Equine diseases encompass a wide range of health conditions that can affect horses, including infectious diseases, metabolic disorders, and genetic conditions. These diseases can impact the overall health, performance, and well-being of horses. Common equine diseases include equine influenza, equine herpesvirus, laminitis, and equine metabolic syndrome. Diagnosis and management of these diseases often require a combination of clinical evaluation, laboratory testing, and appropriate treatment strategies. This page gathers peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnosis, and treatment options for various equine diseases, providing valuable insights for veterinarians and researchers in the field.
Scott R, Nankervis K, Stringer C, Westcott K, Marlin D.Water treadmill exercise is often incorporated into rehabilitation programmes for horses yet little is known about the biomechanical and physiological responses to water walking. Objective: To establish whether stride frequency (SF) reached steady state as a result of 6 introductory water treadmill sessions and then to investigate the effect of increasing water height on SF, stride length (SL) and heart rate (HR). Methods: Nine horses with no previous experience of water treadmills completed 6 sessions of walking for between 15 and 30 min. Each horse was fitted with a leg mounted accelerometer...
Sleutjens J, Voorhout G, Van Der Kolk JH, Wijnberg ID, Back W.In dressage, the head and neck position has become an issue of concern as certain extreme positions may imply a welfare risk for the horse. In man, extension and flexion of the cervical spine cause a decrease and increase in intervertebral foramina dimensions, respectively. However, in horses, the influence of flexion and extension on foramina dimensions and its possible interference with peripheral nerve functioning remains unknown. Objective: To determine the effect of ex vivo flexion and extension on intervertebral foramina dimensions in the equine cervical spine. Methods: Computed tomograp...
Jönsson L, Dalin G, Egenvall A, Näsholm A, Roepstorff L, Philipsson J.Disturbances in skeletal development, primarily osteochondrosis (OC) and palmar/plantar osseous fragments (POF), have been commonly reported as problems in young horses. However, there are few reports of such findings for epidemiological analyses or breeding purposes. Objective: To evaluate equine hospital data as a possible source of information for genetic evaluations by estimating prevalence and heritability of OC in the stifle, hock and fetlock joints and of POF in the fetlock. Methods: Data on Swedish Warmblood (SWB) horses were obtained from a large equine hospital in south Sweden. Preva...
Zsoldos RR, Groesel M, Kotschwar A, Kotschwar AB, Licka T, Peham C.The motion of the atlanto-occipital, cervical vertebral and cervicothoracic joints play an important role in equestrian sports and they are also common sites for lesions limiting performance in horses. Objective: To calculate inverse kinematics based on cervical vertebral motion and to develop a model close to the measured neck movements. Methods: Measurements were recorded in 6 horses without neck pain. Reflective markers were placed on both cristae facialis, both sides of cervical vertebra 1, 3 and 6 on the withers and hooves. The neck model was reconstructed from CT scans of the osseus stru...
Silver IA, Jeffcott LB, Rossdale PD.The British Equine Veterinary Association (BEVA) was established in 1961 and launched the Equine Veterinary Journal (EVJ) in 1968. This review outlines some of the major advances in equine science and practice that have occurred in that time and the role played by the Journal in facilitating those developments.
Thomsen MH, Persson AB, Jensen AT, Sørensen H, Andersen PH.Equine lameness examination is based on subjective visual scoring of lameness. Instrumented objective methods for lameness examinations may be complicated to perform and the equipment is often stationary. Accelerometry has a potential clinical use; however, the reduction and interpretation of equine accelerometric data are not yet routine and the value of accelerometry in equine lameness examination is unclear. Objective: To use accelerometric data to calculate 2 different accelerometric symmetry scores and to evaluate the agreement of these with traditional lameness scores done by experienced...
Lejeune JP, Sandersen C, Votion D, Caudron I, Vander Heyden L, Franck T, Ceusters J, Mouithys-Mickalad A, Niesten A, De La Rebière de Pouyade G....Intensive exercise induces a systemic inflammatory response characterised by an increase of blood neutrophil count and myeloperoxidase (MPO) release. Neutrophil elastase (NE) could also contribute to tissues lesions by its proteinase activities. Objective: To compare plasmatic NE concentrations before and after different forms of intensive exercise. Methods: EDTA blood samples were taken from 51 eventing horses (EvH) and 32 endurance horses (EndH) were sampled before the race (T0). Blood sampling was performed 2 h (T1) after completing either phase D of a one or 2 star eventing competition (n ...
