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.
Rose BV, Cabrera-Sharp V, Firth MJ, Barrelet FE, Bate S, Cameron IJ, Crabtree JR, Crowhurst J, McGladdery AJ, Neal H, Pynn J, Pynn OD, Smith C....Early pregnancy loss occurs in 6-10% of equine pregnancies making it the main cause of reproductive wastage. Despite this, reasons for the losses are known in only 16% of cases. Lack of viable conceptus material has inhibited investigations of many potential genetic and pathological causes. We present a method for isolating and culturing placental cells from failed early equine pregnancies. Trophoblast cells from 18/30 (60%) failed equine pregnancies of gestational ages 14-65 days were successfully cultured in three different media, with the greatest growth achieved for cells cultured in Amnio...
Dominguez M, Münstermann S, de Guindos I, Timoney P.An analysis of the factors leading to equine disease events was used to support the development of international recommendations for mitigating the risk of disease dissemination through sport horse movements (high health, high performance - 'HHP' horses). Objective: A review was undertaken to identify the factors resulting in equine disease events following international movement of horses to draw lessons in support of the development of international recommendations for the safe movements of a specific subpopulation of horses: the HHP sport horses. Methods: Systematic review carried out in ac...
Back H, Berndtsson LT, Gröndahl G, Ståhl K, Pringle J, Zohari S.Equine Influenza Virus (EIV) is a major cause of respiratory disease in horses and the virus constantly undergoes antigenic drift. Here we characterize and describe the HA1 and the NA genes of H3N8 within samples obtained from outbreaks in Sweden during November-December 2011. Both clade 1 and clade 2 viruses of the Florida sublineage were identified. The index case of clade 2 was transported to Sweden from Spain through the Netherlands, whereas the clade 1 had its origin from a Swedish stud farm. The clade 1 virus was efficiently spread between training yards by unvaccinated young horses, but...
McKenzie RK, Hill FI, Habyarimana JA, Boemer F, Votion DM.During April and May 2014 four horses aged between 5 months and 9 years, located in the Canterbury, Marlborough and Southland regions, presented with a variety of clinical signs including recumbency, stiffness, lethargy, dehydration, depression, and myoglobinuria suggestive of acute muscle damage. Two horses were subjected to euthanasia and two recovered. In all cases seeds of sycamore maple (Acer pseudoplatanus) or box elder (A. negundo) were present in the area where the horse had been grazing. Unassigned: The samaras (seeds) of some Acer spp. may contain hypoglycin A, that has been associat...
Sarkar S, Balasuriya UB, Horohov DW, Chambers TM.Equine herpesvirus-1 (EHV-1) infects equine endothelial cells (EECs) lining the small blood vessels in the central nervous system. However, the effect of type I IFN on EHV-1 replication in the EECs is not well studied. Thus, the primary objective of this study was to investigate the effect of type-I IFN on the replication of the neuropathogenic T953 strain of EHV-1 in vitro in EECs. The initial data showed that the EHV-1 was partly resistant to the biological effect of exogenously supplied recombinant equine IFN-α. Subsequent investigation into the mechanism of resistance showed that EHV-1 in...
Svala E, Jin C, Rüetschi U, Ekman S, Lindahl A, Karlsson NG, Skiöldebrand E.The glycoprotein lubricin contributes to the boundary lubrication of the articular cartilage surface. The early events of osteoarthritis involve the superficial layer where lubricin is synthesised. Objective: To characterise the glycosylation profile of lubricin in synovial fluid from horses with osteoarthritis and study secretion and degradation of lubricin in an in vitro inflammation cartilage model. Methods: In vitro study. Methods: Synovial fluid samples collected from horses with joints with normal articular cartilage and structural osteoarthritic lesions; with and without osteochondral f...
Elvander M, Persson B, Sternberg Lewerin S.As in most European countries, anthrax was common in Swedish livestock during the centuries leading up to the mid-twentieth century. After 1957, the disease was regarded as practically extinct. However, in the past 7 years, three outbreaks have caused public alarm because of the risk of environmental contamination. Properly buried carcasses should present little risk of spore contamination, and instructions were in place to ensure this since the 1890s. However, as has been demonstrated in recent outbreaks, carcasses were not always adequately buried and viable spores may remain in some sites....
