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.
Perry E, Cross TL, Francis JM, Holscher HD, Clark SD, Swanson KS.The effects of travel stress on the equine cecal microbiota are poorly understood. We hypothesized that travel would affect the equine cecal microbiota. Cecally-cannulated horses (n = 6) were randomly assigned to one of two groups, travel (n = 3) and control (n = 3). Horses received a basal diet (Strategy, Purina Animal Nutrition) with 1.2% body weight mixed grass/alfalfa. Travel horses were transported to an unfamiliar location, stalled to simulate weekend horse show conditions, and then returned to the Southern Illinois University Equine Center. Control horses remained at the equine cente...
Jaskulak M, Rorat A, Grobelak A, Kacprzak M.The aim of the study was to evaluate sensitivity and potential applications of selected biomarkers in phytoremediation under complex heavy metal contamination in Sinapis alba L., Robinia pseudoacacia L. and Lupinus luteus L as a potential tools in effective phytoremediation management. The toxicity assessment was conducted using selected measurement endpoints, both classical and advanced, i.e., germination index, roots length, guaiacol peroxidase activity (GPX), chlorophyll and protein content, the amount of total phenolic compounds (TPC) and level of expression of one of the ribulose-bisphosp...
Padalino B, Raidal SL, Knight P, Celi P, Jeffcott L, Muscatello G.This study aimed to document the effects of an eight hour journey on behavioural, clinical, haematological, environmental and respiratory parameters, and to identify possible associations between factors. Twelve horses underwent clinical examination, respiratory endoscopy with tracheal wash (TW) aspiration, and collection of venous and arterial blood before (BJ) and after the journey (AJ). TW were submitted for conventional quantitative bacteriological evaluation and genetic microbiome analyses. Behaviour was assessed in stables prior to transportation and throughout the journey. Transportatio...
Ida KK, Sauvage A, Gougnard A, Grauwels M, Serteyn D, Sandersen C.Ponies with tracheal collapse may have an increased anesthetic risk due to airway obstruction during induction and recovery. To our knowledge, there are no anesthetic descriptions of these patients, despite a reported 5.6% incidence and 77% mortality rate. Two Shetland ponies with tracheal collapse, a 12-year-old male (pony 1) and a 27-year-old female (pony 2), were referred for right eye enucleation due to a perforating corneal ulcer and severe recurrent uveitis, respectively. Pony 1 was stressed, had lung stridor and hyperthermia, and developed inspiratory dyspnea with handling. Radiography ...
Malinowski K, Yee C, Tevlin JM, Birks EK, Durando MM, Pournajafi-Nazarloo H, Cavaiola AA, McKeever KH.With the increase in the number of horses being used in Equine-Assisted Activities and Therapies (EAAT) programs and with the increasing concern for animal welfare, it is important to understand the impact of such interventions on the stress level and quality of life for the horses involved. The purpose of the present pilot study was to test the hypothesis that participation in EAAT would acutely alter physiological markers of stress and well-being, including plasma cortisol, plasma oxytocin, and heart rate variability (HRV), in horses and that symptoms of posttraumatic stress disorder (PTSD) ...
Negro S, Bartolomé E, Molina A, Solé M, Gómez MD, Valera M.The stress level is suggested to have a negative effect on horses during equestrian competitions, specifically in trotter racing. The main objectives of this study were to measure stress levels in Spanish Trotter Horse races with a reliable non-invasive method, and determining the threshold level of stress that leads to the best performance results and also shows when the stress perceived by the horse becomes distress. One hundred and thirty individuals were evaluated, measuring their performance (based on racing time per kilometre (TPK)) and their stress (based on eye temperature, assessed wi...
Ferlazzo A, Cravana C, Fazio E, Medica P.In order to acquire a pattern of thyroid involvement in welfare maintenance in Ruminants and Equines, this review summarizes data concerning the reference values of total and free iodothyronines and their modifications in physiological conditions and in different management conditions (pregnancy, lactation, weaning, growth, isolation, restraint, shearing, confinement and transportation). Thyroidal and extrathyroidal tissues efficiently respond to management practices, giving a differentiated contribution to circulating iodothyronine changes. The hormonal response could be mainly attributed to ...
