Disease etiology in horses refers to the study of the causes and development of diseases within equine populations. It encompasses various factors, including genetic predisposition, environmental influences, infectious agents, and nutritional imbalances, that contribute to the onset and progression of diseases in horses. Understanding disease etiology is essential for identifying risk factors and implementing preventative measures in equine health management. This topic includes research on pathogen-host interactions, the impact of management practices on disease incidence, and the role of genetic and environmental factors in disease susceptibility. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, contributing factors, and implications of disease etiology in horses.
de Laat MA, McGree JM, Sillence MN.Compared with some other species, insulin dysregulation in equids is poorly understood. However, hyperinsulinemia causes laminitis, a significant and often lethal disease affecting the pedal bone/hoof wall attachment site. Until recently, hyperinsulinemia has been considered a counterregulatory response to insulin resistance (IR), but there is growing evidence to support a gastrointestinal etiology. Incretin hormones released from the proximal intestine, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide, augment insulin secretion in several species but require invest...
Edwards S, Clode AB, Gilger BC.This retrospective case series evaluates husbandry and environmental conditions in relation to eosinophilic keratitis in horses. While no associations were found between disease and husbandry practices or specific environmental factors such as humidity or temperature, an increased prevalence of presentation in summer months was identified in this population of horses.
D￮ LR, Stefanovski D, Boston RC, Boyle AG.To evaluate predictor variables for and complications associated with Streptococcus equi subsp equi infection (strangles) in horses. Methods: Retrospective case-control study. Methods: 108 horses with strangles (cases) and 215 horses without strangles (controls). Methods: Medical records from January 2005 through July 2012 were reviewed. Cases were defined as horses with clinical signs of strangles (pyrexia, retropharyngeal lymphadenopathy, and mucopurulent nasal discharge) that were associated with a confirmed strangles outbreak or had positive results for S equi on PCR assay or bacteriologic...
Kwasnik M, Gora IM, Rola J, Zmudzinski JF, Rozek W.The phylogenetic analysis of influenza virus is based mainly on the variable hemagglutinin or neuraminidase genes. However, some discrete evolutionary trends might be revealed when more conservative genes are considered. We compared all available in GenBank database full length NS sequences of equine influenza virus including Polish isolates. Four nucleotides at positions A202, A237, T672 and A714 and three amino acids at positions H59, K71 and S216 which are also present in A/eq/Pulawy/2006 and A/eq/Pulawy/2008 may be discriminating for the Florida sublineage. Threonine at position 83 seems t...
Back H, Ullman K, Leijon M, Söderlund R, Penell J, Ståhl K, Pringle J, Valarcher JF.Equid herpesvirus 5 (EHV-5) is related to the human Epstein-Barr virus (human herpesvirus 4) and has frequently been observed in equine populations worldwide. EHV-5 was previously assumed to be low to non-pathogenic; however, studies have also related the virus to the severe lung disease equine multinodular pulmonary fibrosis (EMPF). Genetic information of EHV-5 is scanty: the whole genome was recently described and only limited nucleotide sequences are available. In this study, samples were taken twice 1 year apart from eight healthy horses at the same professional training yard and samples f...
Wylie CE, Shaw DJ, Fordyce FM, Lilly A, Pirie RS, McGorum BC.We hypothesised that the apparent geographical distribution of equine grass sickness (EGS) is partly attributable to suboptimal levels of soil macro- and trace elements in fields where EGS occurs. If proven, altering levels of particular elements could be used to reduce the risk of EGS. Objective: To determine whether the geographical distribution of EGS cases in eastern Scotland is associated with the presence or absence of particular environmental chemical elements. Methods: Retrospective time-matched case-control study. Methods: This study used data for 455 geo-referenced EGS cases and 910 ...
McFadden AM, Hanlon D, McKenzie RK, Gibson I, Bueno IM, Pulford DJ, Orr D, Dunowska M, Stanislawek WL, Spence RP, McDonald WL, Munro G, Mayhew IG.On 9 January 2014 (Day 0) a mare from a stud farm in the Waikato region presented with urinary incontinence without pyrexia. Over the following 33 days 15 mares were clinically affected with neurological signs. All but one mare had a foal at foot. The most commonly observed clinical signs were hind limb paresis and ataxia. In some cases recumbency occurred very early in the course of disease and seven mares were subject to euthanasia for humane reasons. Results: Equid herpesvirus (EHV) type 1 was detected using PCR in various tissues collected post mortem from two mares with neurological signs...
