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.
Reesink HL, Nixon AJ, Su J, Liu S, Sutton RM, Mann S, Watts AE, Peterson RP.Galectins are potent regulators of cell adhesion, growth and apoptosis in diverse cell types, including chondrocytes and synovial fibroblasts. Elevations in synovial fluid galectin-3 have been observed in rheumatoid arthritis, juvenile idiopathic arthritis and experimental inflammatory arthritis in animal models, whereas galectin-1 is thought to be protective. Less is known about galectins-1 and-3 in osteoarthritis (OA). Therefore, the purpose of this study was: (1) to determine whether galectin-1 and-3 synovial fluid concentrations and synovial membrane and cartilage histochemical staining we...
Gaughan EM.An accurate and timely diagnosis of the systemic and local tissue influences of a wound are essential to target successful treatment measures and reach the best result for an affected horse. A complete physical examination should be completed for any wounded horse and appropriate systemic therapies instituted. Visual and manipulative examinations aid in the complete understanding of wounded tissues. Imaging and invasive diagnostic techniques also have value in determining the extent of a wound. Considering what tissues are involved from an inside-out perspective can assist in developing a comp...
Beyer T, Rink BE, Scarlet D, Walter I, Kunert S, Aurich C.In the horse, it is still unclear if and to what extent low progestin concentration contributes to early conceptus loss. In the present study, we have investigated if reduced or elevated progestin concentration in the early luteal phase influences endometrial function and conceptus development. We hypothesized that reduced progestin concentration via delayed downregulation of endometrial progesterone receptors (PR) influences endometrial function in healthy fertile mares while progestin substitution does not. Genitally healthy estrous mares (n = 8; age 4-14 years) were inseminated and trea...
Lanata A, Nardelli M, Valenza G, Baragli P, DrAniello B, Alterisio A, Scandurra A, Semin GR, Scilingo EP.We examined the Autonomic Nervous System (ANS) activity of horses in response to human body odors (BOs) produced under happy and fear states. The ANS response of horses was analyzed in terms of Heart Rate Variability (HRV) features extracted in the frequency domain. Our results revealed that human BOs induce sympathetic and parasympathetic changes and stimulate horses emotionally, suggesting interspecies transfer of emotions via BOs. These preliminary findings open the way to measure changes in horse's ANS dynamics in response to human internal states via human BOs, and allow us to better unde...
Bastos HBA, Martinez MN, Camozzato GC, Estradé MJ, Barros E, Vital CE, Vidigal PMP, Meikle A, Jobim MIM, Gregory RM, Mattos RC.There is a complex cascade involving proteins during early embryo development and maternal recognition, which is very important for maintenance of a conceptus. The aim of this study was to compare proteomic profile of uterine fluid after ovulation in pregnant and cyclic mares. In the first cycle, samples of uterine fluid of 30 cyclic mares were collected on days 7 (n = 10), 10 (n = 10) and 13 (n = 10) post ovulation and constituted the Cyclic group. In the second cycle, the same mares were bred to a fertile stallion. At days 7, 10 and 13 uterine fluid samples were collected. Immedi...
Jo A, Lee HE, Kim HS.Horses (Equus caballus) have been domesticated and bred to enhance speed, strength, and agility. Members of the Equus caballus Endogenous Retrovirus (EqERV) family affect several of these abilities in horses. EqERV elements have been integrated in the horse genome during evolution and generate repeat elements such as long terminal repeats (LTRs). LTR sequences are involved in retrovirus replication and play an essential function in post-transcriptional control mechanisms, such as by providing binding sites for microRNAs (miRNAs) or generating miRNA precursors. In this study, we identified a no...
Romero-Aguirregomezcorta J, Sugrue E, Martínez-Fresneda L, Newport D, Fair S.The journey of spermatozoa through the female genital tract is facilitated by rheotaxis, or the cell's preference to swim against a flow, as well as thigmotaxis, the wall tracking behaviour, which guides them to the site of fertilisation. The aim of this study was to characterise the rheotactic and thigmotactic response of stallion sperm within a microfluidic channel. Stallion sperm rheotaxis was assessed within the microfluidic channel with regard to: (i) A range of flow velocities, (ii) Varying media viscosity and (iii) Sperm hyperactivation. Sperm distribution across the microfluidic channe...
