The physiology of horses encompasses the study of the biological functions and processes that occur within the equine body. This includes the examination of various systems such as the cardiovascular, respiratory, musculoskeletal, digestive, and nervous systems. Understanding equine physiology is essential for comprehending how horses adapt to different environmental conditions, perform physical activities, and respond to health challenges. Research in this field often focuses on the mechanisms of energy metabolism, thermoregulation, and muscle function during exercise, as well as the physiological responses to stress and disease. This page compiles peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine physiology, providing insights into the biological processes that support the health and performance of horses.
Pereira RR, Nogueira BG, Milan B, Acacio BR, Freitas-Dell'Aqua CP, Souza MI, Sampaio BF.The aim of this study was to determine an ozone dosage capable of inducing pro-oxidation, and to verify its action on sperm cells during the process of cooling and cryopreservation of equine semen. In this study, we evaluated the ozone concentrations of 2µg/mL,15µg/mL, 30µg/mL e 60 µg/mL added in equine semen cooling and freezing extenders. Samples were evaluated for sperm kinetics patterns, function of sperm structures and lipid peroxidation. In the experiment, the concentration of 15 µg/mL showed higher total and progressive motility when comparing to control (60.3±3 and 40.7±3.4 vs. ...
de Souza AF, Pascual CJ, Maia BT, do Valle De Zoppa AL.This study aimed to evaluate the distribution of dye at two perineural injection sites of the palmar/plantar nerves and describe their anatomical variations of positioning at the level of the distal metacarpus/metatarsus in horses. Two ml of 1% methylene blue solution was injected in 24 limbs (12 forelimbs and 12 hindlimbs) of horse cadavers at two different points: Group 1: between the branch of the suspensory ligament and deep digital flexor tendon, and Group 2: between the deep and superficial digital flexor tendons. This was followed by dissection and evaluation of the solution diffusion. ...
Egenvall A, Clayton H, Engell MT, Roepstorff C, Engström H, Byström A.The study investigated between-rider differences in pelvic roll and pitch motion during horseback riding as the horse walked around circles without rein contact (walk on long reins), with rein contact, and with moderate collection. Ten horses were ridden by five riders on left and right 10 m circles, in a partly crossed design, yielding 14 trials. Each trial included each of the three walk variations in both directions. Riders wore an inertial measurement unit (IMU), logging at 100 Hz, dorsally on the pelvis. Pelvic roll and pitch data were split into strides based on data from IMU-sensors on ...
Monteiro FDO, Borges LPB, Cardoso TDS, Teixeira PPM, Filho DZ, Sartori VC, Pereira RN, Flores FN, Coelho CMM, Silva MAM, Valadão CAA.This study aimed to describe an animal model for studying equine visceral pain using minimally invasive and video-assisted cecum and ileum instrumentation. The access to the cecum and ileum was affected because of a previous typhlostomy. For video-assisted distention of the cecum and ileum, a distention device, which we developed using an endotracheal Rusch probe, was used, adapted, and coupled to a cuffometer to inflate and measure the pressure of the cuff attached to its distal portion. In a video-assisted manner, the distal portion of the device was introduced into the cecum and ileum, whic...
Angel-Velez D, De Coster T, Azari-Dolatabad N, Fernandez-Montoro A, Benedetti C, Bogado Pascottini O, Woelders H, Van Soom A, Smits K.Equine oocyte vitrification would benefit the growing in vitro embryo production programs, but further optimization of the protocol is necessary to reach clinical efficiency. Therefore, we aimed to perform a direct comparison of non-permeating and permeating cryoprotective agents (CPAs) during the vitrification and warming of equine immature oocytes. In the first experiment, cumulus oocytes complexes (COCs) were vitrified comparing sucrose, trehalose, and galactose in combination with ethylene glycol (EG) and dimethyl sulfoxide (DMSO). In the second experiment, the COCs were vitrified using th...
Wiśniewska A, Janczarek I, Wilk I, Tkaczyk E, Mierzicka M, Stanley CR, Górecka-Bruzda A.Ridden horses have been reported to be fearful of cows. We tested whether cows could provoke behavioural and cardiac fear responses in horses, and whether these responses differ in magnitude to those shown to other potential dangers. Twenty horses were exposed to cow, a mobile object or no object. The time spent at different distances from the stimulus was measured. In a separate test, heart rate (HR), root mean square of successive differences between heartbeats (RMSSD) and the horses' perceived fear were assessed at various distances from the stimuli. The horses avoided the area nearest to a...
