Veterinary research in horses encompasses the study of diseases, health management, and medical treatments specific to equine species. This field investigates various aspects of horse health, including infectious diseases, metabolic disorders, and musculoskeletal conditions. Researchers focus on understanding the pathophysiology of equine ailments, developing diagnostic tools, and evaluating therapeutic interventions. The study of horse health also involves examining preventive measures such as vaccination protocols and nutritional management to promote overall well-being. This page collects peer-reviewed research studies and scholarly articles that explore the diverse areas of veterinary science related to horses, providing insights into disease mechanisms, treatment strategies, and advancements in equine healthcare.
Loughrey CM, Smith GL, MacEachern KE.Both the cardiac action potential duration (APD) (0.6-1 s) and resting heart rate (30-40 beats/min) in the horse are significantly different from humans and smaller mammals, including the rabbit. This would be anticipated to have consequences for excitation-contraction (EC) coupling and require adaptation of the individual processes involved. The sarcoplasmic reticulum (SR) is one of the main components involved in EC coupling. This study examines and compares the activity of this organelle in the horse with that of the rabbit. In particular, the study focuses on SR Ca2+ release via the Ca2+ r...
Tandon R, Kaplan RM.A larval development assay (LDA, DrenchRite) was evaluated to determine the effectiveness of this method in detecting anthelmintic resistance in cyathostomin nematodes of horses. A total of 15 horse farms from Georgia and South Carolina (USA) and Population S ponies from the University of Kentucky (USA) were included in this study. Nematode eggs were extracted from pooled fecal samples and placed into the wells of a DrenchRite plate for testing against thiabendazole (TBZ), levamisole (LEV) and 2 ivermectin (IVM) analogs (IVM-1, IVM-2). After a 7-day incubation larvae in each well were counted ...
den Boon S, Schellekens JF, Schouls LM, Suijkerbuijk AW, Docters van Leeuwen B, van Pelt W.To obtain detailed information about the current geographical distribution and incidence of tick bites and Lyme borreliosis in the Netherlands and to identify regional differences in the ecological risk factors that might be involved. Methods: Retrospective questionnaire study. Methods: All Dutch general practitioner's (GP) practices. Methods: In April 2002, all GPs in the Netherlands were asked to complete a short questionnaire on the number of cases of tick bites and erythema migrans seen in 2001 and the size of their practice. Associations with possible risk factors were determined at the m...
Eddy AL, Galuppo LD, Stover SM, Taylor KT, Jensen DG.To compare mechanical properties and failure characteristics of 2 methods of fixation for repair of a transverse, midbody fracture of the proximal sesamoid bone (PSB): 4.5-mm AO cortical bone screw (AO) placed in lag fashion and 4/5-mm Acutrak (AT) self-compressing screw. Methods: An in vitro biomechanical evaluation of intact forelimb preparations and forelimb preparations with a simulated midbody PSB fracture stabilized by a bone screw. Methods: Sixteen paired and 8 unilateral cadaveric equine forelimbs. Methods: A midbody transverse osteotomy was created in the medial PSB of bilateral forel...
Parbhakar OP, Duke T, Townsend HG, Singh B.Pulmonary intravascular macrophages (PIMs) are present in horses and are believed to increase their sensitivity to endotoxin-induced cardio-pulmonary shock. However, owing to a lack of a marker for PIMs and the inability to isolate them, their precise contributions in the horse remain unknown. We designed this study to identify an immuno-phenotypic marker for PIMs and to develop a protocol for their transient depletion with gadolinium chloride (GC). GC is a lanthanide that has been used to deplete liver and lung macrophages. The horses (N = 15) were divided into control (n = 5) and GC-treated ...
De Carli GA, Tasca T, Pires Borges F.The in vitro hemolytic activity of Tritrichomonas foetus was investigated. The parasite was tested against human erythrocytes of groups A, B, AB, and O, and against erythrocytes of nine adult animals of different species (the rabbit, rat, chicken, cat, dog, swine, horse, bovine, and sheep). The results showed that T. foetus strains (ATCC KV1, K, PAL, 5022, RJ, 90) did not present any hemolytic activity against any human erythrocyte group nor against rabbit, rat, chicken, cat, dog and swine erythrocytes. T. foetus strains, however, lysed horse, bovine, and sheep erythrocytes. No hemolysin relea...
