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.
van der Vekens N, Decloedt A, de Clercq D, Ven S, Sys S, van Loon G.Studies on the use of atrial natriuretic peptide (ANP) as a biomarker for left atrial dilatation in horses have produced variable results. Few have been performed, and the results may have been influenced by ANP instability, differences in sampling protocol and changes in the assay over time. N-Terminal proANP (NT-proANP) is a more stable molecule and might be a good alternative for clinical use. Objective: To compare ANP and NT-proANP in terms of the detection of left atrial dilatation and to determine the influence of sample storage at temperatures of -80 and -20°C. Methods: Prospective cli...
Hughes K, Scase TJ, Foote AK.Equine mammary tumors are uncommon, and relatively sparse histopathologic and molecular data exist. The present study describes the histopathologic features of 7 such tumors, which exhibited infiltrative growth, intermediate to high mitotic rates, and focally extensive necrosis. The tumors exhibited variably strong staining for vimentin and cytokeratin 14, as well as frequently weak cytoplasmic staining for pan-cytokeratin. E-cadherin expression was strong. Interestingly, a subgroup of the tumors exhibited strong nuclear staining for estrogen receptor α. Three of 7 tumors exhibited nuclear ex...
Jiang L, Campagne C, Sundström E, Sousa P, Imran S, Seltenhammer M, Pielberg G, Olsson MJ, Egidy G, Andersson L, Golovko A.Constitutive activation of the ERK pathway, occurring in the vast majority of melanocytic neoplasms, has a pivotal role in melanoma development. Different mechanisms underlie this activation in different tumour settings. The Grey phenotype in horses, caused by a 4.6 kb duplication in intron 6 of Syntaxin 17 (STX17), is associated with a very high incidence of cutaneous melanoma, but the molecular mechanism behind the melanomagenesis remains unknown. Here, we investigated the involvement of the ERK pathway in melanoma development in Grey horses. Methods: Grey horse melanoma tumours, cell lines ...
Wolff C, Egenvall A, Hanche-Olsen S, Gröndahl G.Acquired equine polyneuropathy (AEP) is an emerging disease in horses in Sweden, Norway and Finland since 1995. Affected horses show bilateral pelvic limb knuckling and weakness, sometimes progressing to recumbency and euthanasia. The aetiology is unknown but is thought to be non-infectious and non-genetic, though possibly toxic or toxico-infectious. The objectives of this study were to describe the spatial, temporal and spatio-temporal features of AEP in Norway and Sweden for the period of 1995 to 2012. Data from all documented case farms (n = 136) were used. Space-time interaction cluste...
Santos VG, Bettencourt EM, Ginther OJ.Mares with persistent CL (PCL) with no known etiology (idiopathic) were matched with mares with an interovulatory interval (IOI) of apparent physiological length, so that ovulation at the beginning of each PCL and IOI occurred during the same month (n = 6/group). Blood samples were collected daily from Days 12 to 22 (Day 0 = ovulation). Mean progesterone (P4) decreased in both groups on Days 14 and 15 and then diverged with a continued decrease in the IOI group and the beginning of constant and greater (P < 0.05) P4 concentration on each day in the PCL group. Before P4 divergence betw...
Fjordbakk CT, Revold T, Goodwin D, Piercy RJ.The pathogenesis of bilateral dynamic laryngeal collapse associated with poll flexion (DLC) of horses is unknown but might be associated with intrinsic laryngeal muscle weakness. Objective: To investigate histopathological characteristics of the cricoarytenoideus dorsalis, the cricothyroid (CT) and the cricoarytenoideus lateralis muscles in DLC-affected horses and compare these with unaffected controls. Our hypotheses were that evidence of neurogenic atrophy of the CT or cricoarytenoideus dorsalis muscles would be found in DLC-affected horses and that observed changes would be symmetrically (l...
Lewis SR, Ellison SP, Dascanio JJ, Lindsay DS, Gogal RM, Werre SR, Surendran N, Breen ME, Heid BM, Andrews FM, Buechner-Maxwell VA, Witonsky SG.Sarcocystis neurona is the most common cause of Equine Protozoal Myeloencephalitis (EPM), affecting 0.5-1% horses in the United States during their lifetimes. The objective of this study was to evaluate the equine immune responses in an experimentally induced Sarcocystis neurona infection model. Neurologic parameters were recorded prior to and throughout the 70-day study by blinded investigators. Recombinant SnSAG1 ELISA for serum and CSF were used to confirm and track disease progression. All experimentally infected horses displayed neurologic signs after infection. Neutrophils, monocytes, an...