Frontiers in agingOctober 27, 2021
Volume 2 708918 doi: 10.3389/fragi.2021.708918
Latham CM, Owen RN, Dickson EC, Guy CP, White-Springer SH.In aged humans, low-intensity exercise increases mitochondrial density, function and oxidative capacity, decreases the prevalence of hybrid fibers, and increases lean muscle mass, but these adaptations have not been studied in aged horses. Effects of age and exercise training on muscle fiber type and size, satellite cell abundance, and mitochondrial volume density (citrate synthase activity; CS), function (cytochrome c oxidase activity; CCO), and integrative (per mg tissue) and intrinsic (per unit CS) oxidative capacities were evaluated in skeletal muscle from aged (n = 9; 22 ± 5 yr) and yea...
Antczak DF, Allen WRT.This chapter focuses on the early stages of placental development in horses and their relatives in the genus Equus and highlights unique features of equid reproductive biology. The equine placenta is classified as a noninvasive, epitheliochorial type. However, equids have evolved a minor component of invasive trophoblast, the chorionic girdle and endometrial cups, which links the equine placenta with the highly invasive hemochorial placentae of rodents and, particularly, with the primate placenta. Two types of fetus-to-mother signaling in equine pregnancy are mediated by the invasive equine tr...
Ganeshpurkar A, Singh R, Kumar D, Gutti G, Sardana D, Shivhare S, Singh RB, Kumar A, Singh SK.Machine learning (ML), an emerging field in drug design, has the potential to predict toxicity, shape-based analysis of inhibitors, scoring function (SF) etc. In the present study, a homology model, docking protocol, and a dedicated SF have been developed to identify the inhibitors of horse butyrylcholinesterase (BChE) enzyme. Horse BChE enzyme has homology with human BChE and is a substitute for the screening of inhibitors. The developed homology model was validated and the active site residues were identified from Cavityplus to generate grid box for docking. The validation of docking invol...
Pimentel KL, Carmalt JL. There is conflicting evidence regarding communication between the two compartments of the equine temporomandibular joint (TMJ). Understanding the inter-relationship between TMJ compartments is critical for diagnostic and clinical management purposes. To determine the frequency of communication between the discotemporal joint (DTJ) and the discomandibular joint (DMJ) of the equine TMJ in horses free of overt disease. A randomized, blinded, controlled cadaveric study. Equine cadaver heads ( = 20), with no reported history of potential TMJ disease, were collected and stored frozen until use. ...
Montgomery JB, Klein M, Boire JR, Beck C, Häusermann D, Maksimenko A, Hall CJ.Laminitis is an extremely painful and debilitating condition of horses that can affect their athletic ability and even quality of life. The current gold standard for assessment of laminar tissue is histology, which is the only modality that enables detailed visualization of the lamina. Histology requires dissection of the hoof and therefore can only represent one specific time point. The superior spatial and contrast resolution of synchrotron computed tomography (sCT), when compared with readily available imaging modalities, such as radiographs and conventional CT, provides an opportunity for ...
Premont A, Balthes S, Marr CM, Jeevaratnam K.Atrial fibrillation (AF) is the most common pathological arrhythmia in horses. Although it is not usually a life-threatening condition on its own, it can cause poor performance and make the horse unsafe to ride. It is a complex multifactorial disease influenced by both genetic and environmental factors including exercise training, comorbidities or ageing. The interactions between all these factors in horses are still not completely understood and the pathophysiology of AF remains poorly defined. Exciting progress has been recently made in equine cardiac electrophysiology in terms of diagnosis ...
Dupont J, Gougnard A, Salciccia A, Detilleux J, Serteyn D, Sandersen C.To compare the efficacy of single-breath continuous positive airway pressure manoeuvre (CPAP-M) with inhaled salbutamol, and a combination of both. Methods: Randomized, clinical study. Methods: A total of 62 client-owned horses (American Society of Anesthesiologists status III-V) anaesthetized for laparotomy. Methods: Horses were premedicated with intravenous (IV) xylazine (0.4-0.6 mg kg), anaesthesia was induced with midazolam (0.06 mg kg IV) and ketamine (2.2 mg kg IV) and maintained with isoflurane in oxygen using volume-controlled ventilation without positive end-expiratory pressure. If Pa...