Petersen HH, Nielsen JP, Heegaard PM.The body's early defence in response to trauma, inflammation or infection, the acute phase response, is a complex set of systemic reactions seen shortly after exposure to a triggering event. One of the many components is an acute phase protein response in which increased hepatic synthesis leads to increased serum concentration of positive acute phase proteins. The serum concentration of these acute phase proteins returns to base levels when the triggering factor is no longer present. This paper provides a review of the acute phase proteins haptoglobin, C-reactive protein and serum amyloid A an...
Soma LR, Uboh CE, Guan F, Moate P, Luo Y, Teleis D, Li R, Birks EK, Rudy JA, Tsang DS.The pharmacokinetics of clenbuterol (CLB) following a single intravenous (i.v.) and oral (p.o.) administration twice daily for 7 days were investigated in thoroughbred horses. The plasma concentrations of CLB following i.v. administration declined mono-exponentially with a median elimination half-life (t(1/2k)) of 9.2 h, area under the time-concentration curve (AUC) of 12.4 ng.h/mL, and a zero-time concentration of 1.04 ng/mL. Volume of distribution (V(d)) was 1616.0 mL/kg and plasma clearance (Cl) was 120.0 mL/h/kg. The terminal portion of the plasma curve following multiple p.o. administrati...
Boxell AC, Gibson KT, Hobbs RP, Thompson RC.To assess the occurrence of gastrointestinal parasites in horses in Perth. To apply polymerase chain reaction (PCR) for the identification of some species of encysted larval cyathostomes. Methods: Between February and September of 2000, the gastrointestinal tracts of 29 horses submitted to a local knackery and Murdoch University Veterinary hospital in Perth were examined post mortem for the presence of gastrointestinal parasites. Methods: The gastrointestinal tract was divided into six sections, which were screened for the presence of parasites such as Gasterophilus sp, Anoplocephala sp and Pa...
Li Y, Yao J, Chang M, Nikolic D, Yu L, Yager JD, Mesecar AD, van Breemen RB, Bolton JL.Catechol-O-methyltransferase (COMT) plays an important role in the inactivation of biologically active and toxic catechols. It has been shown that COMT is genetically polymorphic with a wild-type and variant form where a valine has been substituted with a methionine. Several, but not all, epidemiological studies have shown that women, homozygous with the variant form, have an increased risk of developing breast cancer. Previously, we showed that 4-hydroxyequilenin (4-OHEN), a cytotoxic/genotoxic equine catechol estrogen metabolite, is both a substrate of COMT and an irreversible inhibitor of t...
Hughes KJ, Malikides N, Hodgson DR, Hodgson JL.To compare a fast Romanowsky cytological stain (Diff-Quik) and Leishman's stain for the detection of mast cells in samples from the lower airways of racehorses, and to compare the proportion of mast cells and eosinophils in the total inflammatory cells in tracheal aspirate (TA) with those in paired bronchoalveolar lavage (BAL) samples. Methods: Retrospective case series of 48 young Thoroughbred and Standardbred racehorses. Methods: Fifty-one paired TA and BAL samples were collected after treadmill exercise from 48 horses with poor racing performance. Two slides were prepared from each sample; ...
Malikides N, Hughes KJ, Hodgson DR, Hodgson JL.To determine whether diagnosis of airway inflammation, using cut-off percentages for neutrophils, differs when based on samples from tracheal aspirate (TA) and bronchoalveolar lavage (BAL) collected concomitantly from the same racehorse. Methods: Retrospective case series of 48 young Thoroughbred and Standardbred racehorses in race training, but showing poor performance. PROCEDURE TA and BAL samples were collected from all horses 1 to 2 h after high-speed treadmill exercise. Aliquots of the retrieved fluid were cytocentrifuged and smears stained with Diff-Quik. The mean percentage of neutrophi...
Foote CE, Gilkerson JR, Whalley JM, Love DN.To examine the prevalence of equine herpesvirus 1 antibody in mares and foals on a large Hunter Valley Thoroughbred stud farm in New South Wales before and after the introduction of an inactivated whole virus vaccine. Methods: Cross-sectional serological surveys performed in February 1995 and 2000 to determine the prevalence of EHV-1 antibody-positive mares and foals. A further cross-sectional survey was carried out in 2001 to complement the 2000 data. Methods: Two hundred and twenty-nine mares and their foals were sampled in 1995 and 236 mares and their foals were sampled in 2000. The study p...