Balasuriya UB.Equine arteritis virus (EAV), the causative agent of equine viral arteritis (EVA), is a respiratory and reproductive disease that occurs throughout the world. EAV infection is highly species-specific and exclusively limited to members of the family Equidae, which includes horses, donkeys, mules, and zebras. EVA is an economically important disease and outbreaks could cause significant losses to the equine industry. The primary objective of this article is to summarize current understanding of EVA, specifically the disease, pathogenesis, epidemiology, host immune response, vaccination and treat...
Issel CJ, Cook RF, Mealey RH, Horohov DW.In the absence of an effective vaccine, the success of the test and removal approach for the control of equine infectious anemia (EIA) cannot be overstated, at least in those areas where testing has been traditionally routine. This article addresses 4 main aspects: what has been learned about EIA virus, host control of its replication, and inapparent carriers; international status regarding the control of EIA; diagnostic and laboratory investigation; and reducing the spread of blood-borne infections by veterinarians. An attempt is made to put these issues into practical contemporary perspectiv...
Howe DK, MacKay RJ, Reed SM.Equine protozoal myeloencephalitis (EPM) can be caused by either of 2 related protozoan parasites, Sarcocystis neurona and Neospora hughesi, although S. neurona is the most frequent etiologic pathogen. Horses are commonly infected, but clinical disease occurs infrequently; the factors influencing disease occurrence are not well understood. Risk factors for the development of EPM include the presence of opossums and prior stressful health-related events. Attempts to reproduce EPM experimentally have reliably induced antibody responses in challenged horses but have not consistently produced acut...
Andersson MG, Faverjon C, Vial F, Legrand L, Leblond A.In this work we propose the adoption of a statistical framework used in the evaluation of forensic evidence as a tool for evaluating and presenting circumstantial "evidence" of a disease outbreak from syndromic surveillance. The basic idea is to exploit the predicted distributions of reported cases to calculate the ratio of the likelihood of observing n cases given an ongoing outbreak over the likelihood of observing n cases given no outbreak. The likelihood ratio defines the Value of Evidence (V). Using Bayes' rule, the prior odds for an ongoing outbreak are multiplied by V to obtain the post...
Ploeg M, Gröne A, Saey V, de Bruijn CM, Back W, van Weeren PR, Scheideman W, Picavet T, Ducro BJ, Wijnberg I, Delesalle C.Megaesophagus appears to be more common in Friesian horses than in other breeds. A prevalence of approximately 2% was observed among Friesian horses presented to the Wolvega Equine Clinic and the Utrecht University Equine Clinic. In this study, morphologic changes in the esophagi of Friesian horses with megaesophagus were compared with those of 6 control horses. Of 18 horses with clinically observed megaesophagus, only 12 animals had esophageal dilation at necropsy, usually involving the thoracic portion. Muscular hypertrophy of the distal esophagus was present in only one-third of the affecte...
Adeppa J, Ananda KJ, Krishna Murthy CM, Satheesha GM.A study was conducted to ascertain the incidence of gastrointestinal parasites in horses of Shimoga region, to generate the data regarding status of parasitic infections of equines in Karnataka state due to paucity of information. A total of 100 fresh fecal samples of equines were collected and examined by direct and sedimentation method for the detection of parasitic egg/ova. Among 100 samples examined, 84 (84.0 %) were found positive for various gastrointestinal helminths. Out of 84 positive cases, 44 (52.38 %) were found positive for Strongylus spp. eggs, 09 (10.71 %) showed Parascaris e...
Hedenström UO, Olsson U, Holm AW, Wattle OS.It has not yet been shown that ossification of ungular cartilages (OUC) is a pathological condition. Beside heredity, factors such as sex, age, repeated concussion, local trauma, hoof and body size have been suggested as contributing factors for OUC development. By comparing radiographs of front hooves from cold-blooded trotters with different age we wanted to evaluate when development of OUC in cold-blooded trotters occurs and if and when it stabilizes in relation to age and workload. Diagnosis and grading of OUC were based on radiological field examinations of 649 Swedish and Norwegian cold-...
