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.
Hoekstra KE, Nielsen BD, Orth MW, Rosenstein DS, Schott HC, Shelle JE.Sixteen Arabian yearlings were assigned randomly to 2 groups, confined to stall and pastured, to investigate the effects of confinement vs. pasture-rearing on bone mineral content and biochemical markers of bone metabolism over a 140 day period. Following an 84 day pretraining period, 6 horses from each group were selected randomly to complete a 56 day training period. Serum osteocalcin concentrations were determined from blood samples collected every 14 days. Urinary deoxypyridinoline concentrations and mineral content of the third metacarpus, as determined by lateral and medial radiographic ...
Bayly WM, Redman MJ, Sides RH.It has been postulated that the hypoxaemia and hypercapnoea that characterize strenuous equine exercise are partly due to flow limitations imposed by high breathing frequencies (fb), and that gas exchange would be improved if fb could be lowered. To evaluate this possibility, 6 Thoroughbred horses underwent 4 incremental treadmill exercise tests at inclines of 0, 5, 10 and 25%, respectively. In the test, horses were given a warm-up for 2 min, then ran sequentially for 1 min each at 60, 100 and 115% VO2max. Oxygen consumption (VO2), blood gas tensions (PaO2, PaCO2), fb, tidal volume (VT), minut...
Greene HM, Wickler SJ, Anderson TP, Cogger EA, Lewis CC, Wyle A.Arterial and venous blood were analysed at rest and post exercise for pH, PCO2, and PO2, and bicarbonate ([HCO3-]), base excess (BE), and strong ion difference (SID) were calculated in response to a 10 day sojourn to 3800 m. Pulmonary artery pressures (PAP) were measured at rest. Post exercise samples were restricted to venous blood. The equids (n = 6) experienced a profound hypoxia-hypocapnia and a respiratory alkalosis. PaO2 decreased 42% and PaCO2 41%. PaCO2 increased to 80% of initial values after 8 days at altitude. Arterial [HCO3-] decreased by 34%; however, it returned to normal by Day ...
Düsterdieck KF, Schott HC, Eberhart SW, Woody KA, Coenen M.To replace electrolytes lost in sweat during endurance competitions, riders frequently supplement horses with hypertonic oral electrolyte pastes. To determine whether this practice and concurrent administration of the so-called hyperhydrating substance glycerol are of benefit, weight loss, voluntary water intake, plasma osmolality, and plasma protein and electrolyte concentrations were measured in 6 Arabian horses supplemented with a total of 2.4 ml/kg bwt of water (W); 0.2 g/kg bwt KCl and 0.4 g/kg bwt NaCl in 2.4 ml/kg bwt of water (E); or 0.2 g/kg bwt KCl and 0.4 g/kg bwt NaCl in 2.4 ml/kg ...
Greene S, Keegan R, Brown J, Kingston J, Bayly WM.This study evaluated the effects of pre-exercise frusemide administration and hypertonic saline (H) infusion during anaesthesia on arterial pH, blood gases and electrolytes in 6 Thoroughbred horses anaesthetised immediately post exercise. Horses received either frusemide (F) (0.5 mg/kg, i.v.) or a saline placebo (P) injection 4 h prior to treadmill exercise. Exercise consisted of a 3 min warm-up at 40% VO2max followed by exercise to fatigue. Detomidine (40 micrograms/kg, i.v.) was given within 5 min of stopping and followed 5 min later by zolazepam-tiletamine (1.25 mg/kg, i.v.) to induce anaes...
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...
Roepstorff L, Johnston C, Drevemo S.The increasing range of of horseshoes and hoofpads makes it important to be able to evaluate their influence on performance and stress in the locomotor apparatus. The aim of this study was to describe the changes in ground reaction forces and locomotion pattern during the stance phase due to the application of a standard iron shoe. Six Swedish Warmblood horses were evaluated kinetically and kinematically before and after they were shod with an 8 mm iron shoe. Data were used to calculate ground reaction forces in the vertical and craniocaudal directions, point of application of the force, hoof ...
Kallings P, Johnston C, Drevemo S.An often discussed and controversial issue is the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on performance. The purpose of this study was to investigate the effect of the NSAID flunixin on the movement pattern and performance capacity of Standardbred trotters using a standardised track model. Five adult Standardbred horses in training trotted at 2 occasions with a 2 week interval on the same oval dirt track. Before each occasion the horses were either injected with flunixin meglumine (Finadyne) or normal saline solution i.m. 4 h before the performance test (double blind crossover...
