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.
Azimpour S, Emami Alagha H, Faghihi H, Rajaei SM, Shokoohimand A.The purpose of this study was to determine the effects and potential side effects of topical preservative-free (PF) tafluprost 0.0015% in ophthalmologically normal horses. Methods: Five adult grade horses. Methods: One of the eyes of each horse was randomly chosen as the "treatment" eye, and consequently, the contralateral eye served as the "control." A single dose of PF tafluprost 0.0015% (0.2 mL) was instilled in the treated eye of each horse. Intraocular pressure (IOP), Schirmer's tear test (STT) levels of each eye, and an ophthalmic examination were performed at T0 (baseline), T30, T120, ...
Orsolini MF, Meyers SA, Dini P.As the use of assisted reproductive technologies (ART) and in vitro embryo production (IVP) expand in the equine industry, it has become necessary to further our understanding of available semen selection techniques. This segment of our two-section review will focus on the selection of spermatozoa based on quality and sex for equine intracytoplasmic sperm injection (ICSI), as well as current and future developments in sperm sorting technologies. Ultimately, novel methods of semen selection will be assessed based on their efficacy in other species and their relevance and future application towa...
Ryan A, Gurney M, Steinbacher R.A 10-year-old 466 kg mustang gelding presented to an equine referral hospital for surgical repair of nasal, frontal and lacrimal bone fractures from an unknown trauma. Surgical repair was performed under general anaesthesia, including a right-sided maxillary regional anaesthetic block with mepivacaine hydrochloride. Progressive hyperkalaemia was documented perianaesthetically (T-3 mins; 134 mins after induction; potassium 6.4 mmol/L (ref 3.5-5.1 mmol/L). Perianaesthetic bradycardia was attributed to alpha -2 agonist infusion administration, and other characteristic ECG changes (flattened ...
Bras R, Morrison S.A healthy foot requires a well-balanced foot capable of shock absorption, traction, and normal proprioception. Radiographs and venograms are helpful in assessing health of the external and internal structures of the foot and in early diagnosis. Other techniques to assess foot mechanics include force plate and inertial sensors. When foot pathology ensues, early recognition and emergency mechanical treatment can improve prognosis and overall outcome. Sheared heels, under-run heels, and clubfeet are common problems that need to be corrected early. Successful management and results require he vete...
Giannetto C, Acri G, Giudice E, Arfuso F, Testagrossa B, Piccione G.Raman spectroscopy is an inelastic light-scattering phenomenon that provides vibrational spectrum that contains information relative to chemical bonds and symmetry of a specific molecule, allowing the quali-quantitative simultaneous determination of several components in the biological fluids. Raman spectroscopy measurement returns a spectrum over a wavenumber range constituted by several bands representing biomarkers according to investigated biological matrices. In literature, it has been reported that at the frequencies inside the (1,300-1,360) cm total lipids, and tryptophan have been iden...
Maitan PP, Bromfield EG, Hoogendijk R, Leung MR, Zeev-Ben-Mordehai T, van de Lest CH, Jansen JWA, Leemans B, Guimarães JD, Stout TAE, Gadella BM....Classical in vitro fertilization (IVF) is still poorly successful in horses. This lack of success is thought to be due primarily to inadequate capacitation of stallion spermatozoa under in vitro conditions. In species in which IVF is successful, bicarbonate, calcium, and albumin are considered the key components that enable a gradual reorganization of the sperm plasma membrane that allows the spermatozoa to undergo an acrosome reaction and fertilize the oocyte. The aim of this work was to comprehensively examine contributors to stallion sperm capacitation by investigating bicarbonate-induced m...
Bou T, Han H, Mongke T, Zhao R, La X, Ding W, Jia Z, Liu H, Tiemuqier A, An T, Dugarjaviin M, Bai D.The heterogeneity and plasticity of muscle fibers are essential for the athletic performance of horses, mainly at the adaption of exercises and the effect on muscle diseases. Skeletal muscle fibers can be generally distinguished by their characteristics of contraction as slow and fast type myofibers. The diversity of contractile properties and metabolism enable skeletal muscles to respond to the variable functional requirements. We investigated the muscle fiber composition and metabolic enzyme activities of splenius muscle and gluteus medius muscle from Mongolian horses. The deep RNA-seq analy...
