BP) and respiratory (Resp) waveform were simultaneously recorded from Thoroughbred horses (3-5 years old) and analyzed by power spectrum. There were two major spectral components at low-frequency (LF) and high-frequency (HF) bands for HR variability. The peak of Resp varia...
Rugh KS, Jiang B, Hatfield D, Garner HE, Hahn AW.We evaluated cardiac cycle length variability in ponies at rest and during strenuous exercise with and without premedication with atropine. In the absence of premedication, cardiac cycle length at rest was 1,112 +/- 53 ms, the individual cardiac cycle length standard deviation (SDCL) was 75 +/- 23 ms, and the individual cycle length coefficient of variation (CVCL) was 6.32 +/- 1.62. Exercise significantly decreased (P < 0.05) all three indexes (290 +/- 9 ms, 5 +/- 1 ms, and 1.65 +/- 0.20, respectively). Atropine premedication significantly reduced resting cardiac cycle length (685 +/- 46 ms...
Muir WW.Mechanisms responsible for the positive inotropic effects of dopexamine were investigated in 8 halothane-anesthetized horses. The hemodynamic effects of increasing infusions of dopexamine (5, 10, 15 micrograms/kg of body weight/min) were determined before and after sequential administration of specific antagonists. Using glycopyrrolate and chlorisondamine, and atenolol and ICI 118,551, muscarinic and nicotinic ganglionic, and beta 1, and beta 2-adrenergic receptor blockade, respectively, was induced. Dopexamine infusions induced increase in heart rate, cardiac output, systolic and mean arteria...
Matsui K, Sugano S.Intrinsic heart rate (IHR) and autonomic nervous tone (ANT) were measured using the young and the adult of horses, cows, pigs, goats and chickens in order to elucidate species differences in a decrease of resting heart rate (RHR) with growth or age. The IHR and ANT were estimated from the changes in heart rate after the administration of atropine and/or propranolol. The IHR in all species decreased progressively with an increase in body weight from young to adult, and moreover the ANT altered toward the direction of parasympathetic predominance by a decrease in sympathetic tone and/or an incre...
Gerring EE, Hunt JM.An experimental model of postoperative ileus was developed in ponies using trauma to, and exposure of, a length of small intestine which gave rise to a reproducible and reversible set of changes in gut activity. This was assessed by recordings of electrical and mechanical activity and by propulsion of spheres from stomach to anus. Activity was depressed, especially in the stomach and colon, and transit was slowed. All drugs given increased electromechanical activity but propranolol was the least effective and did not alter the delayed transit of spheres. Yohimbine was more effective and the ad...
Slinker BK, Campbell KB, Alexander JE, Klavano PA.The heart rate (HR) response to stepwise changes in mean arterial pressure (MAP) produced by methoxamine and sodium nitroprusside was studied in conscious horses, pigs, and calves. The respective steady-state arterial baroreflex sensitivities (delta HR/delta MAP expressed as beats min-1 . mm of Hg-1) were -1.20, -1.21, and -0.39 for decreasing MAP and -0.08, -0.91, and -0.56 for increasing MAP. After parasympathetic nervous system (PNS) blockade with atropine, the reflex sensitivity to decreasing MAP in horses and the pigs decreased to -0.62 and -0.65, respectively (P less than 0.05), whereas ...
Boratyński Z, Flieger S, Eustachiewicz R, Sławomirski J.In this paper, structure and position of the centers of the parasympathetic nervous system in the horse spinal cord were presented. Studies were carried out on 2 horse spinal cordis. After sampling, the material was dehydrated in alcohol, embedded in paraffin and cut into 15 micron thick sections. The sections were stained according to Nissl's method. Every third section was studied. Nucleus intermediomedialis in the horse spinal cord is an intermittent tract of nervous cells passing from the I cervical neuromere to the V sacral segment. The cells of this nucleus form round, horizontally--oval...
