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.
Dubin A, Koj A, Chudzik J.Cytoplasmic granules were isolated from horse blood polymorphonuclear leucocytes by the heparin method and extracted with 0.9% NaCl by repeated freezing. Soluble proteins were separated on a column of Sephadex G-75 followed by chromatography on a column of CM-Sephadex with a NaCl gradient. Gel filtration, density-gradient centrifugation, isoelectric focusing and 0.1% sodium dodecyl sulphate/polyacrylamide-gel electrophoresis at pH 7.0 and at pH 4.5 were used to determine molecular parameters of proteinases. Three enzymes hydrolysing both casein and N-benzyloxycarbonyl-L-alanine nitrophenyl est...
Aberle ED, Judge MD, Kirkham WW, Page EH, Crawford BH.Frozen sections of equine musculus semitendinosus were examined for myosin adenosine triphosphatase (ATPase) and reduced nicotinamide adenine dinucleotide-tetrazolium reductase (NADH-TR), using standard histochemical procedures, and the proportions of the various fiber types and average fiber sectional size were determined. With ATPase staining, approximately 70% of the fibers were classified as alpha fibers (ATPase positive), and 30%, as beta fibers (ATPase negative). In addition, 2 populations of alpha fibers could be readily distinguished on the basis of the intensity of the ATPase reaction...
Balun J, Sutta J, Janda J.In this paper the haemocoagulative effect of the Vasolamin preparation was examined after intravenous application in cattle, sheep, and horses by means of tests. After a laboratory confirmation of the coagulative effect of the tested preparation we used it for the purpose of haemostasis in the clinical practice. After an administration of the preparation faster coagulation of the blood was observed in all examined animals. The setting in of the effect could be observed already after 5 minutes, the maximum effect was recorded between the 15th and 30th minutes after application, and the effect l...
Nitschelm D, Van der Horst CJ.The hormonal pattern in the blood of eight mares was studied during the first 5 to 6 weeks of pregnancy; in two of the eight animals early embryonic death was established on D-28 and on D-40, respectively. Progesterone peaks were found in the blood around D-5, D-12 to D-10, and D-17 to D-18. It is suggested that the decrease of the progesterone concentrations in the blood during the intermediate periods is due to the action of oestrogens. During the period from D-18 to about D-34 the concentrations both of progesterone and of pregnenolone were low in the pregnant mares. Thereafter a small incr...
Wetz K, Crichton RR.In apoferritin, but not in ferritin, 1.0 +/- 0.1 cysteine residue per subunit can be modified. In ferritin 3.3 +/- 0.3 lysine residues and 7.1 +/- 0.7 carboxyl groups per subunit can be modified, whilst the corresponding values for apoferritin are 4.4 +/- 0.4 lysine residues and 11.0 +/- 0.4 carboxyl groups per subunit. Modification of lysine residues which maleic anhydride and carboxyl groups with glycineamide in apoferritin which has been dissociated and denatured in guanidine hydrochloride leads to the introduction of 9.1 +/- 0.5 maleyl groups per subunit and 22.0 +/- 0.9 glycineamide resid...
Sells DM, Hildebrandt PK, Lewis GE, Nyindo MB, Ristic M.The ultrastructure of the etiological agent of equine ehrlichiosis, Ehrlichia equi, was studied in equine peripheral leukocytes. The organisms occurred within membrane-lined cytoplasmic vacuoles of neutrophils and eosinophils. Ovoid, round, and rod-shaped profiles were observed. From 1 to 33 organisms were present in a thin-section profile of a cytoplasmic vacuole. Many cells contained multiple organism-containing vacuoles. The organisms had a cell wall and plasma membrane, and internally they consisted of electron-dense and lucid areas. A great variation in size was observed. The morphologica...
Seybert DW, Moffat K, Gibson QH.The reactions of horse globin reconstituted with proto-, deutero-, and mesoheme have been examined by equilibrium and kinetic methods. In virtually all reactions studied, mesohemoglobin displays the more extreme functional behavior, whereas deuterohemoglobin exhibits behavior which is either very similar to native hemoglobin or intermediate between the two. Our kinetic and equilibrium results indicate that the primary effect of heme modification on the functional properties of hemoglobin is to alter the intrinsic reactivities of the deoxy and liganded conformations. Heme modification does not,...