Haussler KK, Martin CE, Hill AE.Spinal mobilisation and spinal manipulative therapy (SMT) are being applied to horses; however, there are limited objective measures of their effects on spinal mobility or stiffness in actively ridden horses. Objective: To quantify passive spinal movements induced during dorsoventral mobilisation of the trunk and to identify any potential effects of SMT on measures of spinal mobility within the thoracolumbar region in standing horses. We hypothesise that displacement amplitudes will be significantly increased across vertebral levels after SMT, compared to spinal mobilisation only within the co...
Thorpe CT, Stark RJ, Goodship AE, Birch HL.Damage to the flexor tendons, particularly the superficial digital flexor tendon (SDFT), is one of the most common musculoskeletal injuries sustained by horses competing in all disciplines. Our previous work has shown that SDFTs from different individuals show a wide variation in mechanical strengths; this is important clinically as it may relate to predisposition to injury. The high mechanical strength of tendon relies on the correct orientation of collagen molecules within fibrils and stabilisation by the formation of chemical cross-links between collagen molecules. It is not known whether t...
Franck T, Votion DM, Ceusters J, De La Rebière de Pouyade G, Mouithys-Mickalad A, Niesten A, Fraipont A, VAN Erck E, Goachet AG, Robert C, Serteyn D.Intense exercise in horses induces an increase of creatine kinase (CK) and stimulation of neutrophils which release the strong oxidant enzyme, myeloperoxidase (MPO) into the blood. It is not known whether active MPO is found in equine muscles and whether oxidant activity of neutrophils could affect muscular tissues and mitochondrial activity. Objective: Specific immuno-extraction followed by enzymatic detection (SIEFED) methods will be employed for the first time to assess both the normal range of MPO and mitochondrial complex I (MCI) activities in equine muscular microbiopsies and to study th...
Geor RJ, Stewart-Hunt L, McCutcheon LJ.There is limited information about factors regulating glucose utilisation post exercise in horses. Objective: To determine the effects of a single bout of moderate intensity exercise on measures of insulin-mediated (IMGU) and noninsulin-mediated (NIMGU) glucose uptake during a hyperglycaemic clamp (HC). Methods: Hyperglycaemic clamps were administered in random order to 8 Standardbreds under 4 conditions: 1) rest, insulinopenia (R-L); 2) rest, hyperinsulinaemia (R-H); 3) post exercise (45 min at ∼ 50% VO2peak), insulinopenia (Ex-L) and 4) post exercise, hyperinsulinaemia (Ex-H). In the R-L a...
McKane SA, Slocombe RF.Histological studies of exercise-induced pulmonary haemorrhage (EIPH) reveals inflammatory infiltrates within areas of lung that contain haemorrhage. This has resulted in the hypothesis that pulmonary inflammation could cause EIPH or contribute to an increased risk or severity of EIPH. Objective: To determine whether experimentally-induced pulmonary inflammation predisposes the lung to haemorrhage during exercise, by evaluating the bronchoalveolar lavage (BAL) cytology of normal and inflamed regions of lung following high speed treadmill exercise. Methods: Transendoscopic airway inoculations o...
Courouce-Malblanc A, Deniau V, Rossignol F, Corde R, Leleu C, Maillard K, Pitel PH, Pronost S, Fortier G.Dorsal displacement of the soft palate (DDSP) is one of the most common obstructive conditions of the upper respiratory tract in the racehorse. This condition has a complex aetiology which may be caused or exacerbated by pharyngeal inflammation. Additionally, lower respiratory airway diseases may be associated with DDSP thereby contributing to exercise intolerance in these horses. Objective: The aim of this study was to measure physiological variables during a standardised exercise test and to assess the prevalence and consequences of lower respiratory airway disease in horses with DDSP. Metho...
Trachsel DS, Bitschnau C, Waldern N, Weishaupt MA, Schwarzwald CC.Frequent supraventricular or ventricular arrhythmias during and after exercise are considered pathological in horses. Prevalence of arrhythmias seen in apparently healthy horses is still a matter of debate and may depend on breed, athletic condition and exercise intensity. Objective: To determine intra- and interobserver agreement for detection of arrhythmias at rest, during and after exercise using a telemetric electrocardiography device. Methods: The electrocardiogram (ECG) recordings of 10 healthy Warmblood horses (5 of which had an intracardiac catheter in place) undergoing a standardised ...