Hopper N, Singer E, Henson F.The exact aetiology and pathogenesis of microdamage-induced long bone fractures remain unknown. These fractures are likely to be the result of inadequate bone remodelling in response to damage. This study aims to identify an association of osteocyte apoptosis, the presence of osteocytic osteolysis, and any alterations in sclerostin expression with a fracture of the third metacarpal (Mc-III) bone of Thoroughbred racehorses. Methods: A total of 30 Mc-III bones were obtained; ten bones were fractured during racing, ten were from the contralateral limb, and ten were from control horses. Each Mc-II...
Johnson RA, Albright DL, Marzolf JR, Bibbo JL, Yaglom HD, Crowder SM, Carlisle GK, Willard A, Russell CL, Grindler K, Osterlind S, Wassman M, Harms N.Large numbers of post-deployment U.S. veterans are diagnosed with post-traumatic stress disorder (PTSD) and/or traumatic brain injury (TBI), leading to an urgent need for effective interventions to reduce symptoms and increase veterans' coping. PTSD includes anxiety, flashbacks, and emotional numbing. The symptoms increase health care costs for stress-related illnesses and can make veterans' civilian life difficult. We used a randomized wait-list controlled design with repeated measures of U.S. military veterans to address our specific aim to test the efficacy of a 6-week therapeutic horseback...
Everett JB, Schumacher J, Doherty TJ, Black RA, Amelse LL, Krawczel P, Coetzee JF, Whitlock BK.OBJECTIVE To determine the effects of stacked wedge pads and chains applied to the forefeet of Tennessee Walking Horses on behavioral and biochemical indicators of pain, stress, and inflamation. ANIMALS 20 Tennessee Walking Horses. PROCEDURES Horses were randomly assigned to 2 treatment groups: keg shoes (control; n = 10) or stacked wedge pads and exercise with chains (10). Ten days before treatment application, an accelerometer was attached at the left metatarsus of each horse to record daily activity. Horses were exercised for 20 minutes daily, beginning on day -7. On day 0, exercise ceased,...
Bohák Z, Szenci O, Harnos A, Kutasi O, Kovács L.Temperament has not been taken into account in previous studies evaluating the stress response to exercise in horses. The aim of the present study was to investigate the cortisol response in Thoroughbred racehorses to a single exercise bout, and to analyse the results based on the basic personality of the horse examined. Twenty healthy Thoroughbred horses were selected for the study based on a 25-item rating questionnaire survey used for characterising equine temperament. Eight temperamental and twelve calm horses took part in the experiment. The horses trotted as a warm-up activity, and then ...
Müller TM, Hopster K, Bienert-Zeit A, Rohn K, Kästner SBR.Standing surgery, especially dental procedures, are commonly performed in horses. This leads to an increasing demand for reliable sedation protocols. Therefore, it was the purpose of this study to investigate the influence of butorphanol, midazolam or ketamine on romifidine based sedation in horses during cheek tooth removal. Methods: Forty horses presented for tooth extraction were divided in four groups using matched pair randomization. Group R was sedated with romifidine (bolus 0.03 mg/kg, followed by a constant rate infusion (CRI) 0.05 mg/kg/h) and group RB with romifidine (same dose) an...
Jacob SI, Geor RJ, Weber PSD, Harris PA, McCue ME.Diagnosis of equine pituitary pars intermedia dysfunction (PPID) remains a challenge as multiple factors (stress, exercise, and time of year) influence ACTH and cortisol concentrations. To assess endocrine status in a study designed to evaluate the effects of age and diet on glucose and insulin dynamics, we performed thyrotropin-releasing hormone (TRH) stimulation tests and overnight dexamethasone suppression tests in March, May, August, and October on 16 healthy Thoroughbred and Standardbred mares and geldings. Horses were grouped by age: adult (mean ± SD; 8.8 ± 2.9 yr; n = 8) and aged (20...
Medica P, Bruschetta G, Cravana C, Ferlazzo A, Fazio E.The objective of current study was to evaluate the effect of transportation stress on the circulating adrenaline (A), noradrenaline (NA) and dopamine (DA) responses of stallions, according to the different distances. Forty-two stallions were studied before and after road transportation of 100, 200 and 300km, for a period of 1-3h. An increase in plasma A after 100km (P<0.001) was observed. A similar result was seen in plasma NA after 100km (P<0.001), and 300km (P<0.001). Increases in plasma DA after 100 and 200km (P<0.0001) were observed, with a decrease after 300km (P<0.0001). S...
