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.
Janicka W, Wilk I, Próchniak T.Living in a herd has multiple advantages for social species and is a primary survival strategy for prey. The presence of conspecifics, identified as a social buffer, may mitigate the individual stress response. Social isolation is, therefore, particularly stressful for horses, which are gregarious animals. However, they are not equally vulnerable to separation from the group. We tested whether more and less socially dependent horses and independent individuals would differ in their responses to novel and sudden sounds occurring in two contexts: non-social and social motivation. Twenty warmbloo...
Fletcher KA, Limon G, Padalino B, Hall GK, Chancellor N, Grist A, Gibson TJ.Current legislation in the United Kingdom stipulates that horses should not be slaughtered within sight of one another. However, abattoir personnel anecdotally report that, for semi-feral horses unused to restraint, co-slaughtering alongside a conspecific could reduce distress through social buffering and improve safety, but there is a lack of evidence to support this. CCTV footage from an English abattoir was assessed retrospectively with welfare indicators from when horses entered the kill pen until they were killed. Of 256 horses analysed, 12% (32/256) were co-slaughtered (alongside a consp...
Colbath AC, Frye CW.Biologic therapies are becoming increasingly utilized by veterinarians. The literature regarding the interaction of biologic therapies with other therapeutics is still in its infancy. Initial studies have examined the effects of exercise, stress, various pharmaceutical interventions, extracorporeal shockwave, therapeutic laser, and hyperbaric oxygen on biologic therapies. Continued research is imperative as owners and veterinarians increasingly choose a multimodal approach to injury and illness. Further, understanding the effects of concurrently administered treatments and pharmaceuticals as w...
Jacquay ET, Harris PA, Adams AA.Transportation of horses on short journeys can lead to an increase in stress. There are known age-associated changes in immune and metabolic responses in horses; however, no research exists evaluating how age may influence these responses to transportation stress. Eleven mares within two age groups, aged (n = 5, 22 ± 1 year) or young (n = 6, 2 ± 1 year), were transported 1 hour and 20 minutes. Peripheral blood and saliva were collected before and after transportation at baseline (2 to 3 weeks prior to transportation), 24 hours pre-transport, 1 hour before loading, 15 minutes, 30 minutes,...
Medill SA, Janz DM, McLoughlin PD.Steroid-hormone concentrations from non-invasively obtained biomarkers, like hair, can provide a representation of circulating hormones diffused over relatively long time periods (e.g., weeks or months). The hormone cortisol is often associated with physiological or even psychological stress, while testosterone is strongly associated with male development and reproductive success. Increasingly, studies are using hormone levels derived from hair to make inferences among both domestic animals and wildlife. For horses, all previous hair hormone analysis has been done on companion or working anima...
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...
Palomar-Ciria N, Bello HJ.Alternative treatments for Post-traumatic-Stress Disorder (PTSD) have attracted attention, especially Equine-Assisted Services (EAS) including psychotherapy and occupational therapy involving horses. In this work, we measured the effectiveness of EAS in PTSD through a meta-analysis. An intensive bibliography search focusing in EAS and PTSD was conducted following the PRISMA recommendations. The search was not restricted by date. For the quantitative analyses, 5 works were selected. They were chosen based on the instrument utilized for the assessment of PTSD symptoms: the PTSD Checklist for DSM...
This study aimed to evaluate the change of white blood cell count, serum concentration of cortisol, C-reactive protein, albumin and globulin fractions in horse after road transport, and to assess the linkage among hypothalamic-pituitary-adrenal axis (HPA) and inflammatory reaction. From 10 horses blood samples were collected at rest, before road transport (218 km) (BT); after unloaded (AT), 30 and 60 min after unloaded (AT30 and AT60) in order to assess white blood cell count (WBC), serum cortisol, C-reactive protein (CRP), total proteins, albumin, α1-, α-2, β1-, β2- and γ-globulins. WB...
Thomson-Parker TL, Fikes KK, Anderson MJ, Wagner AL, Girard ID, Suagee-Bedore JK.Calming supplements are common in the equine industry. This study tested the hypothesis that Phytozen EQ, a blend of citrus botanical oils, magnesium, and yeast would reduce startle response as well as reduce behavioral and physiological signs of stress in young (1.5-6 years of age) horses (n = 14) when tied in isolation and when trailered in isolation. During the 59-day trial, horses were assigned to either the control (CON; n = 7) or treatment (PZEN; n = 7) group that received 56 g of Phytozen EQ daily. Horses underwent a 10-minute isolation test on d 30 and a 15 minute individual trai...