McKenzie EC, Garrett RL, Payton ME, Riehl JH, Firshman AM, Valberg SJ.Dantrolene sodium is used to prevent exertional rhabdomyolysis in predisposed horses. Food intake might negatively impact dantrolene bioavailability in horses; however, prolonged feed restriction might be detrimental to performance. Objective: To determine a minimum duration of feed restriction that would optimise plasma dantrolene concentrations in horses after nasogastric administration. It was hypothesised that feed restriction for 4, 8 or 12 h before dantrolene administration would result in higher plasma dantrolene concentrations than achieved with no feed restriction before treatment. Me...
Clayton HM, Kaiser LJ, Lavagnino M, Stubbs NC.Based upon human data, it is probable that many conditions associated with neck pain in horses may benefit from performing mobilisation exercises as part of the rehabilitation protocol. Objective: To compare sagittal plane intervertebral angulations in a neutral standing position with the angulations at end range of motion in 3 dynamic mobility exercises performed in cervical flexion. Methods: Sagittal plane motion of the head, neck and back were measured in 8 sound horses standing in a neutral position and in 3 end-of-range neck flexion positions: chin-to-chest, chin-between-carpi, and chin-b...
Barrey E.Equine breeding selection has been developed by applying quantitative genetic methods for calculating the heritability of the complex traits such as performance in racing or sport competitions. With the great development of biotechnologies, equine molecular genetics has come of age. The recent sequencing of the equine genome by an international consortium was a major advance that will impact equine genomics in the near future. With the rapid progress in equine genetics, new applications in early performance evaluation and the detection of disease markers become available. Many new biomolecular...
Byström A, Stalfelt A, Egenvall A, Von Peinen K, Morgan K, Roepstorff L.Saddle fit is well recognised as an important factor for the health and performance of riding horses. However, only few studies have addressed general effects of different saddle construction details within a group of horses. Objective: To assess the influence of girth strap placement, traditional vs. v-system, and panel flocking material, wool vs. synthetic foam, on the saddle pressure pattern during riding. Methods: Six horses were ridden by 3 riders in sitting and rising trot and sitting canter. Saddle pressure was measured with 3 different saddle variants: 1) wool flocked panels and tradit...
Lawson SE, Marlin DJ.The function of the forelimb is fundamental to understanding both sound and pathological locomotion. The precise movements of the equine shoulder are hidden by layers of skin and muscle and hence the shoulder is normally modelled as a simple pivot during locomotion which assumes that any translational motion is negligible. Objective: To record and quantify the sliding motion of the scapula during locomotion, using a novel imaging technique. Methods: Scapula motion during locomotion in the horse was calculated by tracking the ripple of the shoulder blade's movement under an array of markers pla...
Ramseyer A, Sides R, Slinker B, Evans D, Bayly W.The ability to obtain breath-by-breath measures of ventilatory mechanics for the entirety of an exercise test, regardless of speed(s) or duration enables evaluations of equine ventilation during exercise that are necessary for assessments of performance. Objective: Evaluation of a new ergospirometer (Quadflow; QF) system's accuracy and repeatability for measuring pulmonary variables in contrast to the established pneumotachometer-based system (control) and assessment of its effects, if any, on exercise capacity at high speeds. Methods: Five Thoroughbred horses each performed 10 incremental exe...
Allen KJ, Franklin SH.Overground endoscopy is being performed with increasing frequency in the UK. A previous study has shown that the type of exercise test may affect the diagnosis of upper respiratory tract (URT) obstructions. The successful clinical application of overground endoscopy systems requires understanding of appropriate field exercise testing protocols. Objective: The aim of this study was to report the exercise test parameters used during overground endoscopy in UK Thoroughbred racehorses and to investigate potential effects of these on the diagnosis of URT obstructions. Methods: The exercise test par...
Sloet van Oldruitenborgh-Oosterbaan MM, Genzel W, van Weeren PR.Welfare concerns over the reasons for interruption or termination of a sporting career in horses have been expressed. Objective: To study the career of competition horses and factors that influence career length. Methods: In 2004, 46,576 rider-horse combinations were registered with the Dutch National Equestrian Federation (KNHS) in dressage, show jumping, eventing and endurance. From this population, approximately 1% of horses in each discipline were selected at random and all recorded competition data from the KNHS registration system collected and supplemented by detailed rider/owner teleph...