Hendriks WK, Colleoni S, Galli C, Paris DBBP, Colenbrander B, Stout TAE.Intracytoplasmic sperm injection is the technique of choice for equine IVF and, in a research setting, 18-36% of injected oocytes develop to blastocysts. However, blastocyst development in clinical programs is lower, presumably due to a combination of variable oocyte quality (e.g. from old mares), suboptimal culture conditions and marginal fertility of some stallions. Furthermore, mitochondrial constitution appears to be critical to developmental competence, and both maternal aging and invitro embryo production (IVEP) negatively affect mitochondrial number and function in murine and bovine emb...
Ortega-Ferrusola C, Martin Muñoz P, Ortiz-Rodriguez JM, Anel-López L, Balao da Silva C, Álvarez M, de Paz P, Tapia JA, Anel L, Silva-Rodríguez A....We hypothesized that thiols and particularly glutathione (GSH) are essential for the regulation of stallion sperm functionality. To test this hypothesis, we initially investigated the relationship between sperm function and GSH content, revealing highly significant correlations between GSH, sperm viability, motility, and velocity parameters (P < 0.001). Furthermore, the deleterious effects of GSH depletion using menadione and 1,3 dimethoxy 1,4, naphtoquinone (DMNQ) were able to be prevented by the addition of cysteine, but no other antioxidant. Pre-incubation with cysteine prevented menad...
Rizzo A, Sciorsci RL.Homocysteine (Hcy) is a thiol-containing essential amino acid, important for the growth of cells and tissues. Several hypotheses exist regarding Hcy toxicity in humans; Hcy is involved in protein structural modifications, oxidative stress, and neurotoxicity induction and is therefore associated with several pathological conditions in humans. In veterinary science, knowledge regarding Hcy has increased recently due to several studies; however, many aspects remain undiscovered. Many details remain unknown regarding the effect of Hcy levels on pregnancy and the optimal management of pathological ...
Leandro RM, Filho RPPF, De Silvio MM, Quilici AP, Sattin MM, Paretsis BF, Souza VA.Anatomy is traditionally regarded as a difficult, non-motivating course involving a large body of theoretical and practical content, and it is often associated with high levels of dropout and failure. Given the relevance of the topic, we propose an alternative active multisensory teaching tool consisting of the construction of a low-fidelity anatomical model assembled into an articulated equine skeleton. Model construction and assembly assists students in the recognition of the topography and anatomical boundaries of the equine abdominal digestive system. Digestive system organs (liver, pancre...
Boere J, Malda J, van de Lest CHA, van Weeren PR, Wauben MHM.The use of extracellular vesicles (EVs) as a potential therapy is currently explored for different disease areas. When it comes to the treatment of joint diseases this approach is still in its infancy. As in joint diseases both inflammation and the associated articular tissue destruction are important factors, both the immune-suppressive and the regenerative properties of EVs are potentially advantageous characteristics for future therapy. There is, however, only limited knowledge on the basic features, such as numerical profile and function, of EVs in joint articular tissues in general and th...
Alizadeh AH, Briah R, Villagomez DAF, King WA, Koch TG.The aim of the present work was to determine proliferation capacity, immunophenotype and genome integrity of mesenchymal stromal cells (MSCs) from horse umbilical cord blood (UCB) at passage stage 5 and 10. Passage 4 cryopreserved UCB-MSCs from six unrelated donors were evaluated. Immunophenotypic analysis of UCB-MSC revealed a cell identity consistent with equine MSC phenotype by high expression of CD90, CD44, CD29, and very low expression of CD4, CD11a/18, CD73, and MHC class I and II antigens. Proliferative differences were noted among the UCB-MSC cultures. UCB-MSCs karyotype characteristic...
Rivera Del Alamo MM, Reilas T, Galvão A, Yeste M, Katila T.Treatment with intrauterine devices (IUD) prolongs luteal phases in mares, but the mechanism for this has not been fully elucidated. The aims of the present study were to examine how IUDs affect the uterus to induce longer luteal phases, particularly the role of cyclooxygenase-2 (COX-2) in the maintenance of the corpus luteum (CL). Twenty-seven reproductively normal mares were included: 12 were inseminated (AI), and 15 were fitted with IUDs. Blood samples for progesterone were obtained on Days 0, 3, 5, 7, 9, 11, 13, 14, and 15 (relative to day of ovulation). The groups were further divided int...