Suske A, Pöschke A, Müller P, Wöber S, Staszyk C.Incomplete cemental filling of the infundibula of equine maxillary cheek teeth (CT) is a common feature. Depending on the extent of the defect, three stages of infundibular decay have been suggested. However, histomorphological criteria to identify non-pathological abnormalities and destructive changes have not been defined. Six hundred and eighty eight CT with no evidence of dental diseases and 55 diseased permanent, fully erupted maxillary CT were evaluated on a macroscopic level by assessing the occlusal surface and horizontal sections, including porphyrin assays to detect residual blood wi...
Mill G.Official Veterinarians (OVs) from across the U.K. came together recently at conference organised to provide targeted CPD for their particular roles. With the theme of 'Reducing the impact of notifiable diseases in the UK', the meeting considered a wide range of topics, spanning large animal, small animal and equine issues. Georgina Mills reports on some of the sessions.
Boudreaux MK, Koehler J, Habecker PL, Del Piero F.Exercise-induced pulmonary hemorrhage (EIPH) is a common disorder of equine athletes. The role of polymorphisms in genes encoding hemostasis-regulatory proteins in horses with abnormal hemorrhage is unknown. Objective: The goal of this study was to evaluate the genes encoding 2 ectonucleotidases, CD39/NTPDase-1 and CD39L1/NTPDase-2, and one ecto-5' nucleotidase, CD73, in horses with abnormal hemorrhage or pathologic changes consistent with EIPH. Methods: Twenty-three horses with histories of abnormal hemorrhage, 8 horses with gastrointestinal signs, and 45 healthy horses were evaluated using p...
Witkowski L, Cywinska A, Paschalis-Trela K, Crisman M, Kita J.Equine recurrent uveitis (ERU) has various etiologies, with Leptospira infection and genetic predisposition being the leading risk factors. Regardless of etiology, expression of ocular proteins associated with maintenance of the blood-ocular barrier is impaired in ERU. The recurring-remitting cycle of ERU repeatedly disrupts the blood-ocular barrier, allowing the previously immune-privileged ocular environment to become the site of a progressive local autoimmune pathology that ultimately results in tissue destruction and vision loss. The immune-mediated process involves humoral and cellular me...
Wong DM, Wilkins PA.Defining and describing the systemic inflammatory response syndrome (SIRS) and sepsis facilitated recognition and investigation of the complex disease processes involving the host response to infection and trauma. Over the years a variety of definitions of SIRS have been examined and applied to numerous research studies to improve critical care in both human and veterinary clinical practice. This article summarizes the history of the development of the SIRS definition, outlines the pathophysiologic processes that are involved in SIRS, and provides a specific definition for use in foal medicine...
Tennent-Brown BS, Morrice AV, Reed S.Neonatal encephalopathy is the most common neurologic condition affecting newborn foals and shares similarities with perinatal asphyxia syndrome of human infants. In many cases of neonatal encephalopathy there is no obvious episode of acute or chronic hypoxia and other mechanisms likely play a role in the pathogenesis. Increased concentrations of neuroactive progestagens are found in affected foals; whether these molecules are protective, as has been suggested, or play a role in the pathogenesis is unknown. Neurologic diseases other than neonatal encephalopathy affect foals occasionally and sh...
Fischer B, Clark-Price S.Anesthetizing the neonatal foal presents significant challenges as a result of physiologic differences from the adult equine. This article gives the reader an overview of these differences and the impact they have on anesthetic drug selection, monitoring, and support of the equine neonate. Special emphasis is directed to the sick neonate and appropriate preparation and maintenance of anesthesia in the face of commonly presented disease conditions.
Luethy D, Habecker P, Murphy B, Nolen-Walston R.Pheochromocytoma is the most common adrenal medullary neoplasm of domestic animals, but it is rare in horses. Antemortem diagnosis in horses is difficult, with clinical signs often being vague or non-specific. Objective: The objective of this study was to describe the clinical, laboratory, and pathologic findings of pheochromocytoma in horses. Methods: Thirty-seven horses diagnosed with pheochromocytoma based on postmortem examination from 2007 to 2014. Methods: Retrospective case series. Results: Pheochromocytoma was identified in 37/4094 horses during postmortem examination. Clinical signs c...