Treiber KH, Boston RC, Geor RJ, Hess TM, Harris PA, Kronfeld DS.Tools and criteria to evaluate and understand glucose metabolism are essential to optimise equine energy utilisation for exercise performance and reduced metabolic health risks. Objective: To re-evaluate models of glucose kinetics in the horse at rest and during endurance type exercise using a single injection technique and compartmental modelling. Methods: Twelve exercise trained Arabian geldings received a bolus of 100 µmol/kg bwt [6,6-(2) H]glucose i.v. while at rest and while running at ∼ 4 m/s on a treadmill. Tracer and tracee glucose curves from 4-150 min after the bolus dose (while t...
Barrey E, Bonnamy B, Barrey EJ, Mata X, Chaffaux S, Guerin G.MicroRNAs (miRNA) are small endogenous noncoding interfering RNA molecules (18-25 nucleotides) regarded as major regulators in eukaryotic gene expression. They play a role in developmental timing, cellular differentiation, signalling and apoptosis pathways. Because of the central function of miRNAs in the proliferation and differentiation of the myoblasts demonstrated in mouse and man, it is assumed that they could be present in equine muscles and their expression profile may be related to the muscle status. Objective: To identify miRNA candidates in the muscles of control and affected horses ...
Finno CJ, McKenzie E, Valberg SJ, Pagan J.Recurrent exertional rhabdomyolysis (RER) occurs in fit, nervous Thoroughbreds fed high nonstructural carbohydrate (NSC) diets. Clinical signs are diminished by feeding low NSC, high fat diets; however, the mechanism is unclear. Objective: To determine if the glucose, insulin and cortisol response to isocaloric diets varying in fat and NSC availability differ in fit vs. unfit Thoroughbreds with RER. Methods: Four fit (10 weeks treadmill training) RER Thoroughbred mares were exercised and fed 3 isocaloric (121 MJ/day) diets in a 5 day/diet block design. Two high NSC concentrates, sweet feed (SF...
Godwin EE, Young NJ, Dudhia J, Beamish IC, Smith RK.Mesenchymal stem (progenitor; stromal) cell (MSC) therapy has gained popularity for the treatment of equine tendon injuries but without reports of long-term follow-up. Objective: To evaluate the safety and reinjury rate of racehorses after intralesional MSC injection in a large study of naturally occurring superficial digital flexor tendinopathy and to compare these data with those published for other treatments. Methods: Safety was assessed clinically, ultrasonographically, scintigraphically and histologically in a cohort of treated cases: 141 client-owned treated racehorses followed-up for a...
Lyons ET, Kuzmina TA, Tolliver SC, Collins SS.Early development and maturation of species of small strongyles have not been studied extensively. Most information is on the first appearance of strongyle eggs in feces of foals. However, species cannot be determined in this manner because of similarity of the morphological features of the eggs. To determine more definitive knowledge on development and species composition of natural infections of small strongyles, eight equid foals were necropsied and examined at various ages (31 to 92 days of age). The entire contents of the large intestine were examined, and all worms (6,671) recovered were...
Andersson LS, Axelsson J, Dubielzig RR, Lindgren G, Ekesten B.Multiple congenital ocular anomalies (MCOA) syndrome is a hereditary congenital eye defect that was first described in Silver colored Rocky Mountain horses. The mutation causing this disease is located within a defined chromosomal interval, which also contains the gene and mutation that is associated with the Silver coat color (PMEL17, exon 11). Horses that are homozygous for the disease-causing allele have multiple defects (MCOA-phenotype), whilst the heterozygous horses predominantly have cysts of the iris, ciliary body or retina (Cyst-phenotype). It has been argued that these ocular defects...
Brito LF, Greene LM, Kelleman A, Knobbe M, Turner R.The objective of this study was to determine the effects of method and clinician on stallion sperm morphology evaluation. Five clinicians evaluated 60 semen samples using wet-mount preparations with phase-contrast, eosin/nigrosin-stained semen smears, and Papanicolaou-stained semen smears. There were significant differences among methods for all sperm morphology categories and most intra-class correlation coefficients were only fair to moderate. The use of wet-mount preparations facilitated detection of acrosome defects, nuclear vacuoles, and cytoplasmic droplets when compared to stained smear...
Joubert P, Cordeau ME, Lavoie JP.Heaves in horses is characterized by lower airway neutrophilic inflammation, and reversible airflow obstruction. Pulmonary macrophages contribute to the inflammation observed in a number of human and animal pulmonary diseases, and it has been postulated that they are responsible for the neutrophilic inflammation present in heaves by the release of cytokines and chemokines. To test this hypothesis, the mRNA expression of TNF-α, IL-1β, IL-8, and MIP-2 by macrophages isolated from bronchoalveolar lavage cells was quantified using real-time RT-PCR in horses with heaves (n-6) and controls (n-6). ...
