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.
Holland RE, Grimes SD, Walker RD, Wilson RA.Hemolytic E. coli strain 807-13, O149:NM:K88(STb+, LT+), was isolated from the feces of a neonatal diarrheic foal. E. coli 807-13 was examined for adhesion to brush border membranes (BBM) from foals, adult horses and pigs, and its pathogenicity was assessed in neonatal foals and pigs. E. coli 807-13 did not adhere to equine BBM but adhered to pig BBM. It did not cause diarrhea nor did it colonize the intestinal epithelium of 3 colostrum-deprived and 3 suckled foals challenged at 24 h of age. Acute ulcerative gastritis and acute suppurative gastritis were observed in 2 colostrum-deprived challe...
Ainsworth DM, Eicker SW, Nalevanko ME, Ducharme NG, Hackett RP, Snedden K.Horses chronically-instrumented with costal diaphragmatic electromyographic electrodes were studied during exercise while unencumbered by a breathing mask. Exercise-associated changes in esophageal (Pes), gastric (Pga) and transdiaphragmatic (Pdi) pressures were measured and related to diaphragmatic electromyographic activity (CS EMG) and to left forelimb impact. In all breaths examined, CS EMG always coincided with decrements in Pes. For all exercise trials, linear increases in CS EMG, Pga and Pdi and linear decreases in Pes, as a function of exercise intensity, always occurred. During all ga...
Gasser RB, Stevenson LA, Chilton NB, Nansen P, Bucknell DG, Beveridge I.Five species of equine strongyle belonging to the subfamily Strongylinae (Strongylus edentatus, S. equinus, S. vulgaris, Oesophagodontus robustus and Triodontophorus serratus) and 11 species belonging to the subfamily Cyathostominae (Poteriostomum imparidentatum, P. ratzii, Cylicocyclus insignis, Cc. leptostomus, Cc. nassatus, Cylicostephanus calicatus, Cs. longibursatus, Cs. goldi, Cyathostomum catinatum, Cy. labiatum and Cy. pateratum) were characterized using a polymerase chain reaction-linked restriction fragment length polymorphism technique (PCR-RFLP). Internal transcribed spacer ribosom...
Haider W, Brehm W, Keller H.An apparently unilateral cryptorchid stallion was referred to the clinic with a history of colic. In the course of laparotomy an ileus caused by strangulation of the small intestine was found and the horse was euthanized because of poor prognosis. During autopsy strictures and ectasia of the jejunum were found as well as hermaphroditism along with male phenotype. The frequency of cryptorchidism in the case of intersexuality is discussed.
Aramaki S, Ishidaka O, Suzuki E, Momose A, Umemura K.In a doping test for racing horses, it is useful for the elucidation of the illegal use of drugs if one can estimate the time at which the detected drug was administered. In order to estimate the time which has elapsed after the administration of caffeine (CA) into horses, the ratios of concentration for the respective metabolites to the unchanged CA in the plasma or the urine were determined. These ratios have been known to be independent of the dose of CA. The relationship between [plasma or urinary concentration of a metabolite]/ [plasma or urinary concentration of the unchanged drug] and t...
Burrell MH, Wood JL, Whitwell KE, Chanter N, Mackintosh ME, Mumford JA.A longitudinal study of respiratory disease in racehorses was carried out to assess its relative associations with different infectious agents and to examine any role that the environmental conditions might play. The relationships between coughing, nasal discharge, pyrexia and lower respiratory tract disease were also examined to provide information for improving clinical diagnosis, particularly of disease of the lower respiratory tract. Lower airway disease was closely associated with infection with Streptococcus zooepidemicus. It was also found that equine herpesvirus seroconversions and S p...
Ragle CA, Southwood LL, Hopper SA, Buote PL.Two mares were admitted for ovariectomy of unilateral granulosa cell tumors. Both mares were ovariectomized (1 unilateral and 1 bilateral) by use of a ventral abdominal laparoscopic technique. This approach required tilting the operative table 30 degrees to elevate the pelvis and to allow observation of the ovaries. Using a single laparoscopic portal and 3 to 4 instrument portals, a triangulation technique was used. The ovarian pedicles were isolated and secured via loop ligation. The ovaries then were divided from the ligated pedicle and placed within specimen bags for extraction. The specime...