Snider C, Grant D, Grant SA.Post-traumatic osteoarthritis (PTOA) is a progressive articular degenerative disease that degrades articular cartilage and stimulates apoptosis in chondrocyte cells. An injectable decellularized, extracellular matrix (ECM) scaffold, that might be able to combat the effects of PTOA, was developed where the ECM was conjugated with 20 nm gold nanoparticles (AuNP) and supplemented with curcumin and hyaluronic acid (HA). Porcine diaphragm ECM was decellularized and homogenized; AuNPs were conjugated using chemical crosslinking followed by mixing with curcumin and/or HA. Injection force testing and...
Bresnahan DR, Lupole RE, Stilz CR, Carnevale EM.Zona pellucida (ZP) proteins are important for fertilization and sperm binding and are closely associated with cumulus cells. Communication between cumulus and oocytes is facilitated by intracellular membrane channels composed of connexins. The extent aging impacts potential differences in fertilization and reductions in fertility is not well understood. This study characterized age-related differences in transcript abundance of ZP proteins and connexins in cells from ovarian follicles. Additionally, differences in sperm binding to oocytes from old and young mares was evaluated. For experiment...
Translation: The 2nd edition of this specialized book by Renate Ettl includes basic knowledge about the use of kinesiological tapes, ranging from their foundations to specific applications in horses. The reader is vividly introduced to the material and adhesive properties of the tapes, the various application techniques, and their correct application. The book is mainly aimed at manual therapists and veterinarians, but interested horse owners can also gain insight into the "world of colorful strips" with this work.
Part 1 of the book provides foundational knowledge necessary for the correct...
Gerard MP.This article provides an overview of foot anatomy and physiology, with a focus on fundamental knowledge. The foot is defined as the epidermal hoof capsule and all structures enveloped by the capsule. The anatomy is described using terminology published in Nomina Anatomica Veterinaria.
Amaral A, Fernandes C, Szóstek-Mioduchowska A, Lukasik K, Rebordão MR, Pinto-Bravo P, Skarzynski DJ, Ferreira-Dias G.Cathepsin G (CAT) is a protease released by neutrophils when forming neutrophil extracellular traps that was already associated with inducing type I collagen (COL1) in equine endometrium in vitro. Endometrosis is a fibrotic condition mainly characterized by COL1 deposition in the equine endometrium. The objective was to evaluate if noscapine (an alkaloid for cough treatment with anti-neoplastic and anti-fibrotic properties) would reduce transcription (evaluated by qPCR) and COL1 protein relative abundance (evaluated by western blot) induced by CAT in equine endometrial explants from follicula...
Ehrle A, Lilge S, Clegg PD, Maddox TW.Flexor tendon injuries are a common cause of lameness and early retirement in equine athletes. While ultrasonography is most frequently utilised, advanced diagnostic imaging modalities are becoming more widely available for detection and monitoring of flexor tendon lesions. Part two of this literature review details current experience with low- and high-field magnetic resonance imaging (MRI) and computed tomography (CT) for the diagnosis of equine flexor tendinopathy with a focus on the deep digital flexor tendon. Implications of the 'magic angle' artefact as well as injection techniques and t...
Hansson E, Skiöldebrand E.To treat osteoarthritic chondrocytes and thereby reduce the inflammation with a drug combination that primarily affects 5-HT- and ATP-evoked Ca2+ signaling. In osteoarthritic chondrocytes, Ca2+ signaling is elevated, resulting in increased production of ATP and inflammatory mediators. The expression of TLR4 and Na+/K+-ATPase was used to evaluate the inflammatory status of the cells. Methods: Equine chondrocytes were collected from joints with mild structural osteoarthritic changes and cultured in monolayers. The cells were treated with a combination of bupivacaine (1 pM) and sildenafil (1 ...
Vincent A, Peth-Pierce RM, Morrissey MA, Acri MC, Guo F, Seibel L, Hoagwood KE.(1) Background: Accounting for the well-being of equine partners is a responsibility of those engaged in Equine-Assisted Services (EAS). Researchers took heed of this call to action by developing an innovative way to collect data to assess the physiological indicators of stress in equine participants. The collection of saliva is considered to be a minimally invasive method of data collection and is typically performed using a cotton swab; however, in equines, the introduction of a foreign object may induce stress; (2) Methods: Researchers used a modified bit to collect pooled saliva in an effo...
de Mira MC, Lamy E, Santos R, Williams J, Pinto MV, Martins PS, Rodrigues P, Marlin D.The purpose of this study was to investigate the usefulness of salivary cortisol (SC) and eye temperature measured by infrared thermography (IRTET) as biomarkers to manage competitions more effectively and monitor horse welfare in endurance competitions. Based on previous studies, it was hypothesised that pre-exercise baseline SC and IRTET would be higher in younger or less experienced horses, and that post-exercise variation from baseline would be higher in the top finishers. Results: Salivary cortisol measured in 61 competing at qualifier 40 km and 80 km rides showed an abrupt variation ...
