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.
Depuydt E, Chiers K, Van Hecke L, Saunders J, Martens A, Pille F, Spaas JH.Injuries to equine tendons and ligaments are career-compromising, causing reduced performance and premature retirement. Promising treatment alternatives have been investigated in the field of mesenchymal stem cells (MSCs). In this study, the tissue adherence and protein expression of tenogenic primed mesenchymal stem cells (tpMSCs) after administration to ex vivo tendon and ligament explants is investigated. First, collagen type I (COL I) and smooth muscle actin (SMA) expression was assessed in cytospins prepared from native MSCs and tpMSCs. Second, equine superficial digital flexor tendon and...
Żak-Bochenek A, Bajzert J, Sambor D, Siwińska N, Szponar B, Łaczmański Ł, Żebrowska P, Czajkowska A, Karczewski M, Chełmońska-Soyta A.The defensive function of the intestinal mucosa depends both on the ability to secrete immunoglobulin A and communication with the mucus microbiome. In horses, the functioning of this system is also influenced by the presence of nematode eggs. Feces collected from healthy horses were examined to determine the fecal egg count, immunoglobulin A level (ELISA), microbiome composition (Next-Generation Sequencing, NGS, V3−V4 and V7−V9 hypervariable regions of the 16S rRNA gene analysis and short-chain fatty acid (SCFA) production ((high-performance liquid chromatography, HPLC). In the taxonomic ...
Lindinger MI.Horses that sweat for prolonged periods lose considerable amounts of water and electrolytes. Maintenance of hydration and prevention of dehydration requires that water and electrolytes are replaced. Dehydration is common in equine disciplines and can be avoided, thus promoting equine wellness, improved performance and enhanced horse and rider safety. Significant dehydration occurs through exercise or transport lasting one hour or more. Oral electrolyte supplementation is an effective strategy to replace water and electrolytes lost through sweating. The stomach and small intestine serve as a re...
Silva CJFL, Trindade KLG, Cruz RKS, Manso HECCC, Coelho CS, Filho JDR, Nogueira CEW, Aragona F, Fazio F, Manso Filho HC.Erosions and gastric ulcers may be present in horses at any age and under different conditions of rearing and handling. In tropical regions, horses can feed on fruits rich in soluble carbohydrates, such as mangoes, but little is known about how these foods interact with their digestive systems. To test the hypothesis that the ingestion of ripe mangoes with peels could cause disturbances in the digestive processes of horses, an experiment was developed to monitor animals that had free access to ripe mangoes in their pasture areas. Horses (purebred Arabians, n = 5; ~340 kg, ~13 years) were evalu...
McGilloway M, Manley S, Aho A, Heeringa KN, Lou Y, Squires EJ, Pearson W.Leaky gut syndrome (LGS) is an idiopathic disorder characterised by alterations in intestinal permeability and low-grade systemic inflammation. Factors contributing to development of LGS are not well-understood but physiological stressors such as exercise and transport may play a role which may be of pathophysiological relevance in horses. Objective: To characterise the combined effect of transport stress and exercise on gastrointestinal permeability, and to determine whether these effects are associated with increased inflammatory biomarkers in plasma. Methods: Controlled, randomised and cros...
Saitua A, Castejón-Riber C, Requena F, Argüelles D, Calle-González N, de Medina AS, Muñoz A.During a water treadmill (WT) exercise, horses change their accelerometric patterns. We aimed to analyze if these changes persist during terrestrial locomotion. Six horses were randomly subjected to 40 min duration WT exercises, without water (WW), at the depth of fetlock (FET), carpus (CAR) and stifle (STF), with a day off between them. Before and after 30 min after WT, horses were evaluated at walk and at trot on a track with a triaxial accelerometer fixed on the pectoral (PECT) and sacrum (SML) regions. The percent of change from baseline (before WT and after each exercise session) were cal...
Malaluang P, Wilén E, Frosth S, Lindahl J, Hansson I, Morrell JM.Antibiotics are added to semen extenders in insemination doses but their effect on the vaginal microbiota of the inseminated female is unknown. The objectives of this study were to define the equine vaginal microbiota and its antimicrobial resistance, and to determine whether it changes after exposure to antibiotics in semen extenders. Vaginal swabs were taken prior to sham-insemination (day 0), and again on days 3, 7, and 14 after insemination. Isolated bacteria were identified by MALDI-TOF and tested for antimicrobial susceptibility by microdilution. The bacteria isolated from the vagina dif...