Staniar WB, Kronfeld DS, Treiber KH, Splan RK, Harris PA.The objective of this study was to establish a procedure for differentiating a baseline curve from a systematic deviation in weight-age data, and hence to develop a physiological growth model for the Thoroughbred. A total of 2,698 records for 175 foals was obtained during a period of 8 yr (1994 to 2001). Weight-age data were fit with a sigmoid growth equation, W = A(1 + be(-kt))M, where W is BW at age t, A is the asymptotic value of W, b is a scaling parameter that defines the degree of maturity at t = 0, k is a rate constant, and M defines the point of inflection in the sigmoid curve in relat...
Du J, White N, Eddington ND.The purpose of this study was to determine if glucosamine (GL) hydrochloride (FCHG49) and low molecular weight (LMW) chondroitin sulfate (CS) (TRH122) are absorbed after oral administration to horses. The bioavailability of LMWCS was evaluated by quantifying the total disaccharides found in the plasma following chondroitinase ABC digestion. Methods: Two separate studies were conducted. In study 1, ten adult horses received the following four treatments in a randomized crossover fashion: (1) i.v. LMWCS (3 g of 8 kDa), (2) p.o. LMWCS (3 g of 8 kDa), (3) i.v. LMWCS (3 g of 16.9 kDa) and (4) p.o. ...
Begg LM, O'Sullivan CB.To report the prevalence and distribution of gastric ulceration within a group of racehorses and to describe the endoscopic appearance of gastric antrum and pyloric ulceration. Methods: Retrospective clinical study. Methods: Medical records from gastroscopic examinations of 345 racehorses (331 Thoroughbreds and 14 Standardbreds) were reviewed. Prevalence, distribution and severity of gastric ulcers were recorded. Lesions involving the squamous mucosa and the glandular mucosa of the antrum and pylorus were graded and compared. Results: Gastric ulceration was found in 86% of racehorses. The squa...
Chateau H, Degueurce C, Denoix JM.To develop a method that allows quantification of the 3 anatomic rotations in the digital joints of moving horses and measure these rotations when horses are walking in a straight line on a hard track. Methods: 4 healthy French Trotter horses. Methods: Triads of ultrasonic kinematic markers were surgically linked to the 4 distal segments of the digits of the left forelimb of each horse. Three-dimensional (3-D) coordinates of these markers were recorded in horses walking in a straight line. The three angles of rotation of each digital joint were calculated by use of a joint coordinate system as...
Stewart AJ, Hardy J, Kohn CW, Toribio RE, Hinchcliff KW, Silver B.To evaluate the diagnostic value of serum concentrations of total magnesium (tMg) and ionized magnesium (iMg), concentrations of magnesium (Mg) in muscle, intracellular Mg (icMg) concentrations, urinary Mg excretion (EMg), Mg clearance (CMg), and fractional clearance of Mg (FCMg) in horses fed diets with Mg content above and below National Research Council recommendations. Methods: 9 young female horses. Methods: 6 horses were fed a reduced-Mg diet for 29 days followed by an Mg-supplemented diet for 24 days. Control horses (n = 3) were fed grass hay exclusively. Blood, urine, and tissue sample...
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, ...
Bennett RC, Steffey EP, Kollias-Baker C, Sams R.To quantitate the dose and time-related effects of morphine sulfate on the anesthetic sparing effect of xylazine hydrochloride in halothane-anesthetized horses and determine the associated plasma xylazine and morphine concentration-time profiles. Methods: 6 healthy adult horses. Methods: Horses were anesthetized 3 times to determine the minimum alveolar concentration (MAC) of halothane in O2 and characterize the anesthetic sparing effect (ie, decrease in MAC of halothane) by xylazine (0.5 mg/kg, i.v.) administration followed immediately by i.v. administration of saline (0.9% NaCI) solution, lo...
Albihn A, Båverud V, Magnusson U.Uterine microbiology and antimicrobial susceptibility was investigated in 239 mares with fertility problems in a prospective study in Sweden. Uterine swab samples were collected with double guarded swabs and transported overnight before being cultured. The Minimum Inhibitory Concentrations (MIC) was determined for a panel of antimicrobials. From 152 of the 239 mares at least one bacterial species was isolated, most frequently E. coli (104 isolates), beta-haemolytic streptococci (31) and fungi (16). beta-haemolytic streptococci were more frequently (p < 0.01) associated with clinical endomet...