Neuhauser S, Gösele P, Handler J.During semen processing for cryopreservation, most seminal plasma is usually removed, and components with protective effects on sperm may be missing after thawing and within the female reproductive tract. The present study evaluated the effect of postthaw addition of autologous seminal plasma on motion characteristics of stallion sperm with fair (n = 4) or poor (n = 3) freezability. Therefore, pure seminal plasma (group SP1), seminal plasma combined with fresh semen extender (group SP2), or seminal plasma mixed with freezing extender (group SP3) were used to fill 0.5 mL straws and frozen sim...
Uliani RC, Conley AJ, Corbin CJ, Friso AM, Maciel LFS, Alvarenga MA.Anti-Müllerian hormone (AMH) is used as a marker of follicle population numbers and potential fertility in several species including horses but limited data exist across the lifespan. No one has decreased ovarian reserve experimentally to investigate whether a corresponding, quantitative decrease in AMH results. Concentrations of AMH across the lifespan were compiled from 1101 equine females sampled from birth to >33 years of age. Young and old mares (averaging 6 and 19 years) were hemi-ovariectomized and circulating AMH was assessed before and daily thereafter for 15 days. The remaining o...
Jacobsen S, Berg LC, Tvermose E, Laurberg MB, van Galen G.Neutrophil gelatinase-associated lipocalin (NGAL) has been shown to be a useful marker of kidney injury in people and dogs, but has not been described in horses. Objective: The aim of the study was to validate a commercially available porcine-specific ELISA to measure serum concentrations of equine NGAL. Methods: Intra- and interassay imprecisions were evaluated by multiple measurements on equine serum pools. Assay inaccuracy was determined by the linearity under dilution. Overlapping performance was assessed by measuring NGAL concentrations in horses with normal and elevated serum creatinine ...
Rebordão MR, Amaral A, Lukasik K, Szóstek-Mioduchowska A, Pinto-Bravo P, Galvão A, Skarzynski DJ, Ferreira-Dias G.Prostaglandin E (PGE) has contradictory effects in many organs. It may have proinflammatory, anti-inflammatory, or anti-fibrotic roles, depending on the type of receptors to which it binds. By signaling through its receptors EP2 and EP4, PGE mediates anti-inflammatory and anti-fibrotic actions. In spite of chronic endometrial fibrosis (endometrosis) being a major cause of mare infertility, its pathogenesis is not fully understood. We have shown that contact of mare endometrium in vitro with neutrophil extracellular traps (NETs) proteases favors endometrial collagen type I production. Therefor...
Cárceles-Rodríguez CM, Fernández-Varón E, Martín-Gimenez T, Aguirre C, Arion A, Rodríguez MJ, Ayala I.Insulin dysregulation (ID) is a common metabolic disorder in horses. Recently, incretin hormone release has been suggested to be involved in ID in horses. In human medicine, metformin and sitagliptin are commonly used in combination for metabolic syndrome. This combination could be useful in treating ID in horses. However, no pharmacokinetics data have been reported in this species. The objective of the present study was to establish the plasma concentration-time profile and to derive pharmacokinetics data for a combination of metformin and sitagliptin in horses after enteral administration. S...
Rooney MF, Hill EW, Kelly VP, Porter RK.Thoroughbred horses are finely-tuned athletes with a high aerobic capacity relative to skeletal muscle mass, attributable to centuries of genetic selection for speed and stamina. Polymorphisms in the myostatin gene (MSTN), a pronounced inhibitor of skeletal muscle growth, have been shown to almost singularly account for gene-based race distance aptitude in racehorses. In Thoroughbreds, two MSTN polymorphisms, a single nucleotide variation in the first intron (SNP g.66493737C>T) and a non-coding transposable element within the promoter region (a 227 bp SINE insertion) are of particular inter...
Ginther OJ, Dangudubiyyam SV.Effect of side (left ovary, LO; right ovary, RO) and intraovarian presence of the regressing corpus luteum (CL) on the preovulatory follicle (PF) and ovulation were studied using ultrasonic- records of complete interovulatory intervals (IOI) for 500 IOI in heifers and 485 IOI in mares. Only IOI with a recording of side of a single PF and a single CL at each end of the IOI were used. In heifers, ovulation at the end of the IOI occurred more frequently (P < 0.0001) from RO (n = 285, 57%) than LO (n = 215, 43%). In mares, frequency of ovulation did not differ between RO (n = 250. ...