Yarnell K, Walker SL.Assessment of faecal glucocorticoid metabolites (FGM) offers a noninvasive method of monitoring adrenal activity in domestic horses. Samples are collected on an opportunistic basis and, if they are not fresh or have been exposed to the elements before they are identified, may not accurately reflect FGM concentrations. Objective: To explore the impact of a range of environmental conditions upon the integrity of FGM levels in equine faeces. Methods: In vitro experiment. Methods: Equine faeces were exposed to six controlled environmental conditions intended to simulate a range of weather and seas...
De Santis M, Contalbrigo L, Borgi M, Cirulli F, Luzi F, Redaelli V, Stefani A, Toson M, Odore R, Vercelli C, Valle E, Farina L.Equine assisted interventions (EAIs) are recently facing an increasing popularity, and are characterized by a wide diversity of practices. However, information on the welfare of animals involved in this kind of activity is often lacking. Horses are highly susceptible to work stressors related to physical constraints and/or to the need to control emotions while interacting with humans. Considerations of the emotional state of horses involved in EAIs have multiple valences: for the safety of humans and animals involved, for the quality and efficacy of interventions, as well as for ethical reason...
Pawluski J, Jego P, Henry S, Bruchet A, Palme R, Coste C, Hausberger M.The hypothalamic-pituitary-adrenal (HPA) axis response to chronic stress is far from straight forward, particularly with regards to animal welfare. There are reports of no effect as well as both decreases and increases in cortisol after chronic stressors. Therefore, the first aim of the present study was to determine how measures of compromised welfare, such as chronic pain and haematological anomalies, related to cortisol levels in domestic horses (Equus caballus). Domestic horses are an informative model to investigate the impact of chronic stress (due to environment, pain, work, housing con...
Pohlin F, Brabender K, Fluch G, Stalder G, Petit T, Walzer C. Ecosystems with seasonal fluctuations in climate and food availability present physiological challenges to resident mammals and may cause "stress." The two predominant physiological responses to stressors are (1) the activation of the hypothalamic-pituitary-adrenal axis and (2) the modulation of the autonomic nervous system. To date, the primary indicator for "stress" in wildlife- and zoo animal research are glucocorticoid levels. By measuring the autonomic regulation of cardiac activity, particularly the vagal tone, heart rate variability (HRV) is presently emerging as a suitable indicator o...
Naste TM, Price M, Karol J, Martin L, Murphy K, Miguel J, Spinazzola J.Emerging research suggests that Equine Facilitated Psychotherapy (EFP) may be beneficial for traumatized youth. In addition, complex trauma (i.e., multiple and/or prolonged developmentally adverse traumatic events which are typically interpersonal in nature) treatment research is still growing and there is a need for the development and examination of novel treatments for youth with complex trauma histories. The current article describes a promising EFP model for this population called Equine Facilitated Therapy for Complex Trauma (EFT-CT). EFT-CT embeds EFP practices within Attachment, Regula...
Decloedt A, De Clercq D, Ven S, Vera L, van Loon G.The disproportionate rise of pulmonary artery pressure compared to systemic blood pressure during exercise can lead to detrimental right ventricular remodelling in endurance athletes. Horses may act as an extreme model of these athletic cardiovascular adaptations, as they show a three fold increase in pulmonary pressures during exercise. Right ventricular function was examined in ten healthy horses using post-exercise and pharmacological stress echocardiography in a randomised cross-over design. Exercise testing was performed on a treadmill while pharmacological testing was performed using an ...
Popescu S, Diugan EA.The aim of this observational study was to investigate if a relationship exists between the calculated overall individual welfare score (as an indicator of the welfare quality) and the neutrophil:lymphocyte (N:L) ratio (as a stress indicator) in working (draught) and reproduction horses (breeding stallions and broodmares), in two different seasons. The welfare of the horses was assessed by a protocol which included health and behavioural parameters. An individual welfare score was computed, the total and differential WBC count was established and the N:L ratio was calculated for each of the 14...
Mach N, Foury A, Kittelmann S, Reigner F, Moroldo M, Ballester M, Esquerré D, Rivière J, Sallé G, Gérard P, Moisan MP, Lansade L.Weaning has been described as one of the most stressful events in the life of horses. Given the importance of the interaction between the gut-brain axis and gut microbiota under stress, we evaluated (i) the effect of two different weaning methods on the composition of gut microbiota across time and (ii) how the shifts of gut microbiota composition after weaning affect the host. A total of 34 foals were randomly subjected to a progressive (P) or an abrupt (A) weaning method. In the P method, mares were separated from foals at progressively increasing intervals every day, starting from five min ...
