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.
Keeling LJ, Jonare L, Lanneborn L.The heart rates (HR) of horses and the people leading them (10 horses, 20 people), and riding them (17 horses, 17 people), were recorded in an indoor arena. The horses were Swedish leisure horses of mixed ages, sex and breed. All except two of the people were female and all were of mixed age and riding experience. Each horse-human pair walked or rode between points A and B (30m) four times on each test occasion. However, just before the fourth pass, participants were told that an umbrella would be opened as they rode, or led, the horse past the assistant. The umbrella was not opened, so this p...
Jansen F, Van der Krogt J, Van Loon K, Avezzù V, Guarino M, Quanten S, Berckmans D.The objective of this research was to develop a non-invasive method to detect an emotional response of a horse to novelty during physical activity. Two horses performed 20 trials each, in which the horse's heart rate (HR) and physical activity were continuously measured. The relationship between the horse's physical activity and HR was described by a mathematical model allowing online decomposition of the horse's HR into a physical component and a component containing information about its emotional state. Exposure to the novel object resulted in an increase in the emotional component of HR, w...
Visser EK, VanDierendonck M, Ellis AD, Rijksen C, Van Reenen CG.In 'sympathetic horsemanship' the importance of the natural behaviour of the horse and the use of body language in communication is emphasised. However, it is unclear what effect sympathetic horsemanship has on the welfare of horses. During a 5-week starting period the effect of a sympathetic (ST) versus a conventional (CT) training method was studied using 28 young Warmblood horses. Behavioural observations during the starting period as well as during a standardised final riding test were performed by trained observers. A Wilcoxon matched-pair test was used to detect differences within groups...
Reijerkerk EP, Visser EK, van Reenen CG, van der Kolk JH.To compare the effects of IV administration of various doses of ovine corticotrophin-releasing hormone (oCRH) on plasma and saliva cortisol concentrations in healthy horses and determine whether an oCRH challenge test protocol is valid for use in adult horses. Methods: 24 healthy Warmblood horses. PROCEDURES-Each horse received oCRH in saline (0.9% NaCl) via IV administration at a dose of 0 (control treatment), 0.01, 0.1, or 1.0 Mg/kg (6 horses/group). Jugular blood and saliva samples were collected simultaneously 15 minutes before and immediately prior to injection (baseline); data from these...
Niinistö KE, Korolainen RV, Raekallio MR, Mykkänen AK, Koho NM, Ruohoniemi MO, Leppäluoto J, Pösö AR.A prospective observational study was performed to evaluate whether the plasma concentration of heat shock protein 72 (HSP72) or beta-endorphin is related to clinical signs, blood chemistry, or severity of pain of colic. Seventy-seven horses with colic and 15 clinically healthy controls were studied. The horses were divided into four groups which reflected increasing severity of colic, from normal control horses to horses with mild, moderate and severe colic. Blood samples were collected before any treatment. Packed cell volume (PCV) and plasma HSP72, beta-endorphin, cortisol, adrenocorticotro...
Aleman M, Nieto JE, Magdesian KG.Anesthetic-induced malignant hyperthermia (MH) has been documented in Quarter Horses with a single point mutation in the ryanodine receptor 1 gene (RyR1) at nucleotide C7360G, generating a R2454G amino acid substitution. However, there have been no reports of nonanesthetic manifestations of MH in horses with the C7360G mutation. Objective: To describe clinical manifestations of Quarter Horses with the C7360G mutation. Methods: Eleven Quarter Horses with the RyR1 C7360G mutation. Methods: This prospective study included horses with suspected MH, undetermined etiology of sudden death, death with...
Dyson PK, Jackson BF, Pfeiffer DU, Price JS.The first major epidemiological study of injury incidence in the UK flat racing Thoroughbred (TB), published in 1985, found lameness to be the single largest reason for days when horses failed to train. It was considered advisable to ascertain if progress has been made in reducing the problem of musculoskeletal injuries in the intervening period. Objective: To quantify injury incidence and days lost from training by 2- and 3-year-old TBs in UK training yards during 2002 and 2003. Methods: One-hundred-and-eighty-two yearling TBs were recruited at the end of 2001 and daily training and injury re...