Herthel D, Hood DM.This article focuses on the initial assessment of the horse affected with chronic laminitis. Variations in the clinical presentation and primary considerations in making a differential diagnosis are included. The elements of a clinical history essential to sound, therapeutic management, and prognosis are summarized. The physical and radiographic assessment of the digital lesions and diagnostic approaches to the common systemic aspects of the disease are presented and discussed.
Steel R, Timms M, Levina V, Vine J.The Dermorphins are a family of peptides that act as potent agonists of the opioid μ receptor. Originally identified as a seven amino acid peptide on the skin of the South American Phyllomedusa frog, peptide chemists have since developed a large number of Dermorphin variants, many with superior opioid activity to the original peptide. Dermorphins are unique among the peptide opioid agonists as they appear to have a limited ability to cross the blood brain barrier, producing effects on both the central and peripheral nervous systems. It is this ability of Dermorphins to provide central anaesth...
Griffiths NJ, Walton JR, Edwards GB.Equine anterior enteritis is an acute syndrome with unknown aetiology, although salmonellosis and infection with Clostridium perfringens have both been suggested as potential causes. The main aim of this preliminary study was to compare the prevalence of toxigenic types of C. perfringens in clinically healthy horses and in horses with anterior enteritis. From horses admitted with colic at Phillip Leverhulme Large Animal Hospital in 1995-1996, samples of gastric reflux, small intestinal contents and faeces were taken for isolation of C. perfringens. Five of those horses were admitted as anterio...
Carroll SL, Sykes BW, Mills PC.Behaviour-related issues are common in horses. Many 'undesirable behaviours' pose important safety concerns for the human handlers / riders / carers, as well as welfare concerns for the horse. Undesirable behaviours can also devalue a horse, or result in the horse being re-homed, relinquished, or euthanased. Undesirable behaviours occur for a range of reasons. These include physiological causes, poor management, and the use of inappropriate or poorly applied handling and training techniques. The potential contribution of each of these aspects must be considered when attempting to reduce or eli...
Gastal EL, Aguiar FLN, Gastal GDA, Alves KA, Alves BG, Figueiredo JR.The mammalian ovary is responsible for essential stages of folliculogenesis and hormonal production, regulating the female physiological functions during the menstrual/estrous cycles. The mare has been considered an attractive model for comparative studies due to the striking similarities shared with women regarding in vivo and in vitro folliculogenesis. The ovarian follicular population in horses contains a large number of oocytes enclosed in preantral follicles that are yet to be explored. Therefore, the in vitro manipulation of equine preantral follicles aims to avoid the process of atre...
De Angelis E, Ravanetti F, Martelli P, Cacchioli A, Ivanovska A, Corradi A, Nasi S, Bianchera A, Passeri B, Canelli E, Bettini R, Borghetti P.The present study investigated the biocompatibility of chitosan films and scaffolds modified with d-(+)raffinose and their capability to support the growth and maintenance of the differentiation of articular chondrocytes in vitro. Primary equine articular chondrocytes were cultured on films and scaffolds of modified d-(+) raffinose chitosan. Their behavior was compared to that of chondrocytes grown in conventional bi- and three-dimensional culture systems, such as micromasses and alginate beads. Chitosan films maintained the phenotype of differentiated chondrocytes (typical round morphology) a...
Stein FJ, Geller SC, Carter JC.To determine whether microchips used for identification migrate after implantation in horses, donkeys, and mules. Methods: Prospective study. Methods: 53 horses, donkeys, and mules. Methods: Twenty horses that had had microchips implanted in the nuchal ligament at a veterinary teaching hospital from 1996 through early 2000 were included (group 1), and the poll-to-withers distance and location of the microchip were determined, measured, and recorded. Additionally, the poll-to-withers distance was measured in 16 horses, 12 donkeys, and 5 mules (group 2), and microchips were implanted in the nuch...
Pfau T, Starke SD, Tröster S, Roepstorff L.Pelvic movement is altered in hind limb lame horses. A simple method using one inertial measurement unit (IMU) attached to the sacrum, which objectively measures 'hip hike', will help detecting hind limb lameness in large scale studies. In this study, IMUs over the sacrum and the left and right tuber coxae (TC) quantified vertical movement symmetry (MS) in 10 clinically lame horses. A simple geometrical model was used to estimate TC movement from the sacrum IMU. The differences between measured and estimated MS values (mean±SD) and MS changes during different exercise conditions (straight, ci...