Patton ME, Leise BS, Baker RE, Andrews FM.To determine the influence of bit chewing on gastrointestinal transit in clinically normal horses. Methods: Prospective crossover designed study. Methods: Six healthy adult horses. Methods: Horses were assigned randomly to treatment (apple flavored bit) and control (no-bit) groups and studied for 2 × 1-week trial periods with a 2-week washout period between trials. Horses were fasted for 24 h and slowly refed over 3 days. The bit was placed for 20 min every 6 h. Duodenal contractions and borborygmi auscultations were evaluated every 12 h, approximately 5 min following bit placemen...
Thompson RE, Meyers MA, Pukazhenthi BS, Hollinshead FK.Reproductive diseases in mares are a significant cause of subfertility and profound economic loss in the equine industry. Utilizing a 3D in vitro cell culture system that recapitulates the in vivo physiology will reduce time, cost, and welfare concerns associated with in vivo reproductive research in mares. If this 3D model is combined with effective cryopreservation, reproductive research on mares can occur year-round, which is not currently possible in this seasonal species. Endometrial organoids, 3D in vitro cell clusters that exhibit in vivo uterine physiology, have been established in mic...
Orsolini MF, Meyers SA, Dini P.As the use of assisted reproductive technologies (ART) and in vitro embryo production (IVP) expand in the equine industry, it has become necessary to further our understanding of semen physiology as it applies to overall fertility. This segment of our two-section review will focus on normal sperm parameters, beginning with development and extending through the basic morphology of mature spermatozoa, as well as common issues with male factor infertility in IVP. Ultimately, the relevance of sperm parameters to overall male factor fertility in equine IVP will be assessed.
Ginther OJ.After the cessation of equine embryo mobility (fixation) on mean Day 16, the embryonic vesicle is rotated or oriented so that the pole with the embryo proper is opposite to the mesometrial attachment. Orientation involves massage of the vesicle by contractions of the turgid uterine horn and greater thickening of the vesicle at the pole with the embryo proper. Thickening of the dorsal endometrium (encroachment) especially on each side of the mesometrial attachment accounts for a guitar-pick shape of the vesicle when viewed in cross section of the uterine horn. On Days 21-40, the allantoic sac e...
Al-Khaldi K, Yimer N, Sadiq MB, Firdaus Jesse Bin Abdullah F, Salam Babji A, Al-Bulushi S.Diluents and various biological products have been used in different animal species, with promising outcomes in post-thaw sperm quality. Nevertheless, only a few reports are available for the semen of Arabian horses. Edible bird's nest (EBN) - a product of the salivary secretions of swiftlet species is widely known to have both antioxidant and anti-inflammatory properties. Presently, there is no data available on the role of EBN supplemented in different extenders and its effect on semen quality in stallion semen. Two in vitro experiments were conducted to examine the effects of edible bird's ...
Klett D, Combarnous Y.In previous studies, we had shown the synergistic effect of 10 M forskolin (FSK) on the detection threshold of the cyclic AMP response to luteinizing hormones (LH) and chorionic gonadotropins (CG) from various species in the mouse Leydig tumor cell (mLTC) cell line. Independently, we started to study the effect of 10-10 M oxytocin (OXT) also on the cyclic AMP response to LH and CG preparations on these same cells and found an amplifying effect on the luminescence response caused by gonadotropins. The aim was then to explore the effects of 10-10 M OXT on the gonadotropin-induced cAMP response, ...
Kiemle J, Hindenberg S, Bauer N, Roecken M.Rapid, accurate detection of serum amyloid A (SAA) is needed in equine practice. We validated a patient-side point-of-care (POC) assay (Stablelab; Zoetis) compared to the turbidimetric immunoassays LZ-SAA (TIA-Hum) and VET-SAA (TIA-Vet; both Eiken Chemical). Analytical performance was assessed at 3 different concentration ranges and with interferences. Inter-method comparison using 49 equine serum samples revealed a significant difference between median SAA results ( < 0.0001), with the strongest bias between the POC and TIA-Vet (median 1,093 vs. 578 mg/L). The median SAA value obtain...