Hawkins JA, Adams WV, Wilson BH, Issel CJ, Roth EE.The mechanical transmission of equine infectious anemia (EIA) virus by Tabanus fuscicostatus was investigated. In 1 of 7 transmission trials, a single horsefly transmitted EIA virus from an acutely infected pony to a susceptible pony. Groups of horseflies isolated for 3, 10, or 30 minutes before refeeding transmitted EIA virus, whereas those isolated for 4 or 24 hours did not. Data from field studies indicate that the home range or flight distance of horseflies may exceed 4 miles. That information together with our observations suggest that segregation of infected horses (usually defined as at...
Walthall JC, McKenzie RA.Horses grazing manily Cenchrus ciliaris and/or Panicum maximum var. trichoglume pastures on over 30 properties in southern central Queensland developed lesions of osteodystrophia fibrosa. Horses on individual properties in coastal Queensland grazing Setaria anceps, Brachiaria mutica or Pennisetum clandestinum also developed the disease. Ill-thrift, lameness, and fibrous swellings of nasal bones, maxillae and mandibles were observed. Calcium and phosphorus levels of pasture were normal but all the above pasture species contained oxalates which were suspected of causing the disease.
Komárek J, Stros K, Sýkora I, Kynclová I, Jadrný L, Selinger P.By means of the Astrup equilibration method the values of the acid-base balance of the blood were determined in 104 cows, 99 horses, 100 pigs, 15 sheep, 20 goats, and in 101 dogs. The pH values of the blood, the partial pressure of CO2, the base excess, the base buffer, the standard bicarbonate, the actual bicarbonate, and the total CO2 were processed statistically and are presented in tables.
Hart LT, Braymer HD, Larson AD, Broussard EA.Equine infectious anemia (EIA) antigen extracted from the spleen of horses infected with EIA virus was purified by pH treatment, (NH4)2SO4 fractionation and affinity chromatography. The homogeneity of the antigen was indicated by sedimentation rate and sedimentation equilibrium experiments. A S20,w of 0.51 was determined and a molecular weight of 7600 was calculated from sedimentation equilibrium analysis. The amino acid composition of the pure antigen indicated the antigen is an acidic protein. Employing radical immunodiffusion (RID) and pure antigen a method for quantitating antigen content ...
Holmes JR.The paper describes the spatial vector changes during ventricular depolarisation in 190 horses using a semi-orthogonal ECG lead system. The replacement of planar vector loops by a plot of 3 parameters to depict the changing spatial vector, with a time base on the X axis, is described and illustrated. Some horses with diastolic murmurs and some with a history of respiratory problems formed 2 distinct groups. As a result of these findings a possible relationship between the vector changes and the anatomical siting of the ventricles is suggested and discussed. Attention is drawn to certain measur...
Allen JL, Herbert G, Muscatello G, Gilkerson JR.Bronchopneumonia caused by Rhodococcus equi is an important disease of young horses throughout the world. Although early diagnosis and treatment improves the prognosis, this also increases the amount of antimicrobial usage and therefore increases the likelihood of resistance developing. Objective: The aim of this study was to determine the level of resistance to commonly prescribed antimicrobial agents of 97 virulent Rhodococcus equi isolates. Methods: Analysis of archived samples. Methods: Virulent Rhodococcus equi isolates were collected between 1991 and 2014 from clinically affected horses ...
Lány P, Pospísil Z, Zendulková D, Cíhal P, Jahn P.A mild outbreak of acute respiratory infection was reported in racing horses in the fall of 1995. Four studs were investigated for the sources and routes of infection. In five horses from two herds, virus isolates were obtained which, in preliminary typing experiments, were identified as the influenza A/equi 2 virus. The presence of this illness in all the examined herds was confirmed by a rise in specific antibody titres. The affected animals included both older vaccinated horses and young horses not yet vaccinated. Epidemiological studies suggested that the spread of infection occurred in si...
Peremans K, Verschooten F, De Moor A, Desmet P.The clinical and radiographic findings in 21 ponies with laminitis and its treatment and results are described. All ponies received non-steroidal anti-inflammatory drugs. All were fed hay and no concentrates. They were box rested for varying periods depending on clinical improvement. Dorsal hoof wall resection was performed in 11 ponies and all regained complete soundness. To shorten the period of non-activity, working ponies were shod and the hoof wall defect was packed with technovit or a combination of glue with cotton cuttings. Ten were treated conservatively; two recovered completely, fou...