Vaziri GJ, Jones MM, Carr HA, Nuñez CMV.The disruption of animals' symbiotic bacterial communities (their microbiota) has been associated with myriad factors including changes to the diet, hormone levels, and various stressors. The maintenance of healthy bacterial communities may be especially challenging for social species as their microbiotas are also affected by group membership, social relationships, microbial transfer between individuals, and social stressors such as increased competition and rank maintenance. We investigated the effects of increased social instability, as determined by the number of group changes made by femal...
Hole C, Murray R, Marlin D, Freeman P.Despite numerous studies investigating responses to visual perception, there is limited research into how horses respond to different auditory stimuli. Although 'noise-damping' ear covers are frequently used on sport horses to minimise distraction from external auditory stimuli, the effectiveness of ear covers has not been established. This study aimed to (i) investigate the responses of horses to different sounds commonly present in a competition environment, and (ii) compare these responses in the presence and absence of ear covers. A total of 18 horses were presented with 5 sounds commonly ...
Kendall A, Lützelschwab C, Lundblad J, Skiöldebrand E.Nerve growth factor (NGF) is a neurotrophin that is increased in osteoarthritic joints of horses. In humans, NGF has been associated with pain, and both synovial and serum NGF concentrations are increased in osteoarthritic patients. Studies in humans also have shown that serum NGF concentration can increase with stress. Serum NGF concentration should be evaluated in horses with osteoarthritis-associated lameness. Objective: Quantify and compare serum NGF concentration in horses with osteoarthritis-associated lameness and sound horses. Additionally, the impact of short-term stress on serum NGF ...
Chalvignac L, Galia P, Faure P, Prieto N.For several years, animal-mediated therapies have been used in the treatment of psychiatric patients. Post-traumatic stress disorder has the particularity of being generated by an external event in a person a priori free of mental pathology. In this disorder, various so-called targeted psychotherapies have proven to be effective, including equine therapy.
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...
Ermers C, McGilchrist N, Fenner K, Wilson B, McGreevy P.Failure to meet the minimum forage requirement of 1.5% of the horse's bodyweight and the opportunity for foraging for a minimum of 8 h a day (not going without this opportunity longer than four to five consecutive hours) can have both physiological and behavioural consequences. To provide an energy source for horses, rations often include starch rather than fibre. This can result in health issues related to the gastrointestinal tract (GIT) in the horse. In the stomach, the main concern is equine gastric ulcer syndrome (EGUS) and, more specifically, equine squamous gastric disease (ESGD). Ulcer...
Grzędzicka J, Dąbrowska I, Malin K, Witkowska-Piłaszewicz O.Increased training loads in both human and equine athletes are generally implemented to improve their physical performance. These loads are tolerated only within appropriate training periodization with regard to recovery time. Otherwise, training overload causes failure in the systemic adaptation, which at first leads to overreaching, and progressively to overtraining syndrome (OTS). Exercise endocrinology, and anabolic/catabolic balance as an indicator of athlete performance status and OTS has continued to attract attention. In human medicine, changes in testosterone and cortisol levels, as w...
Lisboa BRF, da Silva JAR, da Silva WC, Barbosa AVC, Silva LKX, Lourenço-Júnior JB.In Brazil, the study on equine thermoregulation has not shown considerable advances, moreover, in the Amazon, this is a little explored aspect. This study aims to evaluate the thermoregulation of horses submitted to two methods of post-exercise cooling, in the climatic conditions of the Eastern Amazon. The experiment was conducted at Centro Hipico, Ananindeua, Para, for 15 days. Ten male horses, castrated of the Brazilian breed, aged 13 years and with an average weight of 482.3 kg were used. Equestrianism, which was exercised with pre-established protocol in the arena and track, for 30 min. Af...
Kang H, Zsoldos RR, Sole-Guitart A, Narayan E, Cawdell-Smith AJ, Gaughan JB.Healthy adult horses can balance accumulation and dissipation of body heat to maintain their body temperature between 37.5 and 38.5 °C, when they are in their thermoneutral zone (5 to 25 °C). However, under some circumstances, such as following strenuous exercise under hot, or hot and humid conditions, the accumulation of body heat exceeds dissipation and horses can suffer from heat stress. Prolonged or severe heat stress can lead to anhidrosis, heat stroke, or brain damage in the horse. To ameliorate the negative effects of high heat load in the body, early detection of heat stress and im...