Björnsdóttir S, Arnason T, Lord P.A survival analysis was used to compare the culling rate of Icelandic horses due to the presence of radiographic and clinical signs of bone spavin. A follow-up study of 508 horses from a survey five years earlier was performed. In the original survey 46% of the horses had radiographic signs of bone spavin (RS) and/or lameness after flexion test of the tarsus. The horse owners were interviewed by telephone. The owners were asked if the horses were still used for riding and if not, they were regarded as culled. The owners were then asked when and why the horses were culled. During the 5 years, 9...
Donaldson MT, Jorgensen AJ, Beech J.To determine prevalence and clinical features of pituitary pars intermedia dysfunction (PPID) in horses with laminitis. Methods: Case series. Methods: 40 horses with laminitis. Methods: Horses with laminitis that survived an initial episode of pain and were not receiving medications known to alter the hypothalamic-pituitary-adrenal axis were tested for PPID by evaluation of endogenous plasma ACTH concentration. Signalment, suspected cause, month of onset and duration of laminitis, Obel grade of lameness, pedal bone rotation, physical examination findings, results of endocrine function tests, t...
Murray RC, Roberts BL, Schramme MC, Dyson SJ, Branch M.Injury of the distal aspect of the deep digital flexor tendon (DDFT) is a recognized cause of lameness, but diagnosis is difficult. This study aimed to improve understanding of DDFT morphology and pathology using retrospective evaluation of magnetic resonance (MR) images. We hypothesized that: (1) The distal aspect of the DDFT in normal horses would have a repeatable proximal/distal pattern and symmetry between limbs and between lobes; (2) DDFT dimensions would be related to bodyweight, navicular bone dimensions and hoof size; (3) this symmetry and pattern would be lost in DDFT injury; and (4)...
Wallner B, Piumi F, Brem G, Müller M, Achmann R.Y chromosome polymorphisms such as microsatellites or single nucleotide polymorphisms represent a paternal counterpart to mitochondrial DNA (mtDNA) for evolutionary and phylogeographic studies. The use of Y chromosome haplotyping in natural populations of species other than humans is still hindered by the lack of sequence information necessary for polymorphism screening. Here we used representational difference analysis (RDA) followed by a screen of a bacterial artificial chromosome (BAC) library for repetitive sequences to obtain polymorphic Y-chromosomal markers. The procedure was performed ...
Ramirez S, Lester GD, Roberts GR.The aim of this retrospective study was to determine the clinical usefulness of thoracic ultrasonography compared to thoracic radiography in evaluation of Rhodococcus equi pneumonia. Criteria for patient inclusion in this study were: (1) isolation of R. equi from transtracheal aspirate, (2) radiographic evaluation of the pulmonary parenchyma, and (3) sonographic evaluation of the pulmonary parenchyma. Seventeen foals met this criteria and their medical records were reviewed. Pyogranulomatous pneumonia was identified radiographically in 13 foals. Severe consolidative pneumonia with no detectabl...
Johnson R.A review of the literature on intestinal atresia of domestic animal species and humans was done. The 5 types of intestinal occlusions described in human infants are atresia type 1, atresia type 2, atresia type 3, stenosis, and the "apple peel" or "Christmas tree" deformity. The intestinal defects described in domestic animal species such as the bovine, equine and porcine are similar to those of human infants. The "T-formation", an intestinal defect of the bovine resembling atresia type 3, and rectal stricture, an acquired intestinal defect of the porcine resembling stenosis, were described rec...
Toniolo C, Fontana A, Scoffone E.Ultraviolet absorption and circular dichroism studies have been carried out on horse heart apo-cytochrome c and heme-free peptide fragments obtained by cyanogen bromide cleavage of the native protein. It was noted that the various peptides assume predominantly an unordered conformation in water solution. Increasing ionic strength and addition of 2-chloroethanol increase the right-handed helical content. Guanidinium hydrochloride favors the coil state. It was also demonstrated that two non-interacting helical regions of different stability are present in the apo-protein in 2-chloroethanol.
Frippiat T, Paindaveine C, Duprez JN, Delguste C, Mainil J, Art T.Antimicrobial resistance is increasing in both human and veterinary medicine. Bacteria can be part of the etiology of respiratory disorders in horses. Bactericidal activity of silver has been largely described and silver is currently used in veterinary therapeutic applications such as wound dressings. The aim of this study was to assess the in vitro bactericidal effects of nebulized silver nanoparticles (AgNP) on 2 common equine respiratory bacteria, Streptococcus equi subsp. zooepidemicus and Actinobacillus equuli subsp. equuli. Firstly, antimicrobial susceptibility of AgNP was determined ove...