Parker M, McBride SD, Redhead ES, Goodwin D.Significant similarities exist between the neural and behavioural features of environmentally and drug-induced stereotypy. For example, exposure to dopamine agonists, such as amphetamine, induces stereotypy and causes alterations in midbrain neurophysiology similar to those observed following chronic stress. An additional behavioural feature of these neural changes in the drug-induced phenotype is an enhanced rate of switching from response-outcome (R-O) to stimulus-response (S-R) learning. The aim of the current experiment was to examine R-O and S-R learning in horses displaying environmental...
Fazio E, Medica P, Cravana C, Ferlazzo A.To evaluate whether the amount of experience of sport horses and the stress of transport affected their adrenocortical and thyroid responses, the plasma concentrations of total cortisol and total and free iodothyronine of 63 horses were studied before and after show jumping competitions. There were 14 trained inexperienced jumpers (group 1), 20 trained experienced jumpers (group 2), 10 trained inexperienced jumpers that had been transported just before the competition (group 3) and 19 trained experienced jumpers that had been transported just before the competition (group 4). The concentration...
Keenan DM, Alexander S, Irvine C, Veldhuis JD.Cortisol is an important mediator of physiological stress responses. Hypothalamic CRH and arginine vasopressin (AVP) and pituitary ACTH, in addition to hypothalamic and pituitary cortisol feedback, regulate cortisol secretion. Importantly, joint interactions among the four, rather than the signal of any one hormone, govern this life-preserving axis. Quantifying in vivo strength of such joint interactions has been difficult, especially without direct injection of cortisol, CRH, AVP, or ACTH. The goal of the present research was to estimate these joint feedback and feedforward interactions in vi...
Heath TJ.To describe the location, type, support from and effects of their first position for the veterinary graduates of 2005, and to make comparisons with graduates of 1950-2000. Methods: Questionnaires were sent to veterinarians who had graduated from an Australian university in 2005, and data were analysed with SAS System 8 for Windows. Results: One-sixth of the graduates left for overseas, and 55% (Murdoch) to 85% (Melbourne) of the remainder found their first veterinary position in the state where they were trained. More were in small animal (48%) and less in mixed practice (48%) than in previous...
Pollock S, Stover SM, Hull ML, Galuppo LD.The first objective of this study was to experimentally determine surface bone strain magnitudes and directions at the donor site for bone grafts, the site predisposed to stress fracture, the medial and cranial aspects of the transverse cross section corresponding to the stress fracture site, and the middle of the diaphysis of the humerus of a simplified in vitro laboratory preparation. The second objective was to determine whether computing strains solely in the direction of the longitudinal axis of the humerus in the mathematical model was inherently limited by comparing the strains measured...
Pollock S, Hull ML, Stover SM, Galuppo LD.Knowledge of the forces that act upon the equine humerus while the horse is standing and the resulting strains experienced by the bone is useful for the prevention and treatment of fractures and for assessing the proximolateral aspect of the bone as a site for obtaining autogenous bone graft material. The first objective was to develop a mathematical model to predict the loads on the proximal half of the humerus created by the surrounding musculature and ground reaction forces while the horse is standing. The second objective was to calculate surface bone stresses and strains at three cross se...
Visser EK, Van Reenen CG, Blokhuis MZ, Morgan EK, Hassmén P, Rundgren TM, Blokhuis HJ.Cooperation between rider and horse is of major importance in equitation. A balanced team of horse and rider improves (sport) performances and welfare aspects by decreasing stress, frustration, risks of injuries, and accidents. Important features affecting the cooperation are the physical skills, knowledge, and personality of the rider on one hand and the temperament, experience, and physical abilities of the horse on the other. A study with 16 riders and 16 warm-blood riding horses tested the effect of personality of riders and temperament of horses on cooperation between riders and horses. M...