Biau S, Burgaud I.Kinesiology taping (KT) has been used on human subjects for many years. More recently, KT has been used in sport horses. The physiological mechanisms involved remain unclear and its benefits are controversial. Objective: To investigate the effects of application of kinesiology taping to abdominal muscles on locomotor parameters before and after lungeing exercise in horses. Methods: Cross-over study. Methods: Eleven horses were tested twice, once with an application of KT without tension on abdominal muscles (condition 1) and once with a facilitation application of KT on abdominal muscles (cond...
Hotham WE, Thompson C, Szu-Ting L, Henson FMD.Osteoarthritis (OA) in the horse is an economic and welfare issue and there are no current disease modifying drugs available. Stem cells have been suggested as a therapeutic intervention for OA, originally on the basis of their regenerative capacity. However, it is hypothesised that mesenchymal stem cells (MSC) exert their effects via paracrine factors including the production of extracellular vesicles that can themselves recapitulate the MSC effects in the joint. Objective: To isolate extracellular vesicles from bone marrow MSC and investigate their anti-inflammatory effects on chondrocytes. ...
Haneda S, Dini P, Esteller-Vico A, Scoggin KE, Squires EL, Troedsson MH, Daels P, Nambo Y, Ball BA.A sufficient vascular network within the feto-maternal interface is necessary for placental function. Several pregnancy abnormalities have been associated with abnormal vascular formations in the placenta. We hypothesized that growth and expansion of the placental vascular network in the equine () placenta is regulated by estrogens (estrogen family hormones), a hormone with a high circulating concentration during equine gestation. Administration of letrozole, a potent and specific inhibitor of aromatase, during the first trimester (D30 to D118), decreased circulatory estrone sulfate concentrat...
Holl HM, Armstrong C, Galantino-Homer H, Brooks SA.Laminitis results in impaired tissue integrity and Inflammation of the epidermal and dermal lamellae connecting the hoof capsule to the underlying distal phalanx and causes loss-of-use, poor quality of life and euthanasia in horses. Historically, studies to better understand the etiology of laminitis by documenting changes in gene expression were hampered by the paucity of gene annotation specific to hoof tissues. Next-generation sequencing enables improvements to annotation by incorporating equine- and hoof-specific transcripts. Here we characterize the hoof lamellar tissue transcriptome of n...
Pruß D, Oldenhof H, Wolkers WF, Sieme H.The aim of cell preservation technologies is to slow down damaging reactions by lowering the storage temperature. Upon dilution in a stabilizing extender, stallion sperm can be stored at refrigerator temperatures for several days. Cryopreservation allows storage for decades, but freezing and thawing cause damage and viability losses. It is assumed that by storing cells at subzero temperatures in a non-frozen supercooled state, the damaging effects of ice formation can be avoided. In this study, we have investigated if stallion sperm can be stored at -10°C in the absence of ice, and compared v...
Jasiński T, Zdrojkowski Ł, Kautz E, Juszczuk-Kubiak E, Ferreira-Dias G, Domino M.Endometrosis is an important mares' disease which considerably decreases their fertility. As classic endometrial classification methods might be insufficient for tissue pathological evaluation, further categorization into active/inactive and destructive/non-destructive types was developed by Hoffmann and others. This study aimed to compare NF-κB pathway genes transcription among histopathological types of endometrosis, following Hoffmann and co-authors' classification. Endometrial samples, collected postmortem from cyclic mares ( = 100) in estrus or diestrus, were classified histologically an...
Soroko M, Howell K, Dudek K, Waliczek A, Micek P, Flaga J.The aim of the study was to determine the utility of maximum eye temperature measured by infrared thermography (IRT) as a stress indicator compared with plasma cortisol concentration in Thoroughbred and Arabian racehorses. The study included thirty racehorses undergoing standard training for racing. Measurements of maximum eye temperature and blood collection for plasma cortisol concentration were carried out before training (BT), and within 5 (5AT) and 120 minutes (120AT) after the end of the each training session in three repetitions, with a monthly interval. Both parameters were elevated at...