Guglick MA, MacAllister CG, Ewing PJ, Confer AW.A 12-year-old Quarter Horse gelding was admitted to the veterinary medical teaching hospital with a 2-day history of signs of abdominal pain. Initial findings on physical examination included signs of lethargy, dehydration, diarrhea, and gastric reflux. Results of laboratory testing indicated that the horse had panleukopenia with neutrophilic toxic changes, was dehydrated, and was hypocalcemic. During the first 48 hours of hospitalization, 1 abdominal palpation per rectum and 3 analyses of peritoneal fluid were performed; abnormalities were not detected. A preliminary diagnosis of enterocoliti...
The Journal of physiologySeptember 15, 1996
Volume 495 ( Pt 3), Issue Pt 3 863-874 doi: 10.1113/jphysiol.1996.sp021638
Mills PC, Marlin DJ, Demoncheaux E, Scott C, Casas I, Smith NC, Higenbottam T.1. The effects of exercise on the production rate of nitric oxide (NO) in exhaled air (VNO) and the effects of inhaled NO (80 p.p.m.) on cardiovascular and respiratory parameters were investigated in five Throughbred horses. 2. The concentration of NO ([NO]) in exhaled air collected from within the nasal opening was lower when collected at a high flow rate of 80 l min-1 than at a low flow rate of 20 l min-1: when trotting at 3.7 m s-1 the values were 0.78 +/- 0.15 and 1.23 +/- 9.14 p.p.b., respectively, and when cantering at 9 m s-1 the values were 1.69 +/- 0.31 and 2.25 +/- 0.32 p.p.b., respe...
Brinsko SP, Ignotz GG, Ball BA, Thomas PG, Currie WB, Ellington JE.To compare the electrophoretic patterns of proteins synthesized and secreted by oviductal epithelial cell (OEC) explants obtained from young, fertile and aged, subfertile mares. Methods: Young, fertile (n = 5; 2 to 7 years old) and aged, subfertile (n = 5; 17 to 24 years old) mares. Methods: 2-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis and computerized densitometry. Results: Variation in the synthesis and secretion of polypeptides from young, fertile mare OEC (YOEC) and aged, subfertile mare OEC (AOEC) was evidenced by differences in the intensity of radiolabeled pol...
Sweeney CR, Irby NL.To determine which antimicrobial agents were most effective against Pseudomonas sp-infected ulcerative keratitis, and identify any trends in the various clinical conditions associated with these bacteria that might assist in effective treatment of the disease. Methods: Retrospective case series. Methods: 66 horses with 70 Pseudomonas sp-infected corneal ulcers. Methods: We reviewed medical records of horses admitted to the George D. Widener Hospital for Large Animals, University of Pennsylvania between July 1977 and December 1994. Records of horses that had Pseudomonas sp isolated from a corne...
Lunn DP, Schram BR, Vagnoni KE, Schobert CS, Horohov DW, Ginther OJ.Lymphokine activated killing (LAK) is an example of natural cytotoxicity, and as such is a critical means of defense against diseases such as viral infection and neoplasia. Despite this important role, the specific molecular interactions involved in LAK or other forms of natural cytotoxicity are only partially understood. In some species, cells capable of mediating natural cytotoxicity express the CD8 molecule, although no specific role has been demonstrated for CD8 in non-MHC restricted cytotoxicity. In this study the role of the EqCD8 equine homolog of CD8 in LAK cell activity was examined. ...
Gravance CG, Liu IK, Davis RO, Hughes JP, Casey PJ.The heads of stallion spermatozoa were analysed by computer automated sperm head morphometry and the morphometric values of the major subpopulations of sperm heads were assessed. The criteria for normal dimensions of stallion sperm heads are proposed based on the analysis of these measurements. Semen samples were collected from 10 fertile and 10 subfertile stallions, processed by a standard method, smeared onto microscope slides and stained using haematoxylin. At least 200 properly digitized sperm heads were analysed from each stallion. The measurements for length, width, area, perimeter and w...
