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.
Mizukami H, Suzuki T, Nambo Y, Ishimaru M, Naito H, Korosue K, Akiyama K, Miyata K, Yamanobe A, Nagaoka K, Watanabe G, Taya K.Development and endocrine changes in Thoroughbreds colts and fillies were compared between those reared at two facilities of the Japan Racing Association, the Hidaka Training and Research Center (Hidaka) and Miyazaki Yearling Training Farm (Miyazaki). Thoroughbred colts and fillies born in Japan between 2003 and 2010 were used. Each colt group and filly group was divided into 2 groups, respectively, and raised in Hidaka or Miyazaki for 7 months from September at 1 year old to April at 2 years old. For the growth parameters, the body weight, height at withers, and girth and cannon circumference...
Acha D, Hidalgo M, Ortiz I, Gálvez MJ, Carrasco JJ, Gómez-Arrones V, Dorado J.The aim of this study was to compare the effect of two semen extenders and four permeating cryoprotectants on post-thaw sperm quality of Andalusian donkeys. First, 32 ejaculates were pooled, split and frozen in either Gent B or INRA 96 with egg yolk and glycerol. Second, 12 pooled semen samples were simultaneously frozen in Gent B (glycerol) or Gent A containing ethylene glycol (EG; 1 or 1.5%) or dimethyl sulfoxide (DMSO; 1.5 or 2%). Finally, nine pooled samples were simultaneously cryopreserved in Gent A containing 1% EG (as control), dimethylformamide (DMFA; 1 or 2.5%) or a combination of 1%...
Pollitt CC, Collins SN.The suspensory apparatus of the distal phalanx (SADP) is functionally and clinically important. Objective: To investigate SADP form and function and the microanatomy of its insertion zone. Methods: Descriptive gross and microanatomy. Methods: The feet of 6 normal Standardbred horses were sectioned into blocks along the traditional perpendicular transverse axis and along functional axes of the SADP, decalcified and processed for staining with haematoxylin and eosin, Jones' periodic acid silver methenamine or Masson's trichrome stains. Results: In traditional midline toe transverse plane section...
Leipig M, Abenthum K, Wollanke B, Czupalla I, Esposito I, Steiger K, Hermanns W, Herbach N.A 16-year-old Friesian gelding with relapsing colic was humanely destroyed during diagnostic laparotomy due to suspected abdominal neoplasia. On post-mortem examination, the pancreas appeared as a firm mass (20 × 8 × 8 cm). The cut surface had a lobular structure with multiple cavities. Histological examination revealed severe chronic fibrosing pancreatitis with acinar-ductal metaplasia and duct dysplasia, which was considered to be the cause of the recurrent colic. Formation of tubular complexes within a background of acinar-ductal metaplasia is similar to the regressive lesions detect...
Potts S, Thatcher R, Jones AW, Warren LK, Tenbroeck SH, Nottage F, McEwan NR.Sweating is important in regulating body temperature but can be a source of loss of both fluids and electrolytes. Although the process has been studied in horses, the variation in sweat osmolarity across the body has not. Objective: This work describes an investigation to determine if there is regional variation in the osmolarity of sweat across different anatomical regions of the horse. Methods: Ten horses were used in the study and were animals either stabled for riding lessons or had livery on-site. Methods: Sweat samples were collected from five regions on each horse following exercise and...
Ferreira JC, Canesin HS, Ignácio FS, Rocha NS, Pinto CR, Meira C.The present experiment was divided into three studies to investigate the effect of age and endometrial degeneration on uterine blood flow of mares. In study 1, the influence of semen infusion and conception was evaluated using noninseminated (non-AI), inseminated nonpregnant (AI-NP), and inseminated pregnant (AI-P) mares (n = 7 mares/group). In study 2, the effect of age was investigated using young (≤6 years), adult (from 8 to 12 years), and old (≥15 years) pregnant mares (n = 7 mares/group). In study 3, uterine blood flow was also characterized in pregnant mares (n = 7 mares/group) with ...
Zsoldos RR, Licka TF.During both locomotion and body movements at stance, the head and neck of the horse are a major craniocaudal and lateral balancing mechanism employing input from the visual, vestibular and proprioceptive systems. The function of the equine neck has recently become the focus of several research groups; this is probably also feeding on an increase of interest in the equine neck in equestrian sports, with a controversial discussion of specific neck positions such as maximum head and neck flexion. The aim of this review is to offer an overview of new findings on the structures and functions of the...