Veen I, de Grauw JC.Endotracheal intubation is a routine procedure in veterinary anaesthesia, yet no consensus guidelines exist for endotracheal tube (ETT) cuff inflation and pressure measurement. The aim of this study was to assess current practice of ETT cuff inflation and seal verification in veterinary medicine. An online questionnaire was distributed among veterinary professionals who administer anaesthesia, comprising six demographic and twelve ETT cuff-related questions per species. N = 348 questionnaires were completed. Cuff pressure was measured by 30% of respondents in cats, 32% in dogs and 9% in both f...
St George LB, Spoormakers TJP, Smit IH, Hobbs SJ, Clayton HM, Roy SH, van Weeren PR, Richards J, Serra Bragança FM.The relationship between lameness-related adaptations in equine appendicular motion and muscle activation is poorly understood and has not been studied objectively. The aim of this study was to compare muscle activity of selected fore- and hindlimb muscles, and movement of the joints they act on, between baseline and induced forelimb (iFL) and hindlimb (iHL) lameness. Three-dimensional kinematic data and surface electromyography (sEMG) data from the fore- (triceps brachii, latissimus dorsi) and hindlimbs (superficial gluteal, biceps femoris, semitendinosus) were bilaterally and synchronously c...
Okada CTC, Kaps M, Reichart U, Walter I, Gautier C, Aurich J, Aurich C.While detrimental effects of reduced plasma progesterone concentration in the early luteal phase on conceptus development in horses have recently been demonstrated, there is no information on associated effects on the endometrium, allantochorion (AC), and chorionic girdle (CG) in this species. We hypothesised that reduced early postovulatory progesterone concentration in pregnant horses is detrimental to endometrial function and development of the embryonic membranes and is an underlying cause of delayed conceptus development. After insemination and ovulation, mares (n = 11) were assigned to...
Legg KA, Cochrane DJ, Gee EK, Macdermid PW, Rogers CW.To enhance performance in race riding, knowledge of current training workload is required. The objectives of this study were to quantify the physiological demands and profile the muscle activity of jockeys riding track-work. Methods: Ten apprentice jockeys and 48 horses were instrumented with heart-rate monitors, accelerometers, and a surface electromyography BodySuit (recording 8 muscle groups: quadriceps, hamstrings, gluteal, lower back, obliques, abdominal, trapezial, and pectoral) that recorded continuously while riding their normal morning track-work. Data were extracted and time matched ...
Posukonis MN, Daglish J, Wright IM, Kawcak CE.To evaluate bone mineral content patterns between fracture configurations using novel CT image analysis. Methods: CT images from 97 Thoroughbred racehorses with third metacarpal/tarsal condyle fractures provide the case population for analysis. Methods: Fractures were grouped by radiographic appearance. Image analysis objectively measured area of highly attenuating pixels (aHAP), areal density of highly attenuating pixels (dHAP) utilizing novel convex hull analysis, and subjective assessment of apparent attenuation intensity ranking (AAIR) for each fracture. Differences between fracture config...
Thomson P, Pareja J, Núñez A, Santibáñez R, Castro R.Culture-independent techniques have made it possible to expand the knowledge about the composition of bacterial communities present in the healthy uterus and their role in health and disease, mainly in humans. However, in animals like mares, there is a dearth of information regarding this area. To narrow this knowledge gap, the objective of this study was to identify and characterize the composition and function of the uterine microbiome of a group of Chilean purebred mares (CPM), an equine breed with the oldest genealogical record in South America and an economical important reproductive indu...
Poradowski D, Chrószcz A.Histological and morphometrical analysis of the stomach wall was performed during the foetal period divided into three age groups (4th-11th month of gestation). The material was taken from non-glandular (the blind ventricular sac) and glandular parts (the plicated edge margin/cardiac part, the body of stomach and the pyloric part) of the stomach. It was preserved and prepared according to the standard protocol. The histological slides were stained (H-E, Masson-Goldner and PAS). The analyses were performed using the light microscope. All measurements were statistically elaborated. The crown-rum...
Novotny EN, Hässig M, Palme R, Fürst AE, Weishaupt MA.The Zurich's Sechseläuten is a traditional festival of the Zurich guilds, in which around 500 horses take part. After a parade through the old town of Zurich, the riders gather at a big square to canter around a burning woodpile topped with an exploding effigy (the «Böögg»). The level of stress experienced by the horses partaking in this event is subjected to increasing scrutiny. The aim of this study was to evaluate the stress load of the horses participating in the Sechseläuten procession more objectively by measuring heart rate and faecal cortisol metabolites. Twenty-three horse-rider...
