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Topic:Equine Health
Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Evaluation of xylazine and ketamine for total intravenous anesthesia in horses. To evaluate the use of xylazine and ketamine for total i.v. anesthesia in horses. Methods: 8 horses. Methods: Anesthetic induction was performed on 4 occasions in each horse with xylazine (0.75 mg/kg, i.v.), guaifenesin (75 mg/kg, i.v.), and ketamine (2 mg/kg, i.v.). Intravenous infusions of xylazine and ketamine were then started by use of 1 of 6 treatments as follows for which 35, 90, 120, and 150 represent infusion dosages (microg/kg/min) and X and K represent xylazine and ketamine, respectively: X35 + K90 with 100% inspired oxygen (O2), X35 + K120-(O2), X35 + K150-(O2), X70 + K90-(O2), K15...
Superficial keratectomy and cryosurgery as therapy for limbal neoplasms in 13 horses. To determine the usefulness and clinical outcome of a combined procedure of superficial keratectomy and cryosurgery as a treatment for limbal neoplasms in horses. Methods: Retrospective study. Methods: Thirteen horses with 14 limbal tumors. Methods: Medical records of all patients with limbal tumors, referred to the Department of Equine Sciences of Utrecht University between 1995 and 2002, were retrieved. Patient data were analyzed with respect to signalment, tumor surface area and histologic diagnosis. Surgery, performed under general anesthesia, included surgical debulking of the tumor follo...
Kinetics of pulmonary neutrophil recruitment and clearance in a natural and spontaneously resolving model of airway inflammation. Neutrophil apoptosis and phagocytic clearance have been proposed as key determinants affecting the resolution of airway inflammation. Objective To determine the kinetics of neutrophil priming, recruitment, activation and subsequent clearance in a naturally occurring equine disease model of neutrophilic pulmonary inflammation. Results: A 5 h mouldy hay/straw challenge in hypersensitive horses induced transient pulmonary dysfunction lasting 4 days. At 24 h circulating neutrophils were primed and displayed delayed rates of spontaneous apoptosis in vitro. Neutrophil numbers in the airspaces peaked...
Ocular parameters related to drug delivery in the canine and equine eye: aqueous and vitreous humor volume and scleral surface area and thickness. To measure the ocular surface area, scleral thickness, and the aqueous and vitreous humor volumes in the canine and equine eye. Animals studied Fourteen canine and 16 equine cadaver eyes. Methods: Eyes were measured either fresh or following fixation in formalin. Ocular surface area was calculated using the fluid displacement method. Globes were hemisected and aqueous and vitreous humor were collected and quantitated. Scleral thickness was measured by digital caliper, by image projection, and by ultrasonic biomicroscopy (UBM). Results: Mean +/- standard deviation (SD) scleral surface areas in ...
Evaluation of iatrogenic hemarthrosis of the metacarpophalangeal joint as a method of induction of temporary reversible lameness in horses. To determine whether iatrogenic hemarthrosis of the metacarpophalangeal joint could be used as a model for temporary reversible joint pain in horses. Methods: 8 adult horses. Methods: Each horse was evaluated on a treadmill before and after injection of 1 metacarpophalangeal joint with 10 mL of autogenous blood. Horses were evaluated subjectively and objectively by use of a computerized force measurement system at intervals until lameness abated. The mean force difference between injected and noninjected limbs at all time periods after injection was compared with the difference between limbs a...
Post-anaesthetic pulmonary oedema in horses: a review. To review information on the pathogenesis, diagnosis and treatment of post-anaesthetic pulmonary oedema in horses. Methods: Pubmed 1970-present, personal files.
In vitro evaluation of the contractile response to endothelin-1 of the circular and longitudinal myometrial layers of the uterine horn of nongravid mares. To characterize the in vitro response of circular and longitudinal myometrial layers of the uterine horn (CMLH and LMLH, respectively) of horses to endothelin (ET)-1 by use of specific ETA (BQ-123) and ETB (IRL-1038) receptor antagonists. Methods: Uteruses from 10 nongravid mares in anestrus. Methods: Muscle strips from the CMLH and LMLH were suspended in tissue baths and connected to force-displacement transducers interfaced with a polygraph. Strips were incubated for 45-minute intervals with no antagonist (control specimens), and 3 concentrations (10(-9), 10(-7), and 10(-5)M) of BQ-123, IRL-...
