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.
Bonagura JD, Blissitt KJ.Echocardiography encompasses a number of specific imaging techniques. The two-dimensional (2-D) echocardiogram is used to identify lesions of the heart and great vessels, assess myocardial function and provide a template for guiding contrast echocardiography, colour-coded Doppler echocardiography and spectral Doppler studies. M-mode echocardiography is used to measure cardiac size and ventricular function and can be combined with contrast or colour-coded Doppler studies for accurate timing of flow events. Pulsed wave and continuous wave Doppler echocardiography display the direction and veloci...
Muir WW.The haemodynamic effects of milrinone hydrochloride were determined in halothane-anaesthetised horses. Six healthy adult horses were anaesthetised with guaifenesin and thiamylal and maintained with halothane in oxygen (end-tidal halothane concentration of 1.15%). Baseline haemodynamic data were recorded after a 45 min stabilisation period. All 6 horses received a single loading dose of milrinone HCl, 0.2 microgram/kg i.v., followed by progressively increasing infusions of 2.5, 5, 10 and 20 micrograms/kg bwt/min. Each infusion lasted for 15 min and produced dose related increases in heart rate,...
Mogg TD, Palmer JE.The medical records of 23 American Miniature Horses with hyperlipidemia, hyperlipemia, or hepatic lipidosis were reviewed. The most common clinical signs were anorexia and lethargy. The mean duration of clinical signs was 2.4 days. A primary disease was identified in 19 cases. Enterocolitis was the most common primary disease (n = 10). Intentional feed restriction, as part of treatment for colic, resulted in hyperlipemia in 2 horses and hyperlipidemia in 1. Four horses had primary hyperlipemia, 3 of which had signs of hepatoencephalopathy secondary to hepatic lipidosis. Dextrose, heparin, and ...
Lloyd DR, Rose RJ.Sodium bicarbonate given by nasogastric tube has been used by some trainers as the key ingredient in a 'milkshake'. It has been suggested that such treatment given 3-5 h prior to racing may enhance a horse's racing performance by increasing the blood buffering capacity and enhancing lactate clearance from skeletal muscle, thereby delaying the onset of fatigue. Several experiments were conducted to examine the effects on fluid, electrolyte and acid-base values of 0.5 g kg-1 dose of sodium bicarbonate, were examined. The effects of fasting, the simultaneous administration of glucose (0.5 g kg-1)...
Geor R, Hope E, Lauper L, Piela S, Klassen J, King V, Murphy M.The effects of dexamethasone (0.2 mg/kg of body weight; IV, IM, and PO) and methylprednisolone acetate (120 mg given intra-articularly) on serum osteocalcin and cortisol concentrations were studied in 6 horses. Serum osteocalcin and cortisol concentrations were serially monitored after each treatment. A significant (P < 0.05) decrease in serum osteocalcin and cortisol concentrations was observed from 12 to 24 and 2 to 48 hours, respectively, after IV and IM administrations of dexamethasone. Serum osteocalcin and cortisol concentrations were significantly decreased from 6 to 48 and 3 to 72 h...
Tunón AM, Rodriguez-Martinez H, Haglund A, Albihn A, Magnusson U, Einarsson S.Cyclical accumulation of uterine fluid occurs during oestrus and is often seen in excessive volumes in mares considered susceptible to endometritis. Since the mechanisms behind the formation of free uterine fluid remain to be clarified, the fine structure of the secretory equine endometrium was studied in biopsies collect during videoendoscopy from 14 endometritis-free, 4-9-year-old mares during oestrus. A distinct oedema of the tunica mucosa was evident. The surface epithelium had both ciliated and nonciliated cells and, particularly at the uterine body, often presented intra-epithelial macro...
Brinsko SP, Ball BA, Ellington JE.Oocytes were harvested from mare ovaries obtained at slaughter and were divided into 3 groups based on the age of the donor. The age groups consisted of young (2 to 7 yr), middle-aged (8 to 14 yr) and aged (>or=15 yr) mares. There were no differences between age groups in the proportions of follicles available for examination or the proportions of normal, abnormal or total oocytes collected. After 24 h of culture, the overall maturation rate to the second metaphase (MII) was 52.7%. Maturation rates for oocytes obtained from young and middle-aged mares were similar, but oocytes from aged mar...