Tanase M, Ambe Y, Aoi S, Matsuno F.Among quadrupedal gaits, the galloping gait has specific characteristics in terms of locomotor behavior. In particular, it shows a left-right asymmetry in gait parameters such as touchdown angle and the relative phase of limb movements. In addition, asymmetric gait parameters show a characteristic dependence on locomotion speed. There are two types of galloping gaits in quadruped animals: the transverse gallop, often observed in horses; and the rotary gallop, often observed in dogs and cheetahs. These two gaits have different footfall sequences. Although these specific characteristics in quadr...
Naylor RJ, Piercy RJ.To produce a clonal equine myoblast cell line that retains the ability to divide for multiple passages and differentiate into multinucleated myotubes during specific conditions. Methods: Cultured primary equine skeletal muscle-derived cells from a healthy Thoroughbred. Methods: Cell cultures were transfected by electroporation with a plasmid (pNIT) that expresses the temperature-sensitive simian vacuolating virus 40 large T antigen (TAg), which can be controlled by a doxycycline-responsive promoter. Cells that stably integrated the TAg were selected and expanded to passage 25. For each passage...
Aim of this study was to document the normal computed tomographic tenography findings of digital flexor tendon sheath. Six ex vivo normal equine forelimbs were used. An axial approach was used to inject 185 mg/mL of iopamidol in a total volume of 60 mL into the digital flexor tendon sheaths. Single-slice helical scans, with 5 mm thickness, spaced every 3 mm, for a pitch of 0.6, and with bone algorithm reconstruction, were performed before and after injections of contrast medium. To obtain better image quality for multiplanar reconstruction and 3D reformatting, postprocessing retrorecon...
Ríos DL, López C, Álvarez ME, Samudio IJ, Carmona JU.Platelet-rich plasma (PRP) preparations are a common treatment in osteoarthritis (OA) and inflammatory synovitis. However, there is ambiguity regarding the ideal concentration of leukocytes and platelets in these preparations necessary to induce an adequate anti-inflammatory and anabolic response in joint tissues, such as the synovial membrane. This research aimed to study, in normal synovial membrane explants (SME) challenged with lipopolysaccharide (LPS), the temporal effects (at 48 and 96h) of leukocyte- and platelet-rich gel (L-PRG) and pure platelet-rich gel (P-PRG) supernatants on the pr...
Still J.This study reports on clinically significant relief of pain along the gall bladder meridian in 15 sport horses. Both local and distant points were needled in this study. Pain relief was marked not only locally but also in remote areas along the gall bladder meridian. Clinical improvement was observed in all 15 horses within 30 seconds to 2 minutes after the treatment had started. Twelve horses and three horses were rated as "cured" and "improved", respectively, when they were re-examined 1-8 days after the treatment. The relief of somatic pain was often associated with improved riding perfor...
Nelis H, Wojciechowicz B, Franczak A, Leemans B, D'Herde K, Goossens K, Cornillie P, Peelman L, Van Soom A, Smits K.The oviduct undergoes dramatic functional and morphological changes throughout the oestrous cycle of the mare. To unravel the effects of steroids on the morphology, functionality and gene expression of the equine oviduct, an in vitro oviduct explant culture system was stimulated with physiological concentrations of progesterone and 17β-oestradiol. Four conditions were compared: unsupplemented preovulatory explants, preovulatory explants that were stimulated with postovulatory hormone concentrations, unsupplemented postovulatory explants and postovulatory explants that were stimulated with pre...
Brogan PT, Beitsma M, Henning H, Gadella BM, Stout TA.Short-term storage of equine sperm at 5°C in an extender containing milk and/or egg yolk components is common practice in the equine breeding industry. Sperm motility, viability, DNA integrity and, consequently, fertilizing ability decline over time, partly due to reactive oxygen species (ROS) generation. We investigated whether adding the anti-oxidant d-penicillamine to a commercial milk/egg yolk extender delayed the decrease in semen quality. Semen was recovered on four consecutive days from eight 3-year old Warmblood stallions. On day 5, seven of the stallions were castrated and sperm reco...
Natenstedt J, Kok AC, Dankelman J, Tuijthof GJ.Articular cartilage has limited regeneration capacities. One of the factors that appear to affect the in vitro cultivation of articular cartilage is mechanical stimulation. So far, no combination of parameters has been identified that offers the best results. The goal is to review the literature in search of the best available set of quantitative mechanical stimuli that lead to optimal in vitro cultivation.The databases Scopus and PubMed were used to survey the literature, and strict in- and exclusion criteria were applied regarding the presence of quantitative data. The review was performed b...