Tangyuenyong S, Viriyakhasem N, Peansukmanee S, Kongtawelert P, Ongchai S.Cartilage erosion in degenerative joint diseases leads to lameness in affected horses. It has been reported that andrographolide from Andrographis paniculata inhibited cartilage matrix-degrading enzymes. This study aimed to explore whether this compound protects equine cartilage degradation in the explant culture model and to determine its effect on matrix metalloproteinase-2 (MMP-2) expression, a matrix-degrading enzyme, in equine chondrocyte culture. Equine articular cartilage explant culture was induced by 25 ng/mL interleukin-1β, a key inducer of cartilage degeneration, in cultures with...
Page AE, Stills HF, Horohov DW.Multiple hypotheses into the age-based susceptibility of animals to Lawsonia intracellularis exist, including the decline of passively acquired antibodies. Objective: To determine whether the decline in passively acquired antibodies in horses is responsible for the age predilection of equine proliferative enteropathy (EPE). Additional objectives included examination of various risk factors for the development of EPE as well as the determination of naturally occurring attack rates for clinical and subclinical EPE. Methods: Prospective, multifarm field study. Methods: A total of 369 mare and f...
Fielding CL, Higgins JK, Higgins JC, McIntosh S, Scott E, Giannitti F, Mete A, Pusterla N.Equine coronavirus (ECoV) is associated with clinical disease in adult horses. Outbreaks are associated with a low case fatality rate and a small number of animals with signs of encephalopathic disease are described. Objective: The aim of this study is to describe the epidemiological and clinical features of two outbreaks of ECoV infection that were associated with an high case fatality rate. Methods: 14 miniature horses and 1 miniature donkey testing fecal positive for ECoV from two related disease outbreaks. Methods: Retrospective study describing the epidemiological findings, clinicopatholo...
Lassaline M, Cranford TL, Latimer CA, Bellone RR.To describe the prevalence of LSCC in Haflinger horses and to analyze affected horses' pedigrees investigating the genetic mode of inheritance. Methods: Fifteen horses met inclusion criterion of (i) being of the Haflinger breed, as confirmed by North American Haflinger Registry pedigree and (ii) being diagnosed with LSCC, as confirmed by clinical examination by a veterinary ophthalmologist or by histopathology. Pedigrees could not be obtained for four additional horses diagnosed with LSCC that had been identified as Haflingers. Methods: Retrospective medical record review of all 19 horses was ...
Marenzoni ML, Sforna M, Stefanetti V, Casagrande Proietti P, Brignone L, Del Sero A, Falcioni F, Orvieto S, Tamantini C, Tiburzi A, Valentini S....In recent years, there has been increasing evidence of the potential pathogenic significance of equine gammaherpesviruses in the horse. In humans, cattle and mice, gammaherpesviruses have already been associated with uterine infection. The aim of the present study was to investigate the presence of gammaherpesviruses in uterine flushings of mares with reproductive problems and to evaluate if there was a possible statistical association with clinical and laboratory findings in these cases. A total of 80 uterine flushings were collected from 61 mares with different reproductive problems and thes...
Casey MB, Pearson GR, Perkins JD, Tremaine WH.The most prevalent type of equine dental pulpitis due to apical infection is not associated with coronal fractures or periodontal disease. The pathogenesis of this type of pulpitis is not fully understood. Computed tomography (CT) is increasingly used to investigate equine dental disorders. However, gross, tomographic and histopathological changes in equine dental pulpitis have not been compared previously. Objective: To compare gross, CT and histological appearances of sectioned mandibular cheek teeth extracted from horses with clinical signs of pulpitis without coronal fractures or periodont...
Sykora S, Brandt S.Equine hoof canker is a chronic pododermatitis of still unknown aetiology. Recent findings reported for 3 canker-bearing individuals are suggestive for Treponema spp. having a role in disease pathogenesis. Objective: Based on this hypothesised association, we assessed a larger number of DNA samples from hooves with canker and normal hooves for the presence of treponemal DNA. Methods: Retrospective survey of archived material. Methods: The study involved 71 archival, PCR-compatible DNA extractions purified from 59 canker samples obtained from 26 equine cases and from 12 hoof biopsies taken from...