Barr AR, Dyson SJ, Barr FJ, O'Brien JK.Twenty-four horses with ultrasonographic evidence of tendonitis of the deep digital flexor tendon in the metacarpal/metatarsal region were seen over a 7 year period. Most horses had mild to moderate lameness and distension of the digital flexor tendon sheath in the affected limb. Intrasynovial analgesia of the digital flexor tendon sheath consistently improved the degree of lameness. Ultrasonography most commonly revealed small, distinct, often circular, focal hypoechoic areas within the deep digital flexor tendon which usually extended less than 1 cm proximodistally. The degree of lameness an...
Rose PL, Penninck D.Intraoperative ultrasonography was used in six horses to aid localization and removal of bone fragments (3 horses) and foreign bodies (3 horses). The ultrasound transducer was enclosed in a sterile sleeve containing sterile aqueous gel and the examination was performed after aseptic preparation of the surgical site. Using ultrasound guidance a needle was placed in contact with the bone fragment or foreign body and an incision was made along the path of the needle to expose and remove the object. This technique resulted in decreased operative time and minimal tissue dissection.
Kohn CW, Swardson C, Provost P, Gilbert RO, Couto CG.Myeloid and megakaryocytic bone marrow hypoplasia in association with moderate to profound neutropenia was observed in 8 young Standardbred horses sired by the same stallion; 7 horses were intermittently thrombocytopenic. Evaluation of serial neutrophil counts in 2 horses suggested that a cyclic variation in neutrophil numbers was present, that lymphocyte numbers increased when neutrophil counts decreased, and that platelet counts decreased when neutrophil counts decreased. Preliminary bone marrow cultures indicated that myeloid progenitor cells were present and that these cells were able to r...
Patteson MW, Gibbs C, Wotton PR, Cripps PJ.Cardiac dimensions and indices of cardiac function were measured in 29 clinically normal adult Thoroughbreds (TB) which performed minimal exercise using guided M-mode and two-dimensional (2-D) echocardiography, from a variety of image planes and measurement methods, and standardised imaging planes based on intracardiac anatomical landmarks. The different methods of measuring these variables were compared. The variables which were considered to be most valuable for quantitative echocardiography were measured in a further 9 horses. Comparable measurements of cardiac dimensions can be obtained fr...
Lewis DD.A classification scheme for penetrating joint injuries is presented. Diagnostic techniques and treatment recommendations for managing penetrating joint injuries in small animals are described. Techniques used in human and equine patients are discussed for comparison.
Stachel CS, Weik HO.Incubation of equine very low density lipoproteins with lipoprotein lipase isolated from horse postheparin plasma resulted in the formation of lipoproteins of a higher density. Lipoproteins isolated after incubation and plasma lipoproteins had a different chemical composition and triacylglycerol fatty acid pattern. In vitro-obtained low density lipoproteins contained substantially more phospholipids and triacylglycerols but significantly less cholesteryl esters than native low density lipoproteins. Comparing the triacylglycerol fatty acid pattern of plasma very low density lipoproteins and in ...
Reef VB.Ventricular septal defects (VSDs) were diagnosed in 27 horses; in 26 affected horses systolic murmurs were detected over both sides of the chest. Holodiastolic decrescendo murmurs were also detected in 5 horses. Standardbreds and Arabian horses were over-represented, while Thoroughbred horses were under-represented, when compared to the hospital population (P < 0.0001). Five horses had previously raced successfully, one 2-year-old was training successfully and close to racing, and 4 horses had competed successfully in other types of competition. Eleven horses had a history of exercise intolera...
Uboh CE, Rudy JA, Railing FA, Enright JM, Shoemaker JM, Kahler MC, Shellenberger JM, Kemecsei Z, Das DN.Although urine is the sample of choice for drug tests in racehorses, it is rarely obtained following the sudden death of a racehorse on the track while racing. The purpose of this study was to demonstrate the significance of postmortem tissue samples as an alternative to urine and blood samples in equine drug analysis following the sudden death of a racehorse on the track while participating in a competitive race. Postmortem tissue samples were frozen (-80 degrees C) until analyzed. A 30-40-g portion of each organ was homogenized in a 0.1 M phosphate buffer (pH 7.4), deproteinized, hydrolyzed ...
Doxey DL, Tothill S, Milne EM, Davis Z.Three horses suffering from grass sickness were treated successfully but showed clinical signs which varied in severity and duration. They were all characterised by marked and often erratic changes in behaviour and appetite.
Rivero JL, Serrano AL, Henckel P.Biopsies of the gluteus medius muscle were taken at three different depths from 36 endurance horses aged 8.42 +/- 2.85 years and of both sexes. Twenty of the horses were considered to be excellent performers on the basis of the mean speed of their three fastest records in endurance events over the previous two or three years, whereas 16 were moderate performers. The biopsy samples were analysed for the activities of the enzymes citrate synthase (an indicator of citric acid cycle activity), 3-OH-acyl-CoA-dehydrogenase (an indicator of lipid oxidation) and lactate dehydrogenase (an indicator of ...