Ramirez-Perez H, Guerrero-Netro HM, Torres-Rodríguez P, Díaz-Durán M, Boeta-Acosta AM, Diaw M.The objective of this study was to evaluate the effects of caffeine and taurine on the motility and viability of chilled equine semen. Methods: A total of 12 ejaculates were collected from three mature stallions with proven fertility during the breeding season. The gel-free spermatic fraction of each ejaculate was divided into two aliquots and diluted with a semen extender (either INRA 96® or BotuSemen Gold®). The aliquots were then split and assigned to one of the six treatment groups: control (no supplement), caffeine (2 and 4 mM), taurine (25 and 50 mM), and a combination of caffeine (2 m...
Ortolani F, Scilimati N, Gialletti R, Menchetti L, Nannarone S.The purpose of this study was to describe the development and preliminary validation of a composite pain scale, called the Equine Ophthalmic Pain Scale (EOPS), to assess ocular pain in horses. Indicators associated with ocular pain were selected and classified as behavioural, physiological or ocular expressions. Eight horses diagnosed with ocular or adnexa diseases that required medical or surgical treatment were enrolled in the study (group P). The developed EOPS was applied at the baseline (T0) and 1 week later (T7). Moreover, the EOPS was applied twice, 1 week apart, to 15 healthy control h...
Morrice-West AV, Hitchens PL, Walmsley EA, Wong ASM, Whitton RC.Understanding the relationship between the training practices of Thoroughbred racehorses and race performance is important to ensure advice given to trainers for injury prevention or management is practical and consistent. We assessed associations between intended volume and speed of gallop training (i.e., typical workloads for horses free of injury or other performance limiting conditions) and rest practices on official trainer career and previous season success rates (rate of wins and places, prizemoney per start). Sixty-six Australian Thoroughbred trainers were surveyed. Multivariable negat...
Rouge M, Elkhatib R, Delalande C, Cognié J, Reigner F, Barriere P, Deleuze S, Cousty M, Legendre F, Galera P, Hanoux V, Bouraima-Lelong H.Although vitamin D acts in various biological processes, it plays a critical role in the maintenance of bone health, and regulates calcium homeostasis. In humans and rodents, the main tissues involved in vitamin D metabolism are the liver and the kidneys, however it has been shown that the testis has strongly participated in its bioactivation. Indeed, in these different species, enzymes metabolizing vitamin D (CYP27A1, CYP27B1 and CYP2R1) have been demonstrated in this tissue. Moreover, men with hypogonadism have shown a decrease in circulating levels of vitamin D. In equine species, the castr...
Kupratis ME, Gure AE, Benson JM, Ortved KF, Burris DL, Price C.Healthy articular cartilage supports load bearing and frictional properties unmatched among biological tissues and man-made bearing materials. Balancing fluid exudation and recovery under loaded and articulated conditions is essential to the tissue's biological and mechanical longevity. Our prior tribological investigations, which leveraged the convergent stationary contact area (cSCA) configuration, revealed that sliding alone can modulate cartilage interstitial fluid pressurization and the recovery and maintenance of lubrication under load through a mechanism termed 'tribological rehydration...
Henry ML, Velez-Irizarry D, Pagan JD, Sordillo L, Gandy J, Valberg SJ.Horses have one of the highest skeletal muscle oxidative capacities amongst mammals, which, combined with a high glycolytic capacity, could perturb redox status during maximal exercise. We determined the effect of 30 d of oral coenzyme Q10 and N-acetyl-cysteine supplementation (NACQ) on muscle glutathione (GSH), cysteine, ROS, and coenzyme Q10 concentrations, and the muscle proteome, in seven maximally exercising Thoroughbred horses using a placebo and randomized cross-over design. Gluteal muscle biopsies were obtained the day before and 1 h after maximal exercise. Concentrations of GSH, cyste...
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 ...
