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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.
Cryopreservation reduces the ability of equine spermatozoa to attach to oviductal epithelial cells and zonae pellucidae in vitro. Two bioassays were used to evaluate the interaction of fresh and cryopreserved equine semen with oviductal epithelial cells (OEC) and with the zona pellucida (ZP). Split ejaculates were either stored at room temperature or frozen and thawed. In experiment 1, progressive motility and membrane integrity were evaluated for each treatment. Fluorescent labeled spermatozoa were cocultured with monolayers of OEC for 30 minutes, and the number of sperm attached to OEC was counted by fluorescence microscopy and analysis of digitized images. Motility of spermatozoa attached to OEC was observed at 0.5, 3...
Complications of celiotomy incisions in horses. Complications of celiotomy incisions were evaluated retrospectively in 274 horses that survived at least 1 month after surgery, or died or were euthanatized within 1 month of surgery, as a direct result of these complications. Horses were divided into four groups; group A, a ventral median celiotomy for intestinal disease; group B, ventral median celiotomy for nonintestinal disease; group C, repair of an umbilical hernia; and group D, celiotomy in a region other than the midline. Specific incisional complications were peri-incisional edema, drainage, incisional abscess, suture sinus, and dehis...
Equine pulmonary disease: a case control study of 300 referred cases. Part 1: Examination techniques, diagnostic criteria and diagnoses. Three-hundred adult horses, referred from 1990 to 1993 inclusively, for pulmonary examination were assessed using standardised history taking and clinical, intrapleural pressure, arterial blood gases and pH, bronchoscopic and tracheal and broncho-alveolar lavage fluid (BALF) cytological examinations. Two-hundred and thirty-five cases were referred with overt signs of pulmonary disease and the remaining 65 cases were referred for pulmonary examination because of reduced exercise (usually racing) performance or prolonged dyspnoea after racing. No pulmonary disease was detected in 30 cases. The 2...
Effects of exercise on plasma concentrations of caffeine and its metabolites in horses. The effects of exercise on the metabolism of caffeine (CA) were studied 3h after administration of the drug to race horses which then underwent exercise sets (1000-m gallop). Analysis was made of pharmacokinetics of CA, changes in its plasma concentrations, its metabolites, i.e., theophylline (TP), theobromine (TB) and paraxanthine (PX), and the molar concentration ratios of CA to these metabolites. After exercise, AUC and t1/2 tended to decrease, and the concentration of CA decreased, while the concentrations of TP and TB significantly increased. The TP/CA ratio and TB/CA ratio significantly ...
Demonstration of tissue-specific promoters in nonprimate species that express aromatase P450 in placentae. Conversion of androgens to estrogens is catalyzed by aromatase P450 (P450arom; the product of the CYP19 gene). Regulation of tissue-specific expression of P450arom in humans is due, in part, to alternative transcriptional start sites that arise as a consequence of the use of granulosa cells and placental tissue from cows, horses, and pigs (ungulates) in order to determine whether these species, like the human, utilize tissue-specific promoters to drive P450arom expression. The majority of transcripts in the placenta have 5'-termini that differ from those in the ovary upstream of a common site ...
Preparing for and competing in the heat: the human perspective. This review provides an overview of the challenges that face man and horses when exercising in the heat. Some of the strategies that are used and are being developed for human athletes exercising in the heat are reviewed. There are many similarities between human and equine physiological responses to exercise in the heat; and equine exercise science may gain some useful insights from the training, fluid replacement and heat acclimatisation strategies used by human athletes. There are, however, some important differences that impact on the ability of horses to thermoregulate and to regulate flu...
Effect of hepatic isoferritins from iron overloaded rats on lymphocyte proliferative response: role of ferritin iron content. Iron and ferritin impair a variety of immunological functions. To evaluate the effect of ferritin iron content on rat lymphocyte proliferative response, isoferritins that differ in their iron content and isoelectric point (pI) were isolated from iron overload rat livers by ultracentrifugation (isoferritins with high iron content and low pI) or crystallization (isoferritins with low iron content and high pI) methods. Additionally, commercial horse splenic ferritin (with a lower pI and higher iron content than rat isoferritins) was also tested. Proliferative response to Con A was decreased in a ...