Kuwahara M, Hashimoto S, Ishii K, Yagi Y, Hada T, Hiraga A, Kai M, Kubo K, Oki H, Tsubone H, Sugano S.We studied power spectral analysis of heart rate (HR) variability in the horse, with the hypothesis that the quantitative information provided by the spectral analysis of HR variability reflects the interaction between sympathetic and parasympathetic regulatory activities. For this purpose, electrocardiogram, blood pressure (BP) and respiratory (Resp) waveform were simultaneously recorded from Thoroughbred horses (3-5 years old) and analyzed by power spectrum. There were two major spectral components at low-frequency (LF) and high-frequency (HF) bands for HR variability. The peak of Resp varia...
Physick-Sheard PW, Marlin DJ, Thornhill R, Schroter RC.The pattern of variation in heart rate on a beat-to-beat basis contains information concerning sympathetic (SNS) and parasympathetic (PNS) contributions to autonomic nervous system (ANS) modulation of heart rate (HR). In the present study, heart period (RR interval) time series data were collected at rest and during 3 different treadmill exercise protocols from 6 Thoroughbred horses. Frequency and spectral power were determined in 3 frequency bands: very low (VLF) 0-0.01-0.07-< or = 0.5 cycles/beat. Indicators of sympathetic (SNSI = LO/HI) and parasympathetic (PNSI = HI/TOTAL) activity were...
Schwarz BC, Sallmutter T, Nell B.A 6-year-old 680-kg (1,496-lb) German Warmblood gelding was evaluated because of bilateral blepharospasm and head shaking. Results: Moderate blepharospasm was evident bilaterally, and both eyes had hyperemic and edematous conjunctivas and lusterless corneas. For each eye, the Schirmer tear test value was only 7 mm/min. The horse's nasal mucosa was dry. Abnormal behaviors included mild repetitive vertical movement of the head, snorting, and flehmen response (classic signs of head shaking). Touching the horse's nostrils and face revealed paresthesia and dysesthesia with slight nasolabial muscle ...
Ohmura H, Hiraga A, Aida H, Kuwahara M, Tsubone H.To investigate the effects of repeated atropine injection on heart rate (HR) variability in resting Thoroughbred horses, two microg/ kg of atropine as parasympathetic nervous blockade was injected intravenously every 6 min to a total of 8 microg/kg after intravenous administration of 0.2 mg/kg of propranolol as sympathetic nervous blockade. We recorded electrocardiograms and obtained the HR, then evaluated variation in HR from the power spectrum in terms of low frequency (LF, 0.01-0.07 Hz) power and high frequency (HF, 0.07-0.6 Hz) power. Administration of atropine decreased parasympathetic ne...
Nagel C, Erber R, Ille N, von Lewinski M, Aurich J, Möstl E, Aurich C.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)...
Kato T, Ohmura H, Hiraga A, Wada S, Kuwahara M, Tsubone H.To determine the effects of immersion in warm springwater (38 degrees to 40 degrees C) on autonomic nervous activity in horses. Methods: 10 male Thoroughbreds. Methods: Electrocardiograms were recorded from horses for 15 minutes during a warm springwater bath after being recorded for 15 minutes during stall rest. Variations in heart rate (HR) were evaluated from the power spectrum in terms of low frequency (LF, 0.01 to 0.07 Hz) power and high frequency (HF, 0.07 to 0.6 Hz) power as indices of autonomic nervous activity. Results: Mean (+/- SE) HR during stall rest and immersion in warm springwa...
Gerring EE, Hunt JM.An experimental model of postoperative ileus was developed in ponies using trauma to, and exposure of, a length of small intestine which gave rise to a reproducible and reversible set of changes in gut activity. This was assessed by recordings of electrical and mechanical activity and by propulsion of spheres from stomach to anus. Activity was depressed, especially in the stomach and colon, and transit was slowed. All drugs given increased electromechanical activity but propranolol was the least effective and did not alter the delayed transit of spheres. Yohimbine was more effective and the ad...
Baldwin AL, Chea I.This study explored whether aromatherapy increases the parasympathetic component (root mean square of successive differences [RMSSD]) of heart rate variability (HRV) in horses. Horses are highly sensitive, easily stressed, have an acute sense of smell, and have been shown to benefit from aromatherapy. The protocol, performed on eight dressage horses, followed a crossover design with an experimental treatment of humidified essential oil (lavender, Lavandula angustifolia) and a control treatment of humidified air. Heart rate variability was recorded for 7 minutes before, during, and immediately...