Gold JR, Grubb TL, Green S, Cox S, Villarino NF.In humans, gabapentin an analgesic, undergoes non-proportional pharmacokinetics which can alter efficacy. No information exists on the pharmacokinetics of dosages >20 mg/kg, escalating dosages or dose proportionality of gabapentin in horses. Objective: Gabapentin exposure in plasma would not increase proportionally relative to the dose in horses receiving dosages ≥20 mg/kg. To assess the plasma pharmacokinetics of gabapentin after nasogastric administration of gabapentin at dosages of 10 to 160 mg/kg in adult horses. Methods: Nine clinically healthy adult Arabian and Quarter Horses....
Ellenberger MA, Kaeberle ML, Roth JA.A procedure was developed for isolating large numbers of purified polymorphonuclear leukocytes (PMNs) from the peripheral blood of horses. Equine PMN function was evaluated by three procedures: 1) Staphylococcus aureus ingestion, 2) nitroblue tetrazolium reduction, and 3) iodination. Four preparations of R. equi were added to polymorphonuclear leukocytes (PMNs) in each test system. Live bacteria, heat-killed bacteria, the washed pellet from heat-killed bacteria, and the supernatant fluid from heat-killed bacteria were evaluated for effects on equine PMN function. None of the R. equi preparatio...
Marrs J, Small J, Milne EM, John HA.Hepatocellular and hepatobiliary damage was assessed in equine acute, subacute and chronic grass sickness cases (AGS, SAGS, CGS). Histopathological analysis showed that even in some early AGS cases enlarged hepatocytes, hepatocyte vacuolation indicative of lipid accumulation (steatosis), intrahepatocyte, canalicular and periportal deposition of pigments, frequent leucocyte infiltration and cholangitis occurred. Analysis of serum indicated significantly increased levels of unconjugated bilirubin in all groups and conjugated bilirubin in AGS and SAGS groups, increased levels of bile acids in som...
Grimm P, Laroche N, Julliand S, Sorci G.It is increasingly difficult to control equine strongyles with synthetic drugs, as resistance is commonly observed. Here, we investigated the possible anthelmintic effect of sainfoin (), a polyphenol-rich legume, in naturally infected horses. On Day 0 (D0), 17 horses were allocated to three different homogenous groups in terms of fecal egg count (FEC): the control group (CONT) received a diet composed on a DM basis of 83% hay and 17% wheat bran, while in the sainfoin 1 (SF1) and sainfoin 2 (SF2) groups, half or all wheat bran, respectively, was replaced by dehydrated sainfoin pellets. The infe...
Ghosh S, Das PJ, Avila F, Thwaits BK, Chowdhary BP, Raudsepp T.Balanced autosomal translocations are a known cause for repeated early embryonic loss (REEL) in horses. In most cases, carriers of such translocations are phenotypically normal, but the chromosomal aberration negatively affects gametogenesis giving rise to both genetically balanced and unbalanced gametes. The latter, if involved in fertilization, result in REEL, whereas gametes with the balanced form of translocation will pass the defect into next generation. Therefore, in order to reduce the incidence of REEL, identification of translocation carriers is critical. Here, we report about a pheno...
Cutler TJ, MacKay RJ, Ginn PE, Greiner EC, Porter R, Yowell CA, Dame JB.Equine protozoal myeloencephalitis (EPM) is a debilitating neurologic disease of the horse. The causative agent. Sarcocystis neurona, has been suggested to be synonymous with Sarcocystis falcatula, implying a role for birds as intermediate hosts. To test this hypothesis, opossums (Didelphis virginiana) were fed muscles containing S. falcatula sarcocysts from naturally infected brown-headed cowbirds (Molothrus ater). Ten horses were tested extensively to ensure no previous exposure to S. neurona and were quarantined for 14 days, and then 5 of the horses were each administered 10(6) S. falcatula...