Munro CD, Renton JP, Butcher R.Using a range of positive and negative sexual behaviour components, proceptivity of cycling, non-lactating mares and postpartum, lactating Pony mares was quantified around ovulation. Behavioural observations were compared to plasms concentrations of progesterone, total oestrogens and androstenedione. In addition, in cycling mares, comparison with plasma testosterone concentrations was carried out. Overall rejection behaviour by the mare was apparent both during dioestrus and during periods of basal plasma progesterone concentrations. Within cycling, non-lactating mares, and between postpartum ...
Ringeisen H, Pöschke A, Krähling B, Schröck C, Stoll M, Vogelsberg J, Failing K, Staszyk C.Therapy for equine periodontal disease can include filling of the periodontal pockets and widened interproximal spaces. Recommended dental materials are generally adopted from human dentistry. Objective: To evaluate the biocompatibility of dental materials for equine periodontal fillings in vitro. Methods: In vitro experiments. Methods: Four different dental materials (PeriCare , Provicol , Calxyl and Honigum) were tested on equine periodontal fibroblasts. Possible cytotoxic effects were assessed microscopically and by MTT assay, and the expression of inflammatory marker genes was measured by...
Vitour D, Zientara S, Fablet A, Bréard E, Sailleau C.African horse sickness (AHS) is a major arthropod-borne disease that causes significant losses in horses in sub-Saharan Africa. It is caused by the African horse sickness virus (AHSV), which is transmitted during a blood meal by Culicoides biting midges. The distribution of historical African culicoid vectors increases due to global warming. In addition, recent (Thailand, 2020) and earlier (Iberian Peninsula, 1965-66/1987-90) AHS outbreaks outside Africa demonstrate the adaptation of the virus to endogenous species in AHS-free regions, similar to what has been observed for bluetongue disease i...
Ellerbrock RE, Canisso IF, Podico G, Roady PJ, Uhl E, Lima FS, Li Z.While recent work demonstrated that enrofloxacin and ciprofloxacin reach the fetoplacental unit without causing obvious lesions in the 9-month-old equine fetus or resulting foal, many practitioners still hesitate to prescribe a fluoroquinolone during pregnancy. Since early gestation is a critical time for fetal skeletal development, if fluoroquinolones are chondrotoxic to the fetus at any point during gestation, this period would be important. The aim of this study was to assess the effects of 2 weeks' exposure to enrofloxacin on the equine fetus between 46 and 60 days gestation. Twelve pregna...
Hayes AM, Kastl B, Perry E, Moore AR, Springer NL.Myeloma-related disorders, including multiple myeloma, extramedullary plasmacytoma, and solid osseous plasmacytoma, are rare in horses. Clinical complaints for myeloma-related disorders are nonspecific, and when present, M-protein location is more variable on protein electrophoresis in horses relative to dogs and cats. Here, we describe a case of a 15-year-old Thoroughbred mare who presented with recurrent blepharitis. Marked hyperglobulinemia was an incidental finding on routine hematologic and biochemical testing. Bone marrow aspiration consisted of >30% plasma cells, and serum protein el...
Bischoff K, Moiseff J.Feed as a cause of poisoning in horses can occur on small or large scales. It is challenging to work up cases of suspected feed contamination, but there are resources available to veterinarians and owners. Feed contamination can be chemical or biological. This article focuses on and provides examples of chemical feed contamination including misformulation, adulteration, and natural contaminants. Additionally, recommendations for feed sampling and diagnostic submission, including legal documentation, are included.
Costello S, Heffron B, Taddei L, Benoit M, Hurt L, Simpson L, Bishop J, Folker-Calderon D, Negrusz A.Fluphenazine, a potent antipsychotic used to treat schizophrenia in humans, is used in racehorses as a performance-enhancing drug, and for that reason it has been banned by the Association of Racing Commissioners International. A liquid chromatography-tandem mass spectrometry method for detecting and quantitating fluphenazine in equine serum was developed and validated. The method was then employed to quantitate fluphenazine in serum samples collected from three study horses after intramuscular injection of fluphenazine decanoate. Stability testing showed that fluphenazine is stable in unextra...