Altamura G, Strazzullo M, Corteggio A, Francioso R, Roperto F, D'Esposito M, Borzacchiello G.Bovine papillomaviruses (BPVs) types 1 and 2 are the only known papillomaviruses able to jump the species. In fact, BPVs 1/2 induce neoplasia in their natural bovine host but infection is also associated to neoplastic skin lesions in equids termed sarcoids. The equine sarcoid is considered to be the most common equine cutaneous tumour worldwide for which no effective therapy is available. Very little is known about the molecular mechanisms underlying tumourigenesis, although genes contributing to sarcoid development have been identified. Several studies associate the development of cancer to t...
Bird J, Herd RP.The ability of two species of nematophagous fungi, Arthrobotrys oligospora and Arthrobotrys flagrans (syn. Trichothecium flagrans, Duddingtonia flagrans), to control the development of infective larvae in feces from naturally infected horses was assessed in vitro. The horses were from a farm where it had been previously established that cyathostomes accounted for 100% of the strongyle egg output. The feces from these naturally infected horses were mixed with spores of each fungal species at four concentrations: 0 (control), 1, 10, and 100 spores per egg. Five replicates for each group were inc...
Poloumienko A.A growing body of evidence suggests the involvement of sex chromosome genes in mammalian development. We report the cloning and characterization of the complete coding regions of the bovine Y chromosome ZFY and X chromosome ZFX genes, and partial coding regions of porcine and equine ZFX and ZFY genes. Bovine ZFY and ZFX are highly similar to each other and to ZFX and ZFY from other species. While bovine and human ZFY proteins are both 801 amino acids long, bovine ZFX is 5 amino acids shorter than human ZFX. Like in humans, both bovine ZFY and ZFX contain 13 zinc finger motifs and belong to the...
Lyons ET, Tolliver SC.Macrocyclic lactones (MLs) revolutionized parasite control in horses and other animals. They are unique in that they are effective against arthropods and nematodes. The first of the widely used avermectins was ivermectin. In 1983, it was marketed for use in horses as an injectable formulation but was withdrawn in 1984 after about a year and half on the market because of adverse problems. It was replaced by a paste formulation and an oral/stomach tube liquid formulation. Ivermectin is highly active on bots, ascarids, large and small strongyles, pinworms, strongyloides, stomach worms, and some o...
Schaaf KL, Kannegieter NJ, Lovell DK.Ten horses presented with severe distortion of the facial contour, crepitus on palpation and mild to moderate epistaxis. Individual horses also showed ocular damage, ptosis, severe dyspnoea and movement of the facial bones concurrent with respiration. The fracture fragments were exposed using a large curvilinear incision and elevated using a retractor, periosteal elevator, chisel or Steinmann pin. The fracture fragments were unstable following reduction and fixation was necessary. Stabilisation was achieved with polydioxanone sutures placed through holes drilled in opposing sides of the fractu...
Bahar S, Bolat D, Selcuk ML.Although the cervical spinal cord (CSC) of the horse has particular importance in diseases of CNS, there is very little information about its segmental morphometry. The objective of the present study was to determine the morphometric features of the CSC segments in the horse and possible relationships among the morphometric features. The segmented CSC from five mature animals was used. Length, weight, diameter, and volume measurements of the segments were performed macroscopically. Lengths and diameters of segments were measured histologically, and area and volume measurements were performed u...
Ramseyer A, Sides R, Slinker B, Evans D, Bayly W.The ability to obtain breath-by-breath measures of ventilatory mechanics for the entirety of an exercise test, regardless of speed(s) or duration enables evaluations of equine ventilation during exercise that are necessary for assessments of performance. Objective: Evaluation of a new ergospirometer (Quadflow; QF) system's accuracy and repeatability for measuring pulmonary variables in contrast to the established pneumotachometer-based system (control) and assessment of its effects, if any, on exercise capacity at high speeds. Methods: Five Thoroughbred horses each performed 10 incremental exe...
