Stress in horses refers to the physiological and behavioral responses of equines to various stressors, including environmental changes, social dynamics, and physical exertion. These responses can manifest through alterations in heart rate, cortisol levels, and behavior, among other indicators. Stress can affect a horse's overall health, performance, and welfare, making it a significant area of study in equine research. This topic encompasses research on identifying stressors, measuring stress responses, and understanding the implications of stress on equine health and behavior. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, effects, and management of stress in horses.
Dudhia J, Scott CM, Draper ER, Heinegård D, Pitsillides AA, Smith RK.Age-associated and degenerative loss of functional integrity in soft tissues develops from effects of cumulative and subtle changes in their extracellular matrix (ECM). The highly ordered tendon ECM provides the tissue with its tensile strength during loading. As age and exercise collide in the high incidence of tendinopathies, we hypothesized that aged tendons fail due to cumulative damage resulting from a combination of diminished matrix repair and fragmentation of ECM proteins induced by prolonged cyclical loading, and that this is an active cell-mediated process. We developed an equine ten...
Kirkpatrick JF.There are few wildlife populations existing today that can be supported without some form of management. Wildlife fertility control, as one option, has moved from the research stage to actual application with a number of species, including wild horses, urban deer, captive exotic species and even African elephants, but this approach remains controversial in many quarters. Strident debate has arisen over the possible effects of contraception on behaviour, genetics, stress and even management economics, among other parameters. Part of the debate arises from the fact that critics often fail to rec...
Durando MM, Slack J, Reef VB, Birks EK.There is interest in using pharmacological stress testing (PST) as a substitute for exercise stress testing (EST) to evaluate cardiac function in horses. Objective: To compare the effect of PST and EST on right ventricular pressure dynamics and stress echocardiography. Methods: Five horses completed a PST and EST in a randomised crossover design. High fidelity pressure transducers were placed in the right ventricle. Continuous pressure signals were digitally collected and stored, and dP/dtmax, dP/dtmin and tau calculated from these measurements. ECGs were recorded continuously for 20 h. Echoca...
Kinnunen S, Laukkanen R, Haldi J, Hanninen O, Atalay M.Endurance training induces changes in autonomic nervous system functions. High intensity training includes the risk of overtraining, in man and horse. Heart rate variability (HRV) is a noninvasive measurement of the autonomic regulation of the heart rate, which is quick and easy to measure with modern telemetric technology. Objective: Since HRV is affected by changes in the autonomic nervous system, it might be an early stage indicator of poor recovery from a previous bout of exercise or overreaching or overtraining in horses in general. Methods: The aim of the study was to monitor recovery an...
Harris RC, Harris PA, Routledge NB, Naylor JR, Wilson AM.Pharmacological benefits of glutamine supplementation have been shown in athletically and clinically stressed human subjects. In the horse, infection and intense exercise have also been shown to significantly decrease plasma glutamine concentrations, but little is known on how best to supplement. Objective: To evaluate whether ingestion of different foodstuffs, with or without L-glutamine (G) or a peptide (Pep) containing 31.5% w/w G in a water-stable form, could affect plasma glutamine concentrations (P-GC). Methods: Nine feeds (molassed sugar beet-pulp (mSB); naked oats (nO); commercial mix ...
Sandersen C, Detilleux J, Art T, Amory H.Stress echocardiography could be a useful diagnostic test in horses suspected to suffer from exercise-induced myocardial dysfunction as a cause of exercise intolerance. Objective: To evaluate the effect of treadmill exercise and pharmacological stress test on left ventricular echocardiographic parameters. Methods: Echocardiography was performed in 2 groups of 5 healthy horses, either immediately after a near-maximal treadmill exercise (Group EXE) or during a pharmacological challenge (Group DOB) consisting of 35 microg/kg atropine, followed by incremental dobutamine infusion rates of 2-6 micro...
Nankervis KJ, Williams RJ.The use of water treadmill exercise in horses is popular, although little is known about the physiological responses to this form of exercise. No information exists regarding the time taken to acclimate to water treadmill exercise compared to that of high-speed treadmill exercise, for both physiological and biomechanical parameters. Objective: To determine heart rate responses during acclimation to water treadmill exercise with and without sedation on first time exposure. Methods: All horses were exercised on a water treadmill at the walk for 15 min once a day for 4 days. Fourteen horses (mean...