Ko WH, Pediani JD, Bovell DL, Wilson SM.We have explored the properties of a Ca(2+)-dependent cell-signalling pathway that becomes active when cultured equine sweat gland cells are stimulated with ATP. The ATP-regulated, Ca(2+)-influx pathway allowed Sr2+ to enter the cytoplasm but permitted only a minimal influx of Ba2+. Experiments in which cells were repeatedly stimulated with ATP suggested that Sr2+, but not Ba2+, could become incorporated into the agonist-sensitive, cytoplasmic Ca2+ store. Further evidence for this was provided by experiments using ionomycin, a Ca2+ ionophore which has no affinity for Sr2+.
Collatos C, Barton MH, Prasse KW, Moore JN.Components of the coagulation and fibrinolytic cascades, prothrombin and activated partial thromboplastin times, endotoxin activity, and albumin concentration were measured in blood and peritoneal fluid from 20 healthy horses and from 153 horses with acute gastrointestinal tract diseases at admission. Overall, 77% (117/153) of affected horses survived to discharge from the hospital, and 85% (82/97) of horses discharged were reported to be normal 9 to 14 months later. Significant differences in hemostatic factors were more common in peritoneal fluid than in blood. Tissue plasminogen activator, ...
Hogan PM, Embertson RM, Hunt RJ.A 4-month-old Thoroughbred foal was examined because of a history of exercise intolerance and lack of airflow from the right nostril since birth. Endoscopy of the airways revealed complete membranous obstruction of the right nasal passage at the level of the nasopharynx and marked narrowing of the caudal aspect of the right ventral meatus. Unilateral choanal atresia was diagnosed. Laser ablation of the obstructing tissues was attempted through a videoendoscope. Scar tissue occluded the right nasal passage at follow-up examination 7 weeks later. Intranasal resection, using laparoscopic instrume...
Auckburally A, Wiklund MK, Lord PF, Hedenstierna G, Nyman G.To measure changes in pulmonary perfusion during pulsed inhaled nitric oxide (PiNO) delivery in anesthetized, spontaneously breathing and mechanically ventilated ponies positioned in dorsal recumbency. Methods: 6 adult ponies. Methods: Ponies were anesthetized, positioned in dorsal recumbency in a CT gantry, and allowed to breathe spontaneously. Pulmonary artery, right atrial, and facial artery catheters were placed. Analysis time points were baseline, after 30 minutes of PiNO, and 30 minutes after discontinuation of PiNO. At each time point, iodinated contrast medium was injected, and CT angi...
Scott EA, Thrall DE, Sandler GA.Vascular supply of the equine forelimb was partially disrupted by ligation of the medial palmar and medial palmar digital arteries. Vascular architecture was evaluated before and after ligation by angiography. It was apparent from the present study that existing collaterals or newly formed collaterals, or both, were sufficient to maintain limb viability.
McClure SR, Watkins JP, Ashman RB.To evaluate an intramedullary interlocking nail for stabilization of transverse femoral osteotomies in foals. Methods: A transverse osteotomy and restabilization with an intramedullary interlocking nail was performed on the right femur in three foals and the left femur in three foals. Methods: Six foals weighing 149 to 207 kg. Methods: The femur was destabilized with a transverse middiaphyseal osteotomy and repaired with a 0.5-in (12.7 mm) interlocking nail. The implanted femurs were radiographed monthly until completion of the study 6 months after surgery. At the completion of the study, all ...
Fitzgerald AH, Magnin G, Pace E, Bischoff K, Pinn-Woodcock T, Vin R, Myhre M, Comstock E, Ensley S, Coetzee JF.Marijuana toxicosis is typically seen by companion animal veterinarians. However, with increased marijuana availability, there is a greater potential for toxicosis in other species. Herein we describe a case of suspected marijuana toxicosis in a female and a male American Mammoth donkey, aged 8 y and 20 y, respectively, fed cannabis buds. Both cases were presented because of depression and lethargy. However, the jenny had ataxia, mild colic, tachycardia, tachypnea, and decreased tongue tone. Plasma samples from the jenny on presentation and 3 d following hospitalization were submitted to...