Thompson DL, Pickett BW, Squires EL, Nett TM.Sixteen stallions were castrated and 30 days later assigned to one of four treatments: (1) testosterone propionate (175 microgram/kg body weight), (2) 17 beta-estradiol-3-benzoate (44 micrograms/kg body weight), (3) a combination of both steroids or, (4) vehicle only. These dosage were administered every other day for 18 days. The dosages were then doubled and continued for 20 days. Concentrations of testosterone and estradiol in serum decreased rapidly after castration and stabilized within about 6 hours. Mean concentrations of testosterone and estradiol maintained by the steroids were 1.4 an...
Scott JS, Berney CE, Derksen FJ, Robinson NE.Pulmonary function measurements were made in control ponies and in ponies with recurrent obstructive pulmonary disease (principals) during clinical remission and during an attack of acute airway obstruction. The ponies were given beta-adrenergic antagonists and agonists to determine the role of beta receptors in recurrent obstructive pulmonary disease, and to determine the subtypes of beta receptors mediating bronchodilation in ponies. Aerosol administration of the beta antagonists, propranolol (beta 1 and beta 2), atenolol (beta 1), and butoxamine (beta 2) decreased dynamic compliance (Cdyn) ...
Marr CM, Bright JM, Marlin DJ, Harris PA, Roberts CA.We hypothesised that exercise in a hot and humid environment would affect echocardiographic indices of cardiac dimensions and function more than exercise in a cool environment. M-mode echocardiograms were obtained in 5 clinically normal horses before, and at 0, 10, 30 and 60 min after a treadmill exercise test. The test was performed in a controlled environment at 20 degrees C/40% relative humidity (RH) and again at 30 degrees C/80% RH. All the horses completed the exercise test in cool conditions, but only one horse completed the exercise test in the hot/humid environment. The relaxation time...
Lochner F, Sherban DG, Sangiah S, Mauromoustakos A.Using a modified bovine milk enzyme kinetic assay, xanthine oxidase activity of serum collected from 34 adult, healthy horses of both sexes was determined. Enzyme activity varied from 0 to 126 mU litre-1 with a mean of 44.95 +/- 21.05 mU litre-1. The optimal pH and temperature for maximal activity were 7.8 and 28 degrees C, respectively. Freezing the serum for four days at -70 degrees C did not destroy the enzyme activity. Various doses (25, 50 and 75 micrograms kg-1, intraperitoneally) of endotoxin (lipopolysaccharide D1 Escherichia coli O26:B6) previously known to have caused moderate to sev...
Sonea IM, Bowker RM, Broadstone RV, Robinson NE.The tone of respiratory smooth muscle is largely determined by the input from autonomic nerves. The distribution of adrenergic and selected nonadrenergic, non-cholinergic (NANC) nerves in the normal equine trachealis muscle was investigated using immunohistochemistry. The smooth muscle of the trachealis was found to contain numerous nerves immunoreactive for an enzymatic marker of adrenergic nerves, as well as many nerves immunoreactive for a putative NANC neurotransmitter, peptide histidine isoleucine, a potent bronchodilator. The tissue surrounding the respiratory smooth muscle contained num...
Gerken DF, Sams RA.Although all the factors discussed in this article may have an effect on drug withholding time estimates, the factors that have the potential for the greatest effect or that have been found to cause positive tests in the past are 1. Dosage: Increasing the drug dosage will require a longer withholding time. 2. Dosing interval: Narrowing the dosing interval will require a longer withholding time. 3. Administration route: In general, oral administration results in lower peak plasma concentrations but may result in longer excretion in the urine and therefore longer withholding time. 4. Drug intera...
Shamis LD, Sanders-Shamis M, Bramlage LR.A 3-week-old Standardbred filly had a non-weightbearing forelimb lameness caused by scapular neck fracture. The fracture was repaired with 2 dynamic compression plates placed 90 degrees to each other. A 10-hole 4.5-mm narrow dynamic compression plate was placed on the cranial aspect of the scapular spine, and a 10-hole 3.5-mm dynamic compression plate was placed caudal to the scapular spine. One year after surgery, the filly was not lame when exercising in the pasture, and muscle atrophy was not evident on the affected limb. Eighteen months after surgery, the filly was in race training with no...
