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.
Lane JG, Longstaffe JA, Gibbs C.The clinical and radiographic features of 15 cases of paranasal sinus cysts are described. Breed, sex and side frequency were unremarkable but two distinct categories of age incidence emerged. Onset of signs had occurred before one year of age in three cases, while all but two of the remaining 12 animals were older than nine years. The most common clinical signs were nasal airway obstruction, facial swelling and nasal discharge, often occurring in combination. Radiographic changes were recorded in all horses. Sinus opacification was a consistent finding and in several cases the bone surroundin...
Pfeiffer CJ, Murray MJ, Fainter L.The granular columnar epithelial cell of the equine dorsal large colon has been studied by transmission electron microscopy and X-ray microanalysis. Particular attention was focused on nuclear bodies commonly observed as central clusters of spherical, electron-dense inclusions within the nucleus. Ultrastructural morphology as well as X-ray microanalysis spectra reveal great similarity between colonic nuclear bodies and the numerous small granules of the apical cytoplasm in these epithelial cells. X-ray spectra of these cells were distinct from those of goblet cell mucous granules and mast cell...
Reinemeyer R, Henton JE.A program of rotational anthelmintic treatments at eight-week intervals had failed to provide satisfactory equine strongyle control at a stable in southern USA. Anthelmintic resistance had rendered benzimidazoles ineffective, and intervals between treatments with other drugs were too great to prevent environmental contamination with ova. Ivermectin treatments at eight week intervals or pyrantel pamoate treatments at four week intervals successfully reduced egg counts for the majority of the summer grazing period. In southern temperate USA, translation of strongyle ova to larvae was most effici...
Barton MD, Embury DH.Pyogranulomatous pneumonia was induced in Thoroughbred foals by intranasal challenge with freeze-dried cultures of Rhodococcus equi (previously Corynebacterium equi). The incubation period was about 18 days and clinical signs were not seen for a further week. There were marked seasonal and individual foal differences in responses to infection. Elevations in serum caeruloplasmin oxidase activity and copper concentrations appeared to be sensitive indicators of infection. Serum zinc concentrations and serum alpha-mannosidase and alkaline phosphatase activities fell in the more severely infected f...
Houle JJ, Hoffmann EM.A passive hemolysis assay system was developed which permitted comparisons of the hemolytic activities of complement (C) from six species. This system employs a single antigen and an antiserum raised in one species. Thus, variations resulting from different target antigens and those inherent in using antibodies (of different affinities and isotypes) raised in a variety of species were minimized. Of the erythrocytes (E) examined, those from horses and guinea pigs were most susceptible to lysis, and either would be suitable, as a tentative choice, for measuring C activity of a previously unstudi...
Nishita T, Matsushita H, Kai M.The location of carbonic anhydrase III (CA-III) in frozen sections of biopsies of Thoroughbred horse skeletal muscle was studied. Fibre types were determined by ATP-ase and succinate dehydrogenase staining. CA-III isozyme was detected using a peroxidase conjugated anti-CA-III antibody. CA-III was found to be localised in slow twitch oxidative fibres (ST), but was also present in fast twitch oxidative (FTH) fibres in small amounts. Fast twitch glycolytic (FT) fibres were stained lightly compared with control sections. The concentrations of CA-III in muscle and liver were 70 micrograms/mg protei...
Haluska GJ, Lowe JE, Currie WB.Recordings of uterine electrical activity were made from 5 pregnant pony mares from Day 141 to 320 of pregnancy. Three types of activity were identified. Short, medium and long bursts were quantified as the percentage of time each occurred during the hour analysed and further categorized according to frequency, amplitude and duration. The uterus was most active during the early stages recorded and became increasingly quiescent after Day 240. Short-burst activity was greatest when the uterus was most quiescent. Long bursts showed the greatest percentage of activity until Day 220 and then decrea...
Karimi A.Two methods of anaesthesia were evaluated in the horse for their effects on the cardiovascular and respiratory systems and on the acid-base status of the animal. In addition the effect of the position—dorsal and lateral recumbency—of the anaesthetized horse on these systems was evaluated.
Peyrot LM, Little TV, Lowe JE, Weber JA, Woods GL.Embryo autotransfer is defined as the collection of an embryo from and the transfer of this embryo into the same animal. The objectives of this study were to: 1) test the hypothesis that oviduct transport of the equine embryo from the oviduct into the uterus is not dependent on a unilateral embryo-corpus luteum interaction, 2) develop an embryo autotransfer technique for the mare and 3) compare the success rates of Day 4 embryos surgically autotransferred from the oviduct ipsilateral to ovulation to either the oviduct (n=10 mares) or the uterine horn (n=10 mares) contralateral to ovulation. Se...