Martín-Suárez EM, Mesa P, Portillo M, Morgaz J, Moreno O, Guisado A, Galán-Rodríguez A.This study sought to compare the Schirmer Tear Test (STT)-1 results at 30 (STT30) versus 60 (STT60) seconds in healthy horses. This study included a total of 56 healthy horses. STT-1 was performed in both eyes, right eye first, and the wetting lengths were measured in STT30 and STT60. To evaluate the reduction of the initial reflex phase, the wetting length velocity was measured during the first 30 seconds. The effects of eye, age, weight, sex, and ambient temperature and humidity on STT values were evaluated. Mean (standard deviation) STT30 and STT60 were 19.06 (3.88) and 24.26 (4.50) mm. The...
Senra RL, Ramírez-López CJ, Magalhães-Júnior MJ, Neves JGDS, Barros E, Waddington B, Guimarães SEF, Guimarães JD, Baracat-Pereira MC.Horses are seasonal polyoestrous animals, and the photoperiod is the main factor modulating their reproductive activity. There is no consensus on the andrological and biochemical factors that influence breeding seasonality. To assess the involvement of climate in reproduction, Mangalarga Marchador stallions were monitored over 1 year regarding semen quality and seminal plasma proteome. Here, we show that kallikrein (KLKs) proteoforms in seminal plasma are involved in climate conditioning of reproduction. During the breeding season, greater abundance and different types of KLKs occurred simult...
Clark L, Bradley EJ, Mackechnie-Guire R, Taylor A, Ling J.Asymmetry of horses and humans is widely acknowledged, but the influence of one upon the other during horse riding is poorly understood. Riding simulators are popular for education of beginners and analysis of rider biomechanics. This study compares trunk kinematics and saddle forces of 10 experienced riders (ER) and 10 novice riders (NR) performing rising trot on a simulator. Markers were placed on the 4th lumbar (L4) and 7th cervical (C7) spinous processes, and both acromion processes. Displacements in three axes of motion were tracked using 10 high-speed video cameras sampling at 240 Hz. Di...
Bagge J, Berg LC, Janes J, MacLeod JN.Bone marrow (BM)- and adipose tissue (AT)-derived mesenchymal stromal cells (MSCs) have shown potential as cell-based therapies for cartilage and bone injuries and are used increasingly in human and veterinary practice to facilitate the treatment of orthopedic conditions. However, human and rodent studies have documented a sharp decline in chondrogenic and osteogenic differentiation potential with increasing donor age, which may be problematic for the important demographic of older orthopedic patients. The aim of this study was to identify the effect of donor age on the chondrogenic and osteog...
Catalán J, Martínez-Rodero I, Yánez-Ortiz I, Mateo-Otero Y, Bragulat AF, Nolis P, Carluccio A, Yeste M, Miró J.Follicular fluid is formed from the transudation of theca and granulosa cells in the growing follicular antrum. Its main function is to provide an optimal intrafollicular microenvironment to modulate oocyte maturation. The aim of this study was to determine the metabolomic profile of preovulatory follicular fluid (PFF) in jennies. For this purpose, PFF was collected from 10 follicles of five jennies in heat. Then, PFF samples were analysed by nuclear magnetic resonance (NMR) and heteronuclear single quantum correlation (2D H/C HSQC). Our study revealed the presence of at least 27 metabolites i...
Santosuosso E, David F, Massie S, Filho SA, McCrae P, Johnson S, Leguillette R.Cardiac arrhythmias have not been previously reported in horses while swimming. Objective: To describe the type and frequency of encountered arrhythmias during repetitive swimming cycles. Methods: Descriptive observational study. Methods: Sixteen horses swam five pool lengths (75 m), each separated by an active recovery walk. Continuous electrocardiograms (ECGs) were recorded (n = 80) and analysed during the pre-swim, swim and active-recovery periods. Arrhythmias were categorised as sinus arrhythmia (SA), sinus block, sinus pause (compensatory and non-compensatory), second degree atriovent...
Tiwari M, Sodhi M, Verma P, Vivek P, Kataria RS, Niranjan SK, Bharti VK, Masharing N, Gujar G, Chanda D, Mukesh M.The identification of appropriate references genes is an integral component of any gene expression-based study for getting accuracy and reliability in data interpretation. In this study, we evaluated the expression stability of 10 candidate reference genes (GAPDH, RPL4, EEF1A1, RPS9, HPRT1, UXT, RPS23, B2M, RPS15, ACTB) in peripheral blood mononuclear cells of livestock species that are adapted to high altitude hypoxia conditions of Leh-Ladakh. A total of 37 PBMCs samples from six native livestock species of Leh-Ladakh region such as Ladakhi cattle, Ladakhi yak, Ladakhi donkey, Chanthangi goat...