Smyth TT, Carmalt JL, Treen TT, Lanovaz JL.Diseases of the temporomandibular joint (TMJ) are well reported in man and some domestic animals other than the horse. The pathophysiology of equine TMJ disease and the effects of disease on the kinematics of mastication are unknown. Objective: To determine whether transient unilateral inflammation of the equine TMJ results in alterations in the masticatory cycle. Methods: An experimental controlled study utilising 6 horses of various ages with normal dentition. Methods: Each horse was equipped with an optical motion tracking (kinematic) system. Horses were observed chewing grass hay over 3 m...
Decloedt AI, Bailly-Chouriberry L, Vanden Bussche J, Garcia P, Popot MA, Bonnaire Y, Vanhaecke L.Traditionally, steroids other than testosterone are considered to be synthetic, anabolic steroids. Nevertheless, in stallions, it has been shown that β-Bol can originate from naturally present testosterone. Other precursors, including phytosterols from feed, have been put forward to explain the prevalence of low levels of steroids (including β-Bol and ADD) in urine of mares and geldings. However, the possible biotransformation and identification of the precursors has thus far not been investigated in horses. To study the possible endogenous digestive transformation, in vitro simulations of t...
Wilson B, Novakofski KD, Donocoff RS, Liang YX, Fortier LA.Telomere length and telomerase activity are important indicators of cellular senescence and replicative ability. Loss of telomerase is associated with ageing and the development of osteoarthritis. Implantation of telomerase-positive cells, chondrocytes, or stem cells expressing a normal chondrocyte phenotype is desired for cartilage repair procedures. The objective of this study was to identify at what age chondrocytes and at what passage bone marrow-derived mesenchymal stem cells (MSCs) become senescent based on telomerase activity. The effect of osteogenic protein-1 (OP-1) or interleukin-1α...
Flores FM, Dagnese F, Mota CB, Copetti F.Hippotherapy uses horseback riding movements for therapeutic purposes. In addition to the horse's movement, the choice of equipment and types of floor are also useful in the intervention. The quantification of dynamic parameters that define the interaction of the surface of contact between horse and rider provides insight into how the type of floor surface variations act upon the subject's postural control. Objective: To test whether different types of surfaces promote changes in the amplitude (ACOP) and velocity (VCOP) of the center of pressure (COP) displacement during the rider's contact wi...
Kutter AP, Bettschart-Wolfensberger R, Schwarzwald CC, Portier KG, Ringer SK.To evaluate the non-calibrated, minimally invasive cardiac output (CO) monitor FloTrac/Vigileo (FloTrac) against thermodilution (TD) CO in standing horses. Methods: Prospective, experimental trial. Methods: Nine adult horses weighing a median (range) of 535 (470-602) kg. Methods: Catheters were placed in the right atrium, pulmonary artery and carotid artery under local anaesthesia. CO was measured 147 times by TD and FloTrac and indexed to body weight. Changes in CO were achieved with romifidine or xylazine and dobutamine constant rate infusions. Bland-Altman analysis, concordance and polar pl...
Boemer F, Deberg M, Schoos R, Baise E, Amory H, Gault G, Carlier J, Gaillard Y, Marcillaud-Pitel C, Votion D.Hypoglycin A has been recently identified has the causal agent of atypical myopathy (AM) in horses. Its identification and quantification in equine's biological fluids is thus a major concern to confirm maple poisoning and to provide insight into the poorly understood mechanism of hypoglycin A intoxication. Methods: Quantification of hypoglycin A has been achieved with the aTRAQ kit for amino acid analysis of physiological fluids (AB Sciex). Acquisition method on mass spectrometer has been updated to record the hypoglycin A specific MRM transition. Results: Outlined accuracy profiles demonstra...
Thorpe CT, McDermott BT, Goodship AE, Clegg PD, Birch HL.Advancing age is a well-known risk factor for tendon disease. Energy-storing tendons [e.g., human Achilles, equine superficial digital flexor tendon (SDFT)] are particularly vulnerable and it is thought that injury occurs following an accumulation of micro-damage in the extracellular matrix (ECM). Several authors suggest that age-related micro-damage accumulates due to a failure of the aging cell population to maintain the ECM or an imbalance between anabolic and catabolic pathways. We hypothesized that ageing results in a decreased ability of tendon cells to synthesize matrix components and m...