Cayado P, Muñoz-Escassi B, DomÃnguez C, Manley W, Olabarri B, Sánchez de la Muela M, Castejon F, Marañon G, Vara E.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 to examine the effect of show-jumping as well as dressage on stress levels by comparing horses' stress response at a horse show compared to their familiar home. Methods: Fifty-one horses involved in competition were used. EDTA blood samples were collected before exercise, upon arrived to the school...
Bell RJ, Mogg TD, Kingston JK.In recent years, gastric ulceration has been recognised as a common, possibly performance-limiting disease of adult horses. Here, we aim to provide the reader with a useful review of recent literature covering all aspects of equine gastric ulcer syndrome (EGUS) in adult horses. The anatomy and physiology of the stomach, with particular reference to secretion of acid and mucosal protective mechanisms, are reviewed, as are the differing theories relating to the aetiopathogenesis of gastric ulceration. We also explore the possible influence of various management factors on development of the dise...
Jenkinson DM, Elder HY, Bovell DL.The condition of anhidrosis is described in this review, and the latest theories on the causal factors are explored. The evidence supports the hypothesis that anhidrosis is an inappropriate response to prolonged climatic stress (generally combined heat and high humidity), which can be evoked in a small (approximately 10 +/- 5%) proportion of the equine population. It is caused by gradual failure of the glandular secretory cell processes, initiated by desensitization and subsequent down-regulation of the cell receptors as a result of continued adrenaline-driven hyperactivity. It progresses thro...
Berghold P, Möstl E, Aurich C.Stressful events may contribute to low reproductive efficiency due to glucocorticoid-mediated inhibition of hormone secretion in a variety of species. We therefore investigated effects of stress related to management of mares around artificial insemination on secretion of cortisol and fertility parameters. To avoid further disturbance of mares by frequent blood sampling, faecal cortisol metabolites (fCM) were determined instead (sample collection at 8-h intervals). A total of 50 mares (16 maiden, 17 barren, 12 foaling, 5 teaching mares) were included in the study. Mares were brought to the AI ...
Cappelli K, Verini-Supplizi A, Capomaccio S, Silvestrelli M.The knowledge of molecular mechanisms of stress response in athlete horses can allow us to plan an appropriate and high-grade training to obtain better performance and to preserve horse welfare. It is well known that excessive muscular exercise can lead to a number of responses which may be associated with modification of the mRNA levels for a number of metabolic genes such as those involved in the immune response. In the present study cDNA-AFLP technique was applied to Arab endurance horses under stressing conditions to visualise variations of transcriptional profiles; 49 transcript derived f...
Tolleson DR, Teel PD, Stuth JW, Strey OF, Welsh TH, Carstens GE.Anti-tick treatments are often applied concurrent to routine livestock management practices with little regard to actual infestation levels. Prescription treatments against ticks on grazing cattle would be facilitated by non-invasive detection methods. One such method is fecal near infrared spectroscopy (NIRS). Four studies utilizing cattle (Bos spp.) and one with horses (Equus caballus) fed varying diets and infested with either Amblyomma americanum, A. maculatum, A. cajennense or Dermacentor albipictus were conducted to determine the ability of fecal NIRS to identify samples from animals wit...
Christensen JW, Rundgren M, Olsson K.Responses of horses in frightening situations are important for both equine and human safety. Considerable scientific interest has been shown in development of reactivity tests, but little effort has been dedicated to the development of appropriate training methods for reducing fearfulness. Objective: To investigate which of 3 different training methods (habituation, desensitisation and counter-conditioning) was most effective in teaching horses to react calmly in a potentially frightening situation. Objective: 1) Horses are able to generalise about the test stimulus such that, once familiar w...
Gehlen H, Groner U, Rohn K, Stadler P.In 18 horses, the pulmonary artery wedge pressure and the heart rate were measured during pharmacological stress load. 12 horses were healthy (4 trained, 8 untrained) and 6 horses had a heart disease (3 trained, 3 untrained). Pharmacological stress induction was carried out with the sympathomimetic drug dobutamine at a dosage rate of 7.5 microg/kg/min over 10 minutes of infusion. At the fourth minute, the parasympatholytic drug atropine was administered (5 microg/kg bw), and the heart rate and the pulmonary artery wedge pressure were continuously measured over 26 minutes. During sole dobutamin...