Simoens P, Muylle S, Lauwers H.Orbital and intrabulbar arteries were studied in 20 equine eyes by means of latex injections and methylmethacrylate casts. The orbital branches of the external ophthalmic artery arise far caudal to the posterior pole of the eyeball and present a variable topographic arrangement. The intrabulbar arteries are supplied by ciliary and choroidoretinal arteries. Dependent on their entrance into the eyeball, the ciliary arteries are subdivided into a posterior and an anterior group. The posterior ciliary arteries perforate the sclera post equatorially and consist of 4 major vessels that penetrate in ...
Seltzer KL, Stover SM, Taylor KT, Willits NH.The torsional monotonic structural material properties of equine metacarpi with or without, either a 5/16 inch or 3/8 inch diameter bicortical lateromedial middiaphyseal hole were assessed to determine the effect of a hole on metacarpal strength. Torsional stiffness was not significantly effected by the presence of a bicortical hole, whereas yield and failure angles, torques and energies of metacarpi with a hole were 51% to 97% of those of intact bones. Significant differences were not apparent for yield and failure mechanical properties between metacarpi with a 5/16 inch diameter hole and met...
Borgsteede FH, van Beek G.The prevalence of tapeworm infestations was investigated in 70 horses slaughtered in the period February 1994-July 1994. Most horses were half-breed, young (1.5-3 years), and in good condition. They were bought for slaughter by dealers on local markets, and their treatment history was therefore unknown. Tapeworm infestations were seen in 16 horses (23%). Fifteen (21%) had an infection with Anoplocephala perfoliata. One horse had a single specimen of Paranoplocephala mamillana. The average number of A. perfoliata was 45 and the highest number was 508.
Hines MT, Schott HC, Bayly WM, Leroux AJ.Exercise has been recognized as a stress, which can significantly alter the host's immune response and, therefore, its susceptibility to disease. Whereas research in this area has previously focused primarily on human subjects and laboratory animals, it has more recently extended to domestic animals, especially the equine athlete. Despite several studies, defining the relationship among exercise, the immune response, and disease has proven difficult due to a number of factors, including the complexity of the immune system and the variable nature of exercise itself. It now appears that exercise...
Kawcak CE, Trotter GW, Frisbie DD, McIlwraith CW.To evaluate the effects of a commercially defined, serum-free medium additive on equine articular cartilage explants, compared with effects of serum-free and serum-supplemented media. Methods: Articular cartilage from a 3-year-old, mixed breed horse euthanatized for reasons other than musculoskeletal disease or sepsis. Methods: Media were changed every 48 hours, and the glycosaminoglycan (GAG) content was determined in media collected at each time point. Glycosaminoglycan synthesis by explant chondrocytes, and residual GAG content of articular cartilage (as a measure of explant GAG loss) were ...
Klohnen A, Wilson DG.Nonstrangulating indirect scrotal hernias were corrected in two 4-week-old Percheron foals by a laparoscopic technique. After laparoscopic reduction of herniated nonstrangulated small intestine each testes was retracted through the vaginal ring. The ligament of the tail of the epididymis was transected by electrocautery. The testicular vessels and nerves were isolated by cautery of the mesenteric portion of the mesorchium and then ligated. Staples were used to close the opening of the inguinal canal by apposing the peritoneal edges of the vaginal ring. Resection of umbilical stalk remnants via...
Holcombe SJ, Derksen FJ, Stick JA, Robinson NE, Boehler DA.To compare tracheal and pharyngeal inspiratory and expiratory pressures achieved during 60 seconds of nasal occlusion in standing horses with pressures achieved in horses during intense exercise. Methods: 5 Standardbreds. Methods: Tracheal and pharyngeal inspiratory and expiratory pressures were obtained from 5 horses during 60 seconds of nasal occlusion and compared with tracheal and pharyngeal pressures achieved during incremental treadmill exercise tests in which horses ran at 50, 75, and 100% of the speed that resulted in maximal heart rate (HRmax). Results: Significant difference was not ...