Munk R, Jensen RB, Palme R, Munksgaard L, Christensen JW.The main objective of this explorative study was to describe the relationship between competition scores and salivary cortisol concentrations in young horses during dressage and showjumping competitions. The study also investigated whether the diurnal rhythm of salivary cortisol concentrations was affected by competition over consecutive days compared with the home environment. Saliva samples were collected from 126 dressage horses and showjumpers in their home environment and at 3 different events. The relationship between scores given by judges at the competition and cortisol concentrations ...
Liley H, Davies H, Firth E, Besier T, Fernandez J.Fatigue failure of bones of the metacarpo-phalangeal (fetlock, MCP) joint is common in thoroughbred racehorses. Stresses within the fetlock joint cartilages are affected by the morphology of the third metacarpal bone (MC3) and proximal phalangeal bone, and the steepness of the median sagittal ridge of MC3 is believed to be associated with fracture. This study investigated the influence of the steepness of the sagittal ridge on cartilage stress distribution using a finite element model of the joint. Changes to the steepness of the sagittal ridge were made by applying a parabolic function to the...
Ono A, Matsuura A, Yamazaki Y, Sakai W, Watanabe K, Nakanowatari T, Kobayashi H, Irimajiri M, Hodate K.The aim of this study was to evaluate the influence of rider's skill on the plasma cortisol levels of trekking horses on two courses, walking on field and forest courses (about 4.5 to 5.1 km each). Three riders of different skills did horse trekking (HT) in a tandem line under a fixed order: advanced-leading, beginner-second and intermediate-last. A total of six horses were used and they experienced all positions in both courses; a total of 12 experiments were done. Blood samples were obtained before HT, immediately after and 2 h after HT. As a control, additional blood samples were obtained...
Fazio E, Medica P, Cravana C, Ferlazzo A.In this study the effects of short distance road transport on total and free iodothyronine changes in 12 stallions (Equus asinus and Equus caballus) were evaluated. Donkeys (n = 6) and horses (n = 6) were transported for a distance of 50 km. Blood samples were collected 1 week before transport in basal conditions, 1 week later immediately before loading, and after transport and unloading. After transport, donkeys showed significant increases in circulating T4 (P≤0.01), fT3 (P≤0.001), and fT4 (P≤0.01) levels; while horses had significant increases in circulating T3, fT3 and fT4 (P≤0.01)...
Fenner K, Webb H, Starling MJ, Freire R, Buckley P, McGreevy PD.Rein tension is used to apply pressure to control both ridden and unridden horses. The pressure is delivered by equipment such as the bit, which may restrict voluntary movement and cause changes in behavior and physiology. Managing the effects of such pressure on arousal level and behavioral indicators will optimise horse learning outcomes. This study examined the effect of training horses to turn away from bit pressure on cardiac outcomes and behavior (including responsiveness) over the course of eight trials in a standardised learning task. The experimental procedure consisted of a resting p...
Padalino B, Raidal SL, Carter N, Celi P, Muscatello G, Jeffcott L, de Silva K.Horses are transported frequently and often over long distances. Transportation may represent a physiological stressor with consequential health and welfare implications. This study reports the effects of a long distance journey on immunological, clinical, haematological, inflammatory and oxidative parameters in an Experimental Group (EG) of ten horses, comparing them with six horses of similar age and breed used as a non-transported Control Group (CG). Clinical examination and blood sampling were performed twice on all horses: immediately after unloading for the EG, and at rest on the same da...
Mercer-Bowyer S, Kersey DC, Bertone JJ.OBJECTIVE To use noninvasive approaches to assess stress in New York City (NYC) carriage horses during the course of their daily routine to determine whether use of these horses affected their well-being. DESIGN Prospective case control study. ANIMALS 13 (5 mares and 8 geldings) stabled working NYC carriage horses and 5 pastured (nonworking) NYC carriage horses (1 mare and 4 geldings). PROCEDURES Samples for determination of fecal glucocorticoid and salivary cortisol concentrations were collected on 3 successive days from 10, 8, and 9 working carriage horses during rest (time 1), preparation f...
Cravana C, Medica P, Ragonese G, Fazio E.To investigate the effects of training sessions on circulating β-endorphin changes in sport horses before and after competition and to ascertain whether competition would affect this response. Methods: A total of 24 trained jumping horses were randomly assigned to one of two training groups: Group A (competing) and Group B (not competing). To determined plasma β-endorphin concentrations, two pre- and post-competition training weeks at aerobic workout and two competitive show jumping event days at anaerobic workout were measured before, 5 and 30 min after exercise. Exercise intensity is descr...