Auer U, Schramel JP, Moens YP, Mosing M, Braun C.To assess changes in the distribution in pulmonary ventilation in anaesthetized ponies using electrical impedance tomography (EIT). Methods: Prospective experimental study. Methods: A group of eight adult pony geldings. Methods: General anaesthesia was induced and maintained using isoflurane in oxygen with volume-controlled ventilation [tidal volume (VT) (10 mL kg-1), respiratory rate (8-12 breaths minute-1)] to maintain end-tidal carbon dioxide between 35 and 40 mmHg (4.66-5.32 kPa). Regional distribution of ventilation was assessed with EIT (plane of fifth to sixth intercostal space) at 30, ...
Goodwin WA, Pasloske K, Keates HL, Ranasinghe MG, Woldeyohannes S, Perkins N.To determine the suitability of alfaxalone total intravenous (IV) anaesthesia in horses and concurrently evaluate infusion rates, cardiovascular effects, pharmacokinetics and the quality of the anaesthetic recovery period. Methods: Prospective, experimental study. Methods: Eight Standardbred horses. Methods: Horses were premedicated with IV acepromazine (0.03 mg kg) and xylazine (1 mg kg) and anaesthesia was induced with guaifenesin (35 mg kg) and alfaxalone (1 mg kg). Anaesthesia was maintained for 180 minutes using an IV infusion of alfaxalone at a rate determined by a horse's response to a ...
Faramarzi B, Rich LJ, Wu J.Pregnancy in many mammals, including mares, is associated with physiological changes that are reflected in hematological and biochemical profiles. Understanding those physiological changes and differentiating them from pathological changes is imperative for providing care and medical therapy in pregnant mares. Our objective was to compare normal hematological and biochemical profiles in healthy non-pregnant as well as healthy pregnant mares during the 1st and 2nd trimesters of pregnancy. Blood was collected by jugular venipuncture into ethylenediaminetetraacetic acid and serum tubes. Whole blo...
Kwirant LADA, De La Corte FD, Cantarelli C, Cargnelutti JF, Martins M, Cabral MW, Maciel N, Rubin MIB.Equine platelet-rich plasma (PRP) has been used in horses to repair bone, articular and tendinous lesions, laminitis, and even endometritis. However, platelets have a very limited lifespan, which makes it difficult to prepare and use PRP, except in loco. With the aim to produce PRP with higher platelet viability for clinical purposes, the effects of the cryoprotectants dimethyl sulfoxide (DMSO) and trehalose were evaluated on cooled (4°C) and cryopreserved (-196°C) equine PRP. The protocols of cooling and cryopreservation were performed independently, comparing the following treatments: fres...
Guerrero Cota JM, Leale DM, Arzi B, Cissell DD.Temporomandibular joint (TMJ) disorders affect up to 12% of the human population, and naturally occurring TMJ diseases are increasingly recognized in animals. The TMJ disc plays a major role in TMJ disorders in people, but little is known about its role in TMJ pathology in animals. This study characterizes differences in properties of equine TMJ discs associated with age, disc region, and presence of TMJ osteoarthritis (OA). Discs were dissected from both TMJ's of sixteen horses euthanized for reasons unrelated to this study. Each joint was grossly evaluated and scored as normal, mild OA, or s...
Selim MB, Nóbrega FS, Facó LL, Filippo Hagen SC, De Zoppa ALDV, Arana Chavez VE, Corrêa L. The main purpose of this study was to evaluate the characteristics of a vegetal polymeric biomaterial intended for bone substitution in horses and to investigate the responses of the equine third metacarpal bone to biomaterial implantation. Methods: Six horses were submitted to osteotomy on the dorsal aspect of the left and right third metacarpal bones; one bone defect was randomly selected for treatment with biopolymer, while the other was left untreated and served as a control. Bone density was monitored radiographically after surgery and bone biopsy fragments were collected at the end...
Martin EM, Schirmer JM, Jones SL, Davis JL.Misoprostol is an E prostanoid (EP) 2, 3 and 4 receptor agonist that is anecdotally used to treat and prevent NSAID-induced GI injury in horses. Misoprostol elicits anti-inflammatory effects in vivo in men and rodents, and inhibits TNFα production in equine leucocytes in vitro. Objective: Define the pharmacokinetic parameters of oral misoprostol in horses, and determine the inhibitory effect of oral misoprostol administration on equine leucocyte TNFα production in an ex vivo inflammation model. Methods: Pharmacokinetic study, ex vivo experimental study. Methods: Six healthy adult horses ...