Mihelić K, Vrbanac Z, Bojanić K, Kostanjšak T, Ljubić BB, Gotić J, Vnuk D, Bottegaro NB.This study aimed to evaluate if exercise-induced acute phase response (APR) occurs in endurance horses in response to the race. The study included 23 horses competing in an endurance competition with a successfully passed clinical examination before the race. Blood samples were collected before the start and within 30 min after the end of the race. Haematological and biochemical tests were performed and correlated to acute phase biomarkers changes. Values of calprotectin and haptoglobin (Hp) decreased after the races compared to values before, while concentrations of ceruloplasmin and albumin ...
Hodgson S, Bennett-Skinner P, Lancaster B, Upton S, Harris P, Ellis AD.These studies assessed the pressure forces exerted by horses to extract forage from haynets. Study 1 measured horse posture and pressure in Newtons (10 N = 1 kg Force) exerted on haynets when feeding from either a single (SH) or double layered (DH) haynet (3 kg Hay), hung low or high. Mean and maximum pull forces were higher for the DH vs. SH (DH: 81 ± 2 N, max 156 N; SH: 74 ± 2.9 N, max 121 N; p < 0.01). Horses pulled harder on low (max pull 144 ± 8 N) compared to high (109 ± 8 N; p < 0.05) hung haynets. Mean maximum angles (nose-poll-withers) recorded were 90° ± 9 for SH and 127...
Roßgardt J, Heilen LB, Büttner K, Dern-Wieloch J, Vogelsberg J, Staszyk C.In the crown pulp of brachydont teeth, a cell-free and a cell-rich zone are established beneath the odontoblastic layer, indicating a mature status. For the equine dental pulp, there are no descriptions which allow for a comparative analysis with regard to functional requirements in terms of lifelong secondary dentin production to compensate for occlusal wear. For histomorphological and immunohistological investigations, ten incisors and ten check teeth were used from seven adult horses and five foals. In the periphery of the equine dental pulp, a constant predentin and odontoblastic cell laye...
Lan Y, Li Y, Yu G, Zhang Z, Irshad I.Accumulating studies indicated that gut microbial changes played key roles in the progression of multiple diseases, which seriously threaten the host health. Gut microbial dysbiosis is closely associated with the development of diarrhea, but gut microbial composition and variability in diarrheic horses have not been well characterized. Here, we investigated gut fungal compositions and changes in healthy and diarrheic horses using amplicon sequencing. Results indicated that the alpha and beta diversities of gut fungal community in diarrheal horses changed significantly, accompanied by distinct ...
Boakari YL, Legacki E, Alonso MA, Dos Santos ACF, Nichi M, Conley AJ, Fernandes CB.It is necessary to study hormonal patterns from mules to recognize alterations and neonatal maladaptation. Our objective was to evaluate concentrations of hormones in mule (n = 6) and equine foals (n = 6). Blood was collected at T0, 1, 6 and 12 h after birth. Hormone concentrations were evaluated using liquid chromatography tandem mass spectrometry. Effects of time, group and interactions and regression analysis were evaluated (p < 0.05). There was a cubic and quadratic decline in mule and equine foals, respectively, for 3β,20α-dihydroxy-DHP. Mule foals were born with lower circulating 3...
Kinsella HM, Hostnik LD, Toribio RE.Most homeostatic systems in the equine neonate should be functional during the transition from intra- to extrauterine life to ensure survival during this critical period. Endocrine maturation in the equine fetus occurs at different stages, with a majority taking place a few days prior to parturition and continuing after birth. Cortisol and thyroid hormones are good examples of endocrine and tissue interdependency. Cortisol promotes skeletal, respiratory, cardiovascular, thyroid gland, adrenomedullary, and pancreatic differentiation. Thyroid hormones are essential for cardiovascular, respirator...
Wilson KE, Bogers SH, Council-Troche RM, Davis JL.To determine the effects of general anesthesia on the safety and efficacy of co-administered potassium penicillin G (PEN) and gentamicin (GENT) in horses. Methods: Nonrandomized crossover. Methods: Six adult, Thoroughbred horses. Methods: Horses were administered PEN (22 000 IU/kg IV) and GENT (6.6 mg/kg IV). Plasma samples were collected over a 6 h period and synovial fluid was collected at 30 min and 6 h respectively. Drug administration and sample collection protocols were repeated after at least a 48 hour washout period and induction of anesthesia using xylazine/ketamine and main...
Pluháček J, Tučková V, King SRB.Flehmen is frequently explained as part of male sexual behaviour, but it can also be associated with overmarking behaviour and thus individual recognition. We tested three explanatory hypotheses of flehmen behaviour: to detect sexual status of a female, to decide whether to overmark an individual, and to improve individual recognition. Additionally, we examined interspecific flehmen differences in the African equids. We observed 130 individuals of all 4 species among 15 groups in 5 zoos. We recorded 4445 eliminations: 142 were accompanied by flehmen and 1648 were inspected by another animal an...