Drögemüller M, Jagannathan V, Welle MM, Graubner C, Straub R, Gerber V, Burger D, Signer-Hasler H, Poncet PA, Klopfenstein S, von Niederhäusern R....Congenital hepatic fibrosis has been described as a lethal disease with monogenic autosomal recessive inheritance in the Swiss Franches-Montagnes horse breed. We performed a genome-wide association study with 5 cases and 12 controls and detected an association on chromosome 20. Subsequent homozygosity mapping defined a critical interval of 952 kb harboring 10 annotated genes and loci including the polycystic kidney and hepatic disease 1 (autosomal recessive) gene (PKHD1). PKHD1 represents an excellent functional candidate as variants in this gene were identified in human patients with autosoma...
Buczkowska J, Kozdrowski R, Nowak M, Raś A, Mrowiec J.Equine endometrosis is a multifactorial disease considered to be a one of the most important causes of equine infertility, especially in older mares. This article reviews the current knowledge of equine endometrosis: pathogenesis, diagnosis, and optional treatment. Also describes the histomorphological and immunohistochemical characterization of endometrosis as well as potential etiological factors which may influence disease progression. Unfortunately, the etiology and pathogenesis of endometrosis still remains unclear, and consequently no effective treatment has been proposed so far. Therefo...
Bundgaard L, Jacobsen S, Dyrlund TF, Sørensen MA, Harman VM, Beynon RJ, Brownridge PJ, Petersen LJ, Bendixen E.The aim of this study was the development of a quantitative assay that could support future studies of a panel of acute phase proteins (APPs) in the horse. The assay was based on a quantification concatamer (QconCAT) coupled to selected reaction monitoring methodology. Thirty-two peptides, corresponding to 13 putative or confirmed APPs for the Equus caballus (equine) species were selected for the design of a QconCAT construct. The gene encoding the QconCAT was synthesized and expressed as an isotope-labeled chimaeric protein in Escherichia coli. The QconCAT tryptic peptides were analyzed on a ...
Sammons SC, Norman TE, Chaffin MK, Cohen ND.To ascertain the frequency of ultrasonographic identification of liver at sites recommended for blind percutaneous liver biopsy in middle-aged horses and to determine whether the liver is obscured by other organs or too thin for safe sample collection at recommended locations. Methods: Prospective case series. Methods: 36 healthy middle-aged (between 3 and 18 years old) Quarter Horses or Quarter Horse crosses [Corrected]. Methods: Blood samples were collected from each horse and submitted for evaluation of liver function. Horses with any indication of liver dysfunction on serum biochemical ana...
Smith S, Naylor RJ, Knowles EJ, Mair TS, Cahalan SD, Fews D, Dunkel B.Acorn toxicity has been anecdotally reported to cause fatal colitis and colic in horses but reports in the scientific literature are sparse. Objective: This study reports the diagnosis, treatment, prognosis and outcome of 9 cases with suspected acorn toxicity admitted to 2 referral hospitals. Methods: Retrospective case series. Methods: Case records from 2004 to 2013 were reviewed. Horses were included in the study if they met 3 of 4 criteria: exposure to acorns; clinical and laboratory data suggesting alimentary or renal dysfunction; acorn husks in the faeces or gastrointestinal tract; and ne...
Wise LN, Pelzel-McCluskey AM, Mealey RH, Knowles DP.Equine piroplasmosis, caused by the parasites Theileria equi and Babesia caballi, is a globally important disease, affecting a large percentage of the world's horses. This article serves as a review of these divergent parasites. Discussed are the clinical presentation of disease, diagnosis, and treatment. Special attention is given to the current disease status specifically in North America.
Cymerys J, Dzieciatkowski T, Słońska A, Bierla J, Tucholska A, Chmielewska A, Golke A, Bańbura MW.Equine herpesvirus-1 (EHV-1) infections cause significant economic losses for equine industries worldwide as a result of abortion, respiratory illness, and neurologic disease in all breeds of horses. The occurrence of abortions caused by EHV-1 has repeatedly been confirmed in Poland, but neurological manifestations of the infection have not been described yet. Also it is unknown how the infection of neurons with non-neuropathogenic strains is regulated. To further understand the virus-neuron interaction we studied two strains of EHV-1 in murine primary neuron cell cultures. Both strains were i...
Hunyadi L, Sundman EA, Kass PH, Williams DC, Aleman M.Immune-mediated myositis (IMM) is a cause of rhabdomyolysis, stiffness, and muscle atrophy predominantly affecting Quarter horses. Limited information is available with regard to outcome, prognostic indicators, and associations with concurrent diseases. Objective: To report outcomes and associations between outcome and clinical and laboratory parameters, and presence of concurrent illness. Methods: Sixty-eight horses; 52 Quarter horses and related breeds and 16 other breeds. Methods: Retrospective cohort study (1991-2014). Medical records of horses with histological diagnosis of IMM were revie...