Caulfield MJ, Karageorghis CI.We examined the psychological effects of rapid weight loss among a sample of 41 professional jockeys (mean age 30.9 years, s = 7.0). Participants completed the Brunel Mood Scale (BRUMS) and the Eating Attitudes Test-26 (EAT-26) to establish the relationships between rapid weight loss, mood, and attitudes towards eating. These instruments were administered on three occasions: at the jockeys' minimal weight (achieved through rapid weight loss), their optimal riding weight (when they were not excessively restricting their weight and felt healthy), and their relaxed weight (when there were no fort...
Schofield WA.The goal of this review is to provide evidence supporting the physiologic basis for the use of acupuncture as a treatment in equine reproduction, and to discuss current uses of acupuncture for the treatment of anestrus, urine pooling, uterine infection and/or fluid, infertility, maintenance of pregnancy, cryptorchidism, musculoskeletal pain, and poor libido in stallions. The benefits achieved through acupuncture treatment are thought to be a result of hormonal regulation, altered smooth muscle motility, and general stress and/or pain relief from musculoskeletal or environmental conditions.
Merritt JS, Davies HM, Burvill C, Pandy MG.The equine distal forelimb is a common location of injuries related to mechanical overload. In this study, a two-dimensional model of the musculoskeletal system of the region was developed and applied to kinematic and kinetic data from walking and trotting horses. The forces in major tendons and joint reaction forces were calculated. The components of the joint reaction forces caused by wrapping of tendons around sesamoid bones were found to be of similar magnitude to the reaction forces between the long bones at each joint. This finding highlighted the importance of taking into account muscle...
Colas C, Popot MA, Garcia P, Bonnaire Y, Bouchonnet S.LC/ESI-MS n methods have been previously set up to detect the administration of (i) Harpagophytum and (ii) preparations containing a plant capable of anti-stress properties: Eleutherococcus senticosus. Harpagoside has been found to be the main indicator of Harpagophytum administration in the horse. These methods have been applied to a large number of horse urine samples of various origins. Regarding the detection of Harpagophytum administration, harpagoside, harpagide and 8-para-coumaroyl harpagide were detected together in only one sample out of 317. Eleutheroside E was found to be the main i...
Thomason JJ, Faramarzi B, Revill A, Sears W.Differences in hoof morphology have largely been underappreciated in the literature until recently, and it is these that hold the key to interpreting functional adaptation in the hoof. Objective: Primary laminar morphology correlates with hoof capsule shape; and breeds with different hoof shapes and loadings show different patterns of correlation. Methods: Seventeen measurements of capsule shape and 3 of primary epidermal laminae (PEL) morphology (spacing, orientation and curvature) were made on right and left front hooves from 27 Standardbred and 25 Thoroughbred horses, and tested for breed d...
Cappelli K, Felicetti M, Capomaccio S, Spinsanti G, Silvestrelli M, Supplizi AV.Adequate stress response is a critical factor during athlete horses' training and is central to our capacity to obtain better performances while safeguarding animal welfare. In order to investigate the molecular mechanisms underlying this process, several studies have been conducted that take advantage of microarray and quantitative real-time PCR (qRT-PCR) technologies to analyse the expression of candidate genes involved in the cellular stress response. Appropriate application of qRT-PCR, however, requires the use of reference genes whose level of expression is not affected by the test, by ge...
Stull CL, Morrow J, Aldridge BA, Stott JL, McGlone JJ.Thirty-eight mature horses were assigned to one of two equal groups to evaluate two treatments consisting of either 24 hours of continuous road transport (24T) or two 12-hour periods of transport separated by off-loading, resting and feeding the horses for 12 hours (12/12T). A subset of six horses from each group served as controls for the other group. The horses were loaded into a commercial straight-deck trailer and travelled loose in one of two standard-sized compartments. After the journeys the horses were put back into their paddocks for a 24-hour recovery period. Venous blood samples wer...