Dutto DJ, Hoyt DF, Cogger EA, Wickler SJ.Although the forces required to support the body mass are not elevated when moving up an incline, kinematic studies, in vivo tendon and bone studies and kinetic studies suggest there is a shift in forces from the fore- to the hindlimbs in quadrupeds. However, there are no whole-animal kinetic measurements of incline locomotion. Based on previous related research, we hypothesized that there would be a shift in forces to the hindlimb. The present study measured the force produced by the fore- and hindlimbs of horses while trotting over a range of speeds (2.5 to 5 m s(-1)) on both level and up an...
Whitworth DJ, Banks TA.There has been unprecedented interest in recent years in the use of stem cells as therapy for an array of diseases in companion animals. Stem cells have already been deployed therapeutically in a number of clinical settings, in particular the use of mesenchymal stem cells to treat osteoarthritis in horses and dogs. However, an assessment of the scientific literature highlights a marked disparity between the purported benefits of stem cell therapies and their proven abilities as defined by rigorously controlled scientific studies. Although preliminary data generated from clinical trials in huma...
Smits K, Willems S, Van Steendam K, Van De Velde M, De Lange V, Ververs C, Roels K, Govaere J, Van Nieuwerburgh F, Peelman L, Deforce D, Van Soom A.During maternal recognition of pregnancy (MRP), a conceptus-derived signal leads to the persistence of the corpus luteum and the maintenance of gestation. In the horse, the nature of this signal remains to be elucidated. Several studies have focused on the changes in gene expression during MRP, but little information exists at the protein level. The aim of this study was to identify the proteins at the embryo-maternal interface around signalling of MRP in the horse (day 13) by means of mass spectrometry. A distinct influence of pregnancy was established, with 119 proteins differentially expres...
Bonnefoy A, Romijn RA, Vandervoort PA, VAN Rompaey I, Vermylen J, Hoylaerts MF.Binding of von Willebrand factor (VWF) to platelet GPIbalpha and to collagen is attributed to VWF A1 and A3 domains, respectively. Objective: Using VWF, VWF lacking A1 (DeltaA1-VWF) or A3 (DeltaA3-VWF) and VWF with defective A3 (H1786A-VWF), in combination with recombinant A1 (residues 1262-1492) or A3 (residues 1671-1878), fused to glutathione-S-transferase (GST-A1 and GST-A3), we have re-investigated the role of A1 in platelet recruitment to surfaces of collagen. Results: In flow, measurable binding of DeltaA3-VWF occurred to horse tendon, but also to human type III collagen. GST-A1 and GST-...
Hoffman LH, Wooding FB.The cellular origin, structure, and function of trophoblastic giant cells (GC) and binucleate cells (BNC) are reviewed. Mammals in which these cells have received the greatest attention include rodents, rabbits, and humans (GCs), and ruminants and equids (BNCs). In almost all cases these cells arise from the cytotrophoblast. All are large cells and contain either two diploid nuclei (BNCs), multiple nuclei (human placental bed GCs), or single nuclei with amplified DNA content (rodent and rabbit GCs). Giant and binucleate cells typically exhibit the capacity for migration or invasion, although t...
Kleinheinz J, Jung S, Wermker K, Fischer C, Joos U.Current approaches in bone regeneration combine osteoconductive scaffolds with bioactive cytokines like BMP or VEGF. The idea of our in-vitro trial was to apply VEGF165 in gradient concentrations to an equine collagen carrier and to study pharmacological and morphological characteristics of the complex in a circulation model. Methods: Release kinetics of VEGF165 complexed in different quantities in a collagen matrix were determined in a circulation model by quantifying protein concentration with ELISA over a period of 5 days. The structural changes of the collagen matrix were assessed with lig...
Bisgard GE, Forster HV, Orr JA, Buss DD, Rawlings CA, Rasmussen B.Seven ponies were subjected to carotid body denervation (CD) and two ponies were sham operated (S). Measurement of arterial blood gases and arterial blood and cerebrospinal fluid (CSF) acid-base balance were made prior to and 1,2,4,9, and 17 wks after surgery in unanesthetized animals. Resting ventilation and ventilatory responsiveness to hypoxia and NaCN infusion were assessed prior to and 2,9, and 17 wks after surgery. Alveolar hypoventilation in the CD ponies was marked 1-2 wk after surgery when VE and VA were reduced 40% and 10%, respectively, from control and PaCO2 was 12-15 mmHg above co...