Beccati F, Pepe M, Pascucci L, Ceccarelli P, Chiaradia E, Mancini F, Mandara MT.The purpose of this study was to delineate the pattern of sympathetic innervation in the suprasesamoidean region of the deep digital flexor tendon (DDFT) in horses using immunohistochemical staining (IHC) for tyrosine hydroxylase (TH) and alpha-1 adrenergic receptor (α1-AR). Fourteen forelimbs were collected from 10 horses. Longitudinal sections of the suprasesamoidean region of healthy DDFTs were harvested. Most of the sympathetic innervation was found to be in the walls of blood vessels. The tendon tissue proper was sparsely innervated, with a lesser degree of innervation within the dorsal ...
Douglas HF, Southwood LL, Meyer-Ficca ML, Hart SK, Meyer RG.To evaluate the poly (ADP-ribose) polymerase-1 (PARP1) enzyme and its inhibition in horses and explore its potential as a novel therapeutic target for equine intestinal ischemia-reperfusion injury by (1) identifying poly (ADP-ribose) (PAR) as an indication of PARP1 activation in equine cells using available immunoblot analytical techniques, (2) inducing PARP1 activation in an in vitro oxidative DNA damage model, (3) and demonstrating the inhibition of PARP1 in equine cells using commercially available PARP1 inhibitors. Methods: Experimental study. Methods: Blood samples were collected from sys...
Uzal FA, Diab SS.The gastrointestinal system of horses is affected by a large variety of inflammatory infectious and noninfectious conditions. The most prevalent form of gastritis is associated with ulceration of the pars esophagea. Although the diagnostic techniques for alimentary diseases of horses have improved significantly over the past few years, difficulties still exist in establishing the causes of a significant number of enteric diseases in this species. This problem is compounded by several agents of enteric disease also being found in the intestine of clinically normal horses, which questions the va...
Unilateral orchiectomy (UO) may interfere with thermoregulation of the remaining testis caused by inflammation surrounding the incision site, thus altering normal spermatogenesis and consequently sperm quality. Two measures of sperm DNA quality (neutral comet assay and the sperm chromatin structure assay [SCSA]) were compared before UO (0 days) and at 14, 30, and 60 days after UO to determine whether sperm DNA changed after a mild testis stress (i.e., UO). The percent DNA in the comet tail was higher at 14 and 60 days compared to 0 days (P < 0.05) after UO. All other comet tail measures (i....
Badenhorst M, Page P, Ganswindt A, Laver P, Guthrie A, Schulman M.The prevalence of equine herpesvirus types-1 and -4 (EHV-1 and -4) in South African Thoroughbreds at auction sales is currently undefined. Commingling of young Thoroughbreds from various populations together with physiological stress related to their transport and confinement at a sales complex, may be associated with shedding and transmission of EHV-1 and -4. This prospective cohort study sampled 90 young Thoroughbreds consigned from eight farms, originating from three provinces representative of the South African Thoroughbred breeding demographic to a sales complex. Nasal swabs for quantitat...
Peña FJ, Plaza Davila M, Ball BA, Squires EL, Martin Muñoz P, Ortega Ferrusola C, Balao da Silva C.The traditional assessment of stallion sperm comprises evaluation of sperm motility and membrane integrity and identification of abnormal morphology of the spermatozoa. More recently, the progressive introduction of flow cytometry is increasing the number of tests available. However, compared with other sperm structures and functions, the evaluation of mitochondria has received less attention in stallion andrology. Recent research indicates that sperm mitochondria are key structures in sperm function suffering major changes during biotechnological procedures such as cryopreservation. In this p...
Chintapalli SV, Bhardwaj G, Patel R, Shah N, Patterson RL, van Rossum DB, Anishkin A, Adams SH.The mechanism(s) by which fatty acids are sequestered and transported in muscle have not been fully elucidated. A potential key player in this process is the protein myoglobin (Mb). Indeed, there is a catalogue of empirical evidence supporting direct interaction of globins with fatty acid metabolites; however, the binding pocket and regulation of the interaction remains to be established. In this study, we employed a computational strategy to elucidate the structural determinants of fatty acids (palmitic & oleic acid) binding to Mb. Sequence analysis and docking simulations with a horse (E...