Andrade DGA, Cerri FM, Barbosa GVM, Basso RM, Takahira RK, Pantoja JCF, Oliveira-Filho JP, Borges AS.Analysis of the cerebrospinal fluid (CSF) is important as a complementary test in horses with neurologic diseases, and sequential analysis may provide information about the treatment response or evolution and quantitative measures of the CSF drug concentration during treatment. The aim of this study was to compare erythrocyte and nucleated cell counts and protein concentration in multiple CSF samples obtained sequentially from two different puncture sites in clinically healthy horses. Eight and 12 horses, with no evidence of neurologic disease, were subjected to CSF collection from the atlanto...
Gaitskell-Phillips G, Martín-Cano FE, Ortiz-Rodríguez JM, Silva-Rodríguez A, da Silva-Álvarez E, Gil MC, Ortega-Ferrusola C, Peña FJ.Seminal plasma plays an important role in sperm physiology. Seminal plasma proteins vehiculated in microvesicles, carry RNAs and proteins with a potential role in early embryo development. Additionally, proteins present in seminal plasma participate in redox regulation and energy metabolism. In view of these facts, we hypothesized that differences in protein composition of the seminal plasma among stallions may help to explain differences in freeze-ability seen among them. Three independent ejaculates from 10 different stallions of varying breeds were frozen using standard protocols in our lab...
Gaitskell-Phillips G, Martín-Cano FE, Ortiz-Rodríguez JM, da Silva-Álvarez E, Masot J, Redondo E, Gil MC, Ortega-Ferrusola C, Peña FJ.Seminal plasma proteins have important roles in sperm functionality, and different mechanisms including micro-vesicle transport of proteins are involved in the regulation of sperm biology. Due to the role of seminal plasma, we hypothesized that specific proteins present in seminal plasma may be used as discriminant variables with potential to identify stallions producing different quality ejaculates; 10 fertile stallions, with different motility and velocity values (although within normal ranges) were used in this study. Motilities and velocities were studied using computer assisted sperm anal...
Melzer M, Schubert S, Müller SF, Geyer J, Hagen A, Niebert S, Burk J.Mesenchymal stromal cells (MSC) represent a promising therapeutic tool for tendon regeneration. Their tenogenic differentiation is crucial for tissue engineering approaches and may support their beneficial effects after cell transplantation . The transforming growth factor (TGF)-, signalling via intracellular Smad molecules, is a potent paracrine mediator of tenogenic induction. Moreover, scaffold topography or tendon matrix components induced tenogenesis via activation of the Rho/ROCK cascade, which, however, is also involved in pathological adaptations in extracellular matrix pathologies. Th...
Içli S, Soleimani M, Oldenhof H, Sieme H, Wriggers P, Wolkers WF.Cryopreservation can be used to store equine oocytes for extended periods so that they can be used in artificial reproduction technologies at a desired time point. It requires use of cryoprotective agents (CPAs) to protect the oocytes against freezing injury. The intracellular introduction of CPAs, however, may cause irreversible osmotic damage. The response of cells exposed to CPA solutions is governed by the permeability of the cellular membrane towards water and the CPAs. In this study, a mathematical mass transport model describing the permeation of water and CPAs across an oocyte membrane...
Klein C, Bruce P, Hammermueller J, Hayes T, Lillie B, Betteridge K.The current study used RNA sequencing to determine transcriptional profiles of equine endometrium collected 14, 22, and 28 days after ovulation from pregnant mares. In addition, the transcriptomes of endometrial samples obtained 20 days after ovulation from pregnant mares, and from non-pregnant mares which displayed and failed to display extended luteal function following the administration of oxytocin, were determined and compared in order to delineate genes whose expressions depend on the presence of the conceptus as opposed to elevated progesterone alone. A mere fifty-five transcripts were ...
Boyde A, Riggs CM, Bushby AJ, McDermott B, Pinchbeck GL, Clegg PD.Arthropathy of the distal articular surfaces of the third metacarpal (Mc3) and metatarsal (Mt3) bones in the Thoroughbred racehorse (Tb) is a natural model of repetitive overload arthrosis. We describe a novel pathology that affects the articular calcified cartilage (ACC) and subchondral bone (SCB) and which is associated with hyaline articular cartilage degeneration. Parasagittal slices cut from the palmar quadrant of the distal condyles of the left Mc3/Mt3 of 39 trained Tbs euthanized for welfare reasons were imaged by point projection microradiography, and backscattered electron (BSE) scann...