Schwarzwald CC.This article provides an overview on the principles of transthoracic echocardiography in horses. Indications for echocardiography, equipment, and technical considerations are discussed and a systematic approach for a complete echocardiographic examination in horses is described. Methods for assessment of chamber dimensions, allometric scaling of measurements, assessment of systolic and diastolic ventricular function, assessment of atrial function, hemodynamic assessment, and evaluation of valvular regurgitation are explained, focusing on traditional 2-dimensional (2D), motion-mode, and Doppler...
Merkens HW, Schamhardt HC, Van Osch GJ, Van den Bogert AJ.This study was undertaken to establish limb loading patterns of sound horses at the trot, to provide a data base against which results for lame horses could be compared. Ground reaction force (GRF) data were collected from 20 clinically sound Dutch Warmblood horses. The data from at least 5 stance phases of each limb were averaged after standardisation to the animal's body mass and to the stance phase duration and resulted in 'representative' GRF data. The symmetry in the vertical GRF peak amplitudes, impulses and the stance phase duration comparing left and right limbs exceeded 97%. By averag...
Daly K, Al-Rammahi M, Arora DK, Moran AW, Proudman CJ, Ninomiya Y, Shirazi-Beechey SP.The heteromeric sweet taste receptor T1R2-T1R3 is expressed on the luminal membrane of certain populations of enteroendocrine cells. Sensing of sugars and other sweet compounds by this receptor activates a pathway in enteroendocrine cells, resulting in secretion of a number of gut hormones, including glucagon-like peptide 2 (GLP-2). This subsequently leads to upregulation in the expression of intestinal Na(+)/glucose cotransporter, SGLT1, and increased intestinal glucose absorption. On the basis of the current information available on the horse genome sequence, it has been proposed that the ge...
Bertuglia A, Pagliara E, Grego E, Ricci A, Brkljaca-Bottegaro N.Joint impact injuries initiate a progressive articular damage finally leading to post-traumatic osteoarthritis (PTOA). Racehorses represent an ideal, naturally available, animal model of the disease. Standardbred racehorses developing traumatic osteoarthritis of the fetlock joint during the first year of their career were enrolled in our study. Age-matched controls were contemporarily included. Biomarker levels of equine osteoarthritis were measured in serum and synovial fluid (SF) at baseline, and repeated yearly over the next 4 years of training (from T1 to T4). The effect of time and disea...
Skedros JG, Dayton MR, Sybrowsky CL, Bloebaum RD, Bachus KN.This study examined relative influences of predominant collagen fiber orientation (CFO), mineralization (% ash), and other microstructural characteristics on the mechanical properties of equine cortical bone. Using strain-mode-specific (S-M-S) testing (compression testing of bone habitually loaded in compression; tension testing of bone habitually loaded in tension), the relative mechanical importance of CFO and other material characteristics were examined in equine third metacarpals (MC3s). This model was chosen since it had a consistent non-uniform strain distribution estimated by finite ele...
Maumus M, Roussignol G, Toupet K, Penarier G, Bentz I, Teixeira S, Oustric D, Jung M, Lepage O, Steinberg R, Jorgensen C, Noel D.Mesenchymal stem cells isolated from adipose tissue (ASC) have been shown to influence the course of osteoarthritis (OA) in different animal models and are promising in veterinary medicine for horses involved in competitive sport. The aim of this study was to characterize equine ASCs (eASCs) and investigate the role of interferon-gamma (IFNγ)-priming on their therapeutic effect in a murine model of OA, which could be relevant to equine OA. Methods: ASC were isolated from subcutaneous fat. Expression of specific markers was tested by cytometry and RT-qPCR. Differentiation potential was evaluat...
Ciscotto P, Machado de Avila RA, Coelho EA, Oliveira J, Diniz CG, Farías LM, de Carvalho MA, Maria WS, Sanchez EF, Borges A, Chávez-Olórtegui C.Venoms from the bee Apis mellifera, the caterpillar Lonomia achelous, the spiders Lycosa sp. and Phoneutria nigriventer, the scorpions Tityus bahiensis and Tityus serrulatus, and the snakes Bothrops alternatus, Bothrops jararaca, Bothrops jararacussu, Bothrops moojeni, Bothrops neuwiedi, Crotalus durissus terrificus, and Lachesis muta were assayed (800mug/mL) for activity against Staphylococcus aureus. Venoms from B. jararaca and B. jararacussu showed the highest S. aureus growth inhibition and also against other Gram-positive and Gram-negative bacteria. To characterize the microbicidal compon...