Soroko M, Howell K, Dudek K, Waliczek A, Micek P, Flaga J.The aim of the study was to determine the utility of maximum eye temperature measured by infrared thermography (IRT) as a stress indicator compared with plasma cortisol concentration in Thoroughbred and Arabian racehorses. The study included thirty racehorses undergoing standard training for racing. Measurements of maximum eye temperature and blood collection for plasma cortisol concentration were carried out before training (BT), and within 5 (5AT) and 120 minutes (120AT) after the end of the each training session in three repetitions, with a monthly interval. Both parameters were elevated at...
Wolter R, Pantel N, Stefanski V, Möstl E, Krueger K.The maintenance and development of conservation areas by grazing of large herbivores, such as Przewalski's horses, is common practice. Several nature conservation areas house male bachelor groups of this species. When males are needed for breeding they are removed from the groups, often without considering group compositions and individual social positions. However, alpha animals are needed for ensuring group stability and decision making in potentially dangerous situations in several species. To investigate the role of the alpha male in a bachelor group, we observed the behaviour of five Prze...
Wulf M, Aurich C, von Lewinski M, Möstl E, Aurich JE.In this study, readability of reduced-size microchips in horses and the response to implantation were analysed. It was hypothesised that small microchips can be implanted stress-free but are less readable than larger microchips. Adult mares (n=40) were implanted with a reduced-size microchip (10.9×1.6 mm) at the left side of the neck (size of conventional microchips 11.4×2.2 mm). Microchips were identified with three different scanners (A, B, C) immediately, and at 6, 12 and 28 weeks after implantation. Twelve out of the 40 mares were submitted to microchip implantation and control treatment...
Jimenez M, Hinchcliff KW, Farris JW.The responses of the plasma concentrations of catecholamines and cortisol in horses to varied relative intensities of exertion were examined. The plasma concentrations of cortisol, epinephrine and norepinephrine increased significantly (p < 0.05) with exertion. The plasma cortisol concentrations at relative work intensities of 48.3% +/- 1.4%, 82.3% +/- 2.0% and 99.6% +/- 0.4% of VO2max were 114%, 124%, and 126%, respectively, of those at rest, whereas the plasma epinephrine concentrations were 239%, 772% and 3483%, and the norepinephrine concentrations were 138%, 255%, and 1121% of the valu...
Benhajali H, Ezzaouia M, Lunel C, Charfi F, Hausberger M.Discomfort in farm animals may be induced by inappropriate types or timing of food supplies. Thus, time restriction of meals and lack of roughage have been shown to be one source of emergence of oral stereotypies and abnormal behaviour in horses which have evolved to eat high-fibre diets in small amounts over long periods of time. This feeding pattern is often altered in domestic environment where horses are often fed low fibre meals that can be rapidly consumed. This study aimed at determining the effect of the temporal pattern of feeding on reproductive efficiency of breeding mares, One hund...
Zollinger A, Wyss C, Bardou D, Bachmann I.In domestic conditions, adult stallions are mostly housed individually in internal stables to reduce the risk of injuries during social interactions. Social deprivation in horses results in physiological stress and behavioural problems. The aim of this study was to test the "social box" (SB), which allows closer physical contact between neighbouring horses. Eight pairs of stallions (n = 16) were filmed over a 24 h period in the SB and in their usual box stables, "conventional boxes" (CB), which strongly restrict tactile contact. The effect of housing in the SB on behaviour and the occurrence a...
Söder J, Bröjer JT, Nostell KE.Systemic hypertension is a prominent feature in humans with metabolic syndrome (MS) and this is partly caused by an enhanced endothelin-1 (ET-1) mediated vasoconstriction. There are indications that systemic hypertension might be a feature in equine metabolic syndrome (EMS) but if ET-1 is involved in the development of hypertension in horses is not known. Increased levels of cortisol have also been found in humans with MS but there are no reports of this in horses. Before blood pressure, plasma ET-1 and serum cortisol can be evaluated in horses with EMS, it is necessary to investigate the inte...