Sandersen CF, Detilleux J, de Moffarts B, Van Loon G, Amory H.The aim of this study was to investigate the effect of combined atropine low-dose dobutamine stress test on left ventricular parameters in adult warmblood horses, to establish a potential protocol for pharmacological stress echocardiography. Seven healthy untrained warmblood horses aged 9 to 22 years were used. Heart rate (HR) and left ventricular B- and M-mode dimensions were recorded at baseline and during stress testing with 35 microg/kg atropine IV followed by incremental dobutamine infusion of 2 to 6 microg/kg/min. HR increased significantly (P < .05) during the pharmacological challen...
Gehlen H, Marnette S, Rohn K, Stadler P.The purpose of this study was to determine whether the combination of dobutamine and atropine causes cardiac stress equivalent to treadmill exercise. Therefore, electrocardiography and echocardiography were performed on 10 warmblood horses before, during, and after different cardiac stress tests. Stressors consisted of a standardized treadmill exercise and combined administration of dobutamine (7.5 microg/kg/min) and atropine (5 microg/kg). Maxima heart rates were achieved during the treadmill exercise (175 +/- 10 bpm). After exercise, a rapid decrease in heart rate was observed. Subsequently,...
Hartung J.There is public discussion of the new E.U. Animal Transport Regulation No 1/2005 of Dec. 2004 and its advantages and draw-backs. This Regulation is no longer a Directive, so that it is directly applicable in the Members States. Although the Regulation is recognised to have great potential to improve welfare and health of transported animals, it will also increase administrative work. Most improvements will come through better education and the increased responsibilities of animal attendants, drivers, keepers and transport organisers, and through the stricter control mechanisms (log book, train...
van Breda E.This study measured parameters of stress in recreational, trained horses (REC; n = 7) and elite (International Grand Prix level) trained, dressage horses (DRES; n = 5). The training of the DRES horses uses an unnatural head-neck position (Rollkur), whereas in the REC horses such training techniques are not common. The study measured stress by using heart rate variability analysis for 30 min postfeeding in the morning and 30 min postexercise after a morning training session. The study found no significant difference at rest between the REC and DRES horses. During the posttraining measurements, ...
Sloet van Oldruitenborgh-Oosterbaan MM, Blok MB, Begeman L, Kamphuis MC, Lameris MC, Spierenburg AJ, Lashley MJ.'Rollkur' or 'overbending' is the low and deep riding of a dressage horse during training or warming up. Lately, this technique has been criticized, and not necessarily objectively, on welfare grounds. To be able to evaluate these criticisms, more needs to be known about the workload and stress of horses being ridden 'rollkur'. The aim of the present study was to compare the workload of eight riding-school horses when being ridden deep and round with a draw rein ('rollkur') and when being ridden in a natural frame with only light rein contact ('free'). Workload (as measured by heart rate and b...
Ohmura H, Hiraga A, Aida H, Kuwahara M, Tsubone H, Jones JH.To determine whether evaluation of heart rate (HR) and HR variability (HRV) during prolonged road transportation in horses provides a sensitive index of autonomic stimulation. Methods: Five 2-year-old Thoroughbreds. Methods: ECGs were recorded as horses were transported for 21 hours in a 9-horse van. Heart rate, high-frequency (HF) power, low-frequency (LF) power, and LF-to-HF ratio from Fourier spectral analyses of ECGs were calculated and compared with values recorded during a 24-hour period of stall rest preceding transportation. Results: HR, HF power, and LF power had diurnal rhythms durin...
Kaiser L, Heleski CR, Siegford J, Smith KA.To determine whether therapeutic riding resulted in higher levels of stress or frustration for horses than did recreational riding and whether therapeutic riding with at-risk individuals was more stressful for the horses than was therapeutic riding with individuals with physical or emotional handicaps. Methods: Observational study. Methods: 14 horses in a therapeutic riding program. Methods: An ethogram of equine behaviors was created, and horses were observed while ridden by 5 groups of riders (recreational riders, physically handicapped riders, psychologically handicapped riders, at risk chi...
Kraus BM, Ross MW, Boswell RP.Two 2-year-old pacers, a 3-year-old pacer and a 2-year-old-trotter with acute forelimb lameness were admitted for nuclear scintigraphic examination. Horses were grade 3-4/5 lame. There was increased radiopharmaceutical uptake (IRU) in the distal cranial medial aspect of the humerus in one horse and along the caudal humeral cortex in the other three horses. Two of the four horses were affected bilaterally. Radiographic abnormalities consisted of thickening of the caudal cortex of the mid-diaphysis of the humerus but radiographic changes were not present in all horses. All horses were managed wi...
