Veterinary medicine for horses encompasses the study and application of medical practices to diagnose, treat, and prevent diseases in equine species. This field involves a comprehensive understanding of equine anatomy, physiology, pathology, and pharmacology. Veterinary practitioners employ a range of diagnostic tools and therapeutic interventions to address health issues in horses, including lameness, gastrointestinal disorders, respiratory conditions, and infectious diseases. Preventative care, such as vaccination and deworming programs, is also a significant aspect of equine veterinary medicine. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary medicine as it pertains to horses, including advancements in diagnostic techniques, treatment protocols, and preventive health strategies.
Bell K, Arthur H, Breen M.Eleven apparent mutations of the equine plasma transferrin and esterase gene (10 in TF and one in ES) were found in an analysis of approximately 240,000 thoroughbred horses. Eight of the transferrin mutations produced variants not previously recognized in horses. In the two remaining transferrin mutations and the esterase mutation, reduced plasma concentrations of the proteins were demonstrated by immunological techniques and together with the family data indicated the existence of 'null' alleles.
Palmer JL, Bertone AL, Malemud CJ, Carter BG, Papay RS, Mansour J.The relevance of site and the influence of exercise on third carpal articular cartilage proteoglycan (PG) were assessed in 16 horses. Six horses were exercised (exercised group) for 30 minutes, 3 times/wk, for 6 weeks. The other 10 horses (nonexercised group) were housed in box stalls for the same 6-week period. At week 6, articular cartilage from the proximal surface of the right third carpal bone was harvested and cultured with radioactive sulfate to label newly synthesized PG. Endogenous PG was measured by use of a uronic acid assay. Newly synthesized and endogenous PG were characterized by...
Sticker LS, Thompson DL, Bunting LD, Fernandez JM, DePew CL, Nadal MR.Twelve light horse mares were fed a control diet that provided 100% of their maintenance protein and energy requirements for 7 d and were then either continued on the control diet or totally deprived of feed (with access to water) for 3 d . Plasma samples were drawn twice daily throughout the experiment, at 15-min intervals for 9 h beginning 45 h after feed removal, and at 10-min intervals around an exercise bout beginning 73 h after feed removal. Feed deprivation increased (P < or = .06) whole blood beta-hydroxybutyrate and plasma NEFA, urea N, L-lactate, and glucagon concentrations, decrease...
Mills PC, Dunnett M, Smith NC.The pharmacokinetics of oral and intravenous allopurinol was studied in five horses and compared with intravenous oxypurinol. The plasma concentration vs. time curves, following intravenous administration of 5 mg/kg, were best described by the biexponential equations Cp = 106.58e(-25.14t) + 159.93e(-10.96t) for allopurinol and Cp = 321.09e(-9.72t) + 82.39e(-0.44t) for oxypurinol, with an elimination half-life (t1/2 beta) of 0.09 h and an area under the curve (AUC) of 19.8 mumol.h/L after intravenous administration, while the t1/2 beta and AUC of oxypurinol were 1.09 h and 231 mumol.h/L, respec...
Crabill MR, Watkins JP, Schneider RK, Auer JA.To determine the technique used, and the outcome for, double-plate fixation of comminuted fractures of the second phalanx of horses. Methods: Retrospective analysis of medical records. Methods: 10 horses with comminuted fractures of the second phalanx that were treated by use of double-plate fixation. Methods: Two 4- to 6-hole dynamic compression plates were abaxially placed to achieve arthrodesis of the proximal interphalangeal joint and fixation of the fracture of the second phalanx. Results: Arthrodesis and fracture healing were detected in all horses. Conclusions: Horses with comminuted fr...
Larsen M, Nansen P, Henriksen SA, Wolstrup J, Grønvold J, Zorn A, Wedø E.This study was undertaken to examine the potential of the nematode-trapping microfungus Duddingtonia flagrans to survive passage through the gastrointestinal tract of horses and subsequently to destroy free-living stages of cyathostomes in faecal cultures. Three different oral dose levels were tested, two horses being used for each level. Faeces were collected twice daily and the numbers of parasite eggs per gram of faeces were determined. The numbers of infective third stage larvae which developed in faecal cultures were determined after the cultures had been incubated for 2 weeks at 24 degre...