Ringer SK, Lischer CJ, Ueltschi G.To monitor the effect of focused extra-corporeal shock wave therapy (ESWT) on bone and bone-tendon junction of horses without lameness by use of nuclear scintigraphy and thermography. Methods: 6 warmblood horses without lameness. Methods: The origin of the suspensory ligament at the metacarpus (OSL-MC) and the fourth metatarsal bone were treated at 2 time points (days 0 and 16) with 2,000 shocks applied by a focused ESWT device at an energy flux density of 0.15 mJ/mm2. One forelimb and 1 hind limb were treated, and the contralateral limbs served as controls. To document the effect of focused E...
Berg EL, McNamara DL, Keisler DH.The aim of this study was to characterize concentrations of leptin, IGF-I, and thyroid stimulating hormone (TSH) in the blood serum of mares pre-and postpartum, in the milk serum of mares postpartum, and in the blood serum of their foals. Nine pregnant Quarter Horse mares and their offspring were used in this study. Once weekly between 1000 and 1200 h for 2 wk before their predicted parturition date, mares were weighed, assigned a BCS, and blood was sampled via jugular venipuncture. Within 2 h of parturition and before the foals nursed (d 0), blood samples were obtained from the mares and foal...
Brama PA, TeKoppele JM, Beekman B, van Weeren PR, Barneveld A.To investigate the influence of age, osteoarthritis (OA), and osteochondrosis (OC) on the matrix metalloproteinase (MMP) activity in the synovial fluid (SF) of equine joints. Methods: SF was collected from normal and osteoarthritic metacarpophalangeal joints (normal: 14 adult, 28 juvenile; OA: 22 adult). And from normal and osteochondrotic tarsocrural joints (5 months: 11 normal, 8 OC; 11 months: 7 normal, 6 OC). Subsequently, overall MMP activity was measured. Results: The level of active MMPs was almost twofold higher in SF from juvenile horses (age up to 11 months) than in SF from mature an...
Yamada M, Gentry PA.The coagulation factors VII and X and fibrinogen were detected in equine ovarian follicular fluid. The amounts of fibrinogen and factor X were approximately 40 percent of that found in normal equine plasma while the level of factor VII was lower, at approximately 14 percent. The addition of human recombinant tissue factor caused fibrin formation in the follicular fluid. The thrombin generating activity appears to be confined to the tissue factor pathway since no activity associated with factors VIII:C, IX or IX was detected. Fibrinolytic activity, at higher levels than that found in plasma, wa...
De Wael K, De Belder S, Van Vlierberghe S, Van Steenberge G, Dubruel P, Adriaens A.The aim of this paper is to emphasize the strength of gelatin as a stable matrix for redox enzymes. Cyclic voltammetry has been applied for a detailed electrochemical study of horse heart cytochrome c (HHC) entrapped in a gelatin matrix immobilized on a gold electrode. The influence of the HHC concentration, the mass percentage of the gelatin and the nature of the gelatin on the electrochemical behaviour of HHC have been described in detail. In addition, attenuated total reflection infrared (ATR-IR) spectroscopy was used to prove the immobilization on a qualitative and conformational level. Th...
Svistunenko DA, Sharpe MA, Nicholls P, Wilson MT, Cooper CE.A new method of EPR spectral analysis is developed to quantitate overlapping signals. The method requires double integration of a number of spectra containing the signals in different proportions and the subsequent solution of a system of linear equations. The result gives the double integral values of the individual lines, which can then be further used to find the concentrations of all the paramagnetic species present. There is no requirement to deconvolute the whole spectrum into its individual components. The method is employed to quantify different heme species in methemoglobin and metmyo...
Bayless RL, Cooper BL, Sheats MK.Plasma cell-free DNA (cfDNA) is a biomarker of ischemia, systemic inflammation, and mortality in humans with gastrointestinal disease. Cell-free DNA has not been investigated as a biomarker for equine colic, to our knowledge. We hypothesized that cfDNA could be measured accurately in neat equine plasma using a benchtop fluorometer and that plasma cfDNA would be elevated in emergency patients compared to healthy horses. Plasma was obtained from blood collected in Roche DNA stabilizing tubes. We used the Qubit 4 fluorometer and 1× dsDNA HS assay kit to measure cfDNA concentration in neat patien...