Rivero JL, van Breda E, Rogers CW, Lindner A, van Oldruitenborgh-Oosterbaan MM.When inadequate training stress is applied and recovery time is insufficient, performance reduction and chronic maladaptation occurs. Known as overtraining syndrome (OTS), this complex condition afflicts horses in top training. The name of the syndrome implies causation and it is necessary to differentiate it from over-reaching, a term used in horses that, after suffering a loss of performance without an obvious clinical reason, recover their performance within 1 or 2 weeks. The term OTS should be used for horses in heavy training losing performance without an obvious clinical reason and which...
Fazio E, Medica P, Aronica V, Grasso L, Ferlazzo A.Since transport evokes physiological adjustments that include endocrine responses, the objective of this study was to examine the responses of circulating beta-endorphin, adrenocorticotrophic hormone (ACTH) and cortisol levels to transport stress in stallions. Methods: Forty-two healthy Thoroughbred and crossbred stallions were studied before and after road transport over distances of 100, 200 and 300 km. Blood samples were collected from the jugular vein: first in a single box immediately before loading (pre-samples), then immediately after transport and unloading on arrival at the breeding s...
Rogers CW, Firth EC, McIlwraith CW, Barneveld A, Goodship AE, Kawcak CE, Smith RK, van Weeren PR.No data exist on the intensity of exercise required or on possible harmful effects of increasing exercise in foals over the natural level when free at pasture. Objective: To investigate whether an increase in workload over free pasture exercise in the period from directly after birth to the start of training is tolerated by Thoroughbred (TB) foals without increasing injury rate or producing other undesired side effects. Methods: Thirty-three TB foals were allocated to one of 2 exercise groups directly after birth. One group (PASTEX) was raised on pasture and the other (CONDEX) kept under ident...
Christensen JW, Malmkvist J, Nielsen BL, Keeling LJ.In fear-eliciting situations, horses tend to show flight reactions that can be dangerous for both horse and man. Finding appropriate methods for reducing fearfulness in horses has important practical implications. Objective: To investigate whether the presence of a calm companion horse influences fear reactions in naive subject horses. Objective: The presence of a habituated (calm) companion horse in a fear-eliciting situation can reduce fear reactions in naive subject horses, compared to subject horses with a nonhabituated companion (control). Methods: Minimally handled (n = 36), 2-year-old s...
de Graaf-Roelfsema E, Keizer HA, van Breda E, Wijnberg ID, van der Kolk JH.Overtraining is an imbalance between training and recovery leading to symptoms associated with a neuroendocrine dysbalance called the overtraining syndrome, a disease characterized by behavioral, emotional and physical symptoms similar with depression. Although the prevalence of overtraining is high in human and equine athletes, at present no sensitive and specific test is available to prevent or diagnose overtraining. Nowadays, it is believed that combination of different (hormonal) parameters appear to be the best indicators of overtraining. Therefore, this review provides a summary of previ...
Respondek F, Goachet AG, Julliand V.Prebiotic compounds, such as short-chain fructooligosaccharides (scFOS), have been shown to improve health, welfare, or both, in several species, but few studies have been conducted in horses, despite the sensitivity of their hindgut microflora. We hypothesized that prebiotic oligosaccharides, known to be able to stabilize the intestinal microflora in other species, would be of importance in horses. Our study was designed to evaluate the effect of scFOS supplementation on the equine intestinal microflora and to assess its effectiveness in reducing hindgut microbial disturbances related to sudd...