Kim SM, Cho GJ.This study aimed to prove that deep learning can be effectively used for identifying various equine facial expressions as welfare indicators. In this study, a total of 749 horses (healthy: 586 and experiencing pain: 163) were investigated. Moreover, a model for recognizing facial expressions based on images and their classification into four categories, i.e., resting horses (RH), horses with pain (HP), horses immediately after exercise (HE), and horseshoeing horses (HH), was developed. The normalization of equine facial posture revealed that the profile (99.45%) had higher accuracy than the fr...
Holtby AR, McGivney BA, Browne JA, Katz LM, Murphy KJ, Hill EW.Thoroughbred horses are bred for competitive racing and undergo intense training regimes. The maintenance of physical soundness and desirable behavioural characteristics are critical to the longevity of a racing career. Horses intended for Flat racing generally enter training as yearlings and undergo introductory training prior to exercise conditioning for racing. This period requires rapid adjustment to a novel environment. As a prey animal, a horse's 'fight-or-flight' response is highly adapted, in which a well-understood component of this response, the hypothalamic-pituitary-axis, is activa...
Moss A, Leise B, Hackett E.Laminitis is a complex and debilitating disease of horses. Numerous predisposing factors contribute to laminitis development, however the exact pathogenesis remains undetermined. Serum T4, cortisol, and histamine are components of the innate stress response and could play a causative or contributory role. Stress hormone concentrations in laminitis are largely unknown. Objective: To evaluate parameters associated with stress response in horses with laminitis, and compare these to healthy horses and horses with gastrointestinal (GI) disease. Methods: Thirty-eight adult horses presenting for non-...
Holtby AR, Hall TJ, McGivney BA, Han H, Murphy KJ, MacHugh DE, Katz LM, Hill EW.Behavioural plasticity enables horses entering an exercise training programme to adapt with reduced stress. We characterised SNPs associated with behaviour in yearling Thoroughbred horses using genomics analyses for two phenotypes: (1) handler-assessed coping with early training events [coping] (n = 96); and (2) variation in salivary cortisol concentration at the first backing event [cortisol] (n = 34). Using RNA-seq derived gene expression data for amygdala and hippocampus tissues from n = 2 Thoroughbred stallions, we refined the SNPs to those with functional relevance to behaviour by c...
Scholler D, Zablotski Y, May A.Stress has a significant impact on equine welfare. There are some studies on the stress response in horses ridden with tight nosebands, but little is known about other stress parameters than cortisol, which potentially could address an emotional component. In this study, blood samples of a total of 74 warmblood horses were used to establish reference values for plasma substance P (SP) concentrations. Moreover, 16 of these warmblood horses were included in a stress model. Four different stress levels (level 1: horses ridden with loose noseband, level 2: tight noseband, level 3: loose noseband a...
Poochipakorn C, Joongpan W, Tongsangiam P, Phooseerit A, Leelahapongsathon K, Chanda M.The severe outbreak of African horse sickness (AHS) in Thailand has forced horses to reside full-time inside barns that are covered by a small mesh net to prevent minuscule AHS insect vectors from gaining access. However, housing in the net-covered barn induces stress in horses, which compromises their welfare. Implementing strategic airflow adjustment while retaining the vector-protection characteristics has been proposed to help alleviate this problem. The present study aimed to investigate the effect of strategic ventilation adjustment on blood cortisol levels, heart rate and behaviour in h...
Hensel B, Jakop U, Schmicke M, Schröter F, Jung M, Schulze M.Artificial insemination (AI) is commonly used in the equine industry to enhance the genetic value in breeding programs and to effectively utilize ejaculates. Many stallions are used as breeding stallions as well as in high-level sports competitions to improve their market value. The goal of the present study was to investigate whether this dual use of stallions influences the animals´ stress levels and/or the quality of their ejaculates. For this purpose, 18 stallions were grouped into two categories: breeding stallions with (BSC = breeding stallion competition), and breeding stallions with...