Ginther OJ, Castro T, Baldrighi JM, Wolf CA, Santos VG.Five mares that developed idiopathic persistent corpus luteum (PCL) were compared with 5 mares with apparently normal interovulatory intervals (IOIs). Progesterone (P4) and a metabolite of prostaglandin F2α (PGFM) were assayed daily beginning on the day of ovulation (Day 0). Transition between the end of an initial progressive P4 increase and the beginning of a gradual decrease in P4 occurred on mean Day 6. The gradual decrease in P4 between Days 6 and 12 was less (approached significance, P < 0.06) in the PCL group than in the IOI group. The P4 concentration on Day 12 (before luteolysis i...
Schellenbacher C, Shafti-Keramat S, Huber B, Fink D, Brandt S, Kirnbauer R.The consistent and specific presence of Equus caballus papillomavirus type 2 (EcPV2) DNA and mRNA in equine genital squamous cell carcinoma (gSCC) is suggestive of an etiological role in tumor development. To further validate this concept, EcPV2-neutralizing serum antibody titers were determined by an EcPV2 pseudovirion (PsV) neutralization assay. Furthermore, an EcPV2 L1 virus-like particle (VLP)-based vaccine was generated and its prophylactic efficacy evaluated in vivo. All 6/6 gSCC-affected, but only 3/20 tumor-free age-matched animals revealed EcPV2-neutralizing serum antibody titers by P...
Bertuglia A, Lacourt M, Girard C, Beauchamp G, Richard H, Laverty S.The role of osteoclasts in osteochondral degeneration in osteoarthritis (OA) has rarely been investigated in spontaneous disease or animal models of OA. Objective: The objectives of the current study were to investigate osteoclast density and location in post-traumatic OA (PTOA) and control specimens from racehorses. Methods: Cores were harvested from a site in the equine third carpal bone, that undergoes repetitive, high intensity loading. Histological and immunohistochemical (Cathepsin K and Receptor-activator of Nuclear Factor kappa-β ligand (RANKL)) stained sections were scored (global an...
Abraham G.This review provides an overview of the early and current literature including contributions that highlight the parasympathetic cholinergic receptor systems in domestic animal tissues. Muscarinic acetylcholine receptors (mAChRs) belong to the subfamily of G protein-coupled receptors and regulate many fundamental functions of the central and peripheral nervous systems and have been subject to research over at least 40 years. Nonetheless, there are few studies specifying mAChRs in domestic animal tissues. This review focuses on the pharmacology of muscarinic acetylcholine receptor (mAChR) system...
Raftery AG, Garcia NC, Thompson H, Sutton DG.A 15-year-old Clydesdale cross gelding was investigated and managed over a 2-year period for intermittent collapse. The horse presented initially after an observed episode of collapse at rest, and had a resting tachycardia, elevated Cardiac Troponin I and polycythaemia. Multiple dysrhythmias were detected on telemetric electrocardiography. Vital parameters, cardiac rhythm and red cell count returned to reference range with prolonged rest but further resting syncopal episodes were observed, and due to safety concerns and limited treatment options the horse was euthanased. Post mortem evaluation...
Boysen C, Davis EG, Beard LA, Lubbers BV, Raghavan RK.Kansas witnessed an unprecedented outbreak in Corynebacterium pseudotuberculosis infection among horses, a disease commonly referred to as pigeon fever during fall 2012. Bayesian geostatistical models were developed to identify key environmental and climatic risk factors associated with C. pseudotuberculosis infection in horses. Positive infection status among horses (cases) was determined by positive test results for characteristic abscess formation, positive bacterial culture on purulent material obtained from a lanced abscess (n = 82), or positive serologic evidence of exposure to organism ...
May CE, Schulman ML, Howell PG, Lourens CW, Gouws J, Joone C, Monyai MS, le Grange M, Bezuidt OK, Harper CK, Guthrie AJ.Taylorella equigenitalis is the causative agent of contagious equine metritis (CEM), a sexually transmitted infection of horses. We report here the genome sequence of T. equigenitalis strain ERC_G2224, isolated in 2015 from a semen sample collected in 1996 from a Lipizzaner stallion in South Africa.