Bridges CG, Edington N.Six Welsh Mountain pony foals were experimentally infected with a subtype 2 isolate of Equid Herpesvirus 1 (EHV-1) and subsequently examined for T cell mediated cytotoxicity against both subtypes. Cytotoxicity was not observed at 3 or 7 days after primary exposure but virus-specific, and genetically restricted, cytotoxicity of EHV-1-labelled autologous skin fibroblasts could be demonstrated 7 and 21 days after the animals were given a second exposure to live virus. Killing of subtype 2 antigen-labelled targets was more efficient than subtype 1 coated cells. This finding was paralleled by the o...
Fu ZF, Denby L, Lien DH, Robinson AJ.An indirect enzyme-linked immunosorbent assay (ELISA) was developed for the detection of antibodies against equine herpesvirus type 2 (EHV-2) in equine sera. The optimal conditions of antigen concentration, and serum and conjugate dilutions were established by chequerboard titrations. When the standard ELISA test was used for titration of test sera, it was found to give titres approximately 1500 times higher than those obtained in the virus neutralization (VN) test, and a correlation coefficient of 0.815 was obtained between these two tests on 42 equine sera. All the positive serum samples by ...
Kikuchi N, Iguchi I, Hiramune T.A survey of K. pneumoniae was performed on cervical swabs, feces and nasal swabs of mares and on samples from the genital tract of stallions from 1980 to 1986 in south-western Hokkaido, Japan. K1 was the predominant type (79 of 88, 89.8%) in the metritis cases due to K. pneumoniae in mares of racing breeds. The same type was isolated from semen and swabs of the fossa glandis of 6 of 20 (30.0%) of the stallions of racing breeds. Heavily encapsulated and less heavily encapsulated K1 strains were isolated from the stallions. Mares bred to stallions carrying heavily encapsulated strains developed ...
Hedenstierna G, Nyman G, Kvart C, Funkquist B.The multiple inert gas elimination technique was adapted for use in the conscious standing horse. The modifications included increased infusion rate of the inert gases (30 ml/min), extended infusion time (60 mins) in order to reach steady state, and construction of a nose mask mixing box system for collection of expired gas. Eight adult horses with a mean weight of 454 kg and a mean age of 6.1 years were studied while standing under resting conditions. Ventilation was 65.2 liters/min and cardiac output measured by thermodilution 40.2 liters/min. Systemic and pulmonary artery mean pressures wer...
Johnson PJ, Goetz TE, Baker GJ, Foreman JH.Two mares were examined because of urinary incontinence. Abnormalities of the genitourinary tract were identified and were corrected surgically. Urinary incontinence in mares generally is associated with a poor prognosis. The importance of a thorough physical examination of the genitourinary tract in the mare is emphasized, and the simple and successful surgical correction of structural abnormalities of the tract in 2 mares is described.
Johnston JK, Neely DP, Latterman SA.A 4.5-month-old Standard-bred filly was referred for evaluation of pigmenturia. Initially, the pigmenturia had resolved with the administration of antibiotics, only to recur after their withdrawal. A dark red urine sample contained numerous RBC, WBC, and gram-negative rods (Escherichia coli). Ultrasonography revealed the right kidney to be large, with multiple cystic structures and a dilated renal pelvis and calices. Cystoscopy revealed a large blood clot within the bladder and urine coming from the left ureteral opening. Urine was not observed coming from the right ureter. It was suspected th...
Serteyn D, Coppens P, Mottart E, Michelet S, Micheels J, Philippart C, Lamy M.The cardiovascular function of horses was less depressed during anaesthesia with isoflurane than during anaesthesia with halothane. Muscular microcirculation measured by laser Doppler flowmetry was significantly greater in horses anaesthetised with isoflurane.
Baker GJ, Moustafa MA, Boero MJ, Foreman JH, Wilson DA.The caudal cruciate ligament assists the medial femorotibial ligament in supporting the medial aspect of the femorotibial joint. It also limits the outward rotation of the tibia during weight bearing. In two lame horses tearing of the caudal portion of the femoral attachment of the caudal cruciate ligament was recorded together with cracking and tearing of the medial meniscus. In one case, synovitis and restrictive fibrous periarthritis were the sequelae of secondary stifle sepsis.
Chirino-Trejo JM, Prescott JF, Yager JA.Two groups of three one to three week old foals were immunized orally on four occasions over five weeks with two strains of Rhodococcus equi, a clinical isolate from a pneumonic foal and a laboratory passaged Congo red negative variant of this strain. Three nonimmunized foals of similar age acted as controls. Three weeks after the last immunization, all foals were challenged on five occasions over seven days by aerosol infection with about 10(10) of the pneumonic foal isolate on each occasion. Control foals became seriously ill and were euthanized. Immunization with either strain protected foa...