Soiluva J, Häyrinen L, Gangini G, Öistämö R, Gracia-Calvo LA, Raekallio MR.Traditional visual lameness assessment is subjective. Ethograms have been developed for evaluating pain and objective sensors to detect lameness. Heart rate (HR) and heart rate variability (HRV) have been used to evaluate stress and pain. The aim of our study was to compare subjective and behavioral lameness scores, a sensor system measuring movement asymmetry, HR, and HRV. We hypothesized that these measures would show related trends. In 30 horses, an inertial sensor system was used to measure movement asymmetries during trot in-hand. A horse was categorized as sound if each asymmetry was les...
McGilloway M, Manley S, Aho A, Heeringa KN, Whitacre L, Lou Y, Squires EJ, Pearson W.Equine leaky gut syndrome is characterized by gastrointestinal hyperpermeability and may be associated with adverse health effects in horses. The purpose was to evaluate the effects of a prebiotic Aspergillus oryzae product (SUPP) on stress-induced gastrointestinal hyperpermeability. Eight horses received a diet containing SUPP (0.02 g/kg BW) or an unsupplemented diet (CO) (n = 4 per group) for 28 days. On Days 0 and 28, horses were intubated with an indigestible marker of gastrointestinal permeability (iohexol). Half the horses from each feeding group underwent 60 min of transport by trailer ...
Gharehaghajlou Y, Raidal SL, Freccero F, Padalino B.Transportation may lead to oxidative stress (OS) and gastric ulceration in horses, and optimal feed management before, or during, transportation is unclear. This study aimed to evaluate the effects of transportation after three different feeding strategies on OS and to explore possible associations between OS and equine gastric ulcer syndrome (EGUS). Twenty-six mares were transported by truck for 12 hours without food or water. Horses were randomly divided into 3 groups; (1) fed 1 hour before departure (BD), (2) fed 6 hours BD, (3) fed 12 hours BD. Clinical examinations and blood collections w...
Elte Y, Acton K, Martin J, Nielen M, van Weeren R, Wolframm I.Individuals working in the field of veterinary care are regularly affected by their profession. High levels of responsibility to often provide life-saving health care to animals combined with having to manage owners' expectations and irregular working hours can cause considerable levels of work-related stress among professionals in equine veterinary practice. On the positive side, research also shows that working in the veterinary profession can have a positive impact on personal wellbeing and feelings of fulfillment. A limited number of studies has investigated work satisfaction and engagemen...
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...
Lebelt D, Zanella AJ, Unshelm J.The aim of the present study was to obtain information on the possible mechanisms underlying cribbing behaviour in horses. To investigate the horse's responsiveness to an external stimulus, a device for telemetric measurement of thermal threshold, using the forelimb withdrawal reflex, was developed and validated. Measurements of thermal threshold took place in cribbing horses (n = 11) before and during cribbing periods. Heart rate was monitored continuously in the same horses. Blood samples were collected before and during cribbing periods as well and in age- and sex-matched control horses (n ...
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...
Vardy MD, Gardner TR, Cosman F, Scotti RJ, Mikhail MS, Preiss-Bloom AO, Williams JK, Cline JM, Lindsay R.The purpose of this study was to determine effects of ovariectomy (OVX) and conjugated equine estrogens plus medroxyprogesterone acetate (CEE/MPA), or ethinyl estradiol plus norethindrone acetate (EE/NA) on biomechanics of uterosacral (USL) and round (RL) ligaments in postmenopausal (PMP) monkeys. Methods: This was a randomized, triple blind, placebo-controlled study. OVX monkeys received 12 months no treatment (Pbo) (n = 19), CEE/MPA (n = 19), or EE/NA (n = 21). USL and RL step strains and stress-relaxation data were curve-fitted, giving strain-dependent tensile modulus (TM) from 0% to 30%. R...
Ziebell KL, Steinmann H, Kretzdorn D, Schlapp T, Failing K, Schmeer N.The efficacy of an immunomodulator, Baypamun N, was tested in 4-10-month-old horses which were exposed to stress by weaning, transport and commingling with yearlings from different breeders (crowding). Verum (n = 26) and placebo animals (n = 27) received three intramuscular injections of the investigational preparations (days 0, 2, 9) starting at the day of commingling in one stable. The incidence of acute respiratory disease was high during the first 4 weeks after commingling. Approximately 50% of all horses showed seroconversion due to field infection by EHV1 and EHV4 during the observation ...