Feige K, Schwarzwald C, Fürst A, Kaser-Hotz B.The major purpose of this investigation was to describe the causes, possible complications, and prognoses of horses with esophageal obstruction. Of 34 cases presenting with esophageal obstruction, 28 cases were due to impaction of ingesta. Obstruction due to pre-existing esophageal disease occurred in 4 horses with megaesophagus, in 1 horse with stricture in the upper third of the esophagus, and in 1 horse with esophageal diverticulum. There was no significant difference in the contamination of the trachea between horses that subsequently developed aspiration pneumonia and those that did not. ...
Magdesian KG, Dujowich M, Madigan JE, Hansen LM, Hirsh DC, Jang SS.To determine molecular characteristics, antimicrobial susceptibility, and toxigenicity of Clostridium difficile isolates from horses in an intensive care unit and evaluate associations among severity of clinical disease with specific strains of C difficile. Methods: Prospective study. Methods: 130 horses. Methods: Feces were collected from horses admitted for acute gastrointestinal tract disease with loose feces and submitted for microbial culture and immunoassay for toxin production. Polymerase chain reaction assays were performed on isolates for toxins A and B genes and strain identification...
Ramos-Vara JA, Ortiz-Santiago B, Segalès J, Dunstan RW.This report contains the clinical, histologic, immunohistochemical, and electron microscopic findings in two cases of equine cutaneous leishmaniasis. Nodular, sometimes crusty or ulcerated lesions were confined to the pinna and adjacent neck in both animals. The dermal inflammatory infiltrate was lymphohistiocytic in horse No. 1 and pyogranulomatous with formation of tuberculoid granulomas in horse No. 2. Numerous Leishmania organisms were found within macrophages in both animals. There was moderate to intense and specific reaction by immunoperoxidase using a polyclonal antiserum against Leish...
Sweeney CR, Benson CE, Whitlock RH, Meirs DA, Barningham SO, Whitehead SC, Cohen D.The age-specific attack rates of Streptococcus equi infections of the upper respiratory tract and lymph nodes (strangles) in horses for the different age groups were 17.6% for broodmares, 47.5% for 1-year-old horses, and 37.5% for foals. Streptococcus equi was isolated from nasal, pharyngeal, or lymph node specimens in 31 (60.8%) of 51 sick horses. A male 1-year-old horse, shipped from Kentucky to farm A, was considered to be the index case. Six (19.4%) of 31 horses with strangles remained as shedders of S equi after clinical signs of the disease had ended. Shedders of S equi were not identifi...
Chaffin MK, Cohen ND, Martens RJ, Edwards RF, Nevill M, Smith R.Rhodococcus equi causes severe pyogranulomatous pneumonia in foals and in immunocompromised people. In mice, both CD4+ and CD8+ T lymphocytes contribute to host defense against R. equi, but CD4+ T lymphocytes are required for pulmonary clearance of the bacteria. In this prospective study of 208 foals at two equine breeding farms with endemic R. equi infections, we collected peripheral blood samples at 2 and 4 weeks of age and at the time of diagnosis of R. equi pneumonia. Samples were analyzed for concentrations of total and differential leukocytes, EqCD4+ and EqCD8+ T lymphocytes, and B lymph...
Larsen KS, Eydal M, Mencke N, Sigurdsson H.Lice infestations on horses caused by the lice Werneckiella (Damalinia) equi and Haematopinus equi are observed worldwide. In this study, the distribution and clinical manifestations of lice on Icelandic horses were examined. Thirty-eight out of 93 animals (40.86%) were identified as infested with W. equi. Sixty-eight animals (73.12%) presented dermatological lesions associated with lice infestation, while only 32 of these animals presented lice. Six animals had no clinical signs although of being lice-positive, and 19 animals (20.43%) showed neither lice nor clinical manifestations. Lice burd...
Abd El-Rahim IH, Hussein M.This study describes an epizootic of respiratory tract disease caused by influenza virus infection in a large population of equines in Luxor and Aswan, Upper Egypt, during the winter of 2000. The epizootic started in January and the infection rate reached its peak in February before gradually decreasing until the end of April, 2000. Horses, donkeys and mules of all ages and both sexes were affected. Free movement of the infected equines and direct contact between the animals at markets facilitated the rapid spread of the disease. The cause of the epizootic was established by use of serological...