Effects of oral administration of levothyroxine sodium on concentrations of plasma lipids, concentration and composition of very-low-density lipoproteins, and glucose dynamics in healthy adult mares. To evaluate glucose and lipid metabolism in healthy adult horses administered levothyroxine sodium (L-T4). Methods: 12 healthy adult mares. Methods: 8 horses received an incrementally increasing dosage of L-T4 (24, 48, 72, or 96 mg of L-T4/d) for weeks 1 to 8. Each dose was provide between 7 AM and 8 AM in the morning grain meal for 2 weeks. Four additional horses remained untreated. Serum concentrations of nonesterified fatty acids, triglyceride (TG), total cholesterol (TC), and very-low-density lipoprotein (VLDL) were measured and composition of VLDL examined in samples obtained between 8 AM...
The development and application of the modern reproductive technologies to horse breeding. Although the horse was probably the first animal to experience and benefit from artificial insemination, it trailed the field somewhat with regard to the application of embryo transfer and other oocyte and embryo-related modern breeding technologies. But with a late run it is now back in mid-field and gaining fast on the other large domestic species in the application of the many technological advances of the past 20 years to sound breeding practice. Improvements in extenders and cryoprotectants have resulted in a veritable upsurge in the transport and insemination of cooled and frozen stallio...
Effects of oral administration of levothyroxine sodium on serum concentrations of thyroid gland hormones and responses to injections of thyrotropin-releasing hormone in healthy adult mares. To determine the effects of levothyroxine sodium (L-T4) on serum concentrations of thyroid gland hormones and responses to injections of thyrotropin-releasing hormone (TRH) in euthyroid horses. Methods: 12 healthy adult mares. Methods: 8 horses received an incrementally increasing dosage of L-T4 (24, 48, 72, or 96 mg of L-T4/d) for weeks 1 to 8. Each dose was provided for 2 weeks. Four additional horses remained untreated. Serum concentrations of total triiodothyronine (tT3), total thyroxine (tT4), free T3 (fT3), free T4 (fT4), and thyroid-stimulating hormone (TSH) were measured in samples obt...
Use of lithium dilution and pulse contour analysis cardiac output determination in anaesthetized horses: a clinical evaluation. To assess the suitability of a human algorithm for calculation of continuous cardiac output from the arterial pulse waveform, in anaesthetized horses. Methods: Prospective clinical study. Methods: Twenty-four clinical cases undergoing anaesthesia for various conditions. Methods: Cardiac output (Qt), measured by lithium dilution (QtLiDCO), was compared with a preceding, calibrated Qt measured from the pulse waveform (QtPulse). These comparisons were repeated every 20-30 minutes. Positive inotropes or vasopressors were administered when clinically indicated. Cardiac indices from 30.7 to 114.9 mL...
Characterization of an A-kinase anchor protein in equine spermatozoa and examination of the effect of semen cooling and cryopreservation on the binding of that protein to the regulatory subunit of protein kinase-A. To determine whether a homologue of A-kinase anchor protein 4 (AKAP4) is present and functional as an AKAP in equine spermatozoa and examine the effect of semen cooling and cryopreservation on binding of equine AKAP4 to the regulatory (RII) subunit of protein kinase-A (PK-A). Methods: Ejaculated semen collected from 2 fertile stallions, 3 bulls, and 3 humans. Methods: Identification of an equine homologue of AKAP4 was investigated via DNA sequencing. Protein was extracted from the spermatozoa of each species for immunoblot analysis to identify AKAP4 and its precursor protein, pro-AKAP4; immuno...
Response of Tabanidae (Diptera) to natural and synthetic olfactory attractants. The attraction of female tabanids to Malaise traps and canopy traps baited with aged horse urine, 1-octen-3-ol, or a combination of aged horse urine and acetone was studied in the Kopacki rit Nature Park in Eastern Croatia. Malaise traps captured very few tabanids relative to canopy traps. The number of females of Tabanus tergestinus and Haematopotapluvialis collected from 1-octen-3-ol baited canopy traps differed significantly from traps baited with aged horse urine. However, the number of females of Tabanus bromius, Atylotus loewianus, and Tabanus maculicornis collected from canopy traps bai...