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...
Shakeel M, Yoon M.The threat posed by increased surface temperatures worldwide has attracted the attention of researchers to the reaction of animals to heat stress. Spermatogenesis in animals such as stallions is a temperature-dependent process, ideally occurring at temperatures slightly below the core body temperature. Thus, proper thermoregulation is essential, especially because stallion spermatogenesis and the resulting spermatozoa are negatively affected by increased testicular temperature. Consequently, the failure of thermoregulation resulting in heat stress may diminish sperm quality and increase the li...
Science (New York, N.Y.)September 14, 1984
Volume 225, Issue 4667 1172-1174 doi: 10.1126/science.6089344
Lagerweij E, Nelis PC, Wiegant VM, van Ree JM.The twitch procedure in horses attenuates the increase in the heart rate evoked by pain-inducing stimuli and the reaction of the animals to such stimuli. Endorphin systems are probably involved in the effectiveness of the twitch, since its action is blocked by naloxone and its application increases plasma concentrations of immunoreactive beta-endorphin. The mode of action of the twitch cannot be explained by the generally accepted theory of divertive pain and may resemble that of classical acupuncture.
Briefer Freymond S, Bardou D, Briefer EF, Bruckmaier R, Fouché N, Fleury J, Maigrot AL, Ramseyer A, Zuberbühler K, Bachmann I.Stereotypies are repetitive and relatively invariant patterns of behavior, which are observed in a wide range of species in captivity. Stereotypic behavior occurs when environmental demands produce a physiological response that, if sustained for an extended period, exceeds the natural physiological regulatory capacity of the organism, particularly in situations that include unpredictability and uncontrollability. One hypothesis is that stereotypic behavior functions to cope with stressful environments, but the existing evidence is contradictory. To address the coping hypothesis of stereotypies...
Toribio RE.Critical illness challenges many endocrine homeostatic systems to overcome diseases, stress, and hostile conditions that threaten survival. Coordinated and consecutive responses by the autonomic nervous system, endocrine metabolic adaptations to mobilize and conserve energy and electrolytes, cardiovascular adjustments to maintain organ perfusion, and immunomodulation to overcome infections and inflammation are required. Because most admissions to equine intensive care units are related to horses with gastrointestinal disease and septic foals, most endocrine information during critical disease ...
Ralston SL.Abnormally high or low blood glucose and insulin concentrations after standardized glucose tolerance tests can reflect disorders such as pituitary dysfunction, polysaccharide storage myopathies, and other clinical disorders. Glucose and insulin responses, however, are modified by the diet to which the animal has adapted, time since it was last fed, and what it was fed. Body fat (obesity), fitness level, physiologic status, and stress also alter glucose and insulin metabolism. Therefore, it is important to consider these factors when evaluating glucose and insulin tests, especially if only one ...
Ott EC, Cavinder CA, Wang S, Smith T, Lemley CO, Dinh TTN.Oxidative stress caused by routine physical stressors may negatively impact the performance of equine athletes; thus, the present study identifies oxidative biomarkers in the blood plasma of exercising horses. Stock-type horses were subject to a standardized moderate-intensity exercise protocol 3 times per week for 8 wk. Exercise protocol followed NRC guidelines consisting of 30% walk, 55% trot, and 15% canter, with a target heart rate (HR) of 90 BPM. Blood plasma was collected in wk 1, 2, 7, and 8 immediately before and 0, 30, 60, and 90 min after exercise and analyzed for total antioxidant...
Ijichi C, Collins LM, Creighton E, Elwood RW.Objective assessment of animal personality is typically time consuming, requiring the repeated measure of behavioural responses. By contrast, subjective assessment of personality allows information to be collected quickly by experienced caregivers. However, subjective assessment must predict behaviour to be valid. Comparisons of subjective assessments and behaviour have been made but often with methodological weaknesses and thus, limited success. Here we test the validity of a subjective assessment against a battery of behaviour tests in 146 horses (Equus caballus). Our first aim was to determ...
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...
Mengoli M, Pageat P, Lafont-Lecuelle C, Monneret P, Giacalone A, Sighieri C, Cozzi A.Modern day horse-human relationships entail different types of sport and riding activities, which all require learning. In evaluating the interaction between learning and emotions, studying normal coping strategies or adaptive responses to the surroundings is critical. 34 horses were involved in a cognitive test, in the absence of physical effort, to analyze performance, as well as physiological and behavioral responses related to learning, memorization and recall, associated to the capacity to reverse a learned model. Synthetic Equine Appeasing Pheromone (EAP) was used in 17 horses in order t...