Martínez R, Godoy A, Naretto E, White A.1. Packed cell volume (PCV) and plasma catecholamines, cortisol and glucose were determined in blood samples obtained from race horses, after competition. 2. All these parameters were higher than basals but catecholamines increased 6-7 times while cortisol was enhanced only by 25%. 3. The increase of glucose and PCV was related to the rise of catecholamines. 4. In samples withdrawn after overnight stress caused by change of horseshoes, it was not possible to find values from basal values significantly different. 5. Influence of nervous temperament was observed only in the higher hematocrit fou...
Krueger K, Marr I, Dobler A, Palme R.Non-invasive methods enable stress evaluation through measuring fecal glucocorticoid metabolites (FGMs), and immunoglobulin A (IgA) in the feces avoiding stressful blood drawing or stressful restraining of animals in the field. However, FGMs and IgA are mostly analysed in freshly frozen samples, which is difficult when fresh samples cannot be frozen immediately or frozen samples cannot be stored or transported. Good results were also derived from air-dried fecal samples, which are hampered by unstable air humidity in the field. These difficulties may be overcome, when drying of samples could b...
Schumacher J, Wilson AM, Pardoe C, Easter JL.A prosthesis, composed of a steel cable and stress-reducing washers, was developed to prevent failure of laryngoplasty, a common treatment for horses affected by recurrent laryngeal neuropathy. Laryngoplasties were performed on 15 cadaveric larynges using a polyester suture on one side and the cable prosthesis on the other. Each prosthesis was distracted at a displacement rate of 20 mm/s using a servohydraulic materials testing machine until laryngoplasty failed. Distraction force and actuator displacement were recorded and analysed. All 15 laryngoplasties performed with a suture failed at the...
Lassourd V, Gayrard V, Laroute V, Alvinerie M, Benard P, Courtot D, Toutain PL.The influence of a 56-km endurance exercise on cortisol kinetics and production rate was evaluated in six horses administered [3H]cortisol. Exercise resulted in an immediate two- to threefold increase in plasma cortisol, with values returning very rapidly to preexercise levels. During exercise, clearance and steady-state volume of distribution of total cortisol were greatly increased (338 +/- 95 vs. 137 +/- 34 ml.kg-1.h-1 for clearance and 359 +/- 82 vs. 229 +/- 18 ml/kg for volume of distribution), whereas the terminal half-life decreased significantly (0.97 +/- 0.16 vs. 1.55 +/- 0.33 h). The...
Kuhl J, Nagel C, Ille N, Aurich JE, Aurich C.In the present study we have evaluated a possible stress reaction in response to two different PGF2α analogs-luprostiol and D-cloprostenol--and their effects on estrous cycle characteristics. In a cross-over-design eight mares received in alternating order either luprostiol (Treatment LUP; 3.75 mg im), D-cloprostenol (Treatment CLO; 22.5μg im) or saline (Treatment CON; NaCl 0.9% 0.5ml im) on day 8 after ovulation. Injection of either LUP or CLO, but not of CON resulted in a significant decline of progesterone concentration in plasma to baseline concentrations within two days (time: p<0.00...
Alexander SL, Irvine CH, Livesey JH, Donald RA.The effect of an acute fall in plasma cortisol on the secretion of CRH, arginine vasopressin (AVP), and ACTH was studied using our nonsurgical technique for collecting pituitary venous (PV) blood from horses. PV blood from six mares was collected continuously and divided into 30-sec segments for 0.5 h before and during a 3-h infusion of metyrapone, an 11-beta-hydroxylase inhibitor. During treatment, plasma cortisol fell (P < 0.01) to a mean nadir of 15% of pretreatment levels, and 11-deoxy-cortisol rose (P < 0.02). Three mares became mildly agitated during treatment. Mean PV concentratio...
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. ...
Wong CW, Smith SE, Thong YH, Opdebeeck JP, Thornton JR.Chemotactic locomotion and luminol-dependent chemiluminescence of neutrophils, mitogen-induced lymphocyte blastogenesis, serum cortisol concentration, immunoglobulin quantification, and leukocyte counts were determined to evaluate the effect of a single strenuous exercise in horses. Increased serum cortisol concentration (P less than 0.01) and an increased neutrophil-to-lymphocyte ratio (P less than 0.05) indicated that horses had been stressed. The chemotactic index and peak chemiluminescence production decreased significantly (P less than 0.05 and P less than 0.01, respectively) 1 day after ...