Dorrego-Keiter E, Tóth J, Dikker L, Sielhorst J, Schusser GF.In the ongoing discussion regarding the aetiopathogenesis of equine recurrent uveitis (ERU) it was the aim of the present study to elucidate the relationship of leptospira infection and ERU. In a population of 225 horses leptospira were examined in vitreous humor by culture and leptospira antibody were detected in vitreous humor and serum samples. Preoperative serum samples were collected from 221/225 ERU patients of different age, gender and breed. Undiluted vitreous humor was aseptically taken from 198/225 patients that underwent pars plana vitrectomy at the beginning of surgery and from 27/...
Sellon DC, Walker KM, Russell KE, Perry ST, Covington P, Fuller FJ.Equine infectious anemia virus is a lentivirus that replicates in mature tissue macrophages of horses. Ponies were infected with equine infectious anemia virus. During febrile episodes, proviral DNA was detectable, but viral mRNA was not detectable. As cultured blood monocytes from these ponies differentiated into macrophages, viral expression was upregulated. In situ hybridization confirmed that viral transcription occurred in mature macrophages.
Alghamdi AS, Foster DN, Carlson CS, Troedsson MH.Breeding-induced endometritis (BIE) in the mare is resolved by 36 hr after insemination in resistant mares. However, 10-15% susceptible broodmares fail to do so because of impaired uterine contractility between 7 and 19 hr after exposure to seminal or bacterial challenge, which reduces their fertility. Methods: Nitric oxide (NO) in uterine secretions, and expression of nitric oxide synthase (NOS) in uterine biopsies were compared between susceptible and resistant groups 13 hr after insemination. Results: Susceptible mares had a higher NO in their uterine secretions and greater inducible NOS (i...
Mansfield LS, Mehler S, Nelson K, Elsheikha HM, Murphy AJ, Knust B, Tanhauser SM, Gearhart PM, Rossano MG, Bowman DD, Schott HC, Patterson JS.We tested the hypothesis that brown-headed cowbirds (Molothrus ater) harbor Sarcocystis neurona, the agent of equine protozoal myeloencephalitis (EPM), and act as intermediate hosts for this parasite. In summer 1999, wild caught brown-headed cowbirds were collected and necropsied to determine infection rate with Sarcocystis spp. by macroscopic inspection. Seven of 381 (1.8%) birds had grossly visible sarcocysts in leg muscles with none in breast muscles. Histopathology revealed two classes of sarcocysts in leg muscles, thin-walled and thick-walled suggesting two species. Electron microscopy sh...
Webb BA, Barney WE, Dahlman DL, DeBorde SN, Weer C, Williams NM, Donahue JM, McDowell KJ.A new equine abortigenic disease, mare reproductive loss syndrome (MRLS), was recognized and significantly impacted the Ohio Valley in the springs of 2001 and 2002. MRLS caused approximately 330 million US dollars in losses in 2001. An epidemiological investigation of MRLS associated occurrence of the disease with exposure to eastern tent caterpillars (M. americanum). This work investigates the epidemiological association between M. americanum and MRLS to determine if this association was correlative or causative. A pilot study and simulated exposure to M. americanum and their excreta on pastu...
Neuhaus S, Bruendler P, Frey CF, Gottstein B, Doherr MG, Gerber V.Equine recurrent airway obstruction (RAO) shares many characteristics with human asthma. In humans, an inverse relationship between susceptibility to asthma and resistance to parasites is suspected. Objective: Members of a high-incidence RAO half-sibling family (F) shed fewer strongylid eggs compared with RAO-unaffected pasture mates (PM) and that RAO-affected horses shed fewer eggs than RAO-unaffected half-siblings. Methods: Seventy-three F and 73 unrelated, age matched PM. Methods: Cases and controls kept under the same management and deworming regime were examined. Each individual was class...
Mair TS, Sherlock CE, Boden LA.Few studies have evaluated cortisol concentrations in horses with colic. In humans with septic shock, high cortisol levels are associated with an increased risk of death. The objectives of this study were to compare the serum total cortisol concentrations (STCCs) in horses with colic to those without colic, and to assess whether the STCC relates to the pathological nature or outcome of the disease. STCCs were determined at presentation in horses with colic and in systemically healthy 'control' horses. Horses with colic were grouped based on clinical and clinico-pathological parameters at admis...