Hellings IR, Ekman S, Hultenby K, Dolvik NI, Olstad K.Cartilage canals have been shown to contain discontinuous blood vessels that enable circulating bacteria to bind to cartilage matrix, leading to vascular occlusion and associated pathological changes in pigs and chickens. It is also inconsistently reported that cartilage canals are surrounded by a cellular or acellular wall that may influence whether bacterial binding can occur. It is not known whether equine cartilage canals contain discontinuous endothelium or are surrounded by a wall. This study aimed to examine whether there were discontinuities in the endothelium of cartilage canal vessel...
Edson D, Field H, McMichael L, Vidgen M, Goldspink L, Broos A, Melville D, Kristoffersen J, de Jong C, McLaughlin A, Davis R, Kung N, Jordan D....Pteropid bats or flying-foxes (Chiroptera: Pteropodidae) are the natural host of Hendra virus (HeV) which sporadically causes fatal disease in horses and humans in eastern Australia. While there is strong evidence that urine is an important infectious medium that likely drives bat to bat transmission and bat to horse transmission, there is uncertainty about the relative importance of alternative routes of excretion such as nasal and oral secretions, and faeces. Identifying the potential routes of HeV excretion in flying-foxes is important to effectively mitigate equine exposure risk at the bat...
Ducro BJ, Schurink A, Bastiaansen JW, Boegheim IJ, van Steenbeek FG, Vos-Loohuis M, Nijman IJ, Monroe GR, Hellinga I, Dibbits BW, Back W, Leegwater PA.Hydrocephalus in Friesian horses is a developmental disorder that often results in stillbirth of affected foals and dystocia in dams. The occurrence is probably related to a founder effect and inbreeding in the population. The aim of our study was to find genomic associations, to investigate the mode of inheritance, to allow a DNA test for hydrocephalus in Friesian horses to be developed. In case of a monogenic inheritance we aimed to identify the causal mutation. Results: A genome-wide association study of hydrocephalus in 13 cases and 69 controls using 29,720 SNPs indicated the involvement o...
Theoret CL, Bolwell CF, Riley CB.To determine the frequency and type of skin wounds encountered by New Zealand veterinarians in their equine patients, the duration and estimated costs of treatment as well as the expected outcomes for these wounds. Methods: An online survey was sent to all veterinarians registered with the New Zealand Equine Veterinary Association. The survey comprised questions on the location and experience of respondents, the number of wound-related cases in relation to the total equine caseload, the type and anatomical location of wounds treated, the frequency, duration and costs of treatments, the outcome...
Baise E, Habyarimana JA, Amory H, Boemer F, Douny C, Gustin P, Marcillaud-Pitel C, Patarin F, Weber M, Votion DM.Ingestion of sycamore seeds (Acer pseudoplatanus) is the likely source of hypoglycin A in atypical myopathy (AM) but ingestion of seedlings in spring might also contribute to intoxication. Objective: To test for hypoglycin A in seeds and seedlings collected on pastures where AM cases were reported and compare its concentration in serum of affected and healthy horses. Methods: Field investigation of clinical cases. Methods: Whenever present, samaras (the winged nuts that each contain one seed) and/or seedlings were collected from pastures of 8 AM cases and 5 unaffected horses from different pre...
Lacombe VA.Seizures are a diverse and very common set of chronic neurologic disorders in humans and dogs but are less common in horses. Seizures refer to a specific clinical event (described as sudden and severe) regardless of the etiology, which includes both intracranial and extracranial causes. Therefore, after briefly reviewing some definitions, this article aims to describe the use of a standardized classification, which could facilitate a logical approach for the clinician to establish a diagnosis, as well as to use a consistent mode of communication. For instance, seizures can be classified by typ...
Holl HM, Gao S, Fei Z, Andrews C, Brooks SA.Laminitis, the structural failure of interdigitated tissue that suspends the distal skeleton within the hoof capsule, is a devastating disease that is the second leading cause of both lameness and euthanasia in the horse. Current transcriptomic research focuses on the expression of known genes. However, as this tissue is quite unique and equine gene annotation is largely derived from computational predictions, there are likely yet uncharacterized transcripts that may be involved in the etiology of laminitis. In order to create a novel annotation resource, we performed whole transcriptome seque...