Paweska JT, Volkmann DH, Barnard BJ, Chirnside ED.Two in a group of five naturally seropositive donkey stallions were found to shed equine arteritis virus (EAV) in their semen as demonstrated by virus isolation. Direct intramuscular inoculation of sonicated semen from one virus-shedding stallion (S3) caused clinical disease in two donkeys from which virus was recovered and in which seroconversion was detected. Sexual transmission was confirmed in two mares mated to S3 when after a febrile response during which EAV was isolated from huffy coats and nasal and ocular exudates, both mares were found to have seroconverted. In-contact transmission ...
Dame JB, MacKay RJ, Yowell CA, Cutler TJ, Marsh A, Greiner EC.Equine protozoal myeloencephalitis (EPM) is a neurologic disease of horses caused by Sarcocystis neurona. The horse is a dead-end host for S. neurona and the definitive and intermediate hosts have not previously been identified. We hypothesized that S. neurona is actually Sarcocystis falcatula, a parasite that cycles in nature between Virginia opossums (Didelphis virginiana) and any of a variety of avian intermediate hosts. We extracted DNA from S. falcatula sarcocysts in the muscle of a brown-headed cowbird (Molothrus ater) and from schizonts in a fixed specimen of lung from a Moluccan cockat...
Fowden AL, Silver M.With the use of [U-14C]glucose tracer methodology, the rates of umbilical uptake, utilization, oxidation, and production of glucose were determined in nine chronically catheterized fetal foals in the fed state between 268 and 325 days of gestation (term approximately 335 days). At the same time, the rates of umbilical O2 and lactate uptake were measured in all nine fetuses by Fick principle. The mean fetal rates of umbilical glucose uptake, glucose utilization, and CO2 production from glucose carbon were 36.9 +/- 2.5, 36.4 +/- 1.7, and 117.7 +/- 17.4 mumol.min-1.kg fetal body wt-1, respectivel...
Daels PF, Mohammed HO, Odensvik K, Kindahl H.To determine the relative role of endogenous prostaglandin F2 alpha (PGF2 alpha) secretion in cloprostenol-induced abortion in mares that no longer require luteal progesterone secretion for maintenance of pregnancy, and to evaluate the ability of a prostaglandin cyclooxygenase inhibitor (flunixin meglumine) to prevent cloprostenol-induced abortion. Methods: The effect of flunixin meglumine on PGF2 alpha secretion and outcome of pregnancy was compared between mares treated with cloprostenol only and mares treated with cloprostenol plus flunixin meglumine. Methods: Five pregnant mares, aged 4 to...
Johnson PJ.Laboratory electrolyte and acid-base analyses are important for the characterization and assessment of the severity of disorders of fluid balance, and they enable the veterinarian to institute appropriate corrective therapeutic interventions. Abnormalities of electrolytes or acid-base rarely define the diagnosis, but certain diseases are characterized by predictable trends in these parameters. Important clinical situations in which assessment of electrolyte and acid-base status should be regarded as important to the equine practitioner include diarrhea, severe colic, peritonitis, pleuritis, dy...
Blikslager AT, Roberts MC.To assess the ability of clinicians to predict the site and type of lesion as well as outcome in horses with colic. Methods: Prospective case study. Methods: 139 horses admitted for evaluation of signs of colic. Methods: Six interns and residents examined horses with colic and predicted the segment of intestine that was affected, the type of lesion, and whether the horse would survive to discharge. Accuracy of prediction of site and type of lesion and survival prediction was compared between the first and second halves of the year, using chi 2 analysis and 95% confidence intervals on sensitivi...
Yvorchuk-St Jean K, Gaughan E, St Jean G, Frank R.To evaluate the effect of a porous bovine-derived collagen membrane (PBCM) on the rates of wound healing, cellular events, presence of granulation tissue, and appearance at termination of the study in surgically created full-thickness cutaneous wounds of the distal portion of the extremities of horses. Methods: Treated wounds (n = 12) received a PBCM dressing and control wounds were covered with a nonadherent dressing. Forelimbs and hind limbs were cross paired; the right forelimb and left hind limb always received the same dressing application, as did the left forelimb and right hind limb. Li...