Blood ionized calcium concentrations in horses before and after the cross-country phase of three-day event competition. Blood ionized calcium (Ca2+) and pH; plasma lactate concentrations; and total protein, total calcium (CaT), albumin, and phosphorus concentrations in serum were determined in 40 healthy horses before (T1), at the finish line (T2), and 10 minutes after the finish (T3) of the cross-country phase of a 3-day-event competition. Mean (+/- SEM) Ca2+ concentrations decreased from 6.22 +/- 0.04 mg/dl at T1 to 5.04 +/- 0.07 mg/dl at T2 (P < or = 0.05). This decrease was accompanied by a nonsignificant increase in CaT between T1 and T2. The mean (+/- SEM) percent ionization of calcium decreased significa...
Dose titration of moxidectin oral gel against migrating Strongylus vulgaris and Parascaris equorum larvae in pony foals. Moxidectin was tested for efficacy in ponies against experimental infections of 56 day Strongylus vulgaris larvae and 11 day Parascaris equorum larvae. Three dosages of moxidectin were tested: 300 micrograms per kg live body weight, 400 micrograms per kg, and 500 micrograms per kg, and the vehicle served as control. Ponies were first infected with 600 S. vulgaris third-stage larvae (L3) on Experiment Day 0 and then with 3000 embryonated P. equorum eggs on Day 45. Moxidectin treatments were administered on Day 56 and necropsy examinations were performed on Day 91. Strongylus vulgaris fourth-sta...
Clinical observations made in nonheat acclimated horses performing treadmill exercise in cool (20 degrees C/40%RH), hot, dry (30 degrees C/40%RH) or hot, humid (30 degrees C/80%RH) conditions. Four horses (H, J, N and M) undertook a treadmill competition exercise test (CET), designed to simulate the physiological and metabolic stresses of the Speed and Endurance phase of a 3-day-event, under 3 different environmental conditions: 20 degrees C/40% relative humidity (RH) (cool, dry [CD]: 2 sessions); 30 degrees C/40%RH (hot, dry [HD]) and 30 degrees C/80%RH (hot, humid [HH]) (Marlin et al. 1995). A number of subjective clinical observations were made at designated time points throughout the exercise test and initial recovery period including buccal mucous membrane colouration, capillar...
Effects of shortening the steeplechase phase (phase B) of a 3-day-event. Thirty-four horses competing in the Endurance Test of a 3-day-event were divided into 3 groups: horses in Group 1 (n = 15) competing in a 3.5 min steeplechase phase; horses in Group 2 (n = 13) in a 3 min steeplechase phase (Phase B) and horses in Group 3 (n = 6) in a 2.5 min steeplechase phase. The shortening of Phase B was associated with a lengthening of Phase C so that the total distance of the event for all horses was 14,940 m. Bodyweight (BW) was measured and total body water (TBW) and water loss estimated. Blood samples were collected from the horses prior to the Endurance Test, at the e...
Osteochondrosis of the articular-epiphyseal cartilage complex in young horses: evidence for a defect in cartilage canal blood supply. The objectives of this study were to determine in horses 1) the ages at which viable cartilage canal vessels are present in the articular-epiphyseal cartilage complex of three predilection sites and one nonpredilection site of osteochondrosis (OC), 2) the prevalence of lesions of OC in these sites, and 3) whether there was an association of lesions of OC with necrotic cartilage canal blood vessels. The medial femoral condyle, lateral femoral trochlear ridge, and distal ends of the tibia and proximal phalanx were examined grossly, microradiographically, and histologically in 35 horses 18 months...