Van Der Vekens N, Hunter I, Timm A, Decloedt A, De Clercq D, Deprez P, Goetze JP, van Loon G.Equine atrial natriuretic peptide (ANP) plasma concentrations are correlated with left atrial size. However, species-specific assays are lacking and the results from human assays are poorly reproducible. A new methodology called processing independent analysis (PIA) that measures the total proANP product in plasma has proven to be successful in human medicine, but has never been used in horses. The aims were to establish an equine proANP reference interval by measurement of the total proANP product using PIA and to examine the proANP concentrations in horses with atrial dilatation. Sample stab...
Attoui H, Mohd Jaafar F.Many novel emerging orbiviruses have been isolated in the past 15 years. Important viruses include Peruvian horse sickness virus (PHSV) and Yunnan orbivirus (YUOV), pathogens of equids which were originally isolated almost simultaneously from 1997 to 1999 in the People's Republic of China, Australia and Peru. YUOV has also been isolated from cattle, sheep and a dog. The isolation of YUOVfrom a dog is not the first case of an orbivirus being isolated from a carnivore. Bluetongue virus and African horse sickness virus were earlier detected in carnivores which fed on contaminated meat. PHSV and Y...
Issel CJ, Foil LD.There is no credible evidence that the lentivirus that causes equine infectious anaemia (EIA) replicates in invertebrates. The virus persistently infects its equid hosts and is often present in blood in significant quantities. Blood-feeding arthropods thus have the potential to transfer the virus between hosts, especially if their feeding on the first host is interrupted and immediately continued on a second host. The general details and dynamics of mechanical transmission are included in this paper, as this agent presents an excellent model. Mechanical transmission can be effectively controll...
Hardeman LC, van der Meij BR, Back W, van der Kolk JH, Wijnberg ID.In equine laminitis, the deep digital flexor muscle (DDFM) appears to have increased muscle force, but evidence-based confirmation is lacking. Objective: The purpose of this study was to test if the DDFM of laminitic equines has an increased muscle force detectable by needle electromyography interference pattern analysis (IPA). Methods: The control group included six Royal Dutch Sport horses, three Shetland ponies and one Welsh pony [10 healthy, sound adults weighing 411 ± 217 kg (mean ± SD) and aged 10 ± 5 years]. The laminitic group included three Royal Dutch Sport horses, one Friesian, o...
van Niekerk S, Human S, Williams J, van Wilpe E, Pretorius M, Swanepoel R, Venter M.Old World alphaviruses were identified in 52 of 623 horses with febrile or neurologic disease in South Africa. Five of 8 Sindbis virus infections were mild; 2 of 3 fatal cases involved co-infections. Of 44 Middelburg virus infections, 28 caused neurologic disease; 12 were fatal. Middelburg virus likely has zoonotic potential.
Saey V, Famaey N, Smoljkic M, Claeys E, van Loon G, Ducatelle R, Ploeg M, Delesalle C, Gröne A, Duchateau L, Chiers K.Thoracic aortic rupture and aortopulmonary fistulation are rare conditions in horses. It mainly affects Friesian horses. Intrinsic differences in biomechanical properties of the aortic wall might predispose this breed. The biomechanical and biochemical properties of the thoracic aorta were characterized in warmblood horses, unaffected Friesian horses and Friesians with aortic rupture in an attempt to unravel the underlying pathogenesis of aortic rupture in Friesian horses. Samples of the thoracic aorta at the ligamentum arteriosum (LA), mid thoracic aorta (T1) and distal thoracic aorta (T2) we...