Banse HE, Frank N, Kwong GP, McFarlane D.In horses, hyperinsulinemia and insulin resistance (insulin dysregulation) are associated with the development of laminitis. Although obesity is associated with insulin dysregulation, the mechanism of obesity-associated insulin dysregulation remains to be established. We hypothesized that oxidative stress in skeletal muscle is associated with obesity-associated hyperinsulinemia in horses. Thirty-five light breed horses with body condition scores (BCS) of 3/9 to 9/9 were studied, including 7 obese, normoinsulinemic (BCS ≥ 7, resting serum insulin < 30 μIU/mL) and 6 obese, hyperinsulinemic...
Grewar JD, Thompson PN, Lourens CW, Guthrie AJ.Thoroughbred foal body temperature data were collected from shortly after birth until shortly after weaning during the 2007/2008 season on a stud farm in the Western Cape Province of South Africa. Equine encephalosis (EE) caused by EE virus (EEV) serotype 4 (EEV-4) occurred in the foal group during the first autumn after their birth (March and April 2008). A descriptive study was undertaken to provide data on the EEV maternal antibody status, the association between pyrexia and EEV infection, and the incidence of infection amongst the foals prior to and during the episode. This included the fr...
Bergmann T, Moore C, Sidney J, Miller D, Tallmadge R, Harman RM, Oseroff C, Wriston A, Shabanowitz J, Hunt DF, Osterrieder N, Peters B, Antczak DF....Here we describe a detailed quantitative peptide-binding motif for the common equine leukocyte antigen (ELA) class I allele Eqca-1*00101, present in roughly 25 % of Thoroughbred horses. We determined a preliminary binding motif by sequencing endogenously bound ligands. Subsequently, a positional scanning combinatorial library (PSCL) was used to further characterize binding specificity and derive a quantitative motif involving aspartic acid in position 2 and hydrophobic residues at the C-terminus. Using this motif, we selected and tested 9- and 10-mer peptides derived from the equine herpesvir...
Miller SM, Katzwinkel RH.This case report shows that keratomas can occur in both hind feet of equine patients and should be considered as a diagnosis for long-standing, intermittent lameness localised to the hooves. A Thoroughbred racehorse presented with long-standing abscessation of the right hind hoof. Owing to the long-standing nature, the abscess draining tract was surgically explored. A focal mass was found within the solar horn. Histopathology revealed the mass to be a keratoma. A similar mass was removed from the left hind hoof a few months later after similar presenting signs. This case shows that keratomas c...
Kalamanova A, Stringer AP, Freeman SL, Burford JH.Colic is a common reason for owners to seek veterinary treatment for their working equids in Morocco. There is no information available regarding cultural, religious or educational barriers to obtaining treatment or about the typical workload of these animals which may predispose them to colic. Objective: To characterise the typical workload and feeding regimens of working equids in Morocco; to characterise the ability of owners to recognise the clinical signs and causes of colic; and to identify specific barriers to the veterinary treatment of colic. Methods: Questionnaire-based survey. Metho...
Edington N, Bridges CG, Griffiths L.When 23 ponies were infected with equid herpesvirus-1 or -4 (EHV-1 or EHV-4), nasal shedding of interferon (IFN) correlated closely with the duration of viral excretion. Equine interferon (EqIFN) was detected in the serum only from animals infected with the EHV-1 virus, and here high levels correlated with clinical symptoms of locomotor disorder and indicated a poor prognosis. Low levels of IFN were detected in explanted mononuclear cells from ponies infected with either virus.
Niwa H, Hobo S, Kinoshita Y, Muranaka M, Ochi A, Ueno T, Oku K, Hariu K, Katayama Y.Salmonella enterica subsp. enterica serovar Abortusequi is a pathogen restricted to horses. Our investigation targeted 4 draft horses (9-10 months old) kept on a Japanese farm that had suffered an outbreak of S. Abortusequi abortion. The 4 horses were suspected to be carriers of the bacterium owing to their high agglutination titers (≥1:2,560) in tube agglutination testing. The owners' on-farm observations confirmed that the horses had no apparent abnormalities, and S. Abortusequi was not isolated from their blood, rectal swabs, or sternal bone marrow fluid at antemortem investigation. Howev...