Momozawa Y, Terada M, Sato F, Kikusui T, Takeuchi Y, Kusunose R, Mori Y.The aim of the study was to determine parameters reflecting equine anxiety trait by comparing results obtained in a behavior test and an anxiety score assessed by familiar caretakers in response to a questionnaire. In the behavior test, horses were individually led into a novel room by their caretakers and loosely tethered to decrease excessive movement using the common cross-tying technique with two leads and breakable plastic cords. The horses initially remained with their caretaker for 2 min; the caretaker then left and the subject animal was left alone for 2 min. The latency to break the p...
Bigley RF, Gibeling JC, Stover SM, Hazelwood SJ, Fyhrie DP, Martin RB.Materials, including bone, often fail due to loading in the presence of critical flaws. The relative amount, location, and interaction of these flaws within a stressed volume of material play a role in determining the failure properties of the structure. As materials are generally imperfect, larger volumes of material have higher probabilities of containing a flaw of critical size than do smaller volumes. Thus, larger volumes tend to fail at fewer cycles compared with smaller volumes when fatigue loaded to similar stress levels. A material is said to exhibit a volume effect if its failure prop...
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...
te Pas MF, Wijnberg ID, Hoekman AJ, de Graaf-Roelfsema E, Keizer HA, van Breda E, Ducro B, van der Kolk JH.Training horses improves athletic capabilities by inducing skeletal muscle-specific and systemic adaptations. However, rest is required to recover from exercise or else overtraining may occur and affect performance and welfare. Biomarkers would be useful to identify early chronic overtraining in animals. The objective of the current study was to investigate skeletal muscle gene expression patterns and underlying biological mechanisms related to training of different intensities and detraining. Untrained 20 month-old Standardbred geldings were exercised at varying intensities (endurance and spr...
Cordes V, Gardemin M, Lüpke M, Seifert H, Borchers L, Staszyk C.Periodontal diseases occur frequently in equine dentistry and excessive strain in biological tissues is assumed to be a predisposing factor in their development. Finite element (FE) analysis enables strains and stresses occurring in the periodontium to be calculated and is a useful tool for testing this hypothesis. The current study aimed to establish reliable 3-D models from equine maxillary and mandibular cheek teeth for use in FE simulations, with particular attention to the detailed construction of the periodontal ligament (PDL). Age-related morphological aspects of the teeth and the perio...
Thompson DL, Valencia NA, Walker NL, Oberhaus EL.Five experiments were performed to test the hypothesis that α-melanocyte-stimulating hormone (MSH) is secreted in response to various stressors in horses similar to prolactin, growth hormone, and adrenocorticotropin (ACTH). There was considerable variation in resting concentrations of MSH and in the degree of stimulation in responders; thus all data sets were tested for heterogeneity of variance and corrected for as needed before analysis. In experiment 1, 12 mares were used in a switchback design to test the effect of a 2-minute exercise bout on MSH secretion. Plasma MSH concentrations were ...
Hatazoe T, Kubota C, Fujiki M, Misumi K.To evaluate the influence of mating behavior on cardiac function, changes in heart rate (HR), electrocardiogram (ECG), hematocrit (Hct) and serum concentration of alpha-atrial natriuretic peptide (alpha-ANP) were evaluated in 10 clinically sound Thoroughbred stallions before and after mating behavior. The stallions were submitted twice to experimental pseudomating in the same month in 2009 and 2010. Measurements and blood samples were collected at a stable before mating (baseline) and at a covering yard before and after mating. ECG was recorded by a Holter-ECG system. Arrhythmias were detected...
Hemmann K, Ahonen S, Raekallio M, Vainio O, Lohi H.Crib-biting in horses is a stereotypic oral behaviour. Genetic susceptibility has been suggested on a causal basis, together with environmental factors such as stress, gastric discomfort and frustration caused by stall restrictions. This study aimed to test the associations of known or suspected stereotypic genes with equine crib-biting, including Ghrelin, Ghrelin receptor, Leptin, Dopamine receptor, μ-opioid receptor, N-cadherin, Serotonin receptor and Semaphorin. We conducted a candidate gene study with a case-control design, including 98 crib-biting and 135 control horses of two breeds, Fi...