Keen JA, McLaren M, Chandler KJ, McGorum BC.The mechanisms underlying the increased risk of laminitis in horses with equine Cushing's disease (ECD) are poorly understood. Objective: That abnormalities in glucose homeostasis, similar to those which cause microvascular dysfunction in human diabetics, contribute to development of laminitis in horses with ECD. Methods: Thirty-one aged horses were divided into 3 groups based on clinical signs and dexamethasone suppression testing (DST). Group 1 (n = 12) had clinical ECD as evidenced by hirsutism. Group 2 (n = 10) had a positive DST but no hirsutism. Group 3 (n = 9) were controls without ECD,...
Taylor AH, Seymour CJ.Horses may become hypoxaemic during anaesthesia despite a high inspired oxygen fraction (FiO2). A lower FiO2 is used commonly in human beings to minimise atelectasis and to improve lung function, and previously has been shown to be of potential benefit in horses in experimental conditions. Other studies suggest no benefit to using a FiO2 of 0.5 during clinically relevant conditions; however, low FiO2 (0.65) is commonly used in practice and in a large number of studies. The present study was performed to compare the effect of a commonly used FiO2 of 0.65 versus 0.90 on calculated respiratory in...
Rushton JO, Kolodziejek J, Nell B, Weissenböck H, Nowotny N.The role of equid γ-herpesviruses on ocular surface diseases has been disputed, because the diagnosis is usually based on clinical symptoms and detection of viral DNA from samples obtained from live animals. Objective: To describe the clinical course, results of polymerase chain reaction (PCR) analysis, in situ hybridisation, cell culture and pathohistological findings of select cases in a presumed outbreak of herpesvirus infection in a group of 15 Icelandic horses. Methods: Case series. Methods: Pooled ocular and nasal swabs and peripheral blood mononuclear cells of horses diagnosed clinica...
Morens DM, Taubenberger JK.Influenza A viruses are globally enzootic in swine populations. Swine influenza has been recognised only since 1918, but an anecdotal report suggests that a swine-influenza epizootic might have occurred in England in 1892, at the same time as an explosive epidemic (or pandemic recurrence) of human influenza. This outbreak suggests that the ecobiological association between human and swine influenza could extend to before 1918. By contrast with the recent documentation of swine influenza, influenza in horses has been well documented for hundreds of years, and was often linked temporally and geo...
Bush JM, Fredrickson RL, Ehrhart EJ.In horses, osteosarcoma is a rare tumor, with the majority of reported cases occurring in the head, and, more specifically, in the mandible of young horses. The following report documents 8 cases of equine osteosarcoma, the majority occurring in male horses aged 7 years or older with a lack of metastasis identified in any horse. Six arose in the maxilla or mandible and one in the proximal tibia. The predominant subtype was fibroblastic osteosarcoma with fewer osteoblastic type tumors. All had osteoid and most had a chondromucinous matrix. Surgical excision was attempted in the majority of case...
Feary DJ, Abraham S, Woolford L, Trott DJ.A 6-year-old Arabian mare had a 4-week history of a subcutaneous mass (15 × 15 cm) at the base of the neck, cranial and distal to the prescapular lymph node on the right side. The mass was solid and painful on deep palpation. Ultrasonographic examination showed a soft-tissue abscess. Purulent aspirate was submitted for bacterial culture, which showed a moderate growth of an Actinomyces species. 16S rRNA gene sequencing was performed for definitive identification. Gene sequencing demonstrated close nucleotide homology with A. denticolens. Prolonged therapeutic management resulted in resolu...
Choi YH, Love LB, Varner DD, Hinrichs K.This study was conducted to evaluate the in vitro development of equine oocytes with compact cumuli that had been subjected to a period of meiotic suppression with roscovitine before in vitro maturation. In experiment 1, oocytes were recovered from slaughterhouse-derived ovaries and held in M199 + 10% fetal bovine serum containing 66 microM roscovitine with or without an overlay of mineral oil in 5% CO2 in air at 38.2 degrees C for 16-18 or 24 h. No oocytes treated with roscovitine in the absence of an oil overlay for 16-18 h were maturing, compared with 2-4% of oocytes in other treatments. In...
Orth DN, Nicholson WE.Equine Cushing's disease is caused by hypersecretion of ACTH by hyperplasia or adenomas of pars intermedia (PI) cells, in contrast to human Cushing's disease, which is caused by hyperplasia or adenomas of pars distalis (PD) ACTH-secreting cells. We assayed both bioactive and immunoreactive (IR) ACTH in two normal equine pituitary glands and in the PD, PI, and pars nervosa of four such glands, as well as in the PI adenomas of five horses with Cushing's disease. In normal horse pituitaries, as in those of other species, most of the bioactive and IR-ACTH was found in PD, much less in PI, and only...