Perkins JD, Bowen IM, Else RW, Marr CM, Mayhew IG.The parasympathetic terminal cardiac ganglia were examined in three normal horses and in five horses with grass sickness. Histopathological changes, consistent with those observed in other ganglia of horses with grass sickness, were identified in the terminal cardiac ganglia of the affected horses. A functional analysis of cardiac autonomic control by time domain analysis (TDA) of heart rate variability was applied to eight horses with grass sickness, and double-paired to 16 normal horses on the basis of their age, sex and breed, and the time of day at which the electrocardiographs were obtain...
Hada T, Ohmura H, Mukai K, Eto D, Takahashi T, Hiraga A.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. Objective: To investigate whether it is possible to evaluate autonomic function using the time constant in horses. Methods: Five Thoroughbred horses were subjected to a standard exercise test. Following pre-medication with saline, atropine and/or propranolol, the horses ran for 2.5 min at a speed of 8 m/sec at a 10% incline and T was calculated from HR after the exercise. Secondly, 7 Thorough...
Matsuura A, Maruta H, Iwatake T, Kumagai T, Nakanowatari T, Hodate K.The aim of this study was to determine whether autonomic nervous activity of a rider with no disability was altered by one practical and applicable horse trekking (HT) exercise. Changes in autonomic nervous activity were analyzed by heart rate variability (HRV). Twenty-three participants with no disability rode horses along a predetermined HT course at trotting and walking for 60 min. HRV was sampled at 60 min before and immediately, following 60 min, and 120 min after HT. As a control, the same measurements were performed for 22 age-matched participants during their rest. Only in the ...
García-Gómez A, Guerrero-Barona E, García-Peña I, Rodríguez-Jiménez M, Moreno-Manso JM.To examine the effect of equine-assisted therapeutic interventions on users' heart rate variability, using this said variability as an objective biological variable related to stress levels. Methods: A systematic review has been carried out using the methodology suggested in the PRISMA declaration following systematic searches in academic databases. Results: 432 registers were initially identified; however, in the screening and suitability process, nine papers were included in the review. With one exception, all of them reported that equine-assisted therapeutic activities had a favourable effe...
Rugh KS, Jiang B, Hatfield D, Garner HE, Hahn AW.We evaluated cardiac cycle length variability in ponies at rest and during strenuous exercise with and without premedication with atropine. In the absence of premedication, cardiac cycle length at rest was 1,112 +/- 53 ms, the individual cardiac cycle length standard deviation (SDCL) was 75 +/- 23 ms, and the individual cycle length coefficient of variation (CVCL) was 6.32 +/- 1.62. Exercise significantly decreased (P < 0.05) all three indexes (290 +/- 9 ms, 5 +/- 1 ms, and 1.65 +/- 0.20, respectively). Atropine premedication significantly reduced resting cardiac cycle length (685 +/- 46 ms...
Ohtani N, Kitagawa K, Mikami K, Kitawaki K, Akiyama J, Fuchikami M, Uchiyama H, Ohta M.There are many obvious health benefits to riding, including developing a strong core and legs, but there are also many less obvious benefits, such as increased confidence and introspection. Few studies have addressed the effects of horseback riding on children and the mechanisms underlying how riding affects humans. We examined the effects of horseback riding on the ability to distinguish Go/No-go tasks and solve arithmetic problems in children. Methods: The subjects were 34 boys and 72 girls, aged 10-12 years old, which were divided into three groups (horse riding, walking, and resting). Th...
Thayer JF, Hahn AW, Pearson MA, Sollers JJ, Johnson PJ, Loch WE.High heart rate variability (HRV) has been associated with more efficient autonomic control, allowing more responsivity and sensitivity to changing environmental demands. Previous results from spectral analysis of interbeat intervals of equine heart rate (HR) indicated increased HRV, reflecting more effective vagal control of the heart. This study focuses on characterizing equine HR and HRV during increasing then decreasing physical demand. A non-invasive ambulatory monitoring system continuously records HR and HRV as horses exercise on a high speed equine treadmill at increasing then decreasi...