Water and ion losses during the cross-country phase of eventing. Loss of total body water and ions during prolonged exercise can predispose the horse to health and performance problems. This study examined total body water (TBW) losses and extracellular (ECF) ion losses during the cross-country (XC) phase of Preliminary, Intermediate and Advanced Horse Trials and CCI level 3-day-events. Jugular venous blood samples and body mass (BM) were collected on 49 horses at rest, Pre-XC, Post-XC and following 30 min of recovery. Plasma was separated from blood cells within 10 min of collection. Plasma was analysed for [Na+], [K+], [Cl-], ionised [Ca+2], [glucose], [l...
Idiopathic infective arthritis of the coxofemoral joint in a mature horse. A mature thoroughbred-cross gelding developed chronic severe hindlimb lameness. Despite intensive clinical investigation, the diagnosis of infective arthritis of the coxofemoral joint was difficult, and a definitive diagnosis was reached only after synoviocentesis of the joint. The horse was euthanased and examined thoroughly post mortem but no definitive aetiology for the condition was discovered.
Variable-temperature study of the heme-reorientation process in equine myoglobin. The redistribution of the initially-formed myoglobin heme-insertion isomers from the initially formed 50/50 mixture to the equilibrium ratio of 90/10 has long been assumed to occur by one of two mechanisms, both of which require the rupture of the heme iron-protein bond (La Mar, G.N., Toi, H. and Krishnamoorthi, K. (1984) J. Am. Chem. Soc. 106, 6395-6401). In this study we compared the use of nuclear magnetic resonance and optical spectroscopic techniques as methods for studying the reorientation of heme within myoglobin. We found that kinetics determinations of the heme insertion isomer redis...
Endoscopy of the auditory tube diverticula in four horses with otitis media/interna. Endoscopic examination of the auditory tube diverticula was a diagnostic aid in the evaluation of 4 horses with otitis media/interna and associated osseous changes of the stylohyoid and petrous temporal. One of the horses was examined because of persistent head shaking; the other 3 were examined because of an acute onset of facial and vestibulocochlear nerve dysfunction. Proliferative lesions involving the petrous temporal bone and proximal portion of the stylohyoid bone were identified endoscopically in all 4 horses. Endoscopy is a noninvasive procedure that provides an alternative to skull r...
Histologic appearance of axial osteochondral fragments from the proximoplantar/proximopalmar aspect of the proximal phalanx in horses. Osteochondral fragments from the axial proximoplantar/proximopalmar region of the proximal phalanx were removed from 38 joints in 30 horses. Ninety-three percent of the horses were Standardbreds, and 28 of the 30 had a low-grade lameness. All but 1 of the horses had hind limb involvement. A total of 43 fragments were removed. Most (71%) of the fragments involved the medial aspect of the joint and had to be dissected from a covering of synovial tissue. Histologically, the circumference of most fragments consisted of a transition zone at the attachment of the joint capsule, a region of nonarticu...
Use of tension band wires in horses with fractures of the ulna: 22 cases (1980-1992). Twenty-two horses with ulnar fractures were treated, using tension band wires alone or tension band wires in combination with pins or cortical bone screws. Age of the horses ranged from 2 weeks to 12 years (median, 4 months), and body weight ranged from 68 to 477 kg (median, 181 kg). Fractures were classified according to the Donecker and Bramlage ulnar fracture classification and included type 1-a (4 horses), type 1-b (4), type-2 (6), type-3 (1), type-4 (3), and type-5 (4), fractures. Tension band wires alone were used in 7 horses. Tension band wires were used in conjunction with unthreaded p...
[‘Oat bumps’ in horses. Differential diagnosis and nutritional aspects]. Small bumps or swellings of about 0.5 mm in diameter in the skin of horses are called 'haverbultjes' in the Netherlands. Comparable skin diseases described in the literature are 'sweet feed-, protein- and heat bumps'. The differential diagnosis and the possible nutritional causes of 'haverbultjes' are presented.
Continuous monitoring of ECG in horses at rest and during exercise. A method for the continuous monitoring of the electrocardiogram (ECG) of horses at rest and during exercise was evaluated in five healthy horses. The horses spent 24 hours in a loose box and performed a standardised exercise test on a treadmill during this period. Two bipolar leads were recorded, lead 1 between the xiphoid and the left withers, and lead 2 between the left ventral thorax and the left dorsal thorax, using disposable electrodes. The quality of the ECGs enabled both an 'operator-controlled' and an automatic analysis to be made. Lead 1 was the most stable during exercise and lead 2...