Matlina E.The investigation of catecholamine (CA) metabolism in animals subjected to various types of stress (different pain syndromes; cranial trauma; immobilization; cooling) and physical exercise shows considerable similarity among species in the sequence of changes, leading from the activation to the depletion of the sympathoadrenal system. The changes caused by physical exercise tend to be more pronounced in individuals with a genetic predisposition to greater stress responses. Stress adaption, induced by special training or by long-duration exposure to hypoxia, can substantially prevent the change...
Schmucker S, Preisler V, Marr I, Krüger K, Stefanski V.Domestic horses are currently often subject to management practices that can entail social stressors, which in turn can negatively influence immunocompetence and disease susceptibility. The present study therefore aimed to characterize the number of various blood leukocyte subsets in horses, focusing on two potentially stressful housing environments: changes in group composition and relocation to individual stabling. Immune measurements were conducted before as well as one and eight days after changes were made. They were complemented by an assessment of plasma cortisol concentrations as well ...
Nürnberger S, Rentenberger C, Thiel K, Schädl B, Grunwald I, Ponomarev I, Marlovits S, Meyer C, Barnewitz D.The present study reports for the first time the presence of giant crystals in mitochondria of equine chondrocytes. These structures show dark contrast in TEM images as well as a granular substructure of regularly aligned 1-2 nm small units. Different zone axes of the crystalline structure were analysed by means of Fourier transformation of lattice-resolution TEM images proving the crystalline nature of the structure. Elemental analysis reveals a high content of nitrogen referring to protein. The outer shape of the crystals is geometrical with an up to hexagonal profile in cross sections. It ...
Sauer FJ, Bruckmaier RM, Ramseyer A, Vidondo B, Scheidegger MD, Gerber V.The aims of this study were to better characterize the adrenal response to i.v. adrenocorticotropic hormone (ACTH) in horses with and without gastric disease and to validate and simplify the ACTH stimulation test by determining the diagnostic accuracy of six consecutive sampling time points after ACTH administration for equine glandular gastric disease (EGGD) and equine squamous gastric disease (ESGD). Twenty-six endurance and eventing horses without clinical disease [Sport Horse Population (SHP)] and an independent population of 62 horses [General Population (GP)] were grouped by gastroscopic...
Decloedt A, De Clercq D, Ven S, Vera L, van Loon G.The disproportionate rise of pulmonary artery pressure compared to systemic blood pressure during exercise can lead to detrimental right ventricular remodelling in endurance athletes. Horses may act as an extreme model of these athletic cardiovascular adaptations, as they show a three fold increase in pulmonary pressures during exercise. Right ventricular function was examined in ten healthy horses using post-exercise and pharmacological stress echocardiography in a randomised cross-over design. Exercise testing was performed on a treadmill while pharmacological testing was performed using an ...
Reyes AM, Jahr H, van Schie HT, Weinans H, Zadpoor AA.The elastic strain limit (ESL) of tendons is the point where maximum elastic modulus is reached, after which micro-damage starts. Study of damage progression in tendons under repetitive (fatigue) loading requires a priori knowledge about ESL. In this study, we propose three different approaches for predicting ESL. First, one single value is assumed to represent the ESL of all tendon specimens. Second, different extrapolation curves are used for extrapolating the initial part of the stress-strain curve. Third, a method based on comparing the shape of the initial part of the stress-strain curve ...
Arnon S, Fisher PW, Pickover A, Lowell A, Turner JB, Hilburn A, Jacob-McVey J, Malajian BE, Farber DG, Hamilton JF, Hamilton A, Markowitz JC, Neria Y.Equine-assisted therapy (EAT) for post-traumatic stress disorder (PTSD) has attracted great interest despite lacking empirical support, a manual, and a standardized protocol. Our team of experts in EAT and PTSD developed an eight-session group EAT treatment protocol for PTSD (EAT-PTSD) and administered it to two pilot groups of military veterans to assess initial effects. We describe the development of the treatment manual, which was used with two pilot groups of veterans. Protocol safety, feasibility, and acceptability were assessed by reported adverse events, treatment completion rates, and ...
Starzonek J, Roscher K, Blüher M, Blaue D, Schedlbauer C, Hirz M, Raila J, Vervuert I.In horses and ponies numerous medical conditions are known to be linked with inflammation in different tissues, especially in the liver. Besides affecting other metabolic pathways such as the expression of certain interleukins (IL), inflammation is associated with stress of the endoplasmic reticulum (ER). In particular, ER stress leads to adaptive stress response and can be measured by several markers of inflammatory and stress signalling pathways, like nuclear factor κB (NF-kB). Objective: To investigate lipopolysaccharide (LPS)-induced inflammatory reactions and their modulation in horses a...