Rivero JL, Serrano AL.Three different myosin heavy chain (MHC) isoforms have been identified in the equine gluteus medius muscle: the slow or MHC-I and the 2 fast MHC-IIA and MHC-IIX isoforms. They are distributed in 3 fibre types containing a single MHC (I, IIA, IIX) and 2 hybrid types co-expressing 2 isoforms (I + IIA, IIA + IIX). The aim of this study was to determine if heavy carriage training alters skeletal MHC composition in horses. Fourteen Andalusian mares age 42-46 months were used. Seven horses were used as controls to estimate the effects of growth on muscle. The remaining 7 horses underwent a training ...
Hinchcliff KW, McKeever KH.We speculated that frusemide would attenuate the acidosis associated with intense exertion, and that weight carriage would mitigate this effect. Therefore, in each of 2 experiments we measured pulmonary artery and systemic arterial blood pH, PCO2, PO2 and pulmonary artery temperature in 9 horses during exertion on a treadmill after each of 3 treatments. The treatments were: 1) injection of saline solution (C), 2) injection of frusemide (1 mg/kg bwt, i.v. 4 h before running) (FU) and 3) injection of frusemide (F) as for FU and the horses carried weight equal to that lost in the 4 h after frusem...
Hiraga A, Hobo S, Birks EK, Takahashi T, Hada T, Smith BL, Carr EA, Pascoe JR, Jones JH.Three mature Thoroughbred horses were prepared surgically with ultrasonic sonomicrometer crystals affixed to their ventricular pericardia. Signals from crystals recorded dimensions of axes across the left ventricle. Cubic algorithms were fitted to dimensional data to generate volume estimates that matched stroke volumes simultaneously measured using the Fick principle. As horses stood at rest or exercised at various intensities (approx 7, 12, 24, 47 and 100% maximal rate of O2 consumption VO2max[), left ventricular dimensions were recorded and 20 consecutive diastolic and systolic volumes calc...
Foreman JH, Waldsmith JK, Lalum RB.Three-day event horses are subject to various external environmental stresses including changes in ambient temperature, humidity, altitude, and test severity. Considerable research on the adverse effects of increased heat and humidity preceded the 1996 Olympic Summer Games in Atlanta, Georgia USA, but no research has been done previously on the effects of altitude on 3-day eventing. Physical and venous blood gas data were collected on horses (n = 24) competing in the High Prairie Preliminary (CCN*) and Intermediate (CCN**) 3-day events and Preliminary Horse Trials in Parker, Colorado (1900 m a...
Bailey J, Colahan P, Kubilis P, Pablo L.This study was designed to test the hypothesis that a specific beta 2 adrenergic receptor agonist, albuterol sulphate, when delivered by metered-dose inhaler (MDI) would affect the performance of Thoroughbred horses during incremental exercise testing. Six conditioned Thoroughbred horses were randomly assigned to one of 2 treatment groups: Group 1 horses received placebo and Group 2 received albuterol. Each horse received both treatments in a crossover design with a 3 week interval between trials. Horses inspired albuterol (900 micrograms) or placebo over a 5 min period followed by an incremen...
Kirschvink N, Art T, Smith N, Lekeux P.To test whether isoprostanes could be used as markers of oxidative stress in horses, their concentration was determined in plasma and in pulmonary epithelial lining fluid (PELF) in 3 models of oxidative stress: (1) strenuous exercise, (2) acute COPD crisis and (3) exercise combined with COPD crisis. Four horses were investigated twice, once in crisis and once in remission. The animals underwent a standardised treadmill exercise test. Isoprostane assessment was performed in plasma and bronchoalveolar lavage fluid 24 h before and 1 h after exercise and in plasma also immediately after exercise. ...
Whitton RC, Murray RC, Buckley C, Goodship AE, Lekeux P.Training results in marked modelling of the subchondral bone of the carpus, but the effect of training on the subchondral bone of the distal tarsal joints is unknown. The aim of this study was to determine whether training influenced modelling of the third and central tarsal bones in Thoroughbred horses. Twelve untrained Thoroughbred horses were divided into 2 groups. Group 1 underwent a 19 week progressive training regimen on a high speed treadmill. Group 2 were walked for 40 min daily. Images of left tarsi were obtained by magnetic resonance imaging (MRI) with a 0.5 Tesla superconducting mag...