Rice DA.The time it takes audible sound waves to travel across a lobe of excised horse lung was measured. Sound speed, which is the slope in the relationship between transit time and distance across the lobe, was estimated by linear regression analysis. Sound-speed estimates for air-filled lungs varied between 25 and 70 m/s, depending on lung volume. These speeds are less than 5% of sound speed in tissue and less than 20% of sound speed in air. Filling the lung with helium or sulfur hexafluoride, whose free-field sound speeds are 970 and 140 m/s, respectively, changed sound speed +/- 10% relative to a...
Ginther OJ.Movement of the conceptus within the uterine lumen of barren mares was studied by daily ultrasound examinations on days 11-20 and by rectal palpation on days 15-48 (Experiment 1) and by ultrasound examinations 3 or 4 times per day at 2-4 hour intervals on days 11-16 (Experiment 2). In addition, broodfarm records were analyzed to compare side of ovulation with side of embryo attachment (Experiment 3). The vesicle was found in opposite uterine horns for 43% of the successive, daily, ultrasound examinations on days 11 and 12, 12 and 13, 13 and 14, and 14 and 15; 24% of the successive examinations...
Linz D, Hesselkilde E, Kutieleh R, Jespersen T, Buhl R, Sanders P.Atrial fibrillation is triggered by the pulmonary veins in humans. Although atrial fibrillation is known to occur in other species, the mechanisms of disease in these are not known. Here we present evidence for pulmonary vein triggers in the horse, where 3D HD Grid mapping was undertaken in the conscious state in the absence of fluoroscopy.
Knowles EJ, Harris PA, Elliott J, Menzies-Gow NJ.It is recommended that the oral sugar test (OST) for insulin dysregulation (ID) be performed after an overnight fast, but fasting is impractical in ponies kept solely at pasture. There are few data on OST repeatability and reliability in ponies. Objective: To report 1) whether OST results obtained in the morning after an overnight fast or without fasting in the afternoon (FASTING/FED) can be used interchangeably, 2) time of highest insulin concentration T [insulin], repeatability and reliability of insulin response to the OST when FASTING or FED and 3) dichotomous agreement (ID/normal) within ...
Mshelia ES, Adamu L, Wakil Y, Turaki UA, Gulani IA, Musa J.The equine gut harbours complex microbial populations which influence physiology, metabolism, nutrition and immune functions, while disruption to the gut microbiota has been linked with conditions such as lameness, diabetes and obesity. Therefore, the present study was conducted to determine the association between microbial dysbiosis, sex, age and body condition scores (BCS) of horses (Equus equus caballus) in Maiduguri and its environs. Forty horses were assessed by convenient sampling, while faecal samples were collected and analyzed to determine the microbiomes in the various age groups wi...
Sellon DC, Roberts MC, Blikslager AT, Ulibarri C, Papich MG.A randomized, controlled, blinded clinical trial was performed to determine whether butorphanol administered by continuous rate infusion (CRI) for 24 hours after abdominal surgery would decrease pain and surgical stress responses and improve recovery in horses. Thirty-one horses undergoing exploratory celiotomy for abdominal pain were randomly assigned to receive butorphanol CRI (13 microg/kg/h for 24 hours after surgery; treatment) or isotonic saline (control). All horses received flunixin meglumine (1.1 mg/kg IV q12h). There were no significant differences between treatment and control horse...
Dallaire A.Behavioral and physiologic characteristics of sleep are described, with special attention paid to equids. Temporal organization of sleep and environmental influences upon this behavior in horses are reviewed. Anatomic and biochemical bases and function of sleep are discussed briefly.
Barrachina L, Remacha AR, Romero A, Vázquez FJ, Albareda J, Prades M, Ranera B, Zaragoza P, Martín-Burriel I, Rodellar C.Mesenchymal stem cells (MSCs) are gaining relevance for treating equine joint injuries because of their ability to limit inflammation and stimulate regeneration. Because inflammation activates MSC immunoregulatory function, proinflammatory priming could improve MSC efficacy. However, inflammatory molecules present in synovial fluid or added to the culture medium might have deleterious effects on MSCs. Therefore, this study was conducted to investigate the effects of inflammatory synovial fluid and proinflammatory cytokines priming on viability and plasticity of equine MSCs. Equine bone marrow ...