Morales N, Henriquez C, Sarmiento J, Uberti B, Moran G.Neutrophils are terminally differentiated innate effector cells at the first line of host defense. Neutrophil migration within tissues is complex and involves several steps, during which these cells must be able to interpret a variety of chemical and physical signals. Exacerbated neutrophil activity can be harmful to surrounding tissues; this is important in a range of diseases, including equine asthma. Tamoxifen (TX) is a non-steroidal estrogen receptor modulator with effects on cell growth and survival. Previous studies showed that TX treatment in horses with induced acute pulmonary inflamma...
Olave C, Alvarez P, Uberti B, Morales N, Henriquez C, Folch H, Sarmiento J, Moran G.Neutrophils play an important role in the exacerbation and maintenance of severe equine asthma; persistent neutrophil activity and delayed apoptosis can be harmful to surrounding tissues. Tamoxifen (TX) is a nonsteroidal estrogen receptor modulator with immunomodulatory effects and induces early apoptosis of blood and bronchoalveolar lavage neutrophils from horses with acute lung inflammation. This study investigated if the in vitro effects of tamoxifen are produced by its action on nuclear (α and β) and membrane (GPR30) estrogen receptors in healthy equine neutrophils. Results showed that T...
Ford JE, Home WA, Gibson DM.Horse Ig kappa genes have been characterized to determine whether there may be a structural basis for the low level of kappa expression in this species. The overall organization of the J kappa-C kappa locus is remarkably similar to that of the mouse and human loci. A single C kappa exon is separated by 2.9 kb from five J kappa segments, four of which seem functional and three of which are associated with canonical recombination signal sequences. A highly conserved intron enhancer was identified upstream of the C kappa exon and a single restriction fragment in horse genomic DNA hybridized stron...
Hermanson JW.The extensor carpi radialis muscle of the horse is deceptive at first appearance. It has a fusiform shape similar to other forearm extensor muscles. The fiber arrangement also appears long and relatively parallel. However, it may contain two or more compartments that correlate with differing functional roles. Histochemical and immunocytochemical analysis of proximal and distal regions of the muscle (n = 9) demonstrate that the proximal portion of the muscle is composed of a mean of 13% type I, presumed slow twitch, and 61% type IIb, presumed fast twitch fibers. In contrast, the distal compartm...
Pujol R, Girard CA, Richard H, Hassanpour I, Binette MP, Beauchamp G, McDougall JJ, Laverty S.To measure the nerve fiber density in synovial membranes from healthy and OA equine joints and to investigate the relationship between synovial innervation and OA severity, synovial vascularity and synovitis. Twenty-five equine metacarpophalangeal joints were collected post-mortem. The joints were dissected and the macroscopic lesions of the articular cartilage were scored. Synovial membrane specimens (n = 50) were harvested, fixed, sectioned and scored histologically. Immunohistochemical staining and immunofluorescence with S-100 protein, that identifies nerve fibers, and ⍺-actin, that st...
Go YY, Bailey E, Timoney PJ, Shuck KM, Balasuriya UB.We investigated the correlation between in vitro susceptibility of CD3(+) T lymphocytes to equine arteritis virus (EAV) infection and establishment of persistent infection among 14 stallions following natural infections. The data showed that carrier stallions with a CD3(+) T lymphocyte susceptibility phenotype to in vitro EAV infection may be at higher risk of becoming carriers than those that lack this phenotype (P = 0.0002).
Wentink GH.The movements of the right hind limb of horses with normal locomotion were studied using cinephotography and electromyography. A model of the cycle of a stride in the walk and the trot was constructed and the kinetic parameters of the segments of the limb were calculated. A good correlation was obtained between the kinetics and the periods of the cycle of a stride during which individual muscles display activity. The results of this study demonstrate that: at placing and lifting, i.e., when a change occurs in the direction of the movement of the limb; b) At the walk, the greatest forces operan...
Williams KJ, Robinson NE, Defeijter-Rupp H, Millerick-May M, Stack A, Hauptman J, Derksen FJ.Exercise-induced pulmonary hemorrhage (EIPH), which has been reported in humans and a variety of domestic animals following strenuous exercise, is most often documented in racehorses. Remodeling of pulmonary veins (VR) in equine EIPH was recently described, suggesting that it contributes to the pathogenesis of the disease. The cause of VR is unknown. We tested the hypothesis that the development of VR follows pulmonary blood flow distribution, preferentially occurring in the caudodorsal lung region. Furthermore, we hypothesized that VR underpins development of the other lesions of EIPH patholo...