Tyler-McGowan CM, Golland LC, Evans DL, Hodgson DR, Rose RJ.We sought a physiological marker of overtraining in horses, using commonly practised field and laboratory tests to allow early prediction and treatment of the syndrome. Thirteen Standardbred horses were trained as follows: phase 1 (endurance, 7 weeks), phase 2 (high intensity, 9 weeks) and phase 3 (overload, 18 weeks). In phase 3 the horses were divided into 2 groups: overload training (OLT) and control (C). The OLT group exercised at greater intensities, frequencies and durations than the C group. Overtraining occurred after 31 weeks and was defined as a significant decrease in treadmill run ...
Clayton HM, Lanovaz JL, Schamhardt HC, van Wessum R.Ground reaction force (GRF) measurements are often normalised to body mass to facilitate inter-individual comparisons. The objective of this study was to explore the effect of a rider on the GRFs and fetlock joint kinematics of trotting horses. The subjects were 5 dressage-trained horses and 3 experienced dressage riders. Ground reaction force measurements and sagittal view videotapes were recorded as the horses trotted at the same velocity in hand (3.49 +/- 0.52 m/s) and with a rider (3.49 +/- 0.46 m/s). Data were time-normalised to stance duration. Ground reaction force measurements were exp...
Sweeney CR, Tomasic M, Russell GE.The effect of inhaled nitric oxide on pulmonary mechanics was studied in normal standing horses with histamine-induced bronchoconstriction. The respiratory health status of 6 normal horses was established on the basis of history, clinical and bronchoalveolar lavage examination. Intrathoracic pressures were estimated using distal oesophageal pressures. Respiratory gas flows were measured using a heated pneumotachograph. Pulmonary mechanics variables were determined from these measurements on a breath by breath basis. Bronchoconstriction was induced by nebulizing a 0.75% w/v solution of histamin...
Jeffcott LB, Kohn CW.Following public concern about the weather conditions for the 1996 Olympic Games in Atlanta an international research programme was initiated. The primary objective of this effort was to identify strategies for ensuring welfare of horses competing in the heat. Field observations of horses during the endurance test of 3-day events in Europe, Canada, and the USA characterised the work effort of this form of competition; laboratory treadmill studies assessed limitations to performance of heat and humidity, explored the relationships of thermoregulatory demands to the phases of the competition and...
Manohar M, Goetz TE.This study was carried out to examine changes in pulmonary vascular resistance (PVR) induced by moderate and strenuous exercise; the objective being to understand why pulmonary artery blood pressure of exercising horses increases progressively as work intensity increases. Pulmonary arterial and wedge pressures (referenced at the point of the left shoulder) were determined simultaneously with cardiac output in 2 groups of healthy, sound, exercise-trained horses. Horses in Group 1 (n = 8) were studied at rest and during exercise performed at 8 and 13 m/s; the latter workload eliciting maximal he...
Murray RC, Whitton RC, Vedi S, Goodship AE, Lekeux P.Carpal osteochondral injury is frequently observed in strenuously trained horses. It is clear that the integrity of articular cartilage and subchondral bone are intimately related, although there is controversy about which component is the most important. Calcified cartilage provides the mechanical link between soft hyaline cartilage and stiff subchondral bone so it is essential to understand the tissue's response to exercise. Middle carpal calcified and uncalcified (hyaline) cartilage thickness was investigated in horses undergoing high- and low-intensity exercise. Twelve untrained horses (18...
Crandell KG, Pagan JD, Harris P, Duren SE.High-grain diets for the exercising horse were compared with diets which provided 15% of the total caloric intake from either vegetable oil or a highly fermentable fibre source (beet pulp). Six Thoroughbreds age 3 years were fed one of 3 diets or 5 weeks in a replicated 3 x 3 Latin square. The CONTROL diet was 3.65 kg of sweet feed (SF), 0.9 kg of a protein/vitamin/mineral pellet and 5.45 kg of hay cubes. The FAT diet replaced 1.15 kg of SF with 0.45 kg of soybean oil and the FIBRE diet replaced 1.15 kg of SF with 1.36 kg of beet pulp. Horses were exercised 3 times per week on a high-speed tre...