Nishita T, Takahasi M, Kasuya T, Matsui K, Ichihara N, Murakami M, Asari M.Equine carbonic anhydrase isozymes (CA-I and CA-II) were purified from erythrocytes by several column chromatography. Polyclonal anti-CA-I and anti-CA-II sera were produced in rabbits. Sensitive competitive enzyme-linked immunosorbent assays (ELISA) were established to determine the developmental changes in CA-I and CA-II levels in equine erythrocytes. Concentrations of CA-I and CA-II in erythrocytes from 150 clinically normal thoroughbreds (123 racehorses and 27 riding horses) were determined by ELISA. Mean (+/- SD) concentrations of CA-I and CA-II in racehorses were 1.70 +/- 0.48 and 0.94 +/...
Lansade L, Neveux C, Levy F.Learning performance is influenced by emotional reactivity, low reactivity being generally beneficial. Previous experiments show that emotional reactivity can be modified after a period of social isolation. We hypothesized that eleven days of isolation would affect yearlings' emotional reactivity and improve their learning abilities. Twenty-five yearlings were divided into two groups: 12 were continuously isolated for 11 days (isolated) and 13 stayed together (control). During the period of isolation, all yearlings underwent two learning tasks: a habituation procedure in which a novel object w...
Yarnell K, Purcell RS, Walker SL.Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. During a potentially aversive situation, corticotrophin releasing hormone (CRH) is released from the hypothalamus in the brain. This stimulates the release of adrenocorticotrophic hormone (ACTH) from the pituitary gland, which in turn stimulates release of glucocorticoids from the adrenal gland. In horses the glucocorticoid corticosterone is responsible for several adaptations needed to support equine flight behaviour and subsequent removal from the aversive situation. Corticosterone met...
Micera E, Moramarco AM, Zarrilli A.As horses may perceive several odour signals of danger at slaughter, application of mentholated ointment to their nostrils may limit their perception of danger. To assess the effect of the application of a mentholated ointment to horse nostrils on the stress response during pre-slaughter handling, plasma levels were evaluated for cortisol, beta-endorphin, epinephrine and norepinephrine prior to and after stunning. Twenty draught-type horses were divided into control (n=10) and treated (n=10) groups and a mentholated ointment applied to the nostrils of the treated horses following blood samplin...
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)...
Jensen-Waern M, Lindberg A, Johannisson A, Gröndahl G, Lindgren JA, Essén-Gustavsson B.The effects of an endurance ride on neutrophil functions in endurance-trained horses were evaluated and related to metabolic changes and changes in cortisol concentrations. Blood samples were taken from 7 horses (aged 9-15 years) one day before, and then 30-60 min, 1 day and 8 days after the ride. The race resulted in elevated serum cortisol levels (< 465 nmol/l) and an increased neutrophil:lymphocyte ratio. Immediately post race, the neutrophil ability to engulf yeast was increased. One day after the race, a decrease in leukotriene B4 production (approximately 40%) and in the respiratory b...
Zandoná Meleiro MC, de Carvalho HJC, Ribeiro RR, da Silva MD, Salles Gomes CM, Miglino MA, de Santis Prada IL.Racehorses are constantly exposed to stress. Aiming to verify the state of blood components and cortisol alterations during their routine and after races, phagocytosis and oxidative neutrophil burst assays, serum cortisol determination, erythrocytes apoptosis evaluation, lymphoproliferation assays, and blood count tests were performed in thirty Thoroughbred racehorses, which were divided in two groups. The samples were taken right after races (moment 0 d), during rest periods (-11 d, +1 d, +3 d), and after training (-8, +2, +5). In both groups, the phagocytosis showed a decrease in percentage ...