Södersten F, Ekman S, Schmitz M, Paulsson M, Zaucke F.Injuries of the equine superficial digital flexor tendon are common in racing horses. Knowledge of the tendon matrix composition is crucial to understand physiological and pathological processes in the tendon. The aim of this study was to analyze TSP-4 expressed in equine tendon. Equine tendons were extracted with 10 mM EDTA-containing buffer and TSP-4 purified with ion-exchange chromatography followed by heparin affinity chromatography. The purified TSP-4 was analyzed by one- and two-dimensional SDS-PAGE, immunoblotting, and MALDI-TOF mass spectrometry. Purified TSP-4 gave bands reacting with...
Hoyt DF, Wickler SJ, Cogger EA.Using published values for twelve species of birds and mammals, we investigated the effects of limb length and running speed on time of contact and step length. In addition, we measured the time of contact in horses trotting up a 10 % incline and when carrying a load averaging 19 % of their body mass. From these values, we calculated stride period and step length. Our analysis of the interspecific data yielded the following relationship between time of contact (t(c) in s) and leg length (L in m) and running speed (v in m s(-)(1)): t(c)=0.80L(0.84)/v(0.87) (r(2)=0.97). Both exponents in this re...
Mazerbourg S, Overgaard MT, Oxvig C, Christiansen M, Conover CA, Laurendeau I, Vidaud M, Tosser-Klopp G, Zapf J, Monget P.IGF binding protein-4 (IGFBP-4) proteolytic degradation is a common feature of preovulatory follicles from human, ovine, bovine, porcine, and equine ovary. In all these species, the protease is a zinc-dependent metalloprotease and its ability to degrade IGFBP-4 is IGF dependent. The human intrafollicular IGFBP-4-degrading protease has recently been identified as pregnancy-associated plasma protein-A (PAPP-A). The aim of this study was to investigate whether PAPP-A is also involved in IGFBP-4 degradation in ovine, bovine, porcine, and equine preovulatory follicles and to study the expression of...
Arregui L, Rathi R, Zeng W, Honaramooz A, Gomendio M, Roldan ER, Dobrinski I.Xenografting of testis tissue from immature males from several mammalian species to immunodeficient mouse hosts results in production of fertilization-competent sperm. However, the efficiency of testis tissue xenografting from adult donors has not been critically evaluated. Testis tissue xenografting from sexually mature animals could provide an option to preserve the genetic material from valuable males when semen for cryopreservation cannot be collected. To assess the potential use of this technique for adult individuals, testes from adult animals of six species (pig, goat, cattle, donkey, h...
Crevier-Denoix N, Collobert C, Pourcelot P, Denoix JM, Sanaa M, Geiger D, Bernard N, Ribot X, Bortolussi C, Bousseau B.The objective of this study was to mechanically characterise superficial digital flexor tendon (SDFT) lesions. Eight pathological SDFTs, isolated from 6 adult horses, were tested in traction until rupture (at 1 mm/s). The stresses and strains simultaneously undergone by each of the 7 segments of a tendon were determined throughout the test, and the modulus of elasticity of each segment was evaluated from the segmental stress-strain curve thus obtained. These mechanical data were compared to those obtained on 10 normal SDFTs. After the test, the tendinous segments were submitted to a histologic...
Rivero JL, Ruz A, Martí-Korff S, Estepa JC, Aguilera-Tejero E, Werkman J, Sobotta M, Lindner A.This study examined the effects of the intensity and duration of exercise on the nature and magnitude of training adaptations in muscle of adolescent (2-3 yr old) racehorses. Six thoroughbreds that had been pretrained for 2 mo performed six consecutive conditioning programs of varying lactate-guided intensities [velocities eliciting blood lactate concentrations of 2.5 mmol/l (v2.5) and 4 mmol/l (v4), respectively] and durations (5, 15, 25 min). Pre- and posttraining gluteus muscle biopsies were analyzed for myosin heavy chain content, fiber-type composition, fiber size, capillarization, and fi...
Swanson SP, Helaszek C, Buck WB, Rood HD, Haschek WM.The role of faecal and intestinal microflora on the metabolism of trichothecene mycotoxins was examined in this study. Suspensions of microflora obtained from the faeces of horses, cattle, dogs, rats, swine and chickens were incubated anaerobically with the trichothecene mycotoxin, diacetoxyscirpenol (DAS). Micro-organisms from rats, cattle and swine completely biotransformed DAS, primarily to the deacylated deepoxidation products, deepoxy monoacetoxyscirpenol (DE MAS) and deepoxy scirpentriol (DE SCP). By contrast, faecal microflora from chickens, horses and dogs failed to reduce the epoxide ...