Alef M, Oechtering G.Capnography measures carbon dioxide concentration or partial pressure of the respiratory gas continuously and non-invasively. The endtidal value is of great diagnostic value, it corresponds approximately to the arterial value, except for ventilation-perfusion-mismatching (horse), shunting (horse), or increased dead-space-ventilation (panting in the dog). Capnography primarily serves for monitoring of spontaneous and artificial ventilation, it is a reliable method for detecting hypo- and hyperventilation. Because metabolism and circulation influence the amount of carbon dioxide eliminated in th...
Liu C, Cook SJ, Craigo JK, Cook FR, Issel CJ, Montelaro RC, Horohov DW.Unlike other lentiviruses, EIAV replication can be controlled in most infected horses leading to an inapparent carrier state free of overt clinical signs which lasts for many years. While the resolution of the initial infection is correlated with the appearance of virus specific cellular immune responses, the precise immune mechanisms responsible for control of the infection are not yet identified. Since the virus undergoes rapid mutation following infection, the immune response must also adapt to meet this challenge. We hypothesize that this adaptation involves peptide-specific recognition sh...
Ghosh S, Kjöllerström J, Metcalfe L, Reed S, Juras R, Raudsepp T.We present cytogenetic and genotyping analysis of a Thoroughbred foal with congenital neurologic disorders and its phenotypically normal dam. We show that the foal has non-mosaic trisomy for chromosome 26 (ECA26) but normal 2n = 64 diploid number because two copies of ECA26 form a metacentric derivative chromosome der(26q;26q). The dam has normal 64,XX karyotype indicating that der(26q;26q) in the foal originates from errors in parental meiosis or post-fertilization events. Genotyping ECA26 microsatellites in the foal and its dam suggests that trisomy ECA26 is likely of maternal origin and tha...
Ohmura H, Hiraga A, Aida H, Takahashi T, Nukada T.To determine oral dosage and to evaluate the pharmacokinetics in horses of orally administered flecainide, an antiarrhythmic drug, the correlations between its plasma concentration and PR, QRS and QT intervals in equine electrocardiograms (ECG) were investigated. Six healthy horses were administered a randomly ordered dose of 4 or 6 mg/kg of flecainide acetate. The ECG was monitored (heart rate (HR), PR, QRS, and QT intervals) and blood was taken at timed intervals to measure the plasma flecainide concentrations pre- and post-administration. The maximum plasma concentration reached 1014+/-285 ...
Weinstein WL, Moore PA, Sanchez S, Dietrich UM, Wooley RE, Ritchie BW.To determine whether a novel third-generation chelating agent (8 mM disodium EDTA dehydrate and 20 mM 2-amino-2-hydroxymethyl-1, 3-propanediol) would act as an antimicrobial potentiator to enhance in vitro activity of antifungal medications against fungal isolates obtained from horses with mycotic keratitis. Methods: Fungal isolates (3 Aspergillus isolates, 5 Fusarium isolates, 1 Penicillium isolate, 1 Cladosporium isolate, and 1 Curvularia isolate) obtained from horses with mycotic keratitis and 2 quality-control strains obtained from the American Type Culture Collection (ATCC; Candida albica...
Raisis AL.The objective of this review was to describe the methodology and limitations of techniques that have been used to measure skeletal muscle blood flow in anaesthetized horses. Methods: Pubmed, personal files. Conclusions: Numerous techniques have been used in horses to study skeletal muscle blood flow during anaesthesia and after the administration of vasoactive agents. Of the available techniques, blood flow measurements are limited to either microvascular flow (radioactive xenon, laser Doppler flowmetry) or total blood flow (radioactive microspheres, electromagnetic flowmetry, Doppler ultrason...
Morris DD, Harmon BG, Moore JN.A study was performed to determine whether equine antiserum to core lipopolysaccharide (LPS) would enhance phagocytosis of smooth gram-negative (GN) organisms by equine macrophages. Five healthy adult horses (group A) were immunized with a bacterin prepared from the J-5 mutant of Escherichia coli 0111:B4 and Salmonella minnesota R595 to produce antibodies to core LPS. Five horses (group B) served as nonimmunized controls and were given physiologic saline solution instead of the rough mutant bacterin. Serum antibody titers to core LPS and to smooth E coli 0111:B4 were determined by indirect ELI...