Borzacchiello A, Mayol L, Schiavinato A, Ambrosio L.An amphiphilic hyaluronic acid (HA) derivative has been obtained by the amidation of the carboxylic group of the glucuronic acid. This derivative, HYADD4-G (HY4), is the hexadecylamide of 500-730 kDa hyaluronic acid, derived from Streptococcus equi at about 2% degree of substitution (2 mol hexadecylamine per 100 mol hexuronic acid). Its viscoelastic properties, at a concentration of 5 mg/mL in phosphate buffer saline, have been compared with those solutions of native HA, having the same molecular weight. Changes in the viscoelastic properties of equine synovial fluid (SF) when mixed with HY4 o...
Duncan ID, Griffiths IR, Madrid RE.A study has been made of the pathological changes in the recurrent laryngeal nerves from horses with clinical and sub-clinical idiopathic laryngeal hemiplegia. Qualitative and quantitative studies showed in clinical cases there was a progressive distal loss of large myelinated fibres in the left recurrent nerve. Regenerating clusters and onion bulbs were frequently seen in affected nerves both at proximal and distal levels. Degenerating axons were characterized by collections of organelles, and denervated bands of Bungner were common. Similar but less severe changes were seen in the left recur...
Foss R, Ortis H, Hinrichs K.Intracytoplasmic sperm injection (ICSI) is used to produce foals from otherwise infertile mares and from stallions with limited sperm stores, but requires expensive equipment and is technically demanding. Methods to transport oocytes to ICSI laboratories would allow collection of oocytes by the referring veterinarian and enable greater application of this technique. Objective: This study was conducted to evaluate protocols that could be used to transport immature and maturing oocytes for ICSI. Methods: In vitro experiment. Methods: Oocytes were recovered by transvaginal ultrasound-guided folli...
Hall SE, Upton RMO, McLaughlin EA, Sutherland JM.The mare ovary is unique in its anatomical structure; however, the signalling pathways responsible for physiological processes, such as follicular activation, remain uncharacterised. This provided us with the impetus to explore whether signalling molecules from important folliculogenesis pathways, phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) and Janus kinase/signal transducer and activator of transcription (JAK/STAT), are conserved in the mare ovary. Messenger RNA expression of six genes important in follicle development was measured using quantitative polymerase chain reaction and pr...
Kovaleva EG, Plapp BV.Binding of NAD+ to wild-type horse liver alcohol dehydrogenase is strongly pH-dependent and is limited by a unimolecular step, which may be related to a conformational change of the enzyme-NAD+ complex. Deprotonation during binding of NAD+ and inhibitors that trap the enzyme-NAD+ complex was examined by transient kinetics with pH indicators, and formation of complexes was monitored by absorbance and protein fluorescence. Reactions with pyrazole and trifluoroethanol had biphasic proton release, whereas reaction with caprate showed proton release followed by proton uptake. Proton release (200-55...
McPartlin LA, Visconti PE, Bedford-Guaus SJ.Capacitation encompasses the molecular changes sperm undergo to fertilize an oocyte, some of which are postulated to occur via a cAMP-PRKACA (protein kinase A)-mediated pathway. Due to the recent discovery of cAMP-activated guanine nucleotide exchange factors RAPGEF3 and RAPGEF4, we sought to investigate the separate roles of PRKACA and RAPGEF3/RAPGEF4 in modulating capacitation and acrosomal exocytosis. Indirect immunofluorescence localized RAPGEF3 to the acrosome and subacrosomal ring and RAPGEF4 to the midpiece in equine sperm. Addition of the RAPGEF3/RAPGEF4-specific cAMP analogue 8-(p-chl...
Marques-Smith P, Kallerud AS, Johansen GM, Boysen P, Jacobsen AM, Reitan KM, Henriksen MM, Löfgren M, Fjordbakk CT.Biologic' therapies, such as autologous conditioned serum (ACS), are gaining popularity in treating orthopaedic conditions in equine veterinary medicine. Evidence is scarce regarding ACS constituents, and large inter-individual differences in cytokine and growth factor content have been demonstrated. The objective of the current study was to investigate the potential association between cytokine and growth factor content of ACS and clinical effect in harness racehorses with spontaneously occurring low-grade articular lameness. Horses received 3 intra-articular injections of ACS administered at...