Grimmett A, Sillence MN.Preparations that contain tryptophan are marketed world wide as calmative agents to treat excitable horses. Tryptophan is the amino acid precursor for serotonin, a neurotransmitter implicated in sedation, inhibition of aggression, fear and stress, in various animal species and humans. Experiments have shown that tryptophan supplementation decreases aggression in humans, dogs, pigs, poultry, and fish, and that it may reduce fearfulness and stress in calves, vixens and poultry. However, behavioural characteristics more closely linked to excitement, such as hyperactivity in dogs, are not modified...
Capomaccio S, Verini-Supplizi A, Galla G, Vitulo N, Barcaccia G, Felicetti M, Silvestrelli M, Cappelli K.A large proportion of mammalian genomes is represented by transposable elements (TE), most of them being long interspersed nuclear elements 1 (LINE-1 or L1). An increased expression of LINE-1 elements may play an important role in cellular stress-related conditions exerting drastic effects on the mammalian transcriptome. To understand the impact of TE on the known horse transcriptome, we masked the horse EST database, pointing out that the amount is consistent with other major vertebrates. A previously developed transcript-derived fragments (TDFs) dataset, deriving from exercise-stimulated hor...
Medica P, Giunta RP, Bruschetta G, Ferlazzo AM.Exercise represents a physical stress that challenges homeostasis affecting central and peripheral serotoninergic systems. The influence of the exercise on circulating serotonin (5-hydroxytryptamine [5-HT]) levels depends on training state as well as the exercise protocol. The purpose of the present research was to determine changes of plasma 5-HT in sport horses in response to training (T) and simulated race (SR) and in addition to assess the possible presence of significant differences on circulating 5-HT between two different sessions of exercise. In particular, the research was carried out...
Contalbrigo L, Borgi M, De Santis M, Collacchi B, Tuozzi A, Toson M, Redaelli V, Odore R, Vercelli C, Stefani A, Luzi F, Valle E, Cirulli F.Equine-assisted interventions (EAIs) are well-known complementary practices combining physical activity with emotional/cognitive stimulation. They are especially suited for children with autism spectrum disorders (ASD) who need a high degree of physical and psychological enrichment. Even though EAIs have become a common practice, stress responses in horses interacting with individuals that can manifest inappropriate behaviours, such as ASD children, have not been thoroughly investigated. Our multicentre study aimed to investigate behavioural and physiological indices of stress in horses involv...
Squires EL, Keith SL, Graham JK.Although use of cryopreserved stallion spermatozoa is currently accepted by many breed registries, utilization of this technique remains limited due to poor fertility for some stallions. One reason for these results is osmotic stress that spermatozoa experiences when the cryoprotectant (glycerol) is added to the cells prior to freezing and removal from the cells after thawing. In an effort to minimize osmotic damage, alternative cryoprotectants, having lower molecular weights and greater membrane permeability than glycerol, were evaluated to determine their effectiveness for cryopreserving sta...
Grzędzicka J, Dąbrowska I, Malin K, Witkowska-Piłaszewicz O.Increased training loads in both human and equine athletes are generally implemented to improve their physical performance. These loads are tolerated only within appropriate training periodization with regard to recovery time. Otherwise, training overload causes failure in the systemic adaptation, which at first leads to overreaching, and progressively to overtraining syndrome (OTS). Exercise endocrinology, and anabolic/catabolic balance as an indicator of athlete performance status and OTS has continued to attract attention. In human medicine, changes in testosterone and cortisol levels, as w...
Becker-Birck M, Schmidt A, Wulf M, Aurich J, von der Wense A, Möstl E, Berz R, Aurich C.Bringing the head and neck of ridden horses into a position of hyperflexion is widely used in equestrian sports. In our study, the hypothesis was tested that hyperflexion is an acute stressor for horses. Salivary cortisol concentrations, heart rate, heart rate variability (HRV) and superficial body temperature were determined in horses (n = 16) lunged on two subsequent days. The head and neck of the horse was fixed with side reins in a position allowing forward extension on day A and fixed in hyperflexion on day B. The order of treatments alternated between horses. In response to lunging, ...
