Infectious diseases in horses encompass a range of illnesses caused by bacteria, viruses, fungi, or parasites. These diseases can affect various systems within the equine body, leading to symptoms that range from mild discomfort to severe systemic illness. Common infectious diseases in horses include equine influenza, strangles, equine herpesvirus, and West Nile virus. These diseases can be transmitted through direct contact with infected animals, contaminated surfaces, or vectors such as insects. Understanding the mechanisms of transmission, pathogenesis, and immune response is essential for effective prevention and control. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, diagnosis, treatment, and management of infectious diseases in horses.
Bosco-Lauth AM, Panella NA, Root JJ, Gidlewski T, Lash RR, Harmon JR, Burkhalter KL, Godsey MS, Savage HM, Nicholson WL, Komar N, Brault AC.Heartland virus (HRTV; Bunyaviridae: Phlebovirus) has recently emerged as a causative agent of human disease characterized by thrombocytopenia and leukopenia in the United States. The lone star tick (Amblyomma americanum L.) has been implicated as a vector. To identify candidate vertebrate amplification hosts associated with enzootic maintenance of the virus, sera and ticks were sampled from 160 mammals (8 species) and 139 birds (26 species) captured near 2 human case residences in Andrew and Nodaway Counties in northwest Missouri. HRTV-specific neutralizing antibodies were identified in north...
Cohen ND, Slovis NM, Giguère S, Baker S, Chaffin MK, Bernstein LR.Macrolide-resistant isolates of Rhodococcus equi are emerging, prompting the search for clinically effective alternative antimicrobials. Objective: The proportion of foals with ultrasonographic evidence of pneumonia presumed to be caused by R. equi that had a successful outcome when administered gallium maltolate (GaM) PO would not be more than 10% inferior (ie, lower) than that of foals receiving standard treatment. Methods: Fifty-four foals with subclinical pulmonary abscesses among 509 foals at 6 breeding farms in Kentucky. Methods: Controlled, randomized, prospective noninferiority study. ...
Liu XH, Li XY, Li K, Zhang D.Rhinoestrus purpureus (Brauer, 1858) (Diptera: Oestridae) is an economically important parasite that can cause severe nasal myiasis in equids or even attacking humans. The antennae of R. purpureus were examined using stereoscopic microscopy and scanning electron microscopy. The general morphology was provided detailedly, together with distribution, type, size, and ultrastructure of antennal sensilla. All the three antennal segments, antennal scape, pedicel, and funiculus, are interspersed by microtrichiae. Only mechanoreceptors are detected on antennal scape and pedicel. On antennal funiculus,...
Allen LJ, Schwartz EJ.Equine infectious anemia virus (EIAV) is a lentivirus in the retrovirus family that infects horses and ponies. Two strains, referred to as the sensitive strain and the resistant strain, have been isolated from an experimentally-infected pony. The sensitive strain is vulnerable to neutralization by antibodies whereas the resistant strain is neutralization-insensitive. The sensitive strain mutates to the resistant strain. EIAV may infect healthy target cells via free virus or alternatively, directly from an infected target cell through cell-to-cell transfer. The proportion of transmission from f...
Birhanu H, Fikru R, Said M, Kidane W, Gebrehiwot T, Hagos A, Alemu T, Dawit T, Berkvens D, Goddeeris BM, Büscher P.African animal trypanosomosis, transmitted cyclically by tsetse flies or mechanically by other biting flies, causes serious inflictions to livestock health. This study investigates the extent of non-tsetse transmitted animal trypanosomosis (NTTAT) by Trypanosoma (T.) evansi and T. vivax in domestic animals in the tsetse-free regions of Northern Ethiopia, Afar and Tigray. Methods: A cross sectional study was conducted on 754 dromedary camels, 493 cattle, 264 goats, 181 sheep, 84 donkeys, 25 horses and 10 mules. The microhaematocrit centrifugation technique was used as parasitological test. Plas...
Larson KR, Heil GL, Chambers TM, Capuano A, White SK, Gray GC.Equine influenza virus (EIV) is considered enzootic in North America and experimental studies have documented human EIV infections. Methods: This cross-sectional study examined 94 horse-exposed and 34 non-exposed controls for serological evidence of EIV infection. Sera were evaluated for antibodies against three EIV and two human H3N2 viruses using microneutralization (MN), neuraminidase inhibition (NI), enzyme-linked lectin (ELLA), and hemagglutination inhibition (HI) serological assays. Risk factor analyses were conducted using logistic regression and proportional odds modeling. Results: The...