Höfner L, Luther AM, Waberski D.Ongoing progress in proteomic characterization of seminal plasma has stimulated research on the identification of biomarkers for male fertility and sperm preservability. So far, many studies have evaluated the benefits of reconstituting cryopreserved or sex-sorted semen with seminal plasma. Less information is available about the effect of remaining or added seminal plasma in liquid preserved semen. The interaction between seminal plasma and spermatozoa is species -specific, and within species often complex and ambiguous. This article aims to review the action of seminal plasma on sperm functi...
Kindig CA, McDonough P, Erickson HH, Poole DC.There is evidence that oxidative enzyme inertia plays a major role in limiting/setting the O(2) uptake (VO(2)) response at the transition to higher metabolic rates and also that nitric oxide (NO) competitively inhibits VO(2) within the electron transport chain. To investigate whether NO is important in setting the dynamic response of VO(2) at the onset of high-intensity (heavy-domain) running in horses, five geldings were run on a treadmill across speed transitions from 3 m/s to speeds corresponding to 80% of peak VO(2) with and without nitro-L-arginine methyl ester (L-NAME), an NO synthase in...
Wickler SJ, Hoyt DF, Biewener AA, Cogger EA, De La Paz KL.Different locomotor tasks, such as moving up or down grades or changing speed, require that muscles adjust the amount of work they perform to raise or lower, accelerate or decelerate the animal's center of mass. During level trotting in the horse, the triceps had shortening strains of around 10.6% while the vastus shortened 8.1% during the stance phase. Because of the 250% increase in metabolic rate in horses trotting up a 10% incline which is, presumably, a result of the increased requirement for mechanical work, we hypothesized that muscle strain during trotting would be increased in both th...
Cywinska A, Witkowski L, Szarska E, Schollenberger A, Winnicka A.Serum amyloid A (SAA) is the major acute phase protein in horses. Its concentration increases in various pathologies but also in response to prolonged, strenuous effort. The purpose of this study was to establish whether routine race and endurance training produces changes in the SAA level in Arabian horses. Additionally, the differences between SAA response in experienced endurance horses and endurance horses that were beginning their career were investigated. Results: There were no changes in SAA concentrations after race training and endurance training in experienced horses. In horses that ...
Kitaoka Y, Masuda H, Mukai K, Hiraga A, Takemasa T, Hatta H.The aim of this study was to investigate the effects of training and detraining on the monocarboxylate transporter (MCT) 1 and MCT4 levels in the gluteus medius muscle of Thoroughbred horses. Twelve Thoroughbred horses were used for the analysis. For 18 weeks, all the horses underwent high-intensity training (HIT), with running at 90-110% maximal oxygen consumption (VO2 max ) for 3 min, 5 days week(-1). Thereafter, the horses either underwent detraining for 6 weeks by either 3 min of moderate-intensity training (MIT) at 70% VO2 max, 5 days week(-1) (HIT-MIT group) or stall rest (HIT-SR group)....
Boyd NK, Cohen ND, Lim WS, Martens RJ, Chaffin MK, Ball JM.Foals are uniquely susceptible to a wide variety of opportunistic infections normally associated with immunodeficiencies. Little is understood about the immune system of foals during the neonatal period. An apparent age-related susceptibility predisposes neonatal foals to infectious diseases and hinders therapeutic and preventative interventions for these diseases. Cytokine expression is correlated with the type of immune response as well as the severity of a disease. In this study, we measured foal peripheral blood mononuclear cell (PBMC)-specific mRNA cytokine expression from 72 foals from t...
Mellor DJ.About a decade ago, concern was expressed that fetuses might suffer while dying in utero after the death of their dams. However, reference to already published literature provided compelling evidence that fetuses cannot consciously experience negative sensations or feelings, such as breathlessness and pain, and showed that, provided certain precautions are taken, they cannot suffer--their welfare is assured. In this article, I outline the major features of fetal and neonatal physiology that underlie this conclusion as it relates to fetuses that are neurologically exceptionally immature, modera...
Hoogewijs MK, de Vliegher SP, Govaere JL, de Schauwer C, de Kruif A, van Soom A.Sperm motility is considered to be one of the key features of semen analysis. Assessment of motility is frequently performed using computer-assisted sperm analysis (CASA). Nevertheless, no uniform standards are present to analyse a semen sample using CASA. Objective: We hypothesised that the type of counting chamber used might influence the results of analysis and aimed to study the effect of chamber type on estimated concentration and motility of an equine semen sample assessed using CASA. Methods: Commonly used disposable Leja chambers of different depths were compared with disposable and re...