The Journal of protozoologyAugust 1, 1980
Volume 27, Issue 3 288-292 doi: 10.1111/j.1550-7408.1980.tb04259.x
Simpson CF, Mayhew IG.Equine protozoal myeloencephalitis (EPM) was diagnosed in 10 horses. By electron microscopy, schizonts were found in intact host cells of the spinal cords or, more frequently, free in the extracellular spaces. Developmental stages of schizonts differed morphologically, and the late stage of schizogony was characterized by endopolygeny. These findings permitted tentative identification of the protozoon as a Sarcocystis sp. Free merozoites were present in the extracellular spaces or in cells of the spinal cord. Pericytes of capillaries were most frequently parasitized by merozoites were present ...
Trumble TN, Arnoczky SP, Stick JA, Stickle RL.The blood supply to the proximal sesamoid bone of the equine forelimb was examined in 18 cadaver limbs from adult horses, using x-ray computed tomography and a tissue-clearing (Spalteholz) technique. Results of the study indicated that the proximal sesamoid bones were supplied by multiple branches of the medial and lateral palmar digital arteries, which entered the proximal half of the bones on their non-articular, abaxial surface. After entering the bone, the vessels traverse dorsally, axially, and distally, arborizing into several smaller branches that appear to supply the entire bone. The m...
Murray A, Pearson GT, Cottrell DF.Light microscopy was undertaken on sections from the caudal flexure of the duodenum and the terminal ileum proximal to the ileocaecal fold in 5 control horses, 5 horses with acute grass sickness (AGS), and 5 horses with chronic grass sickness (CGS). With the exception of the ileal submucous plexus of the CGS group, the AGS group had the lowest number of neurons as measured using a subjective scoring scheme. The proportion of abnormal neurons in the AGS group was similar in both plexuses and both regions, whereas the values for the CGS group were much higher in the duodenal region than in the i...
Aman JE, Valberg SJ, Elangovan N, Nicholson A, Lewis SS, Konczak J.Cerebellar Purkinje cell axonal degeneration has been identified in horses with shivering but its relationship with abnormal hindlimb movement has not been elucidated. Objective: To characterise surface electromyographic (sEMG) hindlimb muscle activity in horses with shivering, correlate with clinical scores and examine horses for Purkinje axonal degeneration. Methods: Descriptive controlled clinical study. Methods: The hindlimb of seven shivering and six control draught horses were clinically scored. Biceps femoris (BF), vastus lateralis (VL), tensor fasciae latae and extensor digitorum longu...
Sams RA, Ruoff WW.The pharmacokinetics and bioavailability of cefazolin given (IV, IM) to horses at the dosage of 11 mg/kg were investigated. The disposition of cefazolin given by IV route was characterized by a rapid disposition phase with a half-life of 5 to 10 minutes and a subsequent slower elimination phase with a half-life of 35 to 46 minutes. The total plasma clearance of cefazolin averaged 5.51 ml/min/kg and was due mainly to renal clearance (5.39 ml/min/kg) of unchanged drug. The volume of distribution at steady-state averaged 188 ml/kg. Plasma protein binding of cefazolin at a concentration of 10 micr...
Manohar M, Goetz TE, Hassan AS.The objective of the present study was to examine the effects of preexercise NaHCO(3) administration to induce metabolic alkalosis on the arterial oxygenation in racehorses performing maximal exercise. Two sets of experiments, intravenous physiological saline and NaHCO(3) (250 mg/kg i.v.), were carried out on 13 healthy, sound Thoroughbred horses in random order, 7 days apart. Blood-gas variables were examined at rest and during incremental exercise, leading to 120 s of galloping at 14 m/s on a 3.5% uphill grade, which elicited maximal heart rate and induced pulmonary hemorrhage in all horses ...
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...
Kotoyori Y, Yokoo N, Ito K, Murase H, Sato F, Korosue K, Nambo Y.The objective was to assess the optimal procedure for real-time, three-dimensional (3D) ultrasound (US) imaging for assessing the equine fetus during the first half of gestation and the possibility of using 3D US imaging of the equine fetus in clinical applications. Seventeen pregnant mares were examined by 3D US between Days 35 and 180 of gestation. Abdominal and endo-vaginal real-time 3D transducers used in human medicine were used for transrectal and transvaginal examinations, respectively. Images were recorded by both 3D stationary and real-time movies. In a comparison of four methods, tra...