Investigation of the EEG effects of intravenous lidocaine during halothane anaesthesia in ponies. To record the electroencephalographic changes during castration in ponies anaesthetized with halothane and given intravenous (IV) lidocaine by infusion. The hypothesis tested was that in ponies, IV lidocaine is antinociceptive and would therefore obtund EEG changes during castration. Methods: Ten Welsh mountain ponies referred to the Department of Clinical Veterinary Medicine, Cambridge for castration under general anaesthesia. Methods: Following pre-anaesthetic medication with intramuscular acepromazine (0.02 mg kg(-1)) anaesthesia was induced with IV guaiphenesin (60 mg kg(-1)) and thiopenta...
Low-dose insemination–why, when and how. The typical dose for insemination into the uterine body of the mare is > 300 x 10(6) progressively motile spermatozoa (PMS) and an insemination dose of > 200 x 10(6) PMS is recommended for frozen-thawed semen. Low-dose insemination techniques allow for a drastic reduction in the numbers of spermatozoa required to achieve pregnancy. Acceptable pregnancy rates can be achieved with doses ranging from 1 to 25 x 10(6) PMS in volumes ranging from 20 to 1000 microL. Two techniques have been described: hysteroscopic insemination and transrectally guided deep horn insemination using a pipette. Similar ...
Molecular characterisation of equine group A rotavirus, Nasuno, isolated in Tochigi Prefecture, Japan. In this study, equine group A rotavirus (RV-A), Nasuno, isolated from foal diarrhoea in Tochigi Prefecture, Japan was characterised genetically by sequence analysis of the genome segments encoding VP4 and VP7. The nucleotide and deduced amino acid sequences revealed high homology with P[12] RV-As (94.0-99.3% and 94.9-99.4%) and G3 RV-As (86.9-99.5% and 91.1-99.4%). Nasuno was also classified into P[12] and G3 in the phylogenetic analysis of the nucleotide sequences of the genome segments encoding VP4 and VP7.
Osteon interfacial strength and histomorphometry of equine cortical bone. The interfacial strength of secondary osteons from the diaphysis of the Thoroughbred equine third metacarpal was evaluated using the fiber pushout test. The pushout was performed on 300-500 microm sections of 4x4x15 mm bone blocks machined from four anatomic regions of the cortex. Pushout strength was evaluated from proximal to distal location within the diaphysis on four osteon types classified under polarized light on adjacent histologic sections from each block. The shear strength of the interfaces were estimated from shear lag theory. Differences were found in the interfacial strength of o...
Ultrastructural immunolocalization of cartilage oligomeric matrix protein (COMP) in relation to collagen fibrils in the equine tendon. The structure and organisation of the extracellular matrix, and in particular the axial alignment of type I collagen fibrils, are essential for the tensile strength of tendons. The resident tenocytes synthesize and maintain the composition of the extracellular matrix, which changes with age and maturation. Other components of the extracellular matrix include less abundant collagen types II, III, V, VI, XII, proteoglycans and glycoproteins. Cartilage oligomeric matrix protein (COMP) is an abundant non-collagenous pentameric glycoprotein in the tendon, which can bind to collagen types I and II. ...
Saddle pressure measuring: validity, reliability and power to discriminate between different saddle-fits. Saddle-fit is recognised as an important factor in the pathogenesis of back problems in horses and is empirically being evaluated by pressure measurements in clinical practice, although not much is known about the validity, reliability and usability of these devices in the equine field. This study was conducted to assess critically a pressure measurement system marketed for evaluating saddle fit. Validity was tested by calculating the correlation coefficient between total measured pressure and the weight of 28 different riders. Reliability and discriminative power with respect to different sad...
Quantitative assessment of the risks of reducing the routine swabbing requirements for the detection of Taylorella equigenitalis. The transmission of contagious equine metritis (CEM) on stud farms in Britain, Ireland and other European countries is prevented by following the recommendations in the Horserace Betting Levy Board's Code of Practice on CEM. A quantitative risk assessment was undertaken to estimate the likely impact of removing the recommendation, from the 2002 code, to culture endometrial or cervical swabs microaerophilically for the presence of Taylorella equigenitalis, the causative organism. The scientific literature was reviewed for evidence about the anatomical distribution of T. equigenitalis at differe...
Macroscopical and histopathological changes in regressing primary and recurrent equine sarcoids during active specific bio-immunotherapy. Healing sarcoids were followed in 18 horses which had taken part in previous clinical studies on a total of 29 horses suffering from either primary or recurrent sarcoids, treated with bio-immunotherapy. In the present study, attention was paid to changes observed in these fibroblastic skin tumours during their regression. The tumours were surgically debulked leaving the base in the skin. The horses were immunized according to bio-immunotherapy at 2- to 4-week intervals with an autogenous vaccine made from the excised part of the tumour until the base had visibly regressed. Healing was followed...