Millington WR, Dybdal NO, Dawson R, Manzini C, Mueller GP.Equine Cushing's disease is caused by an adenomatous hyperplasia of the intermediate pituitary which secretes high levels of beta-endorphin, ACTH, and other peptide derivatives of POMC. In the present study we found that plasma and cerebrospinal fluid immunoreactive beta-endorphin (i beta-endorphin) levels were 60- and 120-fold higher than control values in horses with Cushing's disease. There were no significant differences in intermediate lobe i beta-endorphin concentrations, although anterior lobe i beta-endorphin was significantly reduced in Cushing's horses, presumably because high levels...
Furr M, McKenzie H.Bloodstream infections (BSI) are common in sick foals and increase foal morbidity and mortality when they occur. Recognition of risk factors for BSI could be an important means to limit their occurrence, but studies on this topic are limited. Objective: Historical as well as maternal and foal physical examination findings will predict risk of BSI in neonatal foals. Methods: Foals <14 days of age admitted to a referral equine hospital for care. Methods: Retrospective case-control study with univariate and multivariable logistic regression analysis. Results: Four hundred twenty-nine (143 cases...
Amavisit P, Markham PF, Lightfoot D, Whithear KG, Browning GF.From 1992 to 1997, multi-drug resistant (MDR) Salmonella Heidelberg isolates were cultured from a number of horses hospitalised in a veterinary hospital in Victoria, Australia. To examine the relationships between the cases, 28 isolates from the hospital were compared by pulsed field gel electrophoresis (PFGE), IS200 element profiles, antimicrobial resistance patterns, plasmid profiles and phage typing. The PFGE patterns following digestion with XbaI and BlnI restriction endonucleases showed that the isolates from the veterinary hospital originated from a common source. These isolates also had...
Mohammed HO, Rebhun WC, Antczak DF.A retrospective case-control study was conducted to identify risk factors in horses associated with the development of the common skin tumours known as sarcoids. The study involved 503 sarcoid cases diagnosed (January 1980-December 1989) at New York State College of Veterinary Medicine and a similar number of controls (non-sarcoid cases). Data on age, breed and sex of cases and controls were obtained from computerised records. Multiple logistic regression analysis was used to identify risk factors. Separate data were obtained for the same 10-year period from the Veterinary Medical Data Program...
Gold JR, Perkins GA, Erb HN, Ainsworth DM.Septicemia initiates the production of pro-inflammatory (interleukin [IL] 1-beta [IL-1beta], interferon-gamma [IFN-gamma], IL-6), and anti-inflammatory (IL-4) cytokines. The transcription of some of these proteins (IL-8, IL-6) is linked to endotoxin-induced activation of the toll-like receptor 4 (TLR4) on peripheral blood mononuclear cells (PBMC). Objective: Septic foals fail to increase gene expression of IFN-gamma. Nonsurviving septic foals exhibit distinctive cytokine profiles. Methods: Twenty-one septic and 20 healthy neonatal foals. Methods: Using real-time polymerase chain reaction, gene...
Suagee JK, Corl BA, Geor RJ.Understanding the mechanisms involved in the development of insulin resistance in horses should enable development of effective treatment and prevention strategies. Current knowledge of these mechanisms is based upon research in obese humans and rodents, in which there is evidence that the increased production of pro-inflammatory cytokines by adipose tissue negatively influences insulin signaling in insulin-responsive tissues. In horses, plasma concentrations of the cytokine, tumor necrosis factor-α, have been positively correlated with body fatness and insulin resistance, leading to the hypo...
Figueiredo AS, de Moraes MVDS, Soares CC, Chalhoub FLL, de Filippis AMB, Dos Santos DRL, de Almeida FQ, Godoi TLOS, de Souza AM, Burdman TR....Recent advances in the study of equine pegivirus (EPgV), Theiler's disease-associated virus (TDAV) and equine hepacivirus (EqHV) highlight their importance to veterinary and human health. To gain some insight into virus distribution, possible risk factors, presence of liver damage and genetic variability of these viruses in Brazil, we performed a cross-sectional study of EPgV and TDAV infections using a simultaneous detection assay, and assessed EqHV coinfection in different horse cohorts. Of the 500 serum samples screened, TDAV, EPgV and EPgV-EqHV were present in 1.6%, 14.2% and 18.3%, respec...