Garlinghouse SE, Burrill MJ.Three-hundred and sixty horses, primarily of Arabian breeding, age 5-22 years and body conditions scores 1.5-5.5 (on 1 to 9 scale as described by Henneke 1985), participated in one of two 160 km endurance races over the same course in August 1995 and July 1996. Condition score, cannon bone circumference, combined rider and tack weight, heart girth and body length were measured 11-18 h prior to the start of the event and bodyweight estimated according to the formula by Carroll and Huntington (1988). A rider weight ratio was calculated as rider weight divided by horse bodyweight. Rider weight an...
Mueller PO, Hay WP, Harmon B, Amoroso L.To evaluate the efficacy of a bioresorbable hyaluronate-carboxymethylcellulose membrane (HA-membrane) for prevention of experimentally induced abdominal adhesions in horses. Methods: Experimental study. Methods: Twelve healthy adult horses. Methods: The effect of an HA-membrane on adhesion formation was evaluated in 12 healthy horses using an established model of serosal trauma to induce adhesions. A ventral median celiotomy and two jejunal resections and end-to-end anastomoses were performed. Two separate jejunal areas were abraded, and three 2-0 chromic gut sutures placed in the abraded area...
Wille KH, Nakov C.The mucous membrane of the caecum and colon ascendens of adult horses was first studied using light and transmission electron microscopy. In the surface epithelium there was an inconspicuous constellation of organelles, otherwise there was a lot of mitochondria as a source of energy for absorptive performances. Moreover, enlarged intercellular spaces exist as an indication of an increased uptake of water and electrolytes. In the basal region of Lieberkühn's crypts there were single enteroendocrine cells and numerous granules in the apical epithelial cytoplasm. The functional meaning of these ...
Soana S, Gnudi G, Bertoni G.The aim of this work was to study the ontogenetic process in teeth from their early appearance in the ossifying matrix of the mandible and maxilla, in different foetuses of scalar ages. Radiographic examinations of the skull and mandible hemisections were performed and the latero-medial (LM) and dorsoventral (DV) projections for the skull and mandible were analysed. A high-definition film-screen combination was used for this study. The exposure values ranged from 35 kV/6 mAs to 58 kV/10 mAs, according to the size of the skulls and their degree of ossification. The first dental germ observed wa...
Hoffmann KL, Wood AK, McCarthy PH, Griffiths KA, Evans DL, Gill RW.Investigations of the equine peripheral vascular system have been constrained by the lack of a non-invasive method of examining the arteries and veins of the limbs of the conscious horse. Precise correlations were established between the gross anatomical features of the peripheral vessels and their B-mode sonographic appearance in each thoracic limb of 35 horses. A sonographic imaging protocol was established. Additional Doppler sonographic recordings defined the arterial waveforms and demonstrated that blood flow to the foot could be evaluated in the lateral proper digital artery, distal to t...
McD○ LA, Stover SM, Bach JM, Taylor KT.To determine the mechanical properties of Equine Interlocking Nail (EIN; JD Wheat Veterinary Orthopedic Research Laboratory, University of California, Davis) stabilized osteotomized tibiae and compare these variables with estimated in vivo loads. Methods: In vitro biomechanical investigation. Methods: Twelve adult equine cadaveric tibiae. Methods: EIN-stabilized tibiae were tested monotonically under compression, 3- and 4-point bending, and torsion. Mechanical properties were compared with estimated in vivo loads. Results: EIN-tibial composite mean compressive yield load (11 kN) and bending mo...
Miller CB, Wilson DA, Keegan KG, Kreeger JM, Adelstein EH, Ganjam VK.To determine if there is a difference in in vitro growth of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies. To determine the effects of a corticosteroid and monokine on in vitro growth of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies. Methods: Growth of fibroblasts from tissues harvested from the trunk and limb were compared from horse and pony samples grown in control media and control media with triamcinolone or monokine added. Methods: Dermal and subcutaneous tissue from 22 horses and 17 ponies of various ages ...