Lykkjen S, Roed KH, Dolvik NI.Developmental orthopaedic diseases (DOD) such as osteochondrosis (OC)/osteochondrosis dissecans (OCD), palmar/plantar osteochondral fragments (POF), ununited palmar/plantar eminences (UPE) and dorsoproximal first phalanx fragments are well recognised in the horse. Aetiopathogeneses are controversial and molecular genetic screening of DNA has recently been employed for their elucidation. Precise phenotypic definition and knowledge of breed-specific prevalence and interrelations are essential for the interpretation of following genomic studies in Standardbred trotters. Objective: To assess the p...
Várady M, Königová A, Corba J.The present study included 19 stud farms, including 243 horses, that were investigated for the occurrence of anthelmintic resistant cyathostomes. The number of horses on the farms varied from nine to more than 100, and horses of all ages were included. A minimum of seven horses were used for faecal egg count reduction (FECR) tests. The anthelmintics included were: fenbendazole (paste formulation), ivermectin (paste formulation) and pyrantel (powder). Resistance to benzimidazoles was detected on 14 farms, with FECR values ranging from 65.1 to 86.3%. Larval cultures after fenbendazole treatment ...
Chipangura JK, Chetty T, Kgoete M, Naidoo V.The continuous increase in prevalence of antimicrobial resistant bacteria presents a significant public health problem and is an indicator that antimicrobial prudent usage guidelines are not being followed, especially in developing countries. Despite trends being available from numerous countries, there is little published for South Africa. This study was aimed at estimating the prevalence and trends of antimicrobial resistance from bacterial isolates from equine clinical samples submitted for culture and susceptibility testing to the veterinary bacteriology laboratory of the University of Pre...
Lakos A, Kőrösi A, Földvári G.Tick-borne lymphadenopathy (TIBOLA) is an emerging infection caused by Rickettsia slovaca. We describe here the seasonal, age and gender characteristics as well as the association with horse contact as risk factors for acquiring TIBOLA in comparison with another, more frequent tick-borne disease, Lyme borreliosis.We analysed a dataset of 855 patients diagnosed with either Lyme (n = 805) or TIBOLA (n = 50) disease using Fisher's exact tests and generalized linear models. Then we performed a matched case-control study in which all TIBOLA patients were paired with one Lyme patient matching in age...
Mirams M, Tatarczuch L, Ahmed YA, Pagel CN, Jeffcott LB, Davies HM, Mackie EJ.Osteochondrosis is a condition involving defective endochondral ossification and retention of cartilage in subchondral bone. The pathophysiology of this condition is poorly characterized, but it has been proposed that the fundamental defect is failure of chondrocyte hypertrophy. The aim of the current study was to characterize phenotypic changes in chondrocytes associated with the initiation of osteochondrosis. Early lesions were induced in an equine model of osteochondrosis by feeding foals a high energy diet for 8 or 15 weeks. Lesions in articular-epiphyseal growth cartilage were examined hi...
Quintana AM, Hussey SB, Burr EC, Pecoraro HL, Annis KM, Rao S, Landolt GA.To evaluate whether an equine-derived canine H3N8 influenza A virus was capable of infecting and transmitting disease to ponies. Methods: 20 influenza virus-seronegative 12- to 24-month-old ponies. Methods: 5 ponies were inoculated via aerosol exposure with 10(7) TCID(50) of A/Canine/Wyoming/86033/07 virus (Ca/WY)/pony. A second group of 5 ponies (positive control group) was inoculated via aerosol exposure with a contemporary A/Eq/Colorado/10/07 virus (Eq/CO), and 4 sham-inoculated ponies served as a negative control group. To evaluate the potential for virus transmission, ponies (3/inoculatio...
Kuttler KL, Zaugg JL, Gipson CA.The therapeutic efficacies of imidocarb and parvaquone were tested against Babesia equi of European origin in carrier horses and for induced acute infections in splenectomized ponies. Imidocarb, at a dosage of 4 mg/kg of body weight, given IM at 72-hour intervals 4 times, was ineffective in eliminating B equi-carrier infection in 9 mature geldings. A single IM administration of 4 mg/kg was not therapeutic in acutely infected splenectomized ponies. When given at 3 different dosages and treatment schedules, parvaquone was ineffective in clearing carrier infection. Parvaquone given IM once at a d...