Flisikowski K, Flisikowska T, Sikorska A, Perkowska A, Kind A, Schnieke A, Switonski M.Cancer is a complex disease caused in part by predisposing germline gene polymorphisms. Knowledge of carcinogenesis in companion mammals (dog and cat) and some livestock species (pig and horse) is quite advanced. The prevalence of certain cancers varies by breed in these species, suggesting the presence of predisposing genetic variants in susceptible breeds. This review summarizes the present understanding of germline gene polymorphisms, including BRCA1, BRCA2, MC1R, KIT, NRAS and RAD51, associated with predisposition to melanoma, mammary cancer, osteosarcoma and histiocytic sarcoma in dogs, c...
Reilas T, Rivera Del Alamo MM, Liepina E, Yeste M, Katila T.Cervical patency is considered to be important for uterine drainage after mating or artificial insemination (AI), and failure to relax or premature tightening of the cervix can lead to persistent endometritis. This study investigated the hypothesis that cervical occlusion after AI increases accumulation of fluid, polymorphonuclear leukocytes (PMNs), and cytokines in the uterine lumen. Endometrial swabs were obtained from 29 normal cyclic mares during the first, third, and fifth estrus and biopsies during the first and fifth estrus. All mares were inseminated during the second and fourth estrus...
Gomez DE, Valberg SJ, Magdesian KG, Hanna PE, Lofstedt J.This report describes a case of severe rhabdomyolysis in a pregnant mare associated with histopathologic and biochemical features of both selenium deficiency and acquired multiple acyl-CoA dehydrogenase deficiency (MADD) due to seasonal pasture myopathy (SPM). This case highlights the importance of assessing plasma selenium levels in horses with clinical signs of pasture myopathy as this deficiency may be a contributing or exacerbating factor. Déficience multiple acquise de déshydrogénase acyl-CoA et carence en sélénium marquée causant une rhabdomyolyse grave chez un cheval. Ce rapport d...
Lohmann KL, Allen AL.A mature Quarter horse was euthanized following colic of 3 days duration. Postmortem, the large intestine, except the descending colon, was diffusely distended and associated with adhesion of the transverse colon to the pancreas, which had changes consistent with chronic active interstitial pancreatitis. Other lesions included hepatic fibrosis, erosive gastritis, and bilateral adrenal cortical hyperplasia. Pancréatite interstitielle chronique active comme cause d’une obstruction du côlon transversal et de coliques chez un cheval. Un cheval Quarter horse adulte a été euthanasié après de...
Houtsma A, Bedenice D, Pusterla N, Pugliese B, Mapes S, Hoffman AM, Paxson J, Rozanski E, Mukherjee J, Wigley M, Mazan MR.Inflammatory airway disease (IAD) in horses, similar to asthma in humans, is a common cause of chronic poor respiratory health and exercise intolerance due to airway inflammation and exaggerated airway constrictive responses. Human rhinovirus is an important trigger for the development of asthma; a similar role for viral respiratory disease in equine IAD has not been established yet. Methods: In a case-control study, horses with IAD (n = 24) were compared to control animals from comparable stabling environments (n = 14). Horses were classified using pulmonary function testing and bronc...
Bergero D, Nery J.The concept 'liver disease' includes several pathological conditions affecting liver's functions. It can either consist of a temporary impaired functioning of the liver and/or it can progress to its failure. The purpose of this review is to update the knowledge on hepatobiliary diseases and in particular on equine hyperlipaemia. Hepatobiliary disease's aetiology, clinical signs, diagnosis and nutritional management are thus described in the first part of the review the second part being devoted to hyperlypaemia's lipid metabolism, epidemiology, clinical signs, post-mortem observations and nutr...
Dunowska M, Holloway SA, Wilks CR, Meers J.Seventeen New Zealand isolates of equine herpesvirus 5 (EHV-5) were compared to the Australian prototype strain. PCR primers were designed to amplify EHV-5 glycoprotein B (gB) gene, and Restriction Fragment Length Polymorphism (RFLP) was used to detect differences between cloned PCR products. EHV-5 isolates from different horses showed a high degree of heterogeneity. However, EHV-5 isolates from individual horses remained homogeneous when examined over a period of time or isolated from different sites. A single EHV-5 gB RFLP profile was detected in isolates from each individual horse but one. ...