Eiler H, Frank N, Andrews FM, Oliver JW, Fecteau KA.To characterize the physiologic response to i.v. bolus injection of glucose and insulin for development of a combined glucose-insulin test (CGIT) in horses. Methods: 6 healthy mares and 1 mare each with pituitary adenoma and urolithiasis. Methods: Horses were given a CGIT (glucose, 150 mg/kg; insulin, 0.1 U/kg); results were compared with a singular i.v. glucose tolerance test (GTT; 150 mg/kg) and a singular i.v. insulin sensitivity test (IST; 0.1 U/kg). Healthy horses were also given a CGIT after receiving xylazine and undergoing stress. Results: Physiologically, the CGIT resulted in a 2-phas...
Janett F, Burkhardt C, Burger D, Imboden I, Hässig M, Thun R.The objective of this study was to investigate changes of quality and freezability of stallion semen in response to repeated acute treadmill exercise. Ejaculates from 11 stallions were collected, evaluated and frozen weekly during four periods of 4 weeks each defined as before (period 1), during (period 2) and after (periods 3 and 4) intense exercise. In fresh semen the gel-free volume, sperm concentration, motility, normal sperm and sperm with major defects (acrosome defects, nuclear vacuoles, abnormal heads, midpiece defects and proximal droplets) were evaluated. In frozen-thawed semen, moti...
Veronesi MC, Faustini M, Villani M, Kindahl H, Galeati G, Battocchio M.The aim of the present study was to highlight the effect of two different techniques of one embryo crushing on some hormonal changes. Ten twinning mares were submitted to the mobile or fixed manual crushing of one blastocyst within day 19 after the last mating. Blood sample was collected from 20 min before to 90 min, 24 and 72 h after the procedure was performed to analyse 15-ketodihydro-PGF(2alpha), cortisol and progesterone plasma concentrations. Singleton pregnancy diagnosis was checked 72 h after crushing and at term of pregnancy. Because the unwanted crushing of both embryos occurred in o...
McClure SR, Carithers DS, Gross SJ, Murray MJ.To determine whether conditions representing activities that are typical in the recreational use of horses, including transport to and from show grounds, stall confinement in unfamiliar surroundings, and light exercise, are associated with increased incidence of gastric ulcers in horses. Methods: Randomized controlled study. Methods: 20 client-owned horses. Methods: Horses had no gastric ulcers as determined by endoscopic examination on study day -1. Ten control horses were maintained on-site with no changes in management variables. Ten horses were transported via trailer for 4 hours on day 0 ...
Hedberg Y, Dalin AM, Ohagen P, Holm KR, Kindahl H.In various species, sex, hormonal treatments and oestrous-cycle stage have been shown to affect the animal's response in behavioural tests. Few such studies have been performed in the horse. The main aim of the present study was to investigate whether oestrous-cycle stage affects mares' response to a novel object test and isolation test and, in part, to study whether mares, assumed to suffer from oestrous-related behavioural problems, respond differently in these tests when compared with controls. Twelve mares were tested twice, in oestrus and dioestrus, in a crossover design. Seven behavioura...
Ake AS, Ayo JO, Aluwong T, Mohammed A.Melatonin is a hormone with antioxidant and anti-inflammatory properties and may alleviate the effects of stress on hematologic and biochemical analytes in working donkeys that pack (load-carry). Objective: We aimed to evaluate the effects of melatonin administration on hematologic and biochemical responses in donkeys subjected to packing during the hot-dry season. We also examined its effects on circadian rhythms. Methods: Ten male Nubian pack donkeys with (Packing + Melatonin; P + M) and without melatonin (Packing-Melatonin; P-M) administration were included. Blood samples were colle...
Janczarek I, Kędzierski W.This study compared the physiological response to novel situations in sex-separated and sex-mixed groups of horses, as measured by heart rate (HR). The study evaluated the possibility of training horses in a mixed-sex system. The study included 41 Purebred Arabian 2½-year-olds during their first walk on an automated horse walker. Four groups, divided by manner of care and training, consisted of 10 colts and 10 fillies kept in separate stables and trained in separate male or female groups and 12 colts and 9 fillies kept in the same stable and trained together. The study measured HR when horses...