Tukov FF, Rimoldi JM, Matthews JC.Repin, a major constituent in extracts of the plant Centaurea repens is thought to be the active principal responsible for the development of equine nigropallidal encephalomalacia (ENE), a fatal Parkinson-like neurodegenerative disorder in horses. Although the exact mechanism by which ingestion of this weed causes ENE is uncertain, a limited body of experimental evidence suggests a critical role for the glutathione redox system. In the present study, the mechanism of repin neurotoxicity was examined in PC12 cells with a focus on determining the role of glutathione (GSH) in repin-induced mitoch...
Lindholm A, Saltin B.LINDHOLM, ARNE and BENGT SALTIN: The physiological and biochemical response of standardbred horses to exercise of varying speed and duration. Acta vet. scand. 1974, 15, 310–324. — Welltrained standardbred horses were studied to examine the metabolic response to excercise of various speeds and duration. Comparisons between interval (400, 700, 1,000 and 2,000 m) and continuous trotting (1 hr., 2 hrs.) and racing were made. Muscle and rectal temperatures were recorded before and immediately after each work bout. Heart rate was linearly related to trotting speed, and maximal heart rate (240 be...
Pasing S, von Lewinski M, Wulf M, Erber R, Aurich C.The aim of this study was to evaluate the stress response of stallions (n = 16) aged 3-13 years with previous sexual experience to semen collection by determination of heart rate, heart rate variability, and cortisol in saliva. Recordings were done on two consecutive days. The time intervals from leaving the box until arrival in the collection barn and from first exposure to the teaser mare until ejaculation as well as the number of mounts until ejaculation were neither affected by collection day nor by age, sexual experience (i.e., the number of breeding seasons the stallion experienced), or ...
Chang M, Zhang F, Shen L, Pauss N, Alam I, van Breemen RB, Blond SY, Bolton JL.The risk factors for women developing breast and endometrium cancers are all associated with a lifetime of estrogen exposure. Estrogen replacement therapy (ERT) in particular has been correlated with a slight increased cancer risk, although the numerous benefits of ERT may negate this harmful side effect. Equilenin and equilin are equine estrogens which make up between 30% and 45% of the most widely prescribed estrogen replacement formulation, Premarin (Wyeth-Ayerst). In this study we have synthesized the catechol metabolites of equilenin [4-hydroxyequilenin (4-OHEN)] and equilin [4-hydroxyequ...
Szcześniak KA, Ciecierska A, Ostaszewski P, Sadkowski T.Adult skeletal muscle myogenesis depends on the activation of satellite cells that have the potential to differentiate into new fibers. Gamma-oryzanol (GO), a commercially available nutriactive phytochemical, has gained global interest on account of its muscle-building and regenerating effects. Here, we investigated GO for its potential influence on myogenesis, using equine satellite cell culture model, since the horse is a unique animal, bred and exercised for competitive sport. To our knowledge, this is the first report where the global gene expression in cultured equine satellite cells has ...
Upjohn MM, Archer RM, Christley RM, McGowan CM.A telephone survey of 51 National Hunt racing yards with 1140 horses in training was made in April and May 2003 to establish the incidence of exertional rhabdomyolysis syndrome during the previous year. A case-control study was used to investigate the risk factors for the syndrome in eight yards selected on the basis that cases had been confirmed by the analysis of serum muscle enzymes. The overall incidence of syndrome was 6.1 cases per 100 horses per year, and 55 per cent of the yards reported at least one case. The risk factors identified were sex, the average length of the training gallop,...
Crossett B, Suire S, Herrler A, Allen WR, Stewart F.One of the major, progesterone-dependent proteins secreted into the uterine lumen of the mare is a 19-kDa lipocalin (P19). It associates strongly with the embryonic capsule that envelops the young horse conceptus in early gestation, suggesting that it may be involved in sustaining early development. However, it was not known whether the protein was transported through the capsule and/or trophoblast layer and into the yolk sac cavity. To address this question, polyclonal antisera were raised against a C-terminal peptide (based on the deduced amino acid sequence of P19) and a recombinant-derived...
Holmes LC, Gaughan EM, Gorondy DA, Hogge S, Spire MF.Infrared thermography is an imaging modality gaining popularity as a diagnostic aid in the evaluation of equine lameness. Anecdotal reports of skin hyperthermia induced by local anesthesia, detected by thermography, have been made; however, no controlled studies have been reported. The purpose of this study was to examine the effects of perineural anesthesia on infrared thermographic images of the forelimb digits in normal horses. After environmental acclimation, infrared thermographs were made at intervals of 0, 5, 10, 15, 30, and 45 min from administration of mepivacaine hydrochloride or pho...