Obesity has become a serious health problem with frequent occurrence both in human and animal populations. It is estimated that it may affect over 85% of the human population and 70-80% of horses and cows by 2030. Fat cow syndrome (FCS) is a combination of metabolic, digestive, infectious, and reproductive disorders that affects obese periparturient dairy cows, and occurs most frequently in loose-housing systems, where periparturient and dry cows are fed and managed in one group disregarding the lactation stages. Equine metabolic syndrome (EMS) was named after human metabolic syndrome (MetS) a...
Berlinguer F, Pasciu V, Succu S, Cossu I, Caggiu S, Addis D, Castagna A, Fontani V, Rinaldi S, Passino ES.REAC technology (acronym for Radio Electric Asymmetric Conveyor) is a technology platform for neuro and bio modulation. It has already proven to optimize the ions fluxes at the molecular level and the molecular mechanisms driving cellular asymmetry and polarization. Methods: This study was designed to verify whether this technology could extend spermatozoa life-span during liquid storage, while preserving their functions, DNA integrity and oxidative status. At 0, 24, 48, and 72 h. of storage at 4 °C, a battery of analyses was performed to assess spermatozoa viability, motility parameters, a...
Epstein K, Short D, Parente E, Reef V, Southwood L.The objective of this study was to determine the characteristics based on ultrasonographic examination of the stomach, duodenum, jejunum, cecum, and peritoneal fluid in normal adult ponies. Abdominal ultrasonographic examination was performed in nine unsedated standing ponies. The duodenum was examined at three sites and the jejunum in 12 regions. Wall thickness, contractility, distention, and luminal contents were recorded. Stomach wall thickness and location, cecal wall thickness, and peritoneal fluid location and character were recorded. Statistical analysis was performed. Wall thicknesses ...
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 ...
Autio E, Neste R, Airaksinen S, Heiskanen ML.It is necessary to consider breed and cold tolerance in the housing and caring of horses. This study demonstrates differences in heat loss between horse types at low temperatures and examines rate of loss in different types during different seasons. Eighteen horses participated. Groups by type were light (L), warmblood (W), coldblood (C), and pony (P). A camera filmed thermographic images at 15 degrees C, 2 degrees C (all types), -8 degrees C (L, W, C), and -12 degrees C (P). The study calculated loss from the neck, trunk, and inner surfaces of front and hind legs. Loss was similar in all type...
Martig S, Lee PV, Anderson GA, Whitton RC.In racehorses, fatigue related subchondral bone injury leads to overt fracture or articular surface collapse and subsequent articular cartilage degeneration. We hypothesised that the fatigue behaviour of equine subchondral bone in compression follows a power law function similar to that observed in cortical and trabecular bone. We determined the fatigue life of equine metacarpal subchondral bone in-vitro and investigated the factors influencing initial bone stiffness. Subchondral bone specimens were loaded cyclically in compression [54MPa (n=6), 66MPa (n=6), 78MPa (n=5), and 90MPa (n=6)] until...
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...
Merkies K, Paraschou G, McGreevy PD.Horses and donkeys belong to the genus Equus, but important differences exist between the species, many of which affect their management and welfare. This study compared skull morphology between horses and donkeys. Horse ( = 14) and donkey ( = 16) heads were obtained post-mortem, sectioned sagittally close to the midline, and photographed for subsequent measurement of various skull structures. Skull, cranial, nasal, and profile indices were calculated for topographical comparisons between the species. The olfactory bulb area (OBA), OB pitch (the angle between the hard palate and the OB axis), ...
Catalán J, Yánez-Ortiz I, Tvarijonaviciute A, González-Aróstegui LG, Rubio CP, Barranco I, Yeste M, Miró J.The objective of this study was to determine the relationship of enzymatic (superoxide dismutase, SOD; glutathione peroxidase, GPX; catalase, CAT; and paraoxonase type 1, PON1) and non-enzymatic antioxidants (measured in terms of: Trolox equivalent antioxidant capacity, TEAC; cupric-reducing antioxidant capacity, CUPRAC; and ferric-reducing ability of plasma, FRAP), as well as the oxidative stress index (OSI) in seminal plasma (SP) with the resilience of horse sperm to freeze-thawing. Twenty-one ejaculates (one per individual) were collected and split into two aliquots: the first was used to h...