Venezuelan equine encephalitis–Colombia, 1995. An outbreak of Venezuelan equine encephalitis (VEE) that began in northwestern Venezuela in April 1995 has spread westward to the Guajira peninsula and to Colombia (Figure 1), resulting in an estimated minimum of 13,000 cases in humans and an undetermined number of equine deaths. Governments of both countries have initiated efforts to control the spread of this outbreak by quarantining and vaccinating equines and applying insecticides. This report summarizes the ongoing investigation of the outbreak in Colombia.
Simultaneous analysis of tiaramide metabolites in horse urine and plasma by solid-phase extraction and reversed-phase ion-pair liquid chromatography. A simple method for the simultaneous analysis of tiaramide (TRA) metabolites in the horse is described. The sample preparation method using a Bond-Elut PH cartridge and stepwise elution with ice-cold, 30% aqueous methanol followed by additional methanol is effective for recovering the metabolites with different properties. The extraction method gives good recoveries (greater than 80%) and reproducibility. Each metabolite is well separated by high-performance liquid chromatography using an octadecyl-type column of polymer-based packing with a solvent system of 20 mM phosphate buffer (pH 6.5)-ac...
Sandwich enzyme-linked immunosorbent assay for quantitative measurement of serum amyloid A protein in horses. To measure the concentration of serum amyloid A (sAA) protein in horses, a sensitive and highly reproducible sandwich (ELISA) was established, using affinity purified SAA antibody. Results of the ELISA were found to have a high correlation (r = 0.95) with those of the single radial immunodiffusion test. Equine SAA concentration was measured by use of this ELISA. In clinically normal horses, the concentration of SAA was high immediately after birth to 2 weeks of age. After that, SAA concentration had periodic fluctuations in the range of approximately 1.0 to 30 micrograms/ml. Mean (+/- SD)) con...
The use of African horse sickness virus NS3 protein, expressed in bacteria, as a marker to differentiate infected from vaccinated horses. Segment 10 of the double-stranded RNA (dsRNA) genome from African horse sickness virus serotype 4 (AHSV-4) was cloned and sequenced. The sequence of the coding region showed a total length of 667 bp. Nucleotide comparisons showed a 95% sequence similarity between serotypes 4 and 9, and 76% between serotypes 4 and 3. cDNA clones containing the coding region were cloned in the vector pET3xb and expressed in Escherichia coli. The NS3 gene product was synthesised at very high level as an insoluble fusion protein. The recombinant protein was used in a differential ELISA to distinguish horses that w...
Seasonal vitamin A depletion in grazing horses is assessed better by the relative dose response test than by serum retinol concentration. Vitamin A influences growth and reproduction in horses. A retinol dose response (RDR) test for retinol has been shown to be better than serum retinol concentration for assessing vitamin A status in other species, so we have compared these two methods in the horse. Forty-five Thoroughbred broodmares were assigned randomly to three groups fed pasture and hay (PH), pasture, hay and vitamin A-free concentrate (PHC), or hay and concentrate (HC) in early summer (May 1991). Mares in pasture groups produced 23 foals (March through June) that had access to their dam's diets and were also studied. In th...
Digital Starling forces and hemodynamics during early laminitis induced by an aqueous extract of black walnut (Juglans nigra) in horses. Starling forces and hemodynamics in the digits of 5 horses were studied during early laminitis induced by oral administration of an aqueous extract of black walnut (Juglans nigra). The black walnut extract was prepared from heartwood shavings and was administered by nasogastric tube. Heart and respiratory rates, rectal temperature, central venous and arterial pressures, digital pulses, and signs of lameness were monitored. Blood samples were collected for determination of WBC count, hemoglobin concentration, and PCV and for endotoxin and tumor necrosis factor assays. Total WBC count and centra...