Kilic S, Dixon PM, Kempson SA.Ultrastructural examinations showed the diameter of cement lacunae to be greater in infundibular cement than in peripheral cement of upper cheek teeth, which in turn was greater than in the peripheral cement of the lower cheek teeth. However, numbers of lacunae/unit area remained similar in these 3 dentinal region. Two types of cemental hypoplasia were found in equine cheek teeth. The first type was termed central infundibular cemental hypoplasia and was confined to the central region of infundibular cement. The cement adjacent to these frequently large defects was very porous and contained la...
Griggers S, Paccamonti DL, Thompson RA, Eilts BE.Urospermia has been reported as a cause of infertility in numerous species. The detrimental effects of urine on spermatozoa are due, at least in part, to changes in pH and osmolarity. Semen was collected and subjected to conditions of varying pH (Experiment 1), of varying osmolarity (Experiment 2), and various quantities and concentrations of urine (Experiment 3) and effects on motility were recorded. Finally, semen was contaminated with urine and then either of 2 semen extenders was added, with or without centrifugation, in an attempt to alleviate the detrimental effect of urine on motility (...
Janis CM, Constable EC, Houpt KA, Streich WJ, Clauss M.It is often assumed that horses chew food more intensively during ingestion than cattle, which - as ruminants - complete part of the mastication during rumination. This has been proposed as a reason for more robust mandibles, larger masseter insertion areas and larger masseter muscles in horses as compared to cattle and other grazing ruminants. In this study, we evaluate results of comparative feeding trials with three horses (338-629 kg) and three cows (404-786 kg), on four different roughages. Ingestion time (s/g dry matter) and chewing intensity (chews/g dry matter) differed among animals w...
Klein C.Relaxin is a peptide hormone best known for its action during the latter half of pregnancy, in particular for its softening effect on pelvic ligaments that aids in preparation of the birth canal for the impending delivery of the fetus. The source of relaxin during early pregnancy varies across species, with the CL being the main source in a number of species. The main source of relaxin during late equine pregnancy is the placenta. In mares with impaired placental function, circulating relaxin levels decline before abortion. During early pregnancy, relaxin promotes endometrial angiogenesis thro...
Daradka M, Pollitt CC.Current theories explaining how the hoof wall 'grows' and moves past the stationary distal phalanx are speculative and based on incomplete evidence. Movement in the lamellar region could occur by cell proliferation or an enzyme-based remodelling process. Since laminitis pathogenesis appears to involve increased transcription and activation of enzymes normally involved in tissue remodelling, it is important to know precisely which process dominates the lamellar region of the hoof.. Objective: To investigate epidermal cell proliferation in the equine hoof wall and calculate a proliferative index...
Burger D, Dolivo G, Wedekind C.Sperm competition theory predicts semen characteristics to be affected by the social environment. We used the polygamous horse (Equus caballus) to experimentally study within-subject plasticity in response to different social environments. Stallions were sequentially exposed, over a period of 8 weeks each, to other stallions and then singly to mares, or vice versa (in adjacent boxes separated by grills). Ejaculates were collected to determine semen characteristics. Highest sperm numbers were found in stallions that were first exposed to other stallions and then to mares, while lowest sperm num...
Pösö AR, Viljanen-Tarifa E, Soveri T, Oksanen HE.Effects of graded intensity exercise on plasma lipids was studied in Standardbred and Finnishbred Trotters. The rate of lipolysis indicated by the elevated plasma concentrations of glycerol increased parallel with the intensity of the trot in the Standardbreds, but not as clearly in the Finnishbred trotters. During the exercise plasma triglyceride concentration increased significantly and the increase correlated with the intensity of the exercise as well as the activity of lipolysis. Together with the increase in plasma triglycerides, there was a parallel increase in the pre-beta fraction of l...
Marunova E, Hoenecke K, Fiske-Jackson A, Smith RKW, Bolt DM, Perrier M, Gerdes C, Hernlund E, Rhodin M, Pfau T.Evaluation of diagnostic anesthesia during equine lameness examination requires comparison of complex movement patterns and can be influenced by expectation bias. There is limited research about how changes in movement asymmetries after successful analgesia are affected by different exercise conditions. Movement asymmetry of head, withers and pelvis was quantified in N = 31 horses undergoing forelimb or hindlimb diagnostic anesthesia. Evaluation on a straight line and a circle was performed with subjective diagnostic anesthesia outcome and quantitative changes recorded. Mixed linear mode...