Freire R, Buckley P, Cooper JJ.It is unknown if different locomotor activities are equally effective at meeting the stabled horse's need for exercise and if they attenuate unwanted behaviour. Objective: Alternative forms of exercise influence the intensity of locomotor activities during a period of turn-out (the so-called rebound effect) and the occurrence of unwanted or undesirable activities during standard handling situations. Methods: Twenty-four horses kept in stables were randomly assigned to one of 4 exercise regimes (walker, treadmill, turn-out and riding) for 4 consecutive days. Because these forms of exercise prov...
Bertram JE, Gosline JM.Tensile moduli and J-integral fracture toughness values were determined for horse hoof-wall keratin at four hydration levels. The stiffness of hoof-wall was influenced by water content to a greater degree than is the stiffness of other mammalian hard keratins. Young's modulus increased from 410 MPa at 100% relative hydration (RH) to 14.6 GPa at 0% RH. Fracture toughness was maximal (22.8 kJ m-2) at an intermediate hydration (75% RH), which represents a two-fold increase over both fully hydrated and dehydrated material. Maximum fracture toughness occurred at a hydration level which is within th...
Derochette S, Franck T, Mouithys-Mickalad A, Ceusters J, Deby-Dupont G, Lejeune JP, Neven P, Serteyn D.In neutrophils (PMNs), superoxide anion (O2*-), the first reactive oxygen species (ROS) produced to kill pathogenic agents, is generated by NADPH oxidase, an enzymatic complex formed by the translocation of cytosolic subunits to the membrane flavocytochrome b558. In horses, excessive activation of PMNs is often associated with deadly pathologies and the modulation of their ROS production by acting on NADPH oxidase is a prime target to manage inflammation. We developed a cell-free assay to measure the activity of equine NADPH oxidase assembled in vitro, in order to test the effects of natural o...
Leong LM, Tan BH, Ho KK.Nonheme iron proteins can be visualized as blue bands in native polyacrylamide gels using a staining method that is both simple and rapid. The reaction of potassium ferricyanide with protein-bound iron atoms to form royal blue complexes occurs almost instantaneously and is sensitive enough to detect 1 microgram of analytical-grade ferritin and 2 micrograms of purified ferredoxin from cyanobacteria. No special treatment of reagents or apparatus was necessary. On comparison, this stain was found to be more specific than the Ferene S stain, not detecting bovine serum albumin even when present as ...
Jeremiasse B, Matta C, Fellows CR, Boocock DJ, Smith JR, Liddell S, Lafeber F, van Spil WE, Mobasheri A.Chondrocytes are exposed to an inflammatory micro-environment in the extracellular matrix (ECM) of articular cartilage in joint diseases such as osteoarthritis (OA) and rheumatoid arthritis (RA). In OA, degenerative changes and low-grade inflammation within the joint transform the behaviour and metabolism of chondrocytes, disturb the balance between ECM synthesis and degradation, and alter the osmolality and ionic composition of the micro-environment. We hypothesize that chondrocytes adjust their physiology to the inflammatory microenvironment by modulating the expression of cell surface prote...
Weishaupt MA.The skill to diagnose lameness in horses is paramount for every equine practitioner. Early recognition of locomotor deficiencies plays a central role in sports medicine management, preventing deterioration of the disease or catastrophic injuries. Horses use characteristic compensatory movements of specific body parts to decrease loading of the affected limb. This article describes the underlying changes in intra- and interlimb coordination and the resulting load redistribution between the limbs. This enables the practitioner to better understand the changes in movement associated with lameness...