Sebastian MM, Bernard WV, Riddle TW, Latimer CR, Fitzgerald TD, Harrison LR.An epidemic of early fetal loss (EFL), late fetal loss (LFL), fibrinous pericarditis, and unilateral uveitis which occurred during the spring of 2001, are together now known as the mare reproductive loss syndrome (MRLS). A similar epidemic with less intensity was reported during the same period of time from southern Ohio, West Virginia, and Tennessee. The same syndrome with lesser intensity recurred in 2002. The estimated economic loss from the syndrome in 2001 and 2002 together was approximately $500 million. Both EFL and LFL were characterized by the absence of specific clinical signs in abo...
Degroote RL, Hauck SM, Kremmer E, Amann B, Ueffing M, Deeg CA.The molecular mechanism which enables activated immune cells to cross the blood-retinal barrier in spontaneous autoimmune uveitis is yet to be unraveled. Equine recurrent uveitis is the only spontaneous animal model allowing us to investigate the autoimmune mediated transformation of leukocytes in the course of this sight threatening disease. Hypothesizing that peripheral blood immune cells change their protein expression pattern in spontaneous autoimmune uveitis, we used DIGE to detect proteins with altered abundance comparing peripheral immune cells of healthy and ERU diseased horses. Among ...
Back H, Kendall A, Grandón R, Ullman K, Treiberg-Berndtsson L, Ståhl K, Pringle J.A standardbred gelding with a history of 10 days pyrexia and lethargy was referred to the Equine Hospital at the Swedish University of Agricultural Sciences in Uppsala, Sweden.The horse had tachypnea with increased respiratory effort and was in thin body condition. Laboratory findings included leukocytosis, hyperfibrinogenemia and hypoxemia. Thoracic radiographs showed signs of pneumonia with a multifocal nodular pattern, which in combination with lung biopsy findings indicated Equine Multinodular Pulmonary Fibrosis (EMPF). EMPF is a recently described disease in adult horses with clinical s...
Gomez D, Toribio R, Caddey B, Costa M, Vijan S, Dembek K.Antimicrobial drug-associated diarrhea (AAD) is the most common adverse effect in horses receiving antimicrobials. Little information on how oral administration of antimicrobials alters intestinal microbiota in horses is available. Objective: Investigate changes of the fecal microbiota in response to oral administration of antimicrobials. Methods: Twenty healthy horses. Methods: Prospective, longitudinal study. Horses were randomly assigned to 4 groups comprising 4 horses each: group 1 (metronidazole); group 2 (erythromycin); group 3 (doxycycline); group 4 (sulfadiazine/trimethoprim, SMZ-TMP);...
Herteman N, Mosing M, Waldmann AD, Gerber V, Schoster A.Equine asthma (EA) causes airflow impairment, which increases in severity with exercise. Electrical impedance tomography (EIT) is an imaging technique that can detect airflow changes in standing healthy horses during a histamine provocation test. Objective: To explore EIT-calculated flow variables before and after exercise in healthy horses and horses with mild-to-moderate (MEA) and severe equine asthma (SEA). Methods: Nine healthy horses 9 horses diagnosed with MEA and 5 with SEA were prospectively included. Methods: Recordings were performed before and after 15 minutes of lunging. Absolute...
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...
Ceriotti S, Bullone M, Leclere M, Ferrucci F, Lavoie JP.Pulmonary hypertension and cor pulmonale are complications of severe equine asthma, as a consequence of pulmonary hypoxic vasoconstriction. However, as pulmonary hypertension is only partially reversible by oxygen administration, other etiological factors are likely involved. In human chronic obstructive pulmonary disease, pulmonary artery remodeling contributes to the development of pulmonary hypertension. In rodent models, pulmonary vascular remodeling is present as a consequence of allergic airway inflammation. The present study investigated the presence of remodeling of the pulmonary arter...
Langley R, Morris T.Millions of individuals are in contact with horses through occupational or recreational activities. Injuries from horses are responsible for over 100,000 emergency room visits each year in the United States. Although various types of traumatic injuries related to direct contact with horses are well described, roughly 3% to 4.5% of all reported injuries are due to bites by equines. The immediate injuries are commonly either blunt or penetrating trauma to local tissue; however, the bite exposure may also transmit a microbial agent of equine origin that can lead to a zoonotic infection. In almost...