Scantlebury CE, Archer DC, Proudman CJ, Pinchbeck GL.The frequency of recurrent colic in the UK equine general practice population is previously unreported. Elucidating risk factors for recurrent colic could provide a basis for clinical decision making and interventions. Objective: To determine the incidence rate of and risk factors for recurrent colic. Objective: Horse management, prophylactic health care and innate behaviour contribute to the risk of recurrent colic. Methods: A cohort of 127 horses was enrolled at the point of a veterinary-diagnosed medical colic episode. Participating owners completed a baseline and 3 follow-up telephone ques...
Lanz S, Gerber V, Marti E, Rettmer H, Klukowska-Rötzler J, Gottstein B, Matthews JB, Pirie S, Hamza E.Equine recurrent airway obstruction (RAO) is an inflammatory, obstructive airway disease induced by exposure of susceptible horses to inhaled organic dust particles. The immunological process underlying RAO is still unclear. Previous studies have shown that RAO is linked to the Interleukin-4 receptor (IL-4R) gene in one Warmblood family (F1), but not in another (F2). It has also been shown that in F1, but not in F2, RAO is associated with resistance against parasites, suggesting that this association may have an immuno-genetic basis. Therefore, we hypothesized that the T helper (h)1/Th2/regula...
Palmer JL, Bertone AL, McClain H.A modification of a colorimetric assay was used to determine synovial fluid total and individual sulphated-glycosaminoglycan concentration in various clinical presentations of joint disease in horses. Concentrations of synovial fluid and serum sulphated-glycosaminoglycan (GAG) were measured by the 1,9-dimethylmethylene blue (DMMB) dye assay in normal horses (n = 49), horses with acute (n = 26) or chronic (n = 27) joint disease (defined by clinical, radiographic, and clinicopathological parameters), and horses with cartilaginous lesions at diagnostic arthroscopy, but with normal radiographs and...
Haliburton JC, Vesonder RF, Lock TF, Buck WB.Signs and lesions characteristic of equine leucoencephalomalacia were produced in one of two donkeys given corn cultured with Fusarium moniliforme Sheldon. Gross and histopathologic lesions of the cerebrum included an extensive necrotic cavitation within one cerebral hemisphere, disruption and rarefication of the subcortical white matter, prominent perivascular hemorrhage, and some mononuclear cell perivascular cuffing. Another donkey and three rabbits fed the cultured corn did not develop characteristic signs or lesions of the toxicosis. Chick bioassay studies indicated that the cultured corn...
Garcia-Etxebarria K, Jugo BM.Endogenous retroviruses (ERVs) are proviral phases of exogenous retroviruses that have become incorporated into the host genome. Little is known about ERVs in the horse genome. By combining 3 bioinformatic approaches, we detected 1947 putative ERVs in the horse genome. These equine ERVs are not scattered randomly across the genome and are especially abundant in the X chromosome. Based on phylogenetic relationships, some of these equine ERVs were classified into 15 previously uncharacterized families of Classes I, II and III. Compared with the cow and other species, the horse genome appears to ...
Scott DW, Wolfe MJ, Smith CA, Lewis RM.In a review of non-viral bullous skin diseases of domestic animals and a 4-year study of cases presented to the New York State College of Veterinary Medicine, we found 15 diseases: pemphigus vulgaris, pemphigus vegetans, pemphigus foliaceus, pemphigus erythematosus, bullous pemphigoid, systemic lupus erythematosus, dermatitis herpetiformis, toxic epidermal necrolysis, drug eruption, epidermolysis bullosa, epidermolysis bullosa simplex, familial acantholysis, bovine congenital porphyria, impetigo and subcorneal pustular dermatosis. The 15 diseases were placed in five categories: autoimmune, imm...
Wilson ME, Holz CL, Kopec AK, Dau JJ, Luyendyk JP, Soboll Hussey G.Equine herpesvirus type 1 (EHV-1) is the cause of respiratory disease, abortion storms, and outbreaks of herpesvirus myeloencephalopathy (EHM). Infection of the spinal cord is characterised by multifocal regions of virally infected vascular endothelium, associated with vasculitis, thrombosis and haemorrhage that result in ischaemia and organ dysfunction. However, the mechanism of thrombosis in affected horses is unknown. Objective: To evaluate tissue factor (TF) procoagulant activity and thrombin-antithrombin complex (TAT) levels in horses following infection with EHV-1. Methods: In vitro and ...