Slinker BK, Campbell KB, Alexander JE, Klavano PA.The heart rate (HR) response to stepwise changes in mean arterial pressure (MAP) produced by methoxamine and sodium nitroprusside was studied in conscious horses, pigs, and calves. The respective steady-state arterial baroreflex sensitivities (delta HR/delta MAP expressed as beats min-1 . mm of Hg-1) were -1.20, -1.21, and -0.39 for decreasing MAP and -0.08, -0.91, and -0.56 for increasing MAP. After parasympathetic nervous system (PNS) blockade with atropine, the reflex sensitivity to decreasing MAP in horses and the pigs decreased to -0.62 and -0.65, respectively (P less than 0.05), whereas ...
Delivery is not easily predictable in horses and the consequences of dystocia can be serious for both the mare and foal. An induction protocol with low doses of oxytocin has been reported as a safe procedure. This study investigates the effect of induced delivery on at-term mares' sympathetic-vagal balance. Fourteen mares were included and divided into two groups, one subjected to spontaneous delivery (SD), and one to induced delivery (ID). In both groups, an ECG was recorded using an elastic belt with integrated smart textile electrodes. The recording started before the delivery (Basal), cont...
Boratyński Z, Flieger S, Eustachiewicz R, Sławomirski J.In this paper, structure and position of the centers of the parasympathetic nervous system in the horse spinal cord were presented. Studies were carried out on 2 horse spinal cordis. After sampling, the material was dehydrated in alcohol, embedded in paraffin and cut into 15 micron thick sections. The sections were stained according to Nissl's method. Every third section was studied. Nucleus intermediomedialis in the horse spinal cord is an intermittent tract of nervous cells passing from the I cervical neuromere to the V sacral segment. The cells of this nucleus form round, horizontally--oval...
Muir WW.Mechanisms responsible for the positive inotropic effects of dopexamine were investigated in 8 halothane-anesthetized horses. The hemodynamic effects of increasing infusions of dopexamine (5, 10, 15 micrograms/kg of body weight/min) were determined before and after sequential administration of specific antagonists. Using glycopyrrolate and chlorisondamine, and atenolol and ICI 118,551, muscarinic and nicotinic ganglionic, and beta 1, and beta 2-adrenergic receptor blockade, respectively, was induced. Dopexamine infusions induced increase in heart rate, cardiac output, systolic and mean arteria...
Matsui K, Sugano S.Intrinsic heart rate (IHR) and autonomic nervous tone (ANT) were measured using the young and the adult of horses, cows, pigs, goats and chickens in order to elucidate species differences in a decrease of resting heart rate (RHR) with growth or age. The IHR and ANT were estimated from the changes in heart rate after the administration of atropine and/or propranolol. The IHR in all species decreased progressively with an increase in body weight from young to adult, and moreover the ANT altered toward the direction of parasympathetic predominance by a decrease in sympathetic tone and/or an incre...
Poochipakorn C, Wonghanchao T, Huangsaksri O, Sanigavatee K, Joongpan W, Tongsangiam P, Charoenchanikran P, Chanda M.During an African horse sickness (AHS) outbreak, horses were able to exercise daily in a net-covered arena, yet the physiological responses to exercise in a netted arena was unknown. In a cross-over study design, eight horses performed a 39-minute aerobic exercise in conventional (CA) and vector-protected arenas (VPA). Horses were slower in some gaits and covered less distance in the VPA arena (P < .01). Cortisol release, hematology, and heart rate variability (HRV) were also examined. An interaction between the riding arena and time was observed in hematocrit (P = .0013), hemoglobin (P = ...
Wonghanchao T, Sanigavatee K, Poochipakorn C, Huangsaksri O, Yalong M, Poungpuk K, Thanaudom K, Lertsakkongkul P, Lappolpaibul K, Deethong N, Chanda M.Cooling down is essential for horse recovery before veterinary inspection during an endurance ride. As salt potentially decreases water temperature, we tested whether adding salt to the water used to cool horses could aid their recovery. Twelve healthy Arabian horses participating in a novice endurance ride were divided evenly into two groups. Heart rate variability (HRV) variables, including time and frequency domains, non-linear results, and autonomic nervous system indices, were determined before recovery and at 1-min intervals for 9 min during recovery using either cold or cold-saline wa...