Nagy A, Murray JK, Dyson SJ.There is limited information on risk factors for elimination from endurance rides. Objective: To assess risk factors for elimination for lameness and metabolic reasons from Fédération Equestre Internationale (FEI) endurance rides of 80-160 km distance. Methods: Unmatched case-control. Methods: Venue-, horse- and rider-related data were collected from the FEI website. Data on weather conditions and terrain were collected at the venue. Univariable and multivariable logistic regression analyses were used to assess risk factors for elimination for lameness and metabolic reasons, respectively. Re...
Lange CE, Tobler K, Ackermann M, Favrot C.The number of recognized papillomavirus (PV) species and potential PV genera has dramatically been increasing throughout the past decade. It seems that every host species might potentially harbour a large set of PVs, while the PVs of each species appear to belong to only a few genera. In horses at least three conditions beside the equine sarcoid have been described, being supposedly PV induced namely classical equine papillomas, genital papillomas and aural plaques. We were able to identify the DNA of novel equine PVs (EcPVs) in the two latter disorders where PV involvement had been predicted....
Lear TL, McGee RB.Abnormalities of sexual development causing infertility in horses have been investigated since the early 1970's. Conventional cytogenetic analysis by karyotyping has been the primary tool used to investigate these horses. Abnormalities have a broad range, from a phenotypically normal mare with gonadal dysgenesis to a horse with ambiguous external genitalia and internal male and female organs. Cytogenetic analysis can determine genetic sex but cannot identify mutations or deletions of genes involved in the sex determination pathway. Molecular technologies have been developed to confirm cytogene...
Cruz AM, Poljak Z, Filejski C, Lowerison ML, Goldie K, Martin SW, Hurtig MB.To determine characteristics, incidence rate, and possible associations with selected demographic characteristics of catastrophic musculoskeletal injuries (CMIs) in Thoroughbred racehorses. Methods: 76 Thoroughbreds with CMIs. Methods: Incidence rates of CMIs during racing or training were calculated with number of CMIs as the numerator and overall numbers of races or training events during 2004 and 2005 as the denominators. Exact 95% confidence intervals were calculated. Associations between incidence and dichotomous exposure factors, nominal factors, and ordinal factors were determined. Only...
Beacham BE, Cooper PH, Buchanan CS, Weary PE.We describe four patients with panniculitis attributable to a combination of cold exposure and equestrian activities. All were young, healthy women who rode horses for at least two consecutive hours per day throughout the winter. Initially, several small, erythematosus, pruritic papules appeared on the superior-lateral portions of one or both thighs. During one week, the lesions progressed to indurated, red-to-violaceous,tender plaques and nodules. Studies for cryofibrinogens and cryoglobulins were negative. The histologic picture was that of a panniculitis with prominent inflammation of veins...
Cox A, Dixon P, Smith S.Equine periodontal disease (EPD) is a common and painful condition, the aetiology and pathology of which are poorly understood. To characterise the histopathological lesions associated with EPD, the skulls of 22 horses were assessed grossly for the presence of periodontal disease, and a standard set of interdental tissues taken from each for histopathological examination. Histological features of EPD included ulceration and neutrophilic inflammation of the gingival epithelium. Mononuclear and eosinophilic inflammation of the gingival lamina propria and submucosa was commonly present irrespecti...
Smith CS, McLAUGHLIN A, Field HE, Edson D, Mayer D, Ossedryver S, Barrett J, Waltisbuhl D.Hendra virus (HeV) was first described in 1994 in an outbreak of acute and highly lethal disease in horses and humans in Australia. Equine cases continue to be diagnosed periodically, yet the predisposing factors for infection remain unclear. We undertook an analysis of equine submissions tested for HeV by the Queensland government veterinary reference laboratory over a 20-year period to identify and investigate any patterns. We found a marked increase in testing from July 2008, primarily reflecting a broadening of the HeV clinical case definition. Peaks in submissions for testing, and visitat...