Taylor PM.Some metabolic and endocrine effects of hypercapnia were studied in six ponies during halothane anaesthesia with neuromuscular blockade and controlled ventilation. Each was anaesthetised twice, once with a 40-minute-period of hypercapnia (10 kPa) and once when normocapnia (5.3 kPa) was maintained throughout two hour's anaesthesia. Routine cardiovascular monitoring was performed and blood samples were taken for assay of cortisol, insulin, glucose, lactate, muscle and liver enzymes and total protein. Anaesthesia induced hypotension and lacticacidaemia which were slightly ameliorated during hyper...
Briefer Freymond S, Bardou D, Beuret S, Bachmann I, Zuberbühler K, Briefer EF.Although stereotypic behaviors are a common problem in captive animals, why certain individuals are more prone to develop them remains elusive. In horses, individuals show considerable differences in how they perceive and react to external events, suggesting that this may partially account for the emergence of stereotypies in this species. In this study, we focused on crib-biting, the most common stereotypy displayed by horses. We compared how established crib-biters ("CB" = 19) and normal controls ("C" = 18) differed in response to a standard "personality" assessment test battery, i.e., react...
Contreras-Aguilar MD, Cerón JJ, Muñoz A, Ayala I.Salivary biomarkers could be useful to evaluate stress, fitness level, and skeletal muscle damage associated to exercise in horses in an easy and non-painful way. Therefore, this study aims to evaluate if cortisol in saliva (sCor), salivary alpha-amylase (sAMY) and butyrylcholinesterase (sBChE) and lactate (sLA) and creatine kinase (sCK) in saliva of horses can show changes during a standardized exercise test, and if they are related to heart rate variability (HRV) parameters related to sympathetic and parasympathetic tone, fitness level or skeletal muscle damage. For this purpose, ten enduran...
Szóstek-Mioduchowska AZ, Shiotani H, Yamamoto Y, Sadowska A, Wójtowicz A, Kozai K, Hojo T, Kimura K, Skarzynski DJ, Okuda K.Glucocorticoids (GCs) are known to play an important role in maintaining basal and stress-related homeostasis by interacting with endocrine mediators and prostaglandins (PGs). Although a growing body of evidence shows that GCs exert their regulatory action at a multitude of sites in the reproductive axis through corticosteroid receptors, little is known about the direct role of cortisol, an active form of GCs, in the equine endometrium. Thus, the study aimed to determine the effect of cortisol on PGF synthesis in the endometrial tissue and cells in vitro. In Exp.1, the immunolocalization and ...
Matsuura A, Tanaka M, Irimajiri M, Yamazaki A, Nakanowatari T, Hodate K.Horse trekking (HT) is having a stroll on a horse along a walking trail in a forest, field, and/or sandy beach. Generally in HT, horses exercise in tandem line outside the riding facilities. Because the leading horse will be confronted with stressors in the forefront, we hypothesized that the leading horse shows higher stress responses than the following one. In order to verify the hypothesis, we compared short-term stress responses between each position in six horses. Exercise consisted of 15 min of ground riding and 45 min of HT with walking and trotting. Heart rate variability was analyzed ...
Ruet A, Biau S, Arnould C, Galloux P, Destrez A, Pycik E, Boichot L, Lansade L.This study investigated the relationships between four behavioral and postural indicators of a compromised welfare state in loose boxes (stereotypies, aggressive behaviors toward humans, withdrawn posture reflecting unresponsiveness to the environment, and alert posture indicating hypervigilance) and the way horses perceived riding. This perception was inferred using a survey completed by the usual riding instructor and during a standardized riding session (assessment of behaviors and postures, qualitative behavior assessment (QBA) and characterization of the horses' locomotion using an inerti...
Chakales PA, Locklear J, Wharton T.This study examined the use of an equine-assisted brief course module on stress and depression among medical students (n = 28), a demographic known to experience high pressure. Evidence supports that animal-assisted therapies can lead to the improvement of health and quality of life, particularly in terms of cognitive, psychological, and physical benefits. This study used the seven-session Kane Medicine and Horsemanship program; students completed pre- and post-measures one week before and after the course. Participation in the course significantly reduced perceived stress (p: 0.001), depressi...