Lemasson A, Remeuf K, Hausberger M.Animal calls are commonly considered indicators of a sudden change in their arousal state. However, reports evidencing associated internal physiological changes are rare. By homology with human "emotional" vocal productions (e.g., laughter and crying), we predicted that animal vocal productions may result in relaxing tenseness or excitement. In this study, 15 stallions equipped with a heart rate monitor were presented a mare at some distance so as to prevent contact, thereby increasing the males' arousal. Stallions' heart rates increased just before whinnying but returned to baseline rates whi...
Erwin SJ, Blikslager AT, Ziegler AL.Colic is a leading cause of death in horses, with the most fatal form being strangulating obstruction which directly damages the intestinal barrier. Following surgical intervention, it is imperative that the intestinal barrier rapidly repairs to prevent translocation of gut bacteria and their products and ensure survival of the patient. Age-related disparities in survival have been noted in many species, including horses, humans, and pigs, with younger patients suffering poorer clinical outcomes. Maintenance and repair of the intestinal barrier is regulated by a complex mucosal microenvironmen...
Lescun TB, Adams SB, Nauman EA, Breur GJ. The aim of this study was to determine how increasing stiffness of fracture site tissues distal to the pins in an equine distal limb transfixation cast influences stress at the bone-pin interface, within the bones distal to the transcortical pins, and contact pressure between the foot and the cast. Methods:  A transfixation cast finite element model was used to compare the bone-pin interface stress, pin stress, bone stress distal to the pins and contact pressure between the foot and the cast, using six stiffness values for a composite tissue block representing progressive stages of fractu...
Linden A, Art T, Amory H, Massart AM, Burvenich C, Lekeux P.This study was carried out to investigate stress induced in a cross-country by measuring plasma cortisol and to compare the changes in cortisol level with the leucocytic changes measured with the quantitative buffy coat (QBC) analysis, which is a new method applicable in field conditions for the evaluation of haematological parameters in horses. Seven healthy horses competing in a national three-day event were investigated. Venous blood was sampled under resting condition, 2 min and 180 min after the completion of the cross-country and analysed for haematological parameters, plasma cortisol, p...
Doxey DL, Milne EM, Gilmour JS, Pogson DM.An attempt has been made to assess the diagnostic value of clinical features seen at initial examination of horses with grass sickness, colic cases and cases submitted as possible grass sickness but diagnosed subsequently as some other condition. There appears to be no single pathognomonic sign for grass sickness. A range of signs has been associated with grass sickness but these are of value only when related to the length of illness and the history. Biochemical tests related to intestinal tissue damage, stress and dehydration were evaluated and most were found to be of value in diagnosing ac...
Okai K, Taharaguchi S, Orita Y, Yokota H, Taniyama H.To contribute to early diagnosis and treatment of gastric ulcer of foals, we examined the gastric mucosa of healthy and affected foals using an endoscope. In healthy foals, the characteristic changes in the development of the squamous mucosa were seen mainly in the squamous mucosa, and maturation of the squamous mucosa in the greater curvature (GC-S) occurred more slowly than that of the squamous mucosa in the lesser curvature (LC-S). Epithelial desquamation in the LC-S and GC-S was observed between 6 and 90 days but was not observed in the LC-S at about 60 days, whereas it was observed in the...
Manohar M.Regional distribution of diaphragmatic blood flow (Q; 15-microns-diam radionuclide-labeled microspheres) was studied in normal (n = 7) and laryngeal hemiplegic (LH; n = 7) ponies to determine whether the added stress of inspiratory resistive breathing during maximal exercise may cause 1) redistribution of diaphragmatic Q and 2) crural diaphragmatic Q to exceed that in maximally exercising normal ponies. LH-induced augmentation of already high exertional work of breathing resulted in diminished locomotor exercise capacity so that maximal exercise in LH ponies occurred at 25 km/h compared with 3...
Minero M, Canali E, Ferrante V, Verga M, Odberg FO.The heart rate and behaviour of 14 adult saddle horses, eight crib-biters and six normal controls, were investigated. Initially, the relationship between crib-biting and heart rate was investigated while the horses were undisturbed. The horses were tested when restrained with a lip twitch, and assessed when they were exposed suddenly to the rapid inflation of a balloon. The heart rate of the crib-biters during crib-biting was lower than during other behaviours. The crib-biters had a higher overall mean heart rate (P<0.05) suggesting that they may have had a higher basal sympathetic activity...