Holland RE, Schmidt A, Sriranganathan N, Grimes SD, Wilson RA, Brown CM, Walker RD.Serotype, biotype, antibiogram, hemolysin production, fimbrial hemagglutinins, select toxin genes (STb, STaP, LT, slt1 and slt2) and the attaching effacing (eae) gene were determined for 99 foal strains of E. coli. E. coli from diarrheic and normal foals could not be distinguished by serotype, biotype, or antibiogram. Differences (P < or = 0.05) were observed in hemolysin production (11.5% vs 0%) and the expression of mannose-resistant hemagglutinins (23% vs 13%) among E. coli from diarrheic and healthy foals, respectively. Three of the E. coli strains from diarrheic foals were positive wit...
Fukushi H, Yamaguchi T, Yamada S.Equine herpesvirus type 9 (EHV-9), which we isolated from a case of epizootic encephalitis in a herd of Thomson's gazelles (Gazella thomsoni) in 1993, has been known to cause fatal encephalitis in Thomson's gazelle, giraffe, and polar bear in natural infections. Our previous report indicated that EHV-9 was similar to the equine pathogen equine herpesvirus type 1 (EHV-1), which mainly causes abortion, respiratory infection, and equine herpesvirus myeloencephalopathy. We determined the genome sequence of EHV-9. The genome has a length of 148,371 bp and all 80 of the open reading frames (ORFs) fo...
Leroux AA, Detilleux J, Sandersen CF, Borde L, Houben RM, Al Haidar A, Art T, Amory H.Risk factors for cardiac diseases in horses have not been explored in a large population of animals. Objective: To describe risk factors for various cardiac diseases in a hospital-based population of horses. Methods: Files of 3,434 horses admitted at the Internal Medicine Department of the Liege Equine Teaching Hospital between 1994 and 2011 were reviewed and of those, 284 were categorized as having moderate-to-severe cardiac disease. Methods: Observational study. After calculating prevalence for each cardiac disease, we tested whether breed (chi-square test) or sex, age, body weight (BW), and...
Rosiles MR, Bautista J, Fuentes VO, Ross F.Equine leukoencephalomalacia (ELEM), swine pulmonary oedema and human oesophageal cancer have been associated with fumonisine B1 (FB1) ingestion. For the first time in this study it is reported that FB1 was identified as being associated with an outbreak of ELEM at Oaxaca, Mexico. Symptoms of ELEM and Equine Venezuelan Encephalitis (EVE) are similar and a different diagnosis is obligatory. In the geographical area (Oaxaca, Mexico) where donkeys died showing a neurological syndrome, 14 corn samples were collected. With the use of TLC (Thin layer chromatography) and HPLC (High performance liquid...
Mullaney T, Murphy AJ, Kiupel M, Bell JA, Rossano MG, Mansfield LS.Opossums (Didelphis spp.) are the definitive host for the protozoan parasite Sarcocystis neurona, the causative agent of equine protozoal myeloencephalitis (EPM). Opossums shed sporocysts in feces that can be ingested by true intermediate hosts (cats, raccoons, skunks, armadillos and sea otters). Horses acquire the parasite by ingestion of feed or water contaminated by opossum feces. However, horses have been classified as aberrant intermediate hosts because the terminal asexual sarcocyst stage that is required for transmission to the definitive host has not been found in their tissues despite...
Cárdenas NC, Galvis JOA, Farinati AA, Grisi-Filho JHH, Diehl GN, Machado G.Glanders is a highly infectious zoonotic disease caused by Burkholderia mallei. The transmission of B. mallei occurs mainly by direct contact, and horses are the natural reservoir. Therefore, the identification of infection sources within horse populations and animal movements is critical to enhance disease control. Here, we analysed the dynamics of horse movements from 2014 to 2016 using network analysis in order to understand the flow of animals in two hierarchical levels, municipalities and farms. The municipality-level network was used to investigate both community clustering and the bala...
Reilas T, Rivera Del Alamo MM, Liepina E, Yeste M, Katila T.Cervical patency is considered to be important for uterine drainage after mating or artificial insemination (AI), and failure to relax or premature tightening of the cervix can lead to persistent endometritis. This study investigated the hypothesis that cervical occlusion after AI increases accumulation of fluid, polymorphonuclear leukocytes (PMNs), and cytokines in the uterine lumen. Endometrial swabs were obtained from 29 normal cyclic mares during the first, third, and fifth estrus and biopsies during the first and fifth estrus. All mares were inseminated during the second and fourth estrus...