Frazer GS, Bucci DM.The aims of this project were to document the protein profile of equine seminal plasma and determine the variability between stallions in the relative composition of proteins in the ejaculate. A single ejaculate was obtained from 14 stallions of varying breed and age. The gel fraction was removed by an in-line filter. The semen was centrifuged and the supernatant seminal plasma aspirated without disturbing the sperm pellet. The seminal plasma was recentrifuged and stored in cryovials at -70 degrees C. Samples were thawed, recentrifuged, assayed for protein concentration (BCA protein assay), di...
Glaser AL, de Vries AA, Rottier PJ, Horzinek MC, Colenbrander B.Sero-epidemiological surveys have revealed that equine arteritis virus (EAV) is prevalent in most European countries. The virus causes sporadic cases of respiratory disease and abortion in horses, the incidence of which has increased in recent years. Mares and geldings eliminate virus after acute infection, but 30% to 60% of stallions become persistently infected. In these animals, EAV is maintained within the reproductive tract and is shed continuously in the semen. Persistent infection with EAV in stallions has no negative consequences for fertility but mares inseminated with virus-contamina...
Skedros JG, Mason MW, Nelson MC, Bloebaum RD.Functionally induced strains provide epigenetic signaling for bone modeling and remodeling activities. Strain gauge documentation of the equine third metacarpal reveals a neutral axis passing through the craniolateral cortex, resulting in a narrow band of cortex loaded predominantly in tension, with the remainder of the cortex experiencing a wide range of compression strain magnitudes that are maximal in the caudomedial cortex. This predictable strain pattern provides a model for examining the hypothesis that strain mode, magnitude, and strain energy density are potential correlates of compact...
Weiss DJ, Monreal L, Angles AM, Monasterio J.Carbohydrate-induced laminitis has been associated with decreased platelet survival, decreased blood flow to the hoof wall and with the deposition of platelets and microthrombi within venules in the dermal laminae. To evaluate further the systemic prothrombotic events occurring in the prodromal stages of laminitis, plasma samples from control and laminitis-affected ponies and horses were tested for the presence of thrombin-antithrombin (TAT) complexes and fibrin fragment D (D-dimer). No statistically significant differences between the control and laminitis-affected animals were observed for e...
Hlastala MP, Bernard SL, Erickson HH, Fedde MR, Gaughan EM, McMurphy R, Emery MJ, Polissar N, Glenny RW.Recent studies using microspheres in dogs, pigs and goats have demonstrated considerable heterogeneity of pulmonary perfusion within isogravitational planes. These studies demonstrate a minimal role of gravity in determining pulmonary blood flow distribution. To test whether a gravitational gradient would be more apparent in an animal with large vertical lung height, we measured perfusion heterogeneity in horses (vertical lung height = approximately 55 cm). Four unanesthetized Thoroughbred geldings (422-500 kg) were studied awake in the standing position with fluorescent microspheres injected ...
Firth EC, Hodge H.The possible relationship between physeal diseases and physeal form prompted investigation of change in steepness of the physis in young foals. The distal and proximal aspects of the longbones were sawn sagittally in the right and frontally in the left bones. The slabs were washed to remove saw debris, arranged in order and inspected. The proximal physes had a flat or gently arched form, without obvious inclination. In the distal physes there were distinct inclinations. Inspection of an identical slab from the medial aspect of the distal radius of two series of foals of different breeds showed...
Slocombe JO, Rendano VT, Owen RR, Pennock PW, McCraw BM.Radiographs of the aorta and abdominal arteries were obtained from a normal anesthetized pony following catheterization of a femoral artery for nonselective, semiselective or selective arteriography. The arteries had smooth borders and regular diameters and the branches of the cranial mesenteric artery could be followed distally on the angiogram through to the smaller branches proximal to the bowel wall. Following arteriography, the pony walked normally and there were minimal alterations of the levels of serum muscle enzymes and blood lactate. The procedures for arteriography were repeated in ...
Meuten DJ, Kociba G, Threlfall WR, Nogode LA.Serum alkaline phosphatase was measured in ten mares during various stages of gestation. No significant change in serum alkaline phosphatase activity was detected during pregnancy. These data suggest that interpretation of serum alkaline phosphatase in horses can be made independently of their pregnancy status.