Landoni MF, Lees P.The bioavailability of S(+) and R(-) ketoprofen (KTP) in six horses was investigated after oral administration of the racemic (rac) mixture. Two oral formulations were studied, an oil-based paste containing micronised rac-KTP and powder from the same source in hard gelatin capsules, each at a dose rate of 2.2 mg/kg. For the oil-based paste two feeding schedules were used; horses were either allowed free access to food or access to food was restricted for 4 h before and 5 h after dosing. The drug in hard gelatin capsules was administered to horses with restricted access to food. After intraveno...
Galey FD.In most competent veterinary diagnostic laboratories, analytical findings are interpreted by the veterinary toxicologist to determine the significance of the finding in view of historic, clinical, and pathologic findings. A veterinary toxicologist also will provide consultation about possible toxic rule-outs for a case, treatment of affected animals, and prevention of additional cases. Once all of the information is available, a complete summary of the findings can be provided to the client. When the procedures outlined are followed, including a systematic approach to collecting all the eviden...
Panu R, Bo Minelli L, Sanna L, Zedda M, Acone F, Gazza F, Palmieri G.The retractor clitoridis muscle originates from the coccygeal vertebrae in the cow, ewe, goat and mare, and from the anal musculature in the sow. It terminates at the base of the clitoris. In all the species considered, a vegetative innervation was found. This was represented by isolated or grouped ganglion cells. Nervous sensitive supply was also present. This was represented by Pacinian, Pacinian-like and Golgi-Mazzoni's corpuscles, and by Krauses's end bulbs. A notable difference was found in the amount and type of these receptors. They were numerous in the sow, ewe and goat, and rare in th...
Chirnside ED, Francis PM, Mumford JA.A series of recombinant fusion proteins derived from equine arteritis virus (EAV) open reading frame (ORF) 7 have been used to define the immunoreactive region of the viral nucleocapsid (N) protein. Reactivities of recombinant N fusion proteins with post-infection equine sera in immunoblots and ELISAs indicate that the major nucleocapsid protein epitope is located within amino acid residues 1-69. In ELISAs two recombinant nucleocapsid fusion proteins containing residues 1-69 (rN1-69) and 1-28 (rN1-28) discriminated between pre- and post-infection, and pre- and post-vaccination serum samples. A...
Sandoval JA, Gil F, Arencibia A, Ayala I, Vazquez JM.By using m-ATPase techniques, under alkaline and acid pre-incubations, as well as metabolic techniques (alpha-MGPDH and NADH-TR), sections from the lumbar and costal portions of diaphragm muscle in horse and dog were analysed. Fibre samples were exposed to image-analysis observations in order to determine the lowest fibre diameter and obtain statistical data. The findings revealed that the lumbar portion of horse diaphragm consists of fibre types I, IIA and IIB; in the costal portion, the fibre type I and IIA were present. In the dog, the lumbar and costal portions consisted of fibre types I, ...
Barlough JE, Madigan JE, DeRock E, Dumler JS, Bakken JS.A Thoroughbred filly that developed clinical signs of equine granulocytic ehrlichiosis following inoculation with the human granulocytotropic ehrlichia was shown to be resistant to challenge with Ehrlichia equi, a closely related agent. This result further substantiates the close and potentially conspecific relationship between these two granulocytotropic ehrlichiae.