Hird DW, Casebolt DB, Carter JD, Pappaioanou M, Hjerpe CA.A case-control study to identify risk factors associated with isolation of Salmonella was accomplished, using data from records of horses hospitalized in the period July 1971 through June 1982. Horses in which nasogastric tubes were passed were at 2.9 times greater risk of having Salmonella isolated, compared with horses that did not undergo this procedure. Horses treated with antibiotics parenterally were at 6.4 times greater risk, and those treated with antibiotics orally and parenterally were at 40.4 times greater risk of developing salmonellosis, compared with horses not receiving such tre...
Barba M, Stewart AJ, Passler T, Wooldridge AA, van Santen E, Chamorro MF, Cattley RC, Hathcock T, Hogsette JA, Hu XP.The route of Corynebacterium pseudotuberculosis infection in horses remains undetermined, but transmission by insects is suspected. Objective: To investigate house flies (Musca domestica L.) as vectors of C. pseudotuberculosis transmission in horses. Methods: Eight healthy, adult ponies. Methods: Randomized, controlled, blinded prospective study. Ten wounds were created in the pectoral region where cages for flies were attached. Three ponies were directly inoculated with C. pseudotuberculosis. Four ponies were exposed for 24 hours to 20 hours C. pseudotuberculosis-inoculated flies. One negativ...
Cowley AB, Lukat-Rodgers GS, Rodgers KR, Benson DR.N-Acetylmicroperoxidase-8 (1) contains heme and residues 14-21 of horse mitochondrial cytochrome c (cyt c). The two thioether bonds linking protein to heme in cyt c are present in 1, and the native axial ligand His-18 remains coordinated to iron. As an approach to probing structural or functional roles played by the double covalent heme-protein linkage in cyt c, we have initiated a study in which the properties of 1 are compared with those of a synthetic mono-His coordinated heme peptide containing a single covalent linkage (2). One consequence of the greater conformational restriction imposed...
de Laat MA, Clement CK, McGowan CM, Sillence MN, Pollitt CC, Lacombe VA.Equine laminitis, a disease of the lamellar structure of the horse's hoof, can be incited by numerous factors that include inflammatory and metabolic aetiologies. However, the role of inflammation in hyperinsulinaemic laminitis has not been adequately defined. Toll-like receptor (TLR) activation results in up-regulation of inflammatory pathways and the release of pro-inflammatory cytokines, including interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α), and may be a pathogenic factor in laminitis. The aim of this study was to determine whether TLR4 expression and subsequent pro-infla...
Swerczek TW.Reports of 148 cases of Tyzzer's disease in foals in central Kentucky were analyzed to identify features of the disease and factors associated with it. The records indicate that Tyzzer's disease is a rapidly progressive, highly fatal hepatitis caused by Clostridium piliforme. Common clinical findings are lethargy, fever, anorexia, and icterus. Seizures, coma, and death may rapidly ensue. Laboratory findings are leukopenia, metabolic acidosis, hypoglycemia, and increased activity of hepatic enzymes. Diagnosis is primarily based on clinical signs and postmortem findings but a polymerase chain re...
Brandt S, Schoster A, Tober R, Kainzbauer C, Burgstaller JP, Haralambus R, Steinborn R, Hinterhofer C, Stanek C.Equine hoof canker is a chronic proliferative pododermatitis of as yet unknown aetiology. Like equine sarcoid disease, canker is a therapy-resistant disorder characterised by hyperkeratosis, acanthosis and a marked tendency to recur. Objective: There is an association of sarcoid-inducing bovine papillomaviruses of types 1 and 2 (BPV-1, BPV-2) with hoof canker disease. Methods: Using PCR-based techniques, we assessed canker tissue, intact skin and/or peripheral blood mononuclear cells (PBMCs) of 25 canker-affected horses for the presence of sarcoid-associated BPV-1 and -2. Results: Conventional...