Gillis C, Pool RR, Meagher DM, Stover SM, Reiser K, Willits N.To assess tendon morphology and non-reducible crosslink concentration, and associations of these findings with horse age and previously reported mechanical and ultrasonographic findings. Methods: Superficial digital flexor tendon samples were obtained from 23 horses aged 2 to 23 years. The tendons had undergone ultrasonography and were submitted to biomechanical testing in the physiologic range prior to sample acquisition. Methods: Samples were sectioned in a transverse plane; then dorsal, palmar, central, lateral, and medial regions were evaluated for fascicle cross-sectional area (CSA), sept...
Trindade PHE, Hartmann E, Keeling LJ, Andersen PH, Ferraz GC, Paranhos da Costa MJR.The horses' responses to exercise are commonly monitored using physiological variables, nonetheless physical and mental states can also be expressed through body language. The aims of this study were: (i) to identify how facial expressions and other behavioural variables change in ranch horses after a routine workday, and (ii) to investigate if these changes can be used as indicators of physical tiredness by relating them to known variables of physical fitness and workload. Fourteen crossbred ranch horses were assessed pre- and post-workday on two farms, recording the body language, physiologi...
Leith GS, Ginther OJ.Intrauterine mobility patterns of the embryonic vesicle were characterized on Days 9 to 17 after ovulation in pony mares using real-time ultrasonography (n=5 or 7 mares per day). The location of the vesicle was determined by dividing the uterus into right horn, left horn, and body. Each uterine horn was further divided into three approximately equal portions (cranial third, middle third, caudal third), yielding seven segments (body plus three portions of each horn). Location of the vesicle within the uterus was recorded every five minutes for two consecutive hours (25 location determinations p...
Alexander SL, Roud HK, Irvine CH.To study the effect of hypoglycaemia on secretion rates of corticotrophin-releasing hormone (CRH), arginine vasopressin (AVP) and ACTH in a non-ruminant species, a non-surgical method was used to collect pituitary venous (PitVen) blood every 0.5 or 1 min from seven horses before and after insulin administration (0.4 U/kg i.v.). To assess the effect of PitVen cannulation on results, peripheral hormones were also measured before and after insulin in five horses without PitVen cannulae. Insulin administration lowered plasma glucose in all horses (P < 0.0001; paired t-test). Cortisol concentrat...
Dybdal NO, Hargreaves KM, Madigan JE, Gribble DH, Kennedy PC, Stabenfeldt GH.Pituitary pars intermedia dysfunction is a slowly progressive disorder that afflicts most breeds of horses. Because it shares features with human Cushing disease, it has been referred to as equine Cushing disease. A variety of tests of pituitary-adrenocortical function were performed on horses with evidence of pituitary pars intermediate dysfunction, and results were compared with those in healthy control horses. Diurnal variations in plasma cortisol concentration were not statistically different between control horses and those with pituitary pars intermedia dysfunction. An ACTH stimulation (...
Bae SE, Corcoran BM, Watson ED.Little is known about neurogenic regulation of uterine contractility in mares. The present study investigated the distribution of adrenergic and peptidergic nerves in the mare uterus. Samples from the uterine horn, body and cervix were collected from 18 cyclic mares for immunohistochemistry. The uterus was well supplied with adrenergic nerves. A large number of tyrosine hydroxylase- and dopamine beta-hydroxylase-immunoreactive nerve bundles and fibres were present in the myometrium and endometrium in all regions of the uterus and cervix. These adrenergic nerve bundles and fibres travelled para...
Enders AC, Liu IK.The structure of the equine chorionic girdle between days 28 and 42 of gestation was examined. Of particular interest were differentiation of trophoblastic cells within the girdle, adhesion between girdle and endometrium, invasion and displacement of the uterine epithelium, and the nature of the endometrium when girdle cells migrate into it to form endometrial cup cells. The chorionic girdle, identified initially as a band of tall columnar cells, becomes a stratified columnar epithelium indented by clefts and pits. Adhesion to and penetration through the endometrial luminal epithelium are rapi...
Erickson BK, Erickson HH, Coffman JR.This study investigated changes in packed cell volume (PCV), pulmonary artery and aortic pressures, and the interaction between oesophageal pressure and pulmonary artery and aortic pressures during strenuous exercise in the horse. It was hypothesised that oesophageal pressure changes summate with pulmonary artery and aortic pressures during exercise and contribute to exercise-induced pulmonary haemorrhage (EIPH). Acute treadmill exercise (10 m/sec, 3 degrees incline) produced increases in heart rate (HR) from 50 to 202 beats/min; mean pulmonary artery pressure (PAP) from 28 to 80 mmHg; mean ao...