Pourcelot P, Audigié F, Degueurce C, Denoix JM, Geiger D.This study was conducted to evaluate a method for quantifying locomotion symmetry at trot in sound and lame horses. Using a 3D kinematic analysis system, the kinematics of the limb joints of sound and lame horses were recorded. The differences in motion between the left and right homologous joints were then quantified using a symmetry index based on an inter-correlation method. This method was used to calculate the symmetry indices of the vertical displacements and angle-time diagrams of the joints of each horse. In order to evaluate the sensitivity of this method of quantifying the locomotion...
Binhazim AA, Harmon BG, Roberson EL, Boerner M.During routine necropsy of a 28-year-old horse with intestinal volvulus, numerous hydatid cysts were discovered in the liver. Viable protoscolices of Echinococcus granulosus were obtained from the cyst. As a 4-year-old, this horse had been imported from an area that is enzootic for equine hydatidosis.
Brownlie SE.The Chiltern Box is a small electrocardiograph designed for home monitoring of human patients. Its veterinary application has been investigated in the dog, the cat and the horse. It has been useful in the diagnosis of previously undiagnosed dysrhythmias in dogs showing signs of exercise intolerance and syncope.
Heath TJ.To define and describe the population of Australian veterinarians who work with horses. Methods: Questionnaires were mailed to 866 veterinarians who had been identified as working with horses, and 87% were completed and returned. Data were entered onto an Excel spreadsheet, and analysed using the SAS System for Windows. Results: About 12% of Australia's veterinarians were doing all the veterinary work with horses, and about 3% worked exclusively (> 90%) with horses, but did more than half (58%) of the horse work. Veterinarians working with horses included more males (80%) than the veterinar...
Moulay S, Zientara S, Sailleau C, Cruciere C.In order to develop a non-radioactive dot-blot hybridization assay, for the detection of African-horse sickness virus (AHSV), genome segment 7 from 9 serotypes was amplified by RT-PCR. The resulting PCR products were denatured, immobilized on nylon membranes and then hybridized to a non-radioactive digoxigenin-labelled probe. This probe (265 bp in length) was generated by nested-PCR using genome segment 7 of AHSV, serotype 4 as a template. The dot-blot was visualized by chemiluminescence. Positives were obtained from the PCR products amplified from all 9 AHSV serotypes, but not from any other ...
Martens P, Ihler CF, Rennesund J.A horse with a suspected injury of the distal phalanx was examined using radiography at day two and 19 after the onset of the lameness, with no definite diagnosis. Using computed tomography an incomplete fracture of the lateral wing of the distal phalanx was diagnosed at day 25. Based on computed tomography it was determined that the fracture probably did not enter the joint or involve the palmar cortex throughout its length which were of prognostic importance. The day following the CT examination a new oblique radiographic projection was made. In this radiography which was based on, and never...
Pellegrini A, Hägeli G, von Fellenberg R.Addition of perchloric acid (6.4% w/v final concentration) to horse alpha 1-proteinase inhibitor or to horse plasma neither precipitated nor inactivated alpha 1-proteinase inhibitor. None of the isoinhibitors of alpha 1-proteinase inhibitor was altered by dilute perchloric acid. This unexpected behavior led to a simplified procedure for the purification of horse alpha 1-proteinase inhibitor, consisting of removal of the bulk of plasma proteins, by perchloric acid precipitation and by gel filtration on Sephadex G-75 and G-200. The resulting preparations of alpha 1-proteinase inhibitor were immu...
AbouEl Ela NA, El-Nesr KA, Ahmed HA, Brooks SA.Severe combined immunodeficiency (SCID) is a fatal genetic disorder and one of the common genetic diseases of the Arabian horse. The genetic mutation responsible for this disease is a five base pair deletion (TCTCA) in the DNA-protein kinase catalytic subunit gene. Severe combined immunodeficiency is a recessive autosomal genetic disorder with 25% chance inheritance of the disease among the progeny of carrier parents. It causes complete absence of certain immune cells, like B and T lymphocytes, leaving foals with immunodeficiency and exposing them to early death within 4 to 6 months. This stud...