Han X, Zou J, Wang X, Guo W, Huo G, Shen R, Xiang W.The Chinese EIAV vaccine is an attenuated live-virus vaccine obtained by serial passage of a virulent horse isolate (EIAV(L)) in donkeys (EIAV(D)), and subsequently in donkey cells in vitro. In this study, we compare the env gene of the original horse virulent virus (EIAV(L)) with attenuated strains serially passaged in donkey MDM (EIAV(DLV)), and donkey dermal cells (EIAV(FDDV)). Genetic comparisons among parental and attenuated strains found that vaccine strains contained amino acid substitutions/deletions in gp90 that resulted in a loss of three potential N-linked glycosylation sites, desig...
Smith BP.Salmonellosis in horses may result in fever, anorexia, and depression without concurrent diarrhea or other obvious gastrointestinal abnormalities and should be considered in cases of fever of unknown origin. The syndrome also is characterized by neutropenia, usually with a left shift, and growth of small numbers of salmonella from feces cultured in selenite enrichment broth. Repeated culturing may be necessary to isolate the organism. All six affected horses of this report recovered in 3 to 7 days without specific therapy.
Peli A, Scagliarini L, Calbucci S, Diegoli G.The increasing awareness of animal welfare issues among consumers and the general public in the European Union has brought about the adoption of laws for the protection of production animals throughout the various steps of the food chain, from breeding to slaughter. Considering that horses may be kept for a variety of reasons, including as companion animals and as farm animals, protective legislation in Europe applies to this species only partially. In consistency with the areas of competence of the European Union, it is the purpose of the activity (be it economic/commercial or neither) and no...
Megid Gomaa NA, Köller G, Fritz Schusser G.To measure serum alcohol dehydrogenase (ADH) activity in horses with acute intestinal obstruction and to determine the diagnostic and prognostic utility of this analyte. Methods: Prospective observational study. Methods: University Veterinary Hospital. Methods: Thirty healthy horses (control group) and 77 horses with acute intestinal obstruction, including 36 horses with nonstrangulating obstruction (23 with left ventral colon impaction and 13 with left dorsal displacement [G1], 22 with small intestinal strangulation [G2], and 19 with colon torsion [G3]). Methods: Serum ADH activity was assaye...
Emmert BJ, Robison CI, Pritchard A, Nielsen BD.Digital radiographs are common for estimating bone mineral content (BMC) in horses with radiographic bone aluminum equivalents (RBAE). Processing algorithms are used to produce clearer images of digital radiographs in clinical settings, but this distorts RBAE. This study compared RBAE from digital radiographs to BMC from bone ash, and physical and digital morphology measurements. Digital radiographs were taken of six third metacarpals (MCIII) from equine cadavers with an aluminum step wedge penetrometer. A 2-cm transverse section of bone was digitally analyzed and excised from each MCIII. For ...
Held JP, Prater P, Toal RL, Blackford JT, McCracken M.A 7-year-old stallion with a history of abdominal pain after it fell was examined and found to have a swelling of the right testis and epididymis. Semen evaluation revealed an increase in secondary sperm abnormalities. The stallion was unilaterally castrated. The histologic diagnosis was sperm granuloma, with no evidence of infection. Periductal fibrosis was observed and appeared to have developed before the trauma occurred. The changes seen could be compatible with chronic blockade of efferent ductules, resulting in extravasation of spermatozoa.
Weber JA, Geary RT, Woods GL.Ultrasonographic images of the accessory sex glands of 8 stallions were recorded immediately prior to sexual preparation, immediately after sexual preparation, and immediately after ejaculation. Relative size changes, determined by measurements of ultrasonograms of accessory sex gland, were contrasted. Length and width of the bulbourethral glands increased significantly (P less than 0.05) after sexual preparation and decreased significantly (P less than 0.05) after ejaculation. The increase in bulbourethral gland volume following sexual preparation was correlated significantly (P less than 0.0...