Valigura HC, Leatherwood JL, Martinez RE, Norton SA, White-Springer SH.Mitigation of exercise-induced stress is of key interest in determining ways to optimize performance horse health. To test the hypothesis that dietary supplementation of a Saccharomyces cerevisiae fermentation product would decrease markers of exercise-induced stress and inflammation in young horses, Quarter Horse yearlings (mean ± SD; 9 ± 1 mo) were randomly assigned to receive either no supplementation (CON; n = 8) or 21 g/d S. cerevisiae fermentation product (10.5 g/feeding twice daily; SCFP; n = 10) top-dressed on a basal diet of custom-formulated grain as well as ad libitum Coastal berm...
Contreras-Aguilar MD, Lamy E, Escribano D, Cerón JJ, Tecles F, Quiles AJ, Hevia ML.This study aims to evaluate the circadian and circannual variations in a panel of analytes in horse saliva that have been previously described as biomarkers related to stress and disease, in order to interpret them correctly when they are measured in this species. This panel of analytes integrated cortisol, salivary alpha-amylase (sAA), lipase (Lip), total esterase (TEA), butyrylcholinesterase (BChE), adenosine deaminase (ADA), γ-glutamyl transferase (gGT), creatine kinase (CK), urea, total bilirubin, total protein (TP), and phosphorus. These analytes were measured in saliva obtained from a p...
Kapteijn CM, Frippiat T, van Beckhoven C, van Lith HA, Endenburg N, Vermetten E, Rodenburg TB.Measuring physiological parameters of stress in horses during groundwork, for example when involved in equine-assisted interventions, is important to gain insight into the stress levels of the horses. Heart rate and heart rate variability can be used as physiological indicators of stress in horses. Heart rate monitors could be easily incorporated into practice, as they are not expensive and easy to use. However, it is questionable whether heart rate monitors present accurate heart rate variability results in exercising horses, similar to electrocardiograms. The aim of this study was to determi...
Christensen JW, Ahrendt LP, Malmkvist J, Nicol C.The mechanisms underlying individual variation in learning are key to understanding the development of cognitive abilities. In humans and primates, curiosity has been suggested as an important intrinsic factor that enhances learning, whereas in domesticated species research has primarily identified factors with a negative effect on cognitive abilities, such as stress and fearfulness. This study presents the first evidence of a link between object-directed curiosity and learning performance in young horses in two very different learning tasks (visual discrimination and pressure-release). We exp...
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 ...
Masko M, Domino M, Lewczuk D, Jasinski T, Gajewski Z.A treadmill is an important tool in the equine analysis of gait, lameness, and hoof balance, as well as for the evaluation of horse rehabilitation or poor performance including dynamic endoscopy. Before all of these uses, horses have to be habituated to a treadmill locomotion. We used principal component analysis to evaluate the relationship between aspects of the horse's temperament and emotional response, and progress in the behavioral habituation to a treadmill. Fourteen horses were tested, by the same familiar handler, using the novel object test, the handling test, and both positive and n...
Ohmura H, Hobo S, Hiraga A, Jones JH.To determine the influence of transportation by road and air on heart rate (HR) and HR variability (HRV) in horses. Animals-6 healthy horses. Methods: ECG recordings were obtained from horses before (quarantine with stall rest [Q]; 24 hours) and during a journey that included transportation by road (RT; 4.5 hours), waiting on the ground in an air stall (W; 5.5 hours), and transportation by air (AT; 11 hours); HR was determined, and HRV indices of autonomic nervous activity (low-frequency [LF; 0.01 to 0.07 Hz] and high-frequency [HF; 0.07 to 0.6 Hz] power) were calculated. Results: Mean ± SD H...
Badenhorst M, Page P, Ganswindt A, Laver P, Guthrie A, Schulman M.The prevalence of equine herpesvirus types-1 and -4 (EHV-1 and -4) in South African Thoroughbreds at auction sales is currently undefined. Commingling of young Thoroughbreds from various populations together with physiological stress related to their transport and confinement at a sales complex, may be associated with shedding and transmission of EHV-1 and -4. This prospective cohort study sampled 90 young Thoroughbreds consigned from eight farms, originating from three provinces representative of the South African Thoroughbred breeding demographic to a sales complex. Nasal swabs for quantitat...
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...