Acker DA, Curran S, Bersu ET, Ginther OJ.To describe the gross and histologic changes that develop in the equine embryo proper (ie, the portion of the embryo that becomes the fetus) from days 17 to 40 after ovulation and to compare the external features of equine embryos with those of porcine, ovine, and human embryos. Methods: 34 embryos collected from mixed-breed pony mares. Methods: External features for each embryo proper, including length, number of branchial arches, growth of appendages, face and head features, and body features, were examined, using a dissecting microscope, for embryos collected on days 17 to 40. Internal feat...
Singha H, Malik P, Saini S, Khurana SK, Elschner MC, Mertens K, Barth SA, Tripathi BN, Singh RK.Burkholderia mallei is a Gram-negative coccobacillus which causes glanders-a fatal disease of equines that may occasionally be transmitted to humans. Several cases of outbreaks have been reported from India since 2006. This paper presents draft genome sequences of two B. mallei strains isolated from equines affected by glanders in India.
de Lorenzi L, Molteni L, Zannotti M, Galli C, Parma P.This report concerns the cytogenetic analysis, using both C-banding and fluorescence in situ hybridisation techniques, of a sterile mare. Results obtained revealed a 2n = 65, XXX condition with no sign of mosaicism. The work supports the suggestion that X trisomy, rare in horse, causes infertility in mares and is not associated to other clearly visible phenotypic features.
Schemann K, Gillespie JA, Toribio JA, Ward MP, Dhand NK.Rapid, evidence-based decision-making is critical during a disease outbreak response; however, compliance by stakeholders is necessary to ensure that such decisions are effective - especially if the response depends on voluntary action. This mixed method study evaluated technical policy decision-making processes during the 2007 outbreak of equine influenza in Australia by identifying and analysing the stakeholder network involved and the factors driving policy decision-making. The study started with a review of the outbreak literature and published policy documents. This identified six policy ...
Saukko AEA, Nykänen O, Sarin JK, Nissi MJ, Te Moller NCR, Weinans H, Mancini IAD, Visser J, Brommer H, van Weeren PR, Malda J, Grinstaff MW....To prevent the progression of posttraumatic osteoarthritis, assessment of cartilage composition is critical for effective treatment planning. Posttraumatic changes include proteoglycan (PG) loss and elevated water content. Quantitative dual-energy computed tomography (QDECT) provides a means to diagnose these changes. Here, we determine the potential of QDECT to evaluate tissue quality surrounding cartilage lesions in an equine model, hypothesizing that QDECT allows detection of posttraumatic degeneration by providing quantitative information on PG and water contents based on the partitions of...
Anderson SL, Bracamonte JL, Hendrick S.The objective of this study was to compare the bursting strength (BS) and mode of failure (MF) of ventral midline (VM) celiotomies closed with USP 7 polydioxanone (7PD) in 1 or 2 simple continuous sections. A bursting strength model, consisting of inserting and inflating a 200-L polyurethane bladder through a 25-cm VM celiotomy, was used on 15 fresh equine cadavers. Celiotomies were closed using 7PD in 2 separate sections (4 knots), 2 continuous sections (3 knots), or a single section (2 knots) using a simple continuous pattern. The horses' signalment, body weight, number of total knots, MF, a...
Leipold SD, Graham JK, Squires EL, McCue PM, Brinsko SP, Vanderwall DK.Information on the number of motile spermatozoa needed to maximize pregnancy rates for frozen-thawed stallion semen is limited. Furthermore, concentration of spermatozoa per 0.5-mL straw has been shown to affect post-thaw motility (7). The objectives of this study were 1) to compare the effect of increasing the concentration of spermatozoa in 0.5-mL straws from 400 to 1,600 x 10(6) spermatozoa/mL on pregnancy rate of mares, and 2) to determine whether increasing the insemination dose from approximately 320 to 800 million progressively motile spermatozoa after thawing would increase pregnancy r...
Nogueira BCF, Orozco AMO, Argumedo AK, de Oliveira Faustino A, de Oliveira LL, da Fonseca LA, Campos AK.Ticks have saliva rich in immunoregulatory molecules that interfere with the host's physiology in order to feed. This study aimed to evaluate the concentration of acute phase proteins and circulating oxidative stress in response to infestation by Amblyomma sculptum and Dermacentor nitens in two breed horses, Mangalarga Marchador and Breton Postier, to define resistance or susceptibility to ticks. Among the oxidative stress markers, we observed lower malondialdehyde and nitric oxide in horses with tick infestation, consequently not altering the antioxidant enzymes. Breton Postier with tick infe...