Zientek KD, Anderson DF, Wegner K, Cole C.A method for the extraction and quantitation of procaine in equine plasma was developed for use with liquid chromatography-mass spectrometry (LC-MS). Procaine was isolated from equine plasma by liquid-liquid extraction at pH 11 with dichloromethane using procaine-d10 as an internal standard. Quantitation was achieved by LC-MS using a 3-microm C-18 column coupled to an electrospray ionization source on a linear ion-trap mass spectrometer. The limit of detection and limit of quantitation was determined to be 50 and 200 pg/mL, respectively. The lowest limit of detection determined by previous met...
Harcourt MM, Smith RL, Hosgood G.Objective comparative evidence of the time to onset and duration of effect provided by local anaesthetic (LA) agents for perineural blocks in the horse is lacking. Clear knowledge of these properties is required to guide clinically appropriate agent selection and aid interpretation of response to diagnostic blocks for lameness examinations. An interventional study, with complete, randomised crossover design was used to compare time to onset and duration of skin desensitisation provided by four LA agents applied to palmar digital nerve blocks in 12 horses. Effect at each time point was determin...
Stratford CH, Pemberton A, Cameron L, McGorum BC.Although a presumptive diagnosis of acute grass sickness (AGS) can be made on the basis of clinical signs, a definitive ante mortem diagnosis currently requires histological examination of enteric ganglia. Development of an accurate noninvasive ante mortem diagnostic test is therefore warranted. The objective of this study was to determine whether quantification of the plasma concentrations of the heavily phosphorylated form of major neurofilament subunit NF-H (pNF-H), which mirror the degree of axonal degeneration in some human and animal neurodegenerative disorders, could distinguish AGS-aff...
Brice AG, Forster HV, Pan LG, Lowry TF, Murphy CL.We determined the effect of acute hypoxia on the ventilatory (VE) and electromyogram (EMG) responses of inspiratory (diaphragm) and expiratory (transversus abdominis) muscles in awake spontaneously breathing ponies. Eleven carotid body-intact (CBI) and six chronic carotid body-denervated (CBD) ponies were studied during normoxia (fractional inspired O2 concn [FIO2] = 0.21) and two levels of hypoxia (FIO2 approximately 0.15 and 0.12; 6-10 min/period). Four CBI and five CBD ponies were also hilar nerve (pulmonary vagal) denervated. Mean VE responses to hypoxia were greater in CBI ponies (delta a...
Yi R, Sandhu J, Zhao S, Lam G, Loganathan D, Morrissey B.Efaproxiral (RSR 13) is an experimental synthetic allosteric modifier of haemoglobin (Hb) that acts by increasing the release of oxygen from Hb to the surrounding tissues. It has been shown to increase maximum oxygen uptake (VO(2max)) in a canine skeletal muscle model. The ability to increase maximal muscle oxygen uptake makes efaproxiral a potential performance-enhancing agent and is therefore prohibited by the World Anti-Doping Agency. In this study, a method for the detection and elimination of efaproxiral in equine plasma and urine after a 2.5 g intravenous administration of efaproxiral ...
Manohar M, Goetz TE.To determine whether intravenous infusion of nitroglycerin would modify pulmonary arterial, capillary, or venous hypertension in strenuously exercising Thoroughbreds. Methods: 5 healthy Thoroughbred horses. Methods: Right atrial, right ventricular, and pulmonary vascular pressures were measured. Each horse was used in a control treatment (not medicated) and a nitroglycerin infusion (20 microg/kg of body weight/min) at rest and during exercise on a treadmill. Sequence of treatments was randomized for each horse, and treatments were separated by a 7-day interval. Galloping at 14.2 m/s on a 5% up...
Orsini JA, Moate PJ, Boston RC, Norman T, Engiles J, Benson CE, Poppenga R.In two studies, six healthy adult horses were given imipenem-cilastatin by slow intravenous (i.v.) infusion at an imipenem dosage of 10 mg/kg (study 1) and 20 mg/kg (study 2). The same horses were used in each dosage schedule, with a 2-week washout period between studies. In each dosage group, serial blood and synovial fluid samples were collected for 6 h after completion of the infusion. HPLC was used to determine the imipenem concentration in all samples. Imipenem was well tolerated by all horses at both dosages; no adverse effects were noted during the study period or during the 24-hour pos...