Buschmann H, Baumann M.During strenuous exercise of horses that are prepared for international Three-Day-Events a significant decrease in the in vitro killing rate of phagocytosed yeast cells by the blood granulocytes has been observed. Other immunological parameters, such as the phorbolmyristate dependent chemiluminescence in granulocytes and the mitogenic stimulation of blood lymphocytes, remained unchanged.
Taylor PM.Some metabolic and endocrine effects of hypoxaemia were studied during halothane anaesthesia in six ponies. Each was anaesthetised twice; on one occasion a 20-minute period of hypoxaemia (arterial oxygen tension between 4.4 and 5.8 [mean 5.3] kPa) was imposed during 120 minutes of anaesthesia. On the second occasion arterial oxygen tension was maintained above 17 kPa throughout. Routine cardiovascular monitoring was performed and blood samples were taken to measure haematocrit, cortisol, insulin, glucose and lactate. Anaesthesia was associated with hypotension in both groups (mean ABP 7.0 kPa...
Dembek K, Timko K, Moore C, Johnson L, Frazer M, Barr B, Toribio R.Sepsis is a major cause of morbidity and mortality in neonatal foals. Relative adrenal insufficiency (RAI), defined as an inadequate cortisol response to stress, has been associated with sepsis, prematurity, and poor outcome in newborn foals. In addition to cortisol, the adrenal gland synthesizes several biologically important steroids and steroid precursors, including aldosterone, androgens, and progestogens. However, concentration of these hormones during hospitalization and their association with the severity of disease and mortality in critically ill foals have not been completely evaluate...
Murray MJ, Crowell-Davis SL.A 4-year-old mixed-breed gelding was presented with colic-type behavior of 5 days' duration that included pawing, looking at the flank area, and kicking and biting at the abdomen and flank when it was eating hay or grain. Medical evaluation did not reveal the cause of the "colic." During its stay in the hospital, the horse improved as regarded the colic-type behavior while eating, but resumed this behavior when it was able to see hay that it was not allowed to eat. It was determined that the persistent colic-type behavior developed as a result of the horse having been repeatedly displaced from...
WiÅ›niewska A, Janczarek I, Ryżak M, Tkaczyk E, KÄ™dzierski W.It is not clear, if modern Konik Polski horses have retained the ability to identify sounds in terms of danger. The aim of the study was to identify differences in their behaviour in response to the reproduction of volcanic eruption and sea storm sounds, assumed to be unfamiliar to these horses, as compared to their response to a thunderclap sound, considered by the horses as potentially dangerous. The study included 13 adult mares of the Konik Polski breed, kept under a free-range system. Their behavioural responses to the reproduction of the three natural sounds with an intensity of over 50â...
Arnbjerg J.With reference to previous reports on hypocalcemia in horses special attention is given to the principal symptoms such as anxiety, increased muscular tension, esp. of the musculature of the extremities, in severe cases leading to ataxia, and to a pulse-synchronized respiration (Synchronous Diaphragmatic Flutter). The time of appearance of the symptoms are much more variable than it is the case for hypocalcemic agalactia in cows. Furthermore the condition has been reported in foals as well as in geldings. Thus the triggering factor seems to be somewhat different from that of agalactia. Hypocalc...
Evans MJ, Mulligan RS, Livesey JH, Donald RA.Perifused equine anterior pituitary cells were used to investigate the relationships between the secretion of ACTH and substances known to either stimulate (corticotrophin-releasing hormone (CRH), and arginine vasopressin (AVP)) or inhibit (cortisol) ACTH secretion. The experiments were designed to mimic the hormone milieu present in vivo in the horse, with cortisol (0 or 100 nmol/l) and CRH (0 or 0.02 nmol/l) perifused continuously, and pulses of AVP (10 nmol/l) applied for 5 min at 30-min intervals. In columns perifused with 0.02 nmol CRH/l there was no significant overall effect of 100 nmol...
Amado-Fuentes M, Gozalo M, Garcia-Gomez A, Barrios-Fernandez S.People with disabilities due to genetic origin often present high levels of stress: non-pharmacological interventions such as Equine-Assisted Interventions (EAI) may be a useful strategy. The objective of this pilot study was to evaluate stress levels in two participants with 22q11.2 deletion syndrome diagnosis, immediately after carrying out the EAI. A single case experimental design methodology was chosen due to the small sample size. Two participants with 22q11.2 Deletion Syndrome, a rare disease, with different comorbidities were included. The present study considered the EAI as the indepe...