Brama PA, TeKoppele JM, Bank RA, Barneveld A, van Weeren PR.The objective of this study was to document the development of biochemical heterogeneity from birth to maturity in equine articular cartilage, and to test the hypothesis that the amount of exercise during early life may influence this process. Neonatal foals showed no biochemical heterogeneity whatsoever, in contrast to a clear biochemical heterogeneity in mature horses. The process of formation of site differences was almost completed in exercised foals age 5 months, but was delayed in those deprived of exercise. For some collagen-related parameters, this delay was not compensated for after a...
Dzikiti TB, Hellebrekers LJ, van Dijk P.Physiological parameters, metabolic parameters and stress-related hormones are evaluated in horses anaesthetized with isoflurane in oxygen combined with lidocaine intravenously. Two groups of horses anaesthetized with isoflurane (six horses in each group) were studied: a lidocaine group (IL), which received intravenous lidocaine and a control group (C), which received intravenous saline. Horses in both groups were premedicated with detomidine (i.v.), and anaesthesia was induced with midazolam-ketamine (i.v.). The lidocaine group received intravenous lidocaine as a loading dose of 2.5 mg kg(-1)...
Guedes A, Galuppo L, Hood D, Hwang SH, Morisseau C, Hammock BD.The roles of soluble epoxide hydrolase and lipid mediators in inflammatory and neuropathic pain could be relevant in laminitis pain management. Objective: To determine soluble epoxide hydrolase (sEH) activity in the digital laminae, sEH inhibitor potency in vitro, and efficacy of a sEH inhibitor as an adjunct analgesic therapy in chronic laminitic horses. Methods: In vitro experiments and clinical case series. Methods: sEH activity was measured in digital laminae from euthanised healthy and laminitic horses (n = 5-6/group). Potency of 7 synthetic sEH inhibitors was determined in vitro using eq...
Carregaro AB, Luna SP, Mataqueiro MI, de Queiroz-Neto A.To investigate spontaneous locomotor activity (SLA) and antinociceptive effects of buprenorphine in horses. Methods: 6 healthy adult horses. Methods: Horses received each of 3 treatments (10 mL of saline [0.9% NaCl] solution, 5 microg of buprenorphine/kg, or 10 microg of buprenorphine/kg). Treatments were administered IV. Order of treatments was randomized, and there was a 10-day interval between subsequent treatments. Spontaneous locomotor activity was investigated in a behavioral box by use of infrared photoelectric sensors connected to a computer, which detected movement of each horse. Anti...
Ginther OJ, Gastal EL, Gastal MO, Utt MD, Beg MA.The temporal relationships between blood flow in the corpus luteum (CL) and circulating progesterone concentrations were studied in 20 mares. Retrospective inspection of plasma progesterone concentrations indicated that a precipitous decrease occurred during Days 15-17 (Day 0 = ovulation) and was defined as the luteolytic period. Mean percentage of CL with color-Doppler signals for blood flow was maximum on Day 10 (77.3%), and Days 10-14 (49.8%) were defined as the preluteolytic period. The cross-sectional area of the CL decreased progressively from Day 4 (9.0 cm2) to Day 19 (1.5 cm2). Progest...
Devienne MF, Guezennec CY.Oxygen consumption (VO2), ventilation (VE) and heart rate (HR) were studied in five recreational riders with a portable oxygen analyser (K2 Cosmed, Rome) telemetric system, during two different experimental riding sessions. The first one was a dressage session in which the rider successively rode four different horses at a walk, trot and canter. The second one was a jumping training session. Each rider rode two horses, one known and one unknown. The physiological parameters were measured during warm up at a canter in suspension and when jumping an isolated obstacle at a trot and canter. This s...
Van Heel MC, Moleman M, Barneveld A, Van Weeren PR, Back W.In order to optimise shoeing and shoeing conditions, it is essential to know how the horse adapts to a common shoeing interval. Objective: To measure changes in location of the centre of pressure (CoP) and hoof-unrollment pattern during a shoeing interval and to assess whether these changes in CoP result directly from changes in hoof conformation or are also influenced by compensatory mechanisms. Methods: Eighteen horses were trotted over a pressure-force measurement system shortly after shoeing and 8 weeks later. The position of the CoP was measured and also predicted using calculations based...