Baxi MK, Efstathiou S, Lawrence G, Whalley JM, Slater JD, Field HJ.Neural tissues from specific pathogen-free ponies that had been experimentally infected with equine herpesvirus 1 (EHV-1) were analysed by in situ hybridization. Digoxigenin-labelled EHV-1 BamHI fragments spanning almost the entire EHV-1 genome were hybridized to RNA in tissue sections from latently infected trigeminal ganglia. The BamHI E fragment detected EHV-1 RNA antisense to gene 63 (HSV-1 homologue ICP0) in a small number of neurons. Sixteen other BamHI fragments gave negative results in 20 sections tested with each fragment. Latency associated transcripts (LATs) were localized to the ne...
van der Kolk JH, Wisse H, van Dijk S.A 20-year-old Arab crossbred gelding was examined because it had apparently suffered an overstimulation of the parasympathetic nervous system for three hours. The clinical signs consisted of hypersalivation, profuse sweating, maximal miosis, fasciculation of the muscles and lateral recumbency in combination with continuous convulsions without diarrhoea. The horse's plasma pseudocholinesterase activity was approximately 10 per cent of normal. It responded well to 10 mg atropine and 50 mg diazepam administered intravenously.
Takai S, Ohashi M, Suzuki Y, Sasaki Y, Kakuda T, Broens EM, Wagenaar JA, van Duijkeren E.Clinical samples from 123 foals with suspected rhodococcosis submitted to the Veterinary Microbiological Diagnostic Centre of the Faculty of Veterinary Medicine between 1993 and 2006 were tested for the presence of the virulence gene vapA. Of the 123 samples, 120 were vapA-positive and 3 vapA-negative Rhodococcus equi were isolated. The 120 vapA-positive R. equi were isolated from 70 tracheal wash, 19 lung tissues, 7 lymph nodes, 6 synovial fluids, 13 abscesses or pus and single isolates from the uterus, gut, cerebrospinal fluid, abdomen fluid and faeces. Of the 120 isolates, 46 were from Dutc...
Combarros D, Wilhelmi-Vilarrasa I, Lacroux C, Semin MO, Delverdier M, Grebert M, Trumel C, Cadiergues MC, Lallemand EA.Mast cell tumor (MCT) has long been considered as an uncommon neoplasm in horses. Cytological and behavioral evidence of its malignancy is usually lacking, and only a few reports have described MCT displaying malignant behavior. An 18-year-old Friesian stallion presented with a one-year history of intermittent and progressive skin lesions on the left forelimb associated with intense, generalized pruritus and apathy temporarily responsive to glucocorticoids and antibiotics. The horse was alert and responsive with poor body condition and marked generalized pruritus. The left forelimb was markedl...
Larrasa J, Garcia A, Ambrose NC, Alonso JM, Parra A, de Mendoza MH, Salazar J, Rey J, de Mendoza JH.Dermatophilus congolensis is the pathogenic actinomycete that causes dermatophilosis in cattle, lumpy wool in sheep and rain scald in horses. Phenotypic variation between isolates has previously been described, but its genetic basis, extent and importance have not been investigated. Standard DNA extraction methods are not always successful for D. congolensis due to its complex life cycle, one stage of which is encapsulated. Here we describe the development of rapid and reliable DNA extraction and random amplified polymorphic DNA (RAPD) methods that can be used for genotyping D. congolensis fie...
Stammers JP, Hull D, Silver M, Fowden AL, Ousey J, Rossdale PD.An in vitro incubation technique was used to examine release of lipids from the equine placenta. Placental tissue was obtained at term (n = 5, term = 320-365 days) and earlier in gestation (n = 8, mean = 266 days). Term placentae were incubated at two temperatures, 4 degrees C (control) and 37 degrees C for 2 h. Pre-term placentae were incubated at 37 degrees C with two different concentrations of fatty acid in the medium. Tissues and media were analysed for their lipid concentrations. Term and pre-term placentae released free fatty acid (FFA) and phospholipid into the incubation medium during...
Mayaki AM, Abdul Razak IS, Mohd Adzahan N, Mazlan M, Abdullah R.Equine chronic back pain (CBP) has been linked to different pathologic processes, which directly or indirectly involve spinal structures. Thus, making diagnosis and management very challenging with most horses with the condition recommended for early retirement from athletic activity. This study described the spinal cord lesions and the development of reactive microgliosis and astrocytosis in the spinal cords of horse with CBP. Thoracolumbar spinal cord segments from three horses euthanized because of unresolved CBP were dissected and grossly and histopathologically examined. The expression of...
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...