Szemplinski KL, Thompson A, Cherry N, Guay K, Smith WB, Brady J, Jones T.The objective of this study was to determine if transportation and exercise stress in horses affect the microflora populations in the equine hindgut. Four horses were subjected to three transport periods (0, 3, and 6 hours) with a 7-d rest period between each transport. Horses were fed 0.91 kg/day of Purina Impact All Stages 12% and had ad libitum access to Cynodon dactylon (Coastal Bermudagrass) hay. Fecal samples were collected before (0 hours) and after (48 hours) transport. In addition, three horses underwent a different standardized exercise test with a 7-d rest period between each ex...
De Ceulaer K, Delesalle C, Van Elzen R, Van Brantegem L, Weyns A, Van Ginneken C.Intestinal strangulation often leads to enterectomy after which ileus can develop. This has prompted research to look into possible pathophysiological processes triggering equine ileus. However, morphological changes of the small intestinal smooth muscle in relation to equine colic have not yet been studied. Objective: The presence of some smooth muscle proteins was morphologically assessed and quantified in control and colic horses. In addition, the up- or down-regulation of heat shock proteins (HSP20 and HSP27) influencing the contractility of smooth muscles was studied. Methods: Cranial res...
Lanci A, Mariella J, Ellero N, Faoro A, Peric T, Prandi A, Freccero F, Castagnetti C.Equine fetal hair starts to grow at around 270 days of pregnancy, and hair collected at birth reflects hormones of the last third of pregnancy. The study aimed to evaluate cortisol (CORT) and dehydroepiandrosterone-sulfate (DHEA-S) concentrations and their ratio in the trichological matrix of foals and mares in relation to their clinical parameters; the clinical condition of the neonate (study 1); the housing place at parturition (study 2). In study 1, 107 mare-foal pairs were divided into healthy (group H; n = 56) and sick (group S; n = 51) foals, whereas in study 2, group H was divided into ...
Hdud IM, Mobasheri A, Loughna PT.Chondrocytes are regularly exposed to load-induced stimuli and have the capability to sense and respond to applied mechanical stress. However, the mechanisms involved in chondrocyte mechanotransduction are not clearly understood. The purpose of this study was to explore the effects of cyclic equibiaxial mechanical stretch on the expression of α-BK and TRPV4 channels. Results: Freshly isolated equine articular chondrocytes were subjected to mechanical stress (8% elongation at frequency of 0.5 Hz for 8 h). Western blotting was used to investigate the expression of BKCa and TRPV4 channel prote...
Monk CS, Hart KA, Berghaus RD, Norton NA, Moore PA, Myrna KE.To determine whether cortisol is present in equine tears at rest and during simulated stress and compare tear cortisol to serum free and total cortisol. Methods: Fourteen healthy adult horses were included. Paired tear total cortisol and serum total and free cortisol concentrations were measured with ELISA, chemiluminescent immunoassay, and ultrafiltration methodology, respectively, in 10 horses at rest once daily for five consecutive days. In an additional four horses, paired tear and serum samples were collected for cortisol measurement before and after adrenocorticotropic hormone (ACTH) sti...
Schulman M, Becker A, Ganswindt S, Guthrie A, Stout T, Ganswindt A.Validation of a method for the minimally-invasive measurement of physiological stress will help understanding of risk factors that may contribute to stress-associated events including recrudescence of Equid herpesvirus (EHV), which is anecdotally associated with sales consignment of pregnant Thoroughbred mares. In this study we compared two similar groups of late-gestation Thoroughbred broodmares on the same farm: a consigned Sales group (N = 8) and a non-consigned Control group (N = 6). The Sales mares were separated from their paddock companions and grouped prior to their preparation...
Wharton T, Whitworth J, Macauley E, Malone M.The objective of this study was to test effectiveness and feasibility of equine-facilitated cognitive processing therapy (EF-CPT), a manualized adaptation of the cognitive processing therapy model for veterans with posttraumatic stress disorder (PTSD) championed by the Department of Veterans Affairs, in which equine-facilitated activities are integrated into face-to-face sessions. Methods: Twenty-seven veterans with a diagnosis of PTSD participated (M = 51; 78% male) in a pretest-posttest design. Veterans were seen by a single psychologist for 12 sessions of individual EF-CPT. Instruments incl...