Nakazawa M, Isayama Y, Kashiwazaki M, Yasui T.A protein antigen that reacted in the agar gel diffusion (AGD) test and which had equi factor(s) activity, was partially purified from the culture supernatant of Rhodococcus equi by successive column chromatography on diethylaminoethyl cellulose and Sepharose 4B. Employing a standard foal serum, the concentration of this antigen was adjusted for the AGD test. Optimal dilutions of the antigen reacted in the AGD test with sera from foals naturally infected with serologically different R. equi. The antigen prepared was considered suitable for use in field surveys of R. equi infection. Accordingly...
McCann JS, Meacham TN, Fontenot JP.The digestibility and heat production values for three fats of different origin were determined. Four pony geldings (225 kg) were used in a study consisting of four successive digestion trials utilizing a 4 X 4 Latin square design. The four dietary treatments were basal alone and supplemented with 15% corn oil, blended fat or inedible tallow. The blended fat was composed of a mixture of animal and vegetable fats. A 7-d preliminary period preceded a 7-d total fecal collection period for each trial. Heat production values were obtained by indirect calorimetry and calculated from oxygen consumpti...
Oge S, Oge H, Yildirim A, Kircali F.Necropsies on 43 horses, 35 donkeys and two mules slaughtered in Ankara, Turkey, revealed that 12 (15%) of the equines harboured adult Setaria equina. When blood samples were checked for microfilariae, using Knott's method and a combination of membrane filtration followed by histochemical staining for acid phosphatase (AP), only three (4%) of the animals were found to be microfilaraemic. When stained for AP, the S. equina microfilariae exhibited diffuse red staining over the entire body, including the sheath, with brighter staining around the anal and excretory pores. Application of Knott's me...
Brink P.To describe surgical transposition of the levator labii superioris muscle to treat oromaxillary sinus fistula in horses. Methods: Clinical study. Methods: Three horses with chronic oromaxillary sinus fistula. Methods: After severing its tendinous insertion, the muscle belly of the levator labii superioris muscle was retracted and transposed through the oromaxillary sinus fistula. The tendon exited the oral cavity through a full-thickness buccal incision created adjacent to the oral end of the fistula and was then tunneled subcutaneously in a ventral direction before being anchored by sutures t...
Glaze MB, McGuire TC, Schmidt GM, Leid RW.A quantitative investigation of equine tear and aqueous humor immunoglobulins was done using normal horses and ponies as well as horses and ponies infected with Onchocerca cervicalis. The equine immunoglobulin isotypes IgGa, IgM, IgA and IgG(T) were quantitated by either single radial immunodiffusion (SRID) or radioimmunoassay (RIA). Tear immunoglobulin levels for IgGa (128 +/- 151 micrograms/ml), IgA (1,664 +/- 1,038 micrograms/ml) and IgM (106 +/- 74 micrograms/ml) were measured, while IgG(T) was not detectable. In horses with ocular inflammation the IgGa was 18-fold higher in the tears, 2,2...
Olive J, Lambert N, Bubeck KA, Beauchamp G, Laverty S.To ultrasonographically quantify experimentally induced effusion of the distal interphalangeal (DIP) joint of horses and compare results with those obtained with palpation. Methods: 8 forelimbs from equine cadavers and forelimbs of 5 mares. Methods: Preliminary ex vivo experiments were performed to validate the methods. Then, the DIP joints of the forelimbs of standing horses were serially distended with saline (0.9% NaCl) solution (1, 4, and 10 mL) by injection through an intra-articular catheter. Two ultrasonographers measured distension of the dorsal recess of the DIP joint, and 2 surgeons,...
Raisbeck MF, Garner HE, Osweiler GD.Gram negative endotoxins play a contributory role in the syndrome which results from over consumption of carbohydrates by horses and ponies. Since the antibiotic polymyxin B exerts a direct anti-endotoxin effect by chemically modifying the active lipid A moiety of endotoxin, it might be expected to protect horses after carbohydrate overload and provide a new therapeutic and experimental tool for this condition. The present study was undertaken to evaluate the effect of polymyxin B on hemostatic, hemodynamic, acid-base, and clinical aspects of the syndrome resulting from carbohydrate overload. ...
Rupić V, Bacar-Huskić L, Lojkić M, Habe F, Ergotić N.Research was carried out into the effect that different quantities and compositions of concentrated portions of meal had on certain haematological properties and on the immune response of mares in the course of hyper-immune antitetanus sera production. The experiment involved 24 Nonius and Lipizzaner cross-bred mares divided into two groups of 12 animals each, a control group and a trial group. The experiment lasted 12 months, with haematological and immunological tests being carried out every 30 days. During the course of the experiment each mare was subjected to 11 immunisation cycles, and i...