Harris RC, Harris PA, Routledge NB, Naylor JR, Wilson AM.Pharmacological benefits of glutamine supplementation have been shown in athletically and clinically stressed human subjects. In the horse, infection and intense exercise have also been shown to significantly decrease plasma glutamine concentrations, but little is known on how best to supplement. Objective: To evaluate whether ingestion of different foodstuffs, with or without L-glutamine (G) or a peptide (Pep) containing 31.5% w/w G in a water-stable form, could affect plasma glutamine concentrations (P-GC). Methods: Nine feeds (molassed sugar beet-pulp (mSB); naked oats (nO); commercial mix ...
Gasthuys F, Messeman C, De Moor A.The influence of hypertonic NaCl 7.2% infusion (4 ml/kg of body weight [BWT]) on plasma (PV) and blood (BV) volumes, sodium (Na), chloride (Cl), potassium (K) plasma concentrations, osmolality (Osm), total protein content (TP), packed cell volume (PCV) and red blood cell count (RBC) was studied in five standing and anaesthetized ponies (standard halothane anaesthesia). Arterial blood gases were followed in the anaesthetized ponies. Isotonic NaCl 0.9% (4 ml/kg of BWT) was used as a placebo in the standing ponies. Isotonic solution in the standing ponies induced few changes: only small decreases...
Shaffer SK, Stover SM, Fyhrie DP.Focal bone lesions are often found prior to clinically relevant stress-fractures. Lesions are characterized by low bone volume fraction, low mineral density, and high levels of microdamage and are hypothesized to develop when bone tissue cannot sufficiently respond to damaging loading. It is difficult to determine how exercise drives the formation of these lesions because bone responds to mechanical loading and repairs damage. In this study, we derive steady-state rate constants for a compartment model of bone turnover using morphometric data from fractured and non-fractured racehorse proximal...
Bush AM, Westneat S, Browning SR, Swanberg J.Occupational illnesses are inadequately reported for agriculture, an industry dominated by a vulnerable Hispanic population and high fatal and nonfatal injury rates. Work-related illnesses can contribute to missed work, caused by a combination of personal and work factors, with costs to the individual, employer, and society. To better understand agricultural occupational illnesses, 225 Hispanic horse workers were interviewed via community-based convenience sampling. Descriptive statistics, bivariate analyses, and log binomial regression modeling were used to: (1) describe the prevalence of mis...
Rendon RA, Shuster L, Dodman NH.Stereotypic cribbing in horses is thought to involve excess dopaminergic activity within the striatum. Various models of stress-induced stereotypies including cribbing in horses postulate that stress stimulates the release of endorphins, triggering the release of striatal dopamine. Dopamine in turn activates basal ganglia motor programs, reinforcing behavior via a reward mechanism. Furthermore, the release of dopamine by endorphins has been shown to depend on activation of NMDA receptors. In the present study, horses identified as cribbers and volunteered by their owners were treated with the ...
Matlina ESh, Bobylev IF, Skorupski K, Pukhova GS.The content of adrenaline, noradrenaline, ACTH, cortisol and insulin in the blood and excretion of catecholamines with urine were studied in horses after physical and emotional exposures. The highest degree of the sympathoadrenal system (SAS) and hypophysioadrenal system (HAS) activation followed by the insulin content decrease was observed after training. The known emotional exposure (the noise of hyppodrome) astivated both parts of SAS and HAS. The unknown emotional experience (electronic music) produced a strong adrenal medullar reaction. Analysis of the correlations showed that the initial...
Muñoz A, Castejón-Riber C, Castejón F, Rubio DM, Riber C.Simulated hypoxic normobaric devices have been used in human beings in order to enhance endurance capacity. These devices are sealed chambers where the athletes are supposed to stay for at least 6-8 hr daily. The current research assesses the changes in time-domain, spectral and non-geometrical heart rate variability (HRV) parameters in 6 horses subjected to progressive duration periods inside of a hermetically sealed chamber. It was pursued, firstly to evaluate the intensity of the stress experienced by the animals and secondly to elucidate whether the horses might require an acclimation per...