Caron JP, Gandy JC, Brown JL, Sordillo LM.Omega-3 fatty acid (n-3 PUFA) supplementation may have beneficial effects in certain chronic diseases, potentially including osteoarthritis. Favorable effects are attributed, in part, to downstream pro-resolving oxylipid metabolites. We investigated the role of n-3 PUFA and docosahexaenoic acid (DHA)-derived oxylipids (docosanoids) on equine synoviocyte metabolism. We hypothesized that n-3 PUFA and selected docosanoids would modulate inflammatory mediator gene expression by recombinant equine (re)IL-1β-stimulated synovial fibroblasts. Synoviocyte monolayer cultures were prepared from grossly ...
Rizzo M, Ducheyne KD, Deelen C, Beitsma M, Cristarella S, Quartuccio M, Stout TAE, de Ruijter-Villani M.Advanced mare age is associated with declining fertility and an increased risk of early pregnancy loss. Compromised oocyte quality is probably the primary reason for reduced fertility, but the defects predisposing to embryonic death are unknown. In women, advanced age predisposes to chromosome segregation errors during meiosis, which lead to embryonic aneuploidy and a heightened risk of miscarriage. Objective: To evaluate the effect of advanced mare age on chromosome alignment and meiotic spindle morphology in in vitro-matured (IVM) oocytes. Methods: Morphometric and morphological analysis. M...
Cocco MJ, Lecomte JT.A proton nuclear magnetic resonance spectroscopic study of horse apomyoglobin was undertaken in order to define the regions of myoglobin that are and that are not structurally affected by the binding of the prosthetic group. It was found that, in spite of the poor spectral resolution, a number of spin systems could be identified by using standard correlated methods. Four clusters consisting mostly of hydrophobic residues were detected by nuclear Overhauser spectroscopy, two of which involved the tryptophan side chains. Extensive similarities to nuclear Overhauser spectroscopy data collected on...
Yoon MJ, Berger T, Roser JF.The insulin-like growth factor-I (IGF-I) is a key regulator of reproductive functions. IGF-I actions are primarily mediated by IGF-IR. The main objective of this research was to evaluate the presence of IGF-I and IGF-I Receptor (IGF-IR) in stallion testicular tissue. The hypotheses of this study were (i) IGF-I and IGF-IR are present in stallion testicular cells including Leydig, Sertoli, and developing germ cells, and (ii) the immunolabelling of IGF-I and IGF-IR varies with age. Testicular tissues from groups of 4 stallions in different developmental ages were used. Rabbit anti-human polyclona...
Pommer AC, Rutllant J, Meyers SA.Phosphorylation of tyrosine residues on sperm proteins is one important intracellular mechanism regulating sperm function that may be a meaningful indicator of capacitation. There is substantial evidence that cryopreservation promotes the capacitation of sperm and this cryocapacitation is frequently cited as one factor associated with the reduced longevity of cryopreserved sperm in the female reproductive tract. This study was designed to determine whether stallion sperm express different levels of tyrosine phosphorylation after in vitro capacitation and whether thawed sperm display similar ph...
Snow DH, Harris RC, Gash SP.Four thoroughbred horses performed 4 gallops (G1-G4) with intervals of 5 min. With one exception, gallops were sustained at maximal speed over 620 m. Muscle biopsy samples of the middle gluteal and brachiocephalicus were taken before, during, and after exercise and assayed for ATP and intermediary metabolites. The results showed a major involvement of the brachiocephalicus, in addition to the middle gluteal, during galloping. In three horses, who were clearly fatigued, muscle ATP decreased by up to 50% by the end of G4. This was matched by an equal rise in inosine 5'-monophosphate. Pronounced ...
Gupte CM, Bull AM, Murray R, Amis AA.The purpose of this study was to investigate the presence, position and relative sizes of the meniscofemoral ligaments (MFL) in three quadrupeds and humans and relate these to the caudal slope of the lateral tibial plateau. Canine, ovine and equine stifles and human knees were dissected to identify the presence of MFLs, their obliquity in relation to the caudal cruciate ligaments (CCL), the relative size and shape of the MFLs compared with the CCL, the points of femoral attachment of the MFLs and CCL, and the distance between the MFLs and CCL at their midpoints. The lateral tibial condyle was ...