Kamali M, Carossino M, Del Piero F, Peak L, Mitchell MS, Willette J, Baker R, Li F, Kenéz Á, Balasuriya UBR, Go YY. subsp. is the etiological agent of sleepy foal disease, an acute form of fatal septicemia in newborn foals. is commonly found in the mucous membranes of healthy horses' respiratory and alimentary tracts and rarely causes disease in adult horses. In this study, we report a case of a 22-year-old American Paint gelding presenting clinical signs associated with an atypical pattern of pleuropneumonia subjected to necropsy. The gross and histopathological examinations revealed a unilateral fibrinosuppurative and hemorrhagic pleuropneumonia with an infrequent parenchymal distribution and heavy iso...
Delbeke FT, Debackere M.The prototype of a commercial ELISA test kit designed for fentanyl determination in human urine has been evaluated for screening fentanyl in horse urine and plasma. The measurement of fentanyl after intravenous (2 mg) and intramuscular (0.25 mg) administration in undiluted plasma was not reproducible while accurate quantification of fentanyl in urine greatly depends on the composition of the horse urine. The ELISA assay, however, is simple and could be successfully used for quantitative measurements in diluted urine and for rapid qualitative screening for fentanyl in large numbers of urine sam...
Yilma T, Perryman LE, McGuire TC.The results of a study on the induction of IFN-alpha, IFN-beta, and IFN-gamma in normal and SCID foals showed a deficiency of IFN-gamma but not IFN-beta in SCID foals. The ability of SCID mononuclear cells to produce IFN-alpha in response to poly I:C but not to NDV may indicate a partial deficiency of IFN-alpha in SCID foals. The deficiency of IFN-gamma and presence of IFN-beta in SCID foals supports the classification of IFN-gamma and IFN-beta as immune and nonimmune interferons, respectively. Furthermore, the deficiency of IFN-gamma in SCID foals may in part explain the high susceptibility t...
Palozzo A, Celani G, Varasano V, Marruchella G, Petrizzi L.Equine sinonasal myxomas (SNM) are very rare; only a few cases/small case series are reported in veterinary literature. The purpose of this report is to describe the diagnostic and surgical procedure adopted to approach the neoplastic mass in a case of equine SNM. A 5 year old, Murgese gelding was presented with mild serous nasal discharge, minimal facial swelling, decreased airflow from the right nostril, and dull frontal sinus percussion. Diagnostic imaging, including endoscopy, revealed a pale mass in the caudal portion of the right middle meatus, which developed inside the right conchofron...
Manley SV.The objectives of monitoring are to gain much information as possible about the anesthetized horse and to follow changes in that information, with the ultimate aim of making anesthesia and surgery as safe as possible for the horse. Information necessary to achieve that aim will vary depending on patient category. For example, a young, healthy horse undergoing a short elective procedure can be clinically well monitored by patient signs, electrocardiogram, and indirect blood pressure response. More invasive monitoring is justified and warranted if the health status of the horse is in question. T...
Tompkins D, Hudgens E, Horohov D, Baldwin CL.This report describes the initial cloning and characterization of the equine interleukin-17 (IL-17) expressed gene sequence from mRNA obtained from equine intestinal tissue and interleukin-23 (IL-23) expressed gene sequence from mRNA obtained from equine peripheral blood mononuclear cells. Equine IL-17 has 462 nucleotides in the translated region, determined by homology with known human and mouse sequences, and shares 84% and 75% identity, respectively. For the deduced amino acid sequences, the identity with human and mouse is 76% and 70%. Equine IL-23 has 579 nucleotides in the translated reg...
Cochran RA, Leonardi-Cattolica AA, Sullivan MR, Kincaid LA, Leise BS, Thompson DL, Godke RA.The effects of exogenous equine somatotropin (eST) administration on ovarian activity and plasma hormone levels were evaluated on horse and pony mares. The objectives of this study were to determine the effects of eST on follicular development and circulating concentrations of leutinizing hormone (LH), estradiol, progesterone, and insulin-like growth factor I (IGF-I) in cyclic horse and pony mares. Sixteen mares received daily injections (i.m.) of eST at a concentration of 25 micrograms/kg body weight on either Days 6 through 12 (Treatment A) or 13 through 19 (Treatment B) postovulation. In ad...
Dumasia MC, Houghton E, Moss MS, Chakraborty J, Marks V.The pro-drugs of dexamethasone, a potent glucocorticoid, are frequently used as anti-inflammatory steroids in equine veterinary practice. In the present study the biotransformation and urinary excretion of tritium labelled dexamethasone were investigated in cross-bred castrated male horses after therapeutic doses. Between 40-50% of the administered radioactivity was excreted in the urine within 24 h; a further 10% being excreted over the next 3 days. The urinary radioactivity was largely excreted in the unconjugated steroid fraction. In the first 24 h urine sample, 26-36% of the total dose was...