Cárdenas S, Gallego M, Valcárcel M, Ventura R, Segura J.A partially automated module for the routine determination of illicit non-steroid antiinflammatory drugs (NSAIDs) in biological fluids from race horses was built, tested, refined, and shown to work. This pretreatment module retains 17 NSAIDs on an Amberlite XAD-2 column before back-elution derivatization with methyl iodide in acetonitrile. Methylated derivatives are manually injected into a gas chromatograph connected to a mass spectrometer. The quantification limits thus achieved are 50-100 ng/mL in 1 mL of urine or plasma. The proposed method is more expeditious than its manual liquid-liquid...
Dawson J, Lees P, Sedgwick AD.Equine polymorphonuclear (PMN) and mononuclear (MN) leucocytes were separated on Percoll gradients and used to study the chemoattractant properties of the polar ether-linked phospholipid, platelet activating factor (PAF). Six concentrations of PAF ranging from 1 ng/ml to 100 micrograms/ml were studied in each of two in vitro assay systems, the agarose microdroplet and a microfilter technique. Very significant (p less than 0.01) increases in the movement of both PMN and MN cells were obtained with most concentrations of PAF. In two instances there was no apparent concentration-response relation...
Leung GN, Kwok WH, Wan TS, Lam KK, Schiff PJ.Formestane (4-hydroxyandrost-4-ene-3,17-dione) is an irreversible steroidal aromatase inhibitor with reported abuse in human sports. In 2011, our laboratory identified the presence of formestane in a horse urine sample from an overseas jurisdiction. This was the first reported case of formestane in a racehorse. The metabolism of formestane in humans has been reported previously; however, little is known about its metabolic fate in horses. This paper describes the in vitro and in vivo metabolic studies of formestane in horses, with the objective of identifying the target metabolite with the lon...
Lecompte F, Combarnous Y.A simple, accurate, sensitive enzyme immunoassay (EIA) has been developed that permits the measurement of equine Chorionic Gonadotropin activity in pregnant mare plasmas or serums as well as in commercial and highly-purified preparations. This assay is specific for eCG and eLH which share the same polypeptide structure but differ in their oligosaccharidic chains. The more important result is that this EIA has been found to be give data in very close agreement with the in vivo assay. Therefore this very rapid and convenient assay can be used to measure the activity of eCG/PMSG in pregnant mares...
Ginther OJ.Twenty-one pregnant pony mares were assigned to one of the following groups: 1) controls, 2) ovariectomy at Day 12, 3) ovariectomy at Day 12 plus daily progesterone treatment on Days 12 to 40, 4) PGF(2alpha) on Day 12, 5) PGF(2alpha) on Day 21, and 6) PGF(2alpha) on Day 30. Based on daily examinations by ultrasound, the embryonic vesicle was maintained to Day 40 in all control mares and in mares that were ovariectomized on Day 12 and given progesterone. The embryonic vesicle was lost in all mares of the other four groups. Administration of progesterone prevented the embryonic loss associated w...
Magdesian KG, Wilson WD, Mihalyi J.To determine disposition kinetics of amikacin in neonatal foals administered high doses at extended intervals. Methods: 7 neonatal foals. Methods: Amikacin was administered (21 mg/kg, i.v., q 24 h) for 10 days. On days 1, 5, and 10, serial plasma samples were obtained for measurement of amikacin concentrations and determination of pharmacokinetics. Results: Mean +/- SD peak plasma concentrations of amikacin extrapolated to time 0 were 103.1 +/- 23.4, 102.9 +/- 9.8, and 120.7 +/- 17.9 microg/mL on days 1, 5, and 10, respectively. Plasma concentrations at 1 hour were 37.5 +/- 6.7, 32.9 +/- 2.6, ...
Bailey VN, Sones JL, Camp CM, Gomes VCL, Oberhaus EL.The objective of this experiment was to determine if incorporation of kisspeptin-10 (Kp10) into treatment with estradiol benzoate (EB) and sulpiride to induce early cyclicity would result in greater endocrine responses and a greater number of mares responding with either follicle(s) > 30 mm or ovulation within 25 days of treatment. Eighteen anestrous mares were blocked by breed, body condition, and age before random assignment to treatment or control. All mares received 50 mg EB before receiving osmotic minipumps containing either saline (n = 9) or Kp10 (50 μg/hour; n = 9) one day ...