Li Y, Lan Y, Zhang S, Wang X.Increasing evidence reveals the importance of gut microbiota in animals for regulating intestinal homeostasis, metabolism, and host health. The gut microbial community has been reported to be closely related to many diseases, but information regarding diarrheic influence on gut microbiota in horses remains scarce. This study investigated and compared gut microbial changes in horses during diarrhea. The results showed that the alpha diversity of gut microbiota in diarrheic horses decreased observably, accompanied by obvious shifts in taxonomic compositions. The dominant bacterial phyla (, and )...
Lacombe VA.Glucose uptake is the rate-limiting step in glucose utilization in mammalians and is tightly regulated by a family of specialized proteins, called the facilitated glucose transporters (GLUTs/SLC2). GLUT4, the major isoform in insulin-responsive tissue, translocates from an intracellular pool to the cell surface and as such determines insulin-stimulated glucose uptake. However, despite intensive research over 50 years, the insulin-dependent and -independent pathways that mediate GLUT4 translocation are not fully elucidated in any species. Insulin resistance (IR) is one of the hallmarks of equin...
Leleu C, Cotrel C, Courouce-Malblanc A.The relationships between V4 (the velocity for a blood lactate concentration of 4 mmol/litre) and V200 (the velocity for a heart rate of 200 bpm) and the performance indices of 223 healthy French trotters were analysed. They were divided into four age groups of three, four, five and six years and over, and into three performance groups (good, intermediate and poor performers) defined by the index of trot (ITR), an annual index of performance calculated by the national stud. V4 and V200 were assessed during the performance of a three-step standardised field exercise test, and four performance i...
Kamus LJ, Theoret C, Costa MC.To use next generation sequencing to characterize the microbiota of horses during healing of skin wounds in two anatomical locations (body and limb) known to present different healing patterns; and to investigate the impact of bandaging on bacterial communities of skin wounds located on the limbs of horses. Full-thickness skin wounds were created on the distal extremity of both thoracic limbs and on one lateral mid-thoracic wall of four healthy horses. Limb wounds were randomly assigned to bandaging or not. A full-thickness sample was collected with a biopsy punch from intact thorax and limb s...
Al-Essawe EM, Wallgren M, Wulf M, Aurich C, Macías-García B, Sjunnesson Y, Morrell JM.Seminal plasma (SP) contains proteins that may influence cryosurvival and prevent capacitation-like changes due to freezing and thawing. The objective of this study was to investigate the effect of adding pooled SP from "good" (GF) or "bad" (BF) freezer stallions on sperm cells' fertilizing ability. "Good freezers" refers to stallions that usually produce ejaculates which can withstand cryopreservation, whilst "bad freezer" stallions produce ejaculates which cannot tolerate the freezing process. A heterologous zona binding assay with in vitro matured bovine oocytes was used to assess the bind...
Hart KA, Slovis NM, Barton MH.Transient hypothalamic-pituitary-adrenal (HPA) axis dysfunction occurs frequently in critically ill humans and impacts survival. The prevalence and impact of HPA axis dysfunction in critically ill neonatal foals are not well characterized. Objective: (1) HPA axis dysfunction occurs in hospitalized neonatal foals, and is characterized by inappropriately low basal serum cortisol concentration or inadequate cortisol response to exogenous adrenocorticotropic hormone (ACTH); (2) hospitalized foals with HPA axis dysfunction have more severe disease and are less likely to survive than hospitalized fo...
Nissen SD, Weis R, Krag-Andersen EK, Hesselkilde EM, Isaksen JL, Carstensen H, Kanters JK, Linz D, Sanders P, Hopster-Iversen C, Jespersen T....Long-term exercise induces cardiac remodeling that potentially influences the electrical properties of the heart. Objective: We assessed whether training alters cardiac conduction in Standardbred racehorses. Methods: Two hundred one trained and 52 untrained Standardbred horses. Methods: Cross-sectional study. Resting ECG recordings were analyzed to assess heart rate (HR) along with standard ECG parameters and for identification of atrial and ventricular arrhythmias. An electrophysiological study was performed in 13 horses assessing the effect of training on sinoatrial (SA) and atrioventricular...