Jin S, Chen C, Montelaro RC.We have previously reported that serial truncation of the Gag p9 protein of equine infectious anemia virus (EIAV) revealed a progressive loss in replication phenotypes in transfected cells, such that a proviral mutant (E32) expressing the N-terminal 31 amino acids of p9 produced infectious virus particles similarly to parental provirus, while a proviral mutant (K30) with two fewer amino acids produced replication-defective virus particles, despite containing apparently normal levels of processed Gag and Pol proteins (C. Chen, F. Li, and R. C. Montelaro, J. Virol. 75:9762-9760, 2001). Based on ...
Odontsetseg N, Uuganbayar D, Tserendorj Sh, Adiyasuren Z.The prevalence of animal rabies differs in each area of Mongolia. Wolves (Canis lupus Linnaeus, 1758), foxes ( Vulpes vulpes Linnaeus, 1758), corsac foxes (Vulpes corsac Linnaeus, 1768) and manuls (Felis manul Pallas, 1778) are considered to be the infective wild animals in natural foci. Amongst livestock, cattle have had the most rabies cases, followed by camels, sheep, goats and horses. The peak prevalence of animal rabies occurred in the 1970s. Dundgovi Province had the highest incidence during that period. The number of rabies cases in animals decreased during the 1980s. This may have been...
Degroote RL, Hauck SM, Treutlein G, Amann B, Fröhlich KJ, Kremmer E, Merl J, Stangassinger M, Ueffing M, Deeg CA.Autoimmune uveitis is characterized by crossing of blood-retinal barrier (BRB) by autoaggressive immune cells. Equine recurrent uveitis (ERU) is a valuable spontaneous model for autoimmune uveitis and analyses of differentially expressed proteins in ERU unraveled changed protein clusters in target tissues and immune system. Healthy eyes are devoid of leukocytes. In ERU, however, leukocytes enter the inner eye and subsequently destroy it. Molecular mechanisms enabling cell migration through BRB still remain elusive. Previously, we detected decreased talin 1 expression in blood-derived granulocy...
Holcombe SJ, Derksen FJ, Stick JA, Robinson NE.To determine the effect of bilateral blockade of the pharyngeal branch of the vagus nerve on soft palate function in horses. Methods: 5 Standardbreds. Methods: Peak tracheal inspiratory and expiratory pressures and airflow were measured while horses exercised at the speeds corresponding to 75 and 100% of the speed that resulted in maximal heart rate, with and without pharyngeal branch of the vagus nerve blockade. Respiratory frequency-to-stride frequency coupling ratio was measured by correlating foot fall measurements with respiratory frequency. The pharyngeal branch of the vagus nerve was bl...
Findlay GM, Maccallum FO.(1) Among 3,100 persons immunized against yellow fever with virus and immune serum over a period of five years, 89 cases of jaundice have been traced.(2) The symptoms are those of a hepatitis and closely resemble those produced by common infective hepatic jaundice, cases of which have frequently been noted as occurring in the same areas.(3) The average period between the time of inoculation and the development of hepatitis is between two and three months.(4) Attention is directed to the occurrence of hepatitis in horses, usually two to three months after immunization against the viruses of hor...
Arent Z, Gilmore C, Brem S, Ellis WA.Strains of Leptospira interrogans belonging to two very closely related serovars – Bratislava and Muenchen – are known to cause widespread infection of the horse population in many parts of the world. Conventional serological typing of isolates has been unable to differentiate between wildlife, pig, dog and possibly horse maintained isolates and therefore has been unable to provide further insight into their diversity and the relationship between them. Twenty-one such European isolates of serovar Bratislava and Muenchen were examined by restriction endonuclease analysis and multiple-locus ...
Kelly JD, Webster JH, Griffin DL, Whitlock HV, Martin IC, Gunawan M.A survey was conducted to determine whether benzimidazole resistant populations of equine strongyles are present in New South Wales and north central Victoria; what is their frequency and geographical distribution; which species are involved; and whether different methods of parasite control could be related to the occurrence and frequency of anthelmintic resistant populations. Resistant populations of strongyles were found over wide areas of New South Wales and in north central Victoria. There was no relationship between geographical location and the occurrence of benzimidazole resistance. Th...