Arroyo LG, Costa MC, Guest BB, Plattner BL, Lillie BN, Weese JS.Duodenitis-proximal jejunitis (DPJ) is an acute sporadic gastrointestinal disorder of horses of unknown cause. Objective: We hypothesize that Clostridium difficile toxins are involved in the pathogenesis of DPJ in horses. The objective of this study was to determine whether experimentally delivered C. difficile toxins cause clinical signs and histologic lesions similar to those of naturally occurring DPJ. Methods: Six healthy mature mixed breed horses. Methods: Experimental study: animal model of animal disease. Fasted horses were administered crude C. difficile toxins via gastroscopy and moni...
Milinovich GJ, Burrell PC, Pollitt CC, Bouvet A, Trott DJ.Four Gram-positive, catalase-negative, coccoid-shaped isolates were obtained from the caecum and rectum of horses with oligofructose-induced equine laminitis. Phenotypic and phylogenetic studies were performed on these isolates. Initial biochemical profiling assigned two of the isolates to Streptococcus bovis. The other two isolates, however, could not be assigned conclusively on the basis of their biochemical profiles. Gene sequence analysis demonstrated that the four new isolates were related most closely to Streptococcus suis based on the 16S rRNA gene and to Streptococcus orisratti based o...
Borges LM, Oliveira PR, Ribeiro MF.Anocentor nitens is a widespread ectoparasite of horses in Brazil. A study of the seasonal dynamics of the parasitic phase of this tick was made by regular census of engorging females (>/=4mm) on free-ranging horses, fortnightly from July 1995 to July 1997, at Pedro Leopoldo, Minas Gerais. Twenty horses were divided into four groups of five animals per group, each having a similar mix of resistant and less resistant animals, based on initial infestation. Every 2 weeks, one of the groups, in sequence, was treated with an acaricide to prevent excessive infestations, and female ticks were cens...
Ragno VM, Zello GA, Klein CD, Montgomery JB.Obesity data in people and companion animals are depicting a future of increasing morbidity, cost for society, and significant health and welfare concerns. Between 25 and 50% of cats, dogs, and horses in developed countries are overweight or obese, which mirrors the situation in humans. Equine metabolic syndrome (EMS) was named after human metabolic syndrome (MetS), which has about 30 years of lead in research efforts. Even though the complications of the two syndromes seem to grossly differ (cardiac vs. laminitis risk), a number of similar disease mechanisms are worthy of investigation. Sinc...
Ikhuoso OA, Monroy JC, Rivas-Caceres RR, Cipriano-Salazar M, Barbabosa Pliego A.Although the strangles disease of Streptococcus equi was discovered many decades ago in 1,251 by Jordanus Ruffus, it has still remained a major frequently diagnosed infection in horses all over the world. The S. equi subspecies pathogen is known to be often resistant to antibiotic treatment, and it makes the antibiotics inefficient; hence, this review was conducted to study how the disease can be managed. The age-long sign of this infection is the oozing of pus through the mucous and skin membranes. Affected horses lose appetite, develop fever, and become depressed, which result in them losin...
Chapman MR, Kearney MT, Klei TR.Historically, surveys of equine parasites either are not quantitative in regard to prevalence and intensities of cyathostome species, or if quantitative, are estimates based on the identification of a very small sample of the population. Commonly 100-200 worms are identified. In the current study cyathostomes from 10 ponies were counted and identified to species in subsets of approximately 200 worms each from 5% aliquots of the large intestine contents until all worms in the aliquot were examined. A mean of 10.9+/-4.3 species were identified by examining 200 cyathostomes from each animal. This...
Brama PA, TeKoppele JM, Beekman B, van El B, Barneveld A, van Weeren PR.To investigate the role of stromelysin (MMP-3) activity in synovial fluid (SF) at different stages of development and in common joint disorders in the horse. Methods: Stromelysin activity was determined with a fluorogenic enzyme activity assay in SF of normal joints of fetal, juvenile and adult horses, and in SF of horses suffering from the developmental orthopaedic disease osteochondrosis (OC) or osteoarthritis (OA). Additionally, MMP-3 activity was expressed as a ratio of previously reported general MMP activity in the same SF samples. Results: The levels of active stromelysin were 30-fold t...