Wyn-Jones G, Peremans KY, May SA.The management of a case of quadrilateral flexural contracture in a 10-year-old pony is described. The animal was restored to normal appearance and function through a combination of surgical desmotomy and management techniques; the importance of analgesia and exercise as adjuncts to surgery is emphasised. The aetiology and pathogenesis of the condition in the immature animal and the adult is compared and a possible association is made between this condition and palmar fibromatosis (Dupuytren's contracture) occurring in man.
Winder NC, von Fellenberg R.In lungs from 22 horses, the number and type of mast cells in histologically normal specimens were compared with those in specimens with various histological lesions. Tissues fixed in Carnoy's solution were superior to those fixed in formalin for the identification of mast cells. Fixation of lung specimens from eight horses in Carnoy's solution and formalin allowed the identification of two subpopulations of mast cells: formalin-sensitive, which predominated and formalin-resistant. Specimens with mild chronic tracheitis and mild and moderate chronic bronchitis generally had slight increases in...
Wong KS, Cheung HW, Choi YC, To NS, Wan TSM, Ho ENM.Recombinant human follistatin (rhFST) is a potential performance-enhancing agent owing to its stimulating effect on muscle growth. Administration of rhFST to athletes is prohibited in human sports by the World Anti-Doping Agency (WADA) and in horseracing according to Article 6 of the International Agreement on Breeding, Racing and Wagering published by the International Federation of Horseracing Authorities (IFHA). For effective control of the potential misuse of rhFST in flat racing, methods for screening and confirmatory analysis are required. This paper describes the development and validat...
Metz GE, Serena MS, Ocampos GM, Panei CJ, Fernandez VL, Echeverría MG.Equine arteritis virus (EAV) was isolated from a testicle of the presumable first stallion infected with EAV in Argentina. This virus isolate (named LT-LP-ARG) was confirmed by GP5-specific PCR and indirect immunofluorescence assays. The PCR product was sequenced, and the phylogenetic analysis revealed that the LT-LP-ARG strain of EAV forms a monophyletic group, together with other strains previously isolated in our laboratory (LP02 group). However, all Argentinean EAV strains belong to a polyphyletic group. We believe that the virus isolate presented in this report could be the origin of EAV ...
Jiang B, Rugh KS, Hatfield DG, Jiang D, Hahn AW.We report on a nonlinear algorithm which identifies R-wave peaks on the surface electrocardiogram, consistent reference points on the left ventricular pressure waveform and the initiation of the QRS complex on the epicardial electrogram. The algorithm has been used to evaluate data from horses, ponies, dogs and humans at rest and during exercise. It permits rapid, accurate evaluation of data on a beat-by-beat basis even with noisy signals and varying waveform configurations. The algorithm facilitates the acquisition of detailed information previously difficult or impossible to obtain by more c...
O'Brien RT, Biller DS.This article addresses the current status and clinical opportunities for portable radiography and ultrasonography. Radiology is indicated for imaging the nasal cavity, larynx, pharynx and thin portions of the neck. In young foals, adequate radiographs of the entire respiratory tract may be possible. Ultrasonography is indicated in superficial parts of the head and neck, the pleural space and diseased parts of the lungfields.
Harland MM, Fedele C, Berens v Rautenfeld D.Horses are highly susceptible to lymphedema. Knowledge of the morphological components of lymphatic collectors is therefore essential to understanding the function of the lymphatic system. A better knowledge of the lymphatic system allows the development of more effective treatments against lymphedema. The composition of hypodermal and deep lymphatic collectors was investigated with immunohistochemical staining, using antibodies against proteins of the collector walls from the skin in the hind limbs of 10 healthy horses. Lymphatic collectors can be subdivided into passive (elastic fibers) and ...
Prado TM, Schumacher J, Kelly GM, Henry RW.The urethral fold of 30 mares was split transversely into dorsal and ventral shelves, and the ventral shelf was used to help create a urethral extension. The dorsal shelf was stretched caudally and sutured to the roof of the extension so that it covered at least the cranial half of the extension. For 20 mares, a relaxing, vaginal incision was created cranial to the external urethral orifice to enable the dorsal shelf to be retracted further caudally. Ten of the 30 mares (33.3 per cent) developed a defect, but none developed a defect in that portion covered by the dorsal shelf of the urethral f...
Gideon L.Esophageal anastomosis was performed on 2 foals after resecting a midcervical stricture. Nasogastric tube alimentation and antibiotic therapy allowed these foals to recover, and they matured to useful performing horses. These cases demonstrated a feasible and successful surgical management regimen for the strictured esophagus.