The minimum infusion rate (MIR) of propofol for total intravenous anesthesia after premedication with xylazine in horses. To investigate an adequate infusion rate of propofol for total intravenous anesthesia (TIVA) in horses, the minimum infusion rate (MIR) comparable to the minimum alveolar anesthetic concentration (MAC) of inhalation anesthetic was determined under constant ventilation condition by intermittent positive pressure ventilation (IPPV). In addition, arterial propofol concentration was measured to determine the concentration corresponding to the MIR (concentration preventing reaction to stimulus in 50% of population, Cp(50)). Further, 95% effective dose (ED(95)) was estimated as infusion rate for acq...
The absence of Rhodococcus equi in Mongolian horses. In native Mongolian horses, the incidence and distribution of Rhodococcus equi are poorly understood. One hundred and fourteen equine fecal samples and 71 soil samples were collected from the camp sites of 26 nomadic families located in three areas less than 100 km from Ulaanbaatar, Mongolia. Five fecal samples were also collected from foals of Przewalski's Horses introduced into the Hustai National Park, Mongolia. No R. equi was isolated from the Mongolian horses or the soil samples. However, three colonies of R. equi were isolated from two fecal samples collected from foals of Przewalski's H...
Genomic diversity among equine herpesvirus-4 field isolates. Infection with equine herpesvirus-4 (EHV-4) is a major cause of respiratory tract disease, equine rhinopneumonitis, in horses. Although the full sequence of EHV-4 has been reported, genomic differences among EHV-4 field isolates have not yet been characterized. In this study, the genomic diversity between 23 Japanese EHV-4 isolates was analyzed by digestion with restriction endonucleases (BamHI, BgIII, EcoRI, SacI, and SalI) and polymerase chain reaction (PCR). The restriction endonuclease digestion patterns of the EHV-4 field isolates showed distinct differences which included mobility shifts...
Changes in malondialdehyde concentrations and glutathione peroxidase activity in purebred Arabian mares with endometritis. Endometritis is an important factor in infertility. Free radicals play an important role in endometritis and we have investigated their possible role and scavenging systems in endometritis in purebred Arabian mares. The plasma concentration of malondialdehyde (MDA) and erythrocyte glutathione peroxidase (GPx) activity were compared in healthy mares and in mares with endometritis. The level of MDA was significantly increased while GPx activity was decreased in the mares with endometritis. Our findings support the notion that GPx is consumed by increased lipid peroxidation in purebred Arabian ma...
Effect of caspase inhibitors on the post-thaw motility, and integrity of acrosome and plasma membrane of cryopreserved equine spermatozoa. The present study was designed to test the hypothesis that addition of anticaspase cocktails (inhibiting caspases and thus blocking apoptosis) to the extenders increases the post-thaw viability of equine spermatozoa. The addition of caspase inhibitors failed to improve the acrosome and plasma membrane integrity of spermatozoa, suggesting that in equine sperm cryopreservation protocols, the addition of these caspase inhibitors to cryopreservation medium may not be beneficial in protecting the sperm from the stress of cryopreservation.
Equine herpesviruses 1 (EHV-1) and 4 (EHV-4)–epidemiology, disease and immunoprophylaxis: a brief review. This review concentrates on the epidemiology, latency and pathogenesis of, and the approaches taken to control infection of horses by equine herpesvirus types 1 (EHV-1) and 4 (EHV-4). Although both viruses may cause febrile rhinopneumonitis, EHV-1 is the main cause of abortions, paresis and neonatal foal deaths. The lesion central to these three conditions is necrotising vasculitis and thrombosis resulting from lytic infection of endothelial cells lining blood capillaries. The initiation of infection in these lesions is likely to be by reactivated EHV-1 from latently infected leukocytes. Howev...
Factors associated with the wastage and achievements in competition of event horses registered in the United Kingdom. The aims of this study were to estimate the wastage of horses registered for eventing in Britain, to investigate the reasons for this wastage and to evaluate factors affecting the horses' achievement of grade I status (at least 61 points) while registered. An analysis of the database of the British Eventing register found that 33.7 per cent of horses registered for the first time in 1999 were not re-registered for eventing in subsequent years. By using multivariable logistic regression analysis, it was shown that horses that were kept at an event yard were more likely to be re-registered than ...