Schork IG, Young RJ.The welfare of an individual depends on its capacity to overcome suboptimal conditions in its environment; otherwise, its physical and psychological health becomes compromised. A situation that clearly indicates lack of control of the environment is the expression of abnormal behaviours, such as stereotypies. This study aimed to verify the well-being of police horses using a new rapid form of welfare assessment: an archaeological approach. To this end, we sampled and quantified marks found on the stables, deposited as a result of abnormal behaviour. We cross-referenced these physical marks wit...
Medill SA, Janz DM, McLoughlin PD.Cortisol is a glucocorticoid hormone produced during activation of the hypothalamic-pituitary-adrenal axis (HPA) in response to psychological or physiological demands. High amounts of circulating cortisol can be found in individuals experiencing energetically demanding physiological events, such as pregnancy, lactation, injury, or starvation, but, also, in individuals who may have less obvious HPA activation from social situations. The feral horse population on Sable Island (Nova Scotia, Canada) provides an opportunity to look at hair cortisol concentration (HCC) as a proxy for circulating cor...
Tapprest J, Audigie F, Radier C, Anglade MC, Voisin MC, Foucher N, Collobert-Laugier C, Mathieu D, Denoix JM.In humans, magnetic resonance (MR) imaging is the method of choice for the diagnosis of stress fractures. In this paper, bilateral stress fracture of the lateral condyle of the third metacarpal bone in a French trotter is described. Results of the radiographic, MR imaging, and histologic examinations are presented, with a focus on the MR signal abnormalities found. Based on this patient, the potential use of MR imaging for the diagnosis of stress fractures in horses is discussed.
Traub-Dargatz JL, McKinnon AO, Bruyninckx WJ, Thrall MA, Jones RL, Blancquaert AM.Four bronchoalveolar lavages were performed sequentially on 9 control and 8 transport-stressed female horses. Alterations in results of fluid cytologic analyses, microbial content, and phagocyte function of recovered pulmonary macrophages in all horses were determined. Seemingly, absolute and relative increase in the number of inflammatory cells detected in the second bronchoalveolar lavage fluid of control horses was the result of irritation of the first lavage. This increased response was not observed in transport-stressed horses until 5 days after transport (third lavage; 10 days after init...
Ralston SL.Problems related to feeding behavior in horses fall into three main categories: underconsumption, overconsumption, and abnormal consumption. Anorexia may be caused by a variety of diseases and overcome by removing the underlying causes (pain, fever), and physical or chemical stimulation of appetite. "Hypophagia" may be caused by poor dentition, disease, or stress. Again, removal of the cause or stimulation by physical or chemical means may improve intakes. Acute and chronic overconsumption of feeds are reflections of the normal controls (or lack thereof) of feeding in the horse. The only relia...
Erickson HH, Lowe BS.This article discusses exercise-induced pulmonary hemorrhage (EIPH), a pathophysiological syndrome which occurs worldwide in the equine athlete. It reviews the history of EIPH, the incidence in performance horses, the etiology, studies performed on the treadmill to determine the mechanisms of EIPH, and the most likely causes of stress failure of the pulmonary capillaries.
Jann HW, Good JK, Morgan SJ, Berry A.Healing of transected superficial digital flexor tendons was evaluated mechanically and histologically in eight horses. Tendons sutured with polyglyconate had higher loads at failure than nonsutured tendons at weeks 5 and 9. The tendon stress at failure (force per unit area) was higher in the sutured tendons at week 5 but not at week 9, reflecting the increased size of the scar at week 9. Histologically, scars after tenorrhaphy were consistently more mature than nonsutured tenotomy scars. The mean maturity score for sutured tendons was higher than for nonsutured tendons at weeks 5 and 9. Overa...