Li C, White SH, Warren LK, Wohlgemuth SE.Skeletal muscle function, aerobic capacity, and mitochondrial (Mt) function have been found to decline with age in humans and rodents. However, not much is known about age-related changes in Mt function in equine skeletal muscle. Here, we compared fiber-type composition and Mt function in gluteus medius and triceps brachii muscle between young (age 1.8 ± 0.1 yr, n = 24) and aged (age 17-25 yr, n = 10) American Quarter Horses. The percentage of myosin heavy chain (MHC) IIX was lower in aged compared with young muscles (gluteus, P = 0.092; triceps, P = 0.012), while the percentages of MHC I (gl...
Hagen A, Lehmann H, Aurich S, Bauer N, Melzer M, Moellerberndt J, Patané V, Schnabel CL, Burk J.Translation of multipotent mesenchymal stromal cell (MSC)-based therapies is advancing in human and veterinary medicine. One critical issue is the culture of MSC before clinical use. Using fetal bovine serum (FBS) as supplement to the basal medium is still the gold standard for cultivation of many cell types including equine MSC. Alternatives are being explored, with substantial success using platelet lysate-supplemented media for human MSC. However, progress lags behind in the veterinary field. The aim of this study was to establish a scalable protocol for equine platelet lysate (ePL) produc...
Aurich JE, Kühne A, Hoppe H, Aurich C.Effects of seminal plasma on post-thaw motility and membrane integrity of cryopreserved horse spermatozoa were investigated. Carboxyfluorescein diacetate staining was used for the assessment of sperm membrane integrity. Adding 30% of seminal plasma from stallions with high post-thaw sperm motility to ejaculates from stallions with low post-thaw sperm motility increased progressive motility from 24.0 +/- 1.6 to 34.5 +/- 1.9% (P < 0.05) and membrane integrity from 27.0 +/- 2.1 to 34.3 +/- 2.3% membrane-intact spermatozoa (P < 0.05). Conversely, the addition of seminal plasma from stallions...
Swegen A, Lambourne SR, Aitken RJ, Gibb Z.Media used for equine sperm storage often contain relatively high concentrations of glucose, even though stallion spermatozoa preferentially utilize oxidative phosphorylation (OXPHOS) over glycolysis to generate ATP and support motility. Rosiglitazone is an antidiabetic compound that enhances metabolic flexibility and glucose utilization in various cell types, but its effects on sperm metabolism are unknown. This study investigated the effects of rosiglitazone on stallion sperm function in vitro, along with the possible role of AMP-activated protein kinase (AMPK) in mediating these effects. Sp...
Beech J, Boston RC, McFarlane D, Lindborg S.To measure plasma ACTH, alpha-melanocyte-stimulating hormone (aloha-MSH), and insulin concentrations during various photoperiods between February and October in horses and ponies with and without pituitary pars intermedia dysfunction (PPID). Methods: Cohort study. Methods: 13 clinically normal (control) ponies, 14 clinically normal (control) horses, 7 ponies with PPID, and 8 horses with PPID. Methods: Blood samples were collected from February through October during 8 photoperiods: 1, February 13 through March 2; 2, April 4 through 6; 3, June 19 through 22; 4, August 6 through 7; 5, August 14 ...
Smith S, Harris PA, Menzies-Gow NJ.The in-feed oral glucose test (OGT) and oral sugar test (OST) are advocated as field tests of insulin sensitivity in horses and ponies but have not been directly compared. Objective: To compare the insulin response to OGT and OST in 8 ponies and 5 horses of unknown insulin sensitivity. Methods: Experimental, randomised crossover study. Methods: Animals were fasted for 8 h overnight before and throughout testing. They were fed 1 g/kg bwt glucose powder with chaff (OGT) or 0.15 ml/kg bwt corn syrup (Karo™ Light Syrup; OST) was administered per os in a randomised crossover study with 48...
McGowan CM, Frost R, Pfeiffer DU, Neiger R.Serum insulin concentration and its use as a prognostic indicator in horses with equine Cushing's syndrome (ECS) have been poorly documented. Objective: To examine daily insulin variations in horses with ECS and the effect of treatment using trilostane, a competitive inhibitor of 3beta-hydroxysteroid dehydrogenase. Further, we aimed to examine the relationship between baseline serum insulin concentration and survival in horses with ECS. Methods: Basal serum insulin concentrations were measured in 20 confirmed ECS cases by taking blood at regular 4 h intervals for 24 h (1200, 1600, 2000, 2400, ...