Schwarzenberger F, Möstl E, Bamberg E, Pammer J, Schmehlik O.Faecal samples were collected at weekly intervals from pregnant Lipizzan mares during Weeks 7-16 following mating and from Lipizzan, Trotter and Thoroughbred mares during the last 3 months of gestation. After parturition, samples were taken daily from the Thoroughbred mares for another 6 days. Non-pregnant mares served as controls. The concentrations of unconjugated oestrogens (Eg), 20 alpha-OH-progestagens (20 alpha-G) and 20 beta-OH-progestagens (20 beta-G) were measured by enzyme immunoassay. In the faeces of Lipizzan mares, immunoreactive progestagens were significantly (P less than 0.01) ...
Khlifaoui M, Battut I, Bruyas JF, Chatagnon G, Trimeche A, Tainturier D.The cryoprotective effect of l-glutamine and an approach of its mechanism of action, in preserving motility of stallion spermatozoa during the freezing-thawing process, were studied. In Experiment 1, thirty-six ejaculates were collected from six stallions (two good, two middle, and two of poor sperm freezability) and were diluted with 10 different freezing media derived from INRA 82 medium supplemented with 20 mM HEPES and 2% (v/v) centrifuged egg yolk (BM). After thawing, sperm motility was evaluated by a computer-assisted semen motility analyser. The effects of glutamine and glycerol at diff...
Schmidt K, Deichsel K, de Oliveira RA, Aurich J, Ille N, Aurich C.We hypothesized that housing of stallions in a thermoneutral temperature zone during autumn and winter does not only influence metabolism and hair shedding but also improves the characteristics of raw and processed semen. Fertile Shetland pony stallions were followed from October to June. This time coincided with the seasons autumn, winter and spring. Ponies were kept in outside paddocks (group CON, n = 8) or in indoor stables (group ST, n = 8) from October to March when ST stallions returned to outdoor paddocks, but ponies remained in the same groups. The rectal temperature was measured o...
Morris EA, McDonald BS, Webb AC, Rosenwasser LJ.Interleukin-1 (IL-1) is a protein secreted by stimulated cells of the monocyte-macrophage line, which has a number of important biologic activities. Interleukin-1 has been implicated in the induction and augmentation of the pathologic processes involved in arthritis and articular cartilage destruction. Horses develop osteoarthritis with a frequency and degree of severity similar to human beings. To further document the similarity of the osteoarthritic process in people and horses, the synovial fluid from 5 horses with clinical osteoarthritis was tested for IL-1 bioactivity. Interleukin-1 activ...
Muhonen S, Sadet-Bourgeteau S, Julliand V.Fibrous feeds are essential for horses. When developing feeding regimens promoting health and performance, we need to understand the digestion of plant cell walls and the functioning of the hindgut microbial ecosystem. Our objective was to investigate the effect of grass fibre maturity and legume forage on the hindgut microbiota and its activity. Six caecum and colon fistulated geldings were fed three diets differing in fibre composition: concentrate and late harvested grass haylage (35:65 energy ratio) (C); early and late harvested grass haylage (80:20) (G); lucerne and late harvested grass h...
Zedda M, Lepore G, Biggio GP, Gadau S, Mura E, Farina V.A high number of differences exist in bone histological features depending on the species, breed, age and bone. Moreover, osteon distribution may vary in the different sides of a bone as a consequence of different biomechanical strains. The aim of this work was to study the distribution and morphology of osteons in different sides of the equine femoral diaphysis with the attempt to correlate them to the main strains operating on them. The following parameters of secondary osteons and Haversian canals were measured in the transverse sections of diaphyses: perimeter, area, minimum and maximum di...
Jordana J, Folch P, Cuenca R.Twelve clinical biochemical parameters were determined in 97 animals of all age groups and both sexes of the endangered Catalonian donkey breed. Significant sex differences were observed for phospholipid concentration (P<0.01). Evaluating the effect of management practices on the various parameters showed significant differences for total bilirubin (P<0.001) and creatinine (P<0.05) concentrations and gamma-glutamyltransferase (P<0.05) activity. Moreover, it was observed that inorganic phosphorus concentration decreased with age (P<0.001), whereas albumin and triglyceride concent...