Pastor J, Cuenca R, Velarde R, Marco I, Viñas L, Lavín S.A semiautomatic electronic blood cell counter (Sysmex F-800) was evaluated with equine blood, according to the protocol of the International Committee for Standardization in Haematology (ICSH, 1984). The precision and overall reproducibility were acceptable for all the parameters studied except for the platelet count, in which a coefficient of variation of 18.8% and 21.7% was obtained for within and between batch precision and 26.76% for overall reproducibility. Carry-over for the haematocrit value and platelet count was unsatisfactory, thus the use of a blank diluent sample between different ...
Bustos CP, Muñoz AJ, Guida N, Waller A, Mesplet M.Strangles is a worldwide infectious disease caused by Streptococcus equi subsp. equi that affects the upper respiratory tract of horses. Streptococcus equi subsp. equi characterisation by seM-typing is internationally used for epidemiological studies and comparison of isolates. Objective: To identify and to compare the seM-types of Argentinian isolates of Streptococcus equi subsp. equi. Methods: Investigation of bacterial isolates using molecular and phylogenetic approaches. Methods: A total of 59 Argentinian isolates of Streptococcus equi subsp. equi obtained between 2007 and 2019 were studie...
Ronéus B, Lindholm A.Glutathione peroxidase (GSH-px) activity in the blood is correlated to the amount of selenium which was given to the horse. Currently recommended doses of selenium seem to be sufficient in order to prevent selenium deficiency. The blood GSH-px in foals reflects the amount of selenium given to the mare during pregnancy.
Tobin T, Harkins JD, Sams RA.Proper veterinary care of horses requires that horses in training have access to modern therapeutic medication. However, the sensitivity of equine drug testing now allows for detection of pharmacologically insignificant concentrations of many therapeutic medications. In 1995, the Association of Racing Commissioners International (ARCI) resolved that members 'address trace level detection so as not to lead to disciplinary action based on pharmacologically insignificant traces of these substances'. The rationale behind this approach is to prevent overly-sensitive testing from inhibiting the prop...
Asbury AC, Schultz KT, Klesius PH, Foster GW, Washburn SM.Ten mares, 5 resistant and 5 susceptible to bacterial endometritis, were examined for differences pertaining to the efficiency of phagocytosis of bacteria by neutrophils in the uterus. An assay for chemiluminescence was used to evaluate various schemes of opsonization and relate them to phagocytic rate. 123I-labelled albumin was used to measure protein migration to the inoculated uterus. Neutrophil numbers moving to the uterine lumen were determined. Before inoculation resistant mares were found to have substances in their uterine secretions that opsonized bacteria, resulting in effective phag...
Gerding JC, Clode A, Gilger BC, Montgomery KW.To review the clinical features, treatments, complications, and outcomes of horses with traumatic orbital fractures. Methods: Retrospective study. Methods: Eighteen horses with confirmed orbital fractures. Methods: Medical records of horses presenting with orbital fractures between 2006 and 2013 were reviewed. Signalment, etiology of fracture, clinical signs, fracture descriptions, diagnostic imaging, treatments, complications, and outcomes were evaluated. Results: Eighteen horses presented with orbital fractures resulting from rearing in a confined space (n = 5), being kicked (4), colliding w...
Hardy J, Bertone AL, Malemud CJ.To determine the functional response of synovium to infection, and the influence of infected synovium on articular cartilage metabolism. Methods: Synovium and articular cartilage explants from the midcarpal and tarsocrural joints of adult horses. Methods: For experiment 1, synovium explants were incubated as follows: control--incubation in standard medium, infected (I)--incubation with Staphylococcus aureus, and infected-filtered (IF)--incubation with medium collected from the infected group and filtered (0.22-micron filter). Daily collected medium was assayed for interleukin 1 beta (IL-1 beta...
Evans MJ, Mulligan RS, Livesey JH, Donald RA.Perifused equine anterior pituitary cells were used to investigate the relationships between the secretion of ACTH and substances known to either stimulate (corticotrophin-releasing hormone (CRH), and arginine vasopressin (AVP)) or inhibit (cortisol) ACTH secretion. The experiments were designed to mimic the hormone milieu present in vivo in the horse, with cortisol (0 or 100 nmol/l) and CRH (0 or 0.02 nmol/l) perifused continuously, and pulses of AVP (10 nmol/l) applied for 5 min at 30-min intervals. In columns perifused with 0.02 nmol CRH/l there was no significant overall effect of 100 nmol...