Breckenridge WC, Kuksis A.The triglyceride compositions of the milk fats of man, dog, guinea pig, cow, sheep, goat, and horse were compared by gas-liquid chromatography of the intact triglycerides and of the butyl esters of the component fatty acids. The milk fats of man, dog, and guinea pig, which were largely made up of long-chain fatty acids, showed a common pattern with major contributions made by the glycerides with 48-54 acyl carbon atoms. The milk fats of cow, sheep, and goat, which were rich in short-chain acids, showed significant proportions of triglycerides with 28-54 acyl carbon atoms. Horse milk, which con...
Alghamdi AS, Foster DN, Troedsson MH.Seminal plasma (SP) is known to have immunosuppressive properties in several species. Equine SP has been reported to reduce or inhibit chemotaxis, phagocytosis and complement activity in vitro. The type and amount of the SP component that suppresses sperm-polymorphonuclear neutrophil (PMN) binding in vitro was determined, and the effect of such suppression on the fertility of mares inseminated in the presence of uterine inflammation, was analyzed. Sperm cells were suspended in either SP, semen extender or a mixture of both, and each was mixed with PMN-rich uterine secretions collected at 12 h ...
Baskurt OK, Farley RA, Meiselman HJ.Horse blood has a higher tendency to form red blood cell (RBC) aggregates compared with human blood, with this enhanced aggregation previously attributed to differences in plasma factors. Our results confirm this observation and further indicate that washed horse RBC also have a significantly higher aggregation tendency in dextran 70 solutions (i.e., horse RBC have a higher "aggregability"). In contrast, the aggregation tendency of rat RBC, both in autologous plasma and in dextran 70, is significantly less compared with human and horse RBC. Other rheological findings for horse and rat RBC incl...
Nichols AEC, Settlage RE, Werre SR, Dahlgren LA.Tendinopathies are common and difficult to resolve due to the formation of scar tissue that reduces the mechanical integrity of the tissue, leading to frequent reinjury. Tenocytes respond to both excessive loading and unloading by producing pro-inflammatory mediators, suggesting that these cells are actively involved in the development of tendon degeneration. The transcription factor scleraxis (Scx) is required for the development of force-transmitting tendon during development and for mechanically stimulated tenogenesis of stem cells, but its function in adult tenocytes is less well-defined. ...
Thorpe CT, Riley GP, Birch HL, Clegg PD, Screen HR.Some tendons, such as the human Achilles and equine superficial digital flexor tendon (SDFT), act as energy stores, stretching and recoiling to increase efficiency during locomotion. Our previous observations of rotation in response to applied strain in SDFT fascicles suggest a helical structure, which may provide energy-storing tendons with a greater ability to extend and recoil efficiently. Despite this specialization, energy-storing tendons are prone to age-related tendinopathy. The aim of this study was to assess the effect of cyclic fatigue loading (FL) on the microstructural strain respo...
Scholtzek AD, Hanke D, Walther B, Eichhorn I, Stöckle SD, Klein KS, Gehlen H, Lübke-Becker A, Schwarz S, Feßler AT.The detection of borderline oxacillin-resistant (BORSA) represents a challenge to both, veterinary and human laboratories. Between 2015 and 2017, 19 equine with elevated minimal inhibitory concentrations for oxacillin were detected in routine diagnostics. The aim of this study was to characterize these isolates to identify factors possibly associated with the BORSA phenotype. All were subjected to antimicrobial susceptibility testing and whole genome sequencing (WGS). A quantifiable β-lactamase activity assay was performed for a representative subset of 13 isolates. The WGS data analysis o...
Perez de Souza L, Naake T, Tohge T, Fernie AR.The grand challenge currently facing metabolomics is the expansion of the coverage of the metabolome from a minor percentage of the metabolic complement of the cell toward the level of coverage afforded by other post-genomic technologies such as transcriptomics and proteomics. In plants, this problem is exacerbated by the sheer diversity of chemicals that constitute the metabolome, with the number of metabolites in the plant kingdom generally considered to be in excess of 200 000. In this review, we focus on web resources that can be exploited in order to improve analyte and ultimately metabol...
Chauret N, Gauthier A, Martin J, Nicoll-Griffith DA.As domestic animals such as cat, horse, and dog increasingly become the clinical targets for drug discovery programs, the need to understand how these animals metabolize xenobiotics becomes more important. In the present study, substrates and inhibitors that were reported to be selective for particular P450 isozymes were used as probes to study in vitro metabolism in horse, dog, cat, and human liver microsomes. Seven selective catalytic activity markers for cytochrome P450-mediated reactions were measured: phenacetin O-deethylase (P4501A1/2), coumarin 7-hydroxylase (P4502A6), tolbutamide hydro...