Martoriati A, Gérard N.A growing body of evidences suggests that the ovary is a site of inflammatory reactions, and thus, ovarian cells could represent sources and targets of the interleukin-1 (IL-1) system. The purpose of this study was to examine the IL-1 system gene expressions in equine granulosa cells, and to study the IL-1beta content in follicular fluid during the follicle maturation. For this purpose, granulosa cells and follicular fluids were collected from the largest follicle at the early dominance stage (diameter 24 +/- 3 mm) or during the preovulatory maturation phase, at T0 h, T6 h, T12 h, T24 h and T3...
Bigley RF, Griffin LV, Christensen L, Vandenbosch R.The interfacial strength of secondary osteons from the diaphysis of the Thoroughbred equine third metacarpal was evaluated using the fiber pushout test. The pushout was performed on 300-500 microm sections of 4x4x15 mm bone blocks machined from four anatomic regions of the cortex. Pushout strength was evaluated from proximal to distal location within the diaphysis on four osteon types classified under polarized light on adjacent histologic sections from each block. The shear strength of the interfaces were estimated from shear lag theory. Differences were found in the interfacial strength of o...
Jacobsen S, Berg LC, Tvermose E, Laurberg MB, van Galen G.Neutrophil gelatinase-associated lipocalin (NGAL) has been shown to be a useful marker of kidney injury in people and dogs, but has not been described in horses. Objective: The aim of the study was to validate a commercially available porcine-specific ELISA to measure serum concentrations of equine NGAL. Methods: Intra- and interassay imprecisions were evaluated by multiple measurements on equine serum pools. Assay inaccuracy was determined by the linearity under dilution. Overlapping performance was assessed by measuring NGAL concentrations in horses with normal and elevated serum creatinine ...
Tangtrongsup S, Kisiday JD.Chondrogenesis of mesenchymal stem cells (MSCs) is induced in culture conditions that have been associated with oxidative stress, although the extent to which the oxidative environment affects differentiation and extracellular matrix (ECM) accumulation is not known. The objectives of this study were to evaluate the oxidative environment during MSCs chondrogenesis in conventional serum-free medium, and the effect of serum-supplementation on intracellular reactive oxygen species (ROS) and chondrogenesis. Young adult equine MSCs were seeded into agarose and cultured in chondrogenic medium, with o...
Merkens HW, Schamhardt HC, Hartman W, Kersjes AW.The ground reaction force patterns from 20 clinically sound Dutch Warmblood horses (Group A) were recorded at the normal walk. The data from four to 10 stance phases of each limb were computer averaged after normalisation to the animal's body mass and to the stance time. This analysis method allowed comparison of data from left and right fore- and hindlimbs within and between horses. The left-to-right symmetry in the reaction force peaks of contralateral limbs of one horse exceeded 90 per cent. The time in the stance phase at which the peaks occur were even more symmetrically distributed. A ch...
Soukup R, Gerner I, Gültekin S, Baik H, Oesterreicher J, Grillari J, Jenner F.Extracellular vesicles (EVs) are nanosized lipid bilayer-encapsulated particles secreted by virtually all cell types. EVs play an essential role in cellular crosstalk in health and disease. The cellular origin of EVs determines their composition and potential therapeutic effect. Mesenchymal stem/stromal cell (MSC)-derived EVs have shown a comparable therapeutic potential to their donor cells, making them a promising tool for regenerative medicine. The therapeutic application of EVs circumvents some safety concerns associated with the transplantation of viable, replicating cells and facilitates...
Matthews NS, Hartsfield SM, Cornick JL, Williams JD, Beasley A.Six combinations of injectable anesthetic agents were administered to six adult horses in a Latin square design. The drug combinations were xylazine-ketamine, xylazine-butorphanol-ketamine, xylazine-tiletamine-zolazepam, xylazine-butorphanol-tiletamine-zolazepam, detomidine-ketamine, and detomidine-butorphanol-ketamine. Measured variables were heart rate, respiratory rate, systolic blood pressure, arterial pH (pHa), PaCO2, PaO2, recumbency time, and number of attempts necessary to stand. Quality of induction and recovery, muscle relaxation, and response to stimulus were evaluated subjectively....