Schmidt AR, Williams MA, Carleton CL, Darien BJ, Derksen FJ.Serial transabdominal amniocentesis was performed on eight mares in late gestation. Ultrasonography was used to identify the two placental fluid sacs and the foetus. A biopsy guide attached to the transducer allowed visualisation of the needle path during insertion. Amniotic fluid was obtained in 85 per cent of the attempts, although as mares approached parturition substantial pools of amniotic fluid were more difficult to locate. Two mares aborted during the study probably because of complications of the procedures, whereas six mares produced normal foals at term. The abortions preclude clini...
Wilson AD, Badnell-Waters AJ, Bice R, Kelland A, Harris PA, Nicol CJ.High carbohydrate diets can affect the health and behaviour of foals, but the mechanisms are not always fully understood. The objective of this study was to compare the effects of feeding a starch and sugar (SS), or a fat (oil) and fibre (FF) rich diet to two groups of eight foals. Diets were fed from 4 to 42 weeks of age, alongside ad libitum forage. Faecal pH levels did not differ significantly between groups and endoscopic examination showed that the gastric mucosa was healthy in both groups at 25 and 42 weeks of age. At 40 weeks of age, SS foals had significantly higher total blood glucose...
Gretler SR, Finno CJ, McKemie DS, Kass PH, Knych HK.To describe the pharmacokinetics and selected pharmacodynamic variables of codeine and its metabolites in Thoroughbred horses following a single oral administration. Methods: Prospective experimental study. Methods: A total of 12 Thoroughbred horses, nine geldings and three mares, aged 4-8 years. Methods: Horses were administered codeine (0.6 mg kg) orally and blood was collected before administration and at various times until 120 hours post administration. Plasma and urine samples were collected and analyzed for codeine and its metabolites by liquid chromatography-mass spectrometry, and plas...
Miyakoshi D, Senba H, Shikichi M, Maeda M, Shibata R, Misumi K.This study aimed to evaluate whether radiographic abnormalities at yearling sales were associated with the failure to start racing at 2-3 years of age. Radiographic abnormalities in the carpal (n=852), tarsal (n=976), metacarpophalangeal (n=1,055), and metatarsophalangeal joints (n=1,031) from 1,082 horses, recorded at yearling sale, were reviewed. Eighty-two horses (7.6%) failed to start racing. Radiographic abnormalities such as wedged or collapsed tarsal bones, irregular lucency of a sagittal ridge at the distal aspect of the distal third metatarsal bone, and proximal dorsal fragmentation o...
Waller T, Rubarth S.The study comprises 49 dogs, 2 horses, and 2 cows with haemangioendothelioma, which have been subjected to autopsy over a period of 26 years. Most of the dogs were old, and there is an over-representation of male dogs. The results also indicate that the Alsation breed of dog is particularly susceptible to these tumours, as is the Boxer to some extent. The disease was in most cases of short duration and the most common clinical symptoms were sluggishness, fever, generalized anaemia, breathing difficulties, increased thirst, and leuco-cytosis. Most of the dogs fell ill and were subjected to auto...
Senju N, Tozaki T, Kakoi H, Matsuyama R, Nakamura K, Takasu M.The Miyako and Yonaguni horses are native horses in Okinawa. Here, we evaluated their genetic relationship using microsatellite data and Kiso horses, which have four subpopulations, as a reference population for evaluating this relationship. Microsatellite data from 35 Miyako, 78 Yonaguni, and 172 Kiso horses were evaluated using the STRUCTURE software for analyzing multilocus genotype data to investigate the population structures and their underlying relationship. The results of the STRUCTURE analysis were stable when ΔK was 2, suggesting that the Okinawan horses are different from the Kiso ...
de Brabander HF, van Hende J, Batjoens P, Hendriks L, Raus J, Smets F, Pottie G, van Ginkel L, Stephany RW.When residues of nortestosterone (NT) were found in the urine of cattle, racehorses or bodybuilders, exogenic administration was thought to be proven. In previous literature, no records were found of the endogenic presence of this molecule. In the horse-racing world, Houghton and Courthot found that NT is normally present in the urine of the stallion. Belgian and Dutch researchers found that NT is also present in the urine and edible parts of the intact boar. Vandenbroeck et al. (1991) suggested the endogenous presence of NT (in the beta form) in the pregnant cow. Meyer (1992) reported the pre...