McGurrin MK, Vengust M, Arroyo LG, Baird JD.An outbreak of protein-losing enteropathy associated with Lawsonia intracelluaris infection was diagnosed in 6 standardbred foals from a farm in Ontario. Wildlife exposure may have been involved in the perpetuation of disease in this outbreak. The clinical presentation, treatment, outcomes, and pathological findings are described. Éclosion d’infections à Lawsonia intracellularis dans un troupeau de Standardbred en Ontario. Une éclosion d’entéropathies exsudatives associée à une infection à Lawsonia intracellularis a été diagnostiquée chez 6 poulains Standardbred d’une ferme de ...
Ward MP, Couëtil LL.To estimate the association between climate and airborne pollen and fungal factors and chronic obstructive pulmonary disease (COPD) in horses. Methods: Data from 1,444 horses with a diagnosis of COPD. Methods: The Veterinary Medical Database was used to identify records of horses admitted to veterinary teaching hospitals in the United States and Canada between 1990 and 1999. Rainfall, mean minimum and maximum temperature, and maximum monthly pollen and fungal spore (mold) counts recorded at the city closest to where the hospital is located were identified for each month data were reported to t...
Allen AL, Doige CE, Fretz PB, Townsend HG.A syndrome of neonatal foals characterized by hyperplasia of the thyroid gland and concurrent musculoskeletal deformities (TH-MSD) has been described in western Canada and may be increasing in incidence. In an attempt to improve recognition and understanding of this syndrome, 2946 records of equine abortuses, stillborns, and dead neonatal foals were examined to determine the laboratory involved, the year and month of submission, the breed and sex of the fetus or foal, the type of perinatal loss, the length of gestation, and whether or not the submission had evidence of a lesion of the thyroid ...
Chowdhury SI, Kubin G, Ludwig H.Out of 30 cases of abortion and perinatal deaths in a Lipizzaner stud in Austria 10 mares died after having shown central nervous system disturbances, ataxias and paralysis. The etiological agent of this "abortion storm" was equine herpesvirus type 1 (EHV-1). The restriction enzyme pattern of the DNA from 5 isolates recovered from fetuses has been analyzed and compared with the known reference strains of EHV-1, -2, -4 and an Austrian vaccine strain. The DNA restriction profiles of the Lipizzaner isolates as well as of the vaccine strain could be identified as being typical of abortigenic strai...
ELISAs are known to have a higher diagnostic sensitivity than the agar gel immunodiffusion (AGID) when employed for serological diagnosis of equine infectious anaemia (EIA). For this purpose, an "in-house" and five commercial ELISAs available in Italy were assessed by the National Reference Centre for EIA for their analytic specificity (Sp); precocity, defined as capability of detecting first antibodies produced during a new infection; precision based on repeatability and reproducibility, estimated from the coefficient of variation (CV); accuracy, estimated from multiple K and relative Sp and ...
Sarkar S, Bailey E, Go YY, Cook RF, Kalbfleisch T, Eberth J, Chelvarajan RL, Shuck KM, Artiushin S, Timoney PJ, Balasuriya UB.Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory, systemic, and reproductive disease of horses and other equid species. Following natural infection, 10-70% of the infected stallions can become persistently infected and continue to shed EAV in their semen for periods ranging from several months to life. Recently, we reported that some stallions possess a subpopulation(s) of CD3+ T lymphocytes that are susceptible to in vitro EAV infection and that this phenotypic trait is associated with long-term carrier status following exposure to the virus. ...
Drogemuller M, Schnieder T, von Samson-Himmelstjerna G.The molecular mechanism of benzimidazole (BZ) resistance in cyathostomins of horses is still unclear. Previous studies revealed that the TTC or TAC polymorphism in codon 200 of the beta-tubulin isotype 1 gene is not as strictly correlated with BZ resistance as in trichostrongyles in sheep. To identify further sites of polymorphism within the beta-tubulin gene related to BZ resistance, complete complementary DNAs (cDNAs) encoding beta-tubulin of adult worms of Cylicocyclus nassatus, Cyathostomum pateratum, Cyathostomum coronatum, Cyathostomum catinatum, Cylicostephanus longibursatus, and Cylico...