Kinoshita Y, Niwa H, Katayama Y.Microbial substitution occasionally occurs following the administration of antimicrobials to horses that have pneumonia or pleuropneumonia. Four specific loop-mediated isothermal amplification (LAMP) assays were developed to detect some equine respiratory pathogens, namely strains of the Bacteroides-Prevotella group, Klebsiella pneumoniae, Stenotrophomonas maltophilia, and Staphylococcus aureus. These four LAMP assays and two previously published LAMP assays targeting Escherichia coli or Pseudomonas aeruginosa were used on clinical respiratory specimens and a high accordance found between the ...
Mehdizadeh Gohari I, Parreira VR, Nowell VJ, Nicholson VM, Oliphant K, Prescott JF.A role for type A Clostridium perfringens in acute hemorrhagic and necrotizing gastroenteritis in dogs and in necrotizing enterocolitis of neonatal foals has long been suspected but incompletely characterized. The supernatants of an isolate made from a dog and from a foal that died from these diseases were both found to be highly cytotoxic for an equine ovarian (EO) cell line. Partial genome sequencing of the canine isolate revealed three novel putative toxin genes encoding proteins related to the pore-forming Leukocidin/Hemolysin Superfamily; these were designated netE, netF, and netG. netE a...
Wobeser BK.During a widespread anthrax outbreak in Canada, miniature horses were vaccinated using a live spore anthrax vaccine. Several of these horses died from an apparent immune-mediated vasculitis temporally associated with this vaccination. During the course of the outbreak, other miniature horses from different regions with a similar vaccination history, clinical signs, and necropsy findings were found. Vaccin contre l’anthrax associé à la mort de chevaux miniatures. Durant une vaste éclosion d’anthrax au Canada, des chevaux miniatures ont été vaccinés en utilisant un vaccin à base de sp...
Marenzoni ML, Stefanetti V, Danzetta ML, Timoney PJ.Although the first equine gammaherpesvirus was identified over 50 years ago, the isolation and characterization of other members of this virus group has been relatively recent. Even so, numerous clinical syndromes have been identified in equid species in association with these viruses. Equid gammaherpesviruses are a genetically heterogeneous viral subfamily, the function of which in host immune modulation and disease pathogenesis has not yet been elucidated. While they share similarities with gammaherpesviruses in humans, the role they play in their relationship with the host is the subject of...
Laabassi F, Amelot G, Laugier C, Zientara S, Nasri AM, Hans A.In order to determine the prevalence of equine viral arteritis in Algeria, 268 sera from non-vaccinated horses were collected from the western and eastern regions. Serological analysis of the sera, which were collected from 2009 to 2011, was performed using the virus neutralisation test, as described by the World Organisation for Animal Health. Overall, 20 sera (7.46%) were seropositive, 152 (56.71%) were negative and 96 sera (35.82%) were cytotoxic. Equine arteritis virus (EAV) seroprevalence was significantly higher in the western region (Tiaret) than in the eastern region (Barika and El-Eul...
Khan I, Wieler LH, Saqib M, Melzer F, Santana VL, Neubauer H, Elschner MC.The complement fixation test (CFT) is the only serological test prescribed by the World Organisation for Animal Health (OIE) for the diagnosis of glanders in international trading of equids. However, false-positive reactions have caused financial losses to the animal owners in the past, and false-negative tests have resulted in the introduction of glanders into healthy equine populations in previously glanders-free areas. Both warm (incubation at 37°C for 1 h) and cold (overnight incubation at 4°C) procedures are recommended by the OIE for serodiagnosis of glanders. In a comparison of the se...
Mir IA, Kumar B, Taku A, Bhardwaj RK, Bhat MA, Badroo GA.The present study was conducted to determine the prevalence of Rhodococcus equi infection in equines of Jammu and Kashmir, India, and evaluate the zoonotic threat posed by this organism to equine owners and tourists. One hundred and forty-one samples (98 samples from adult animals ≥5 years old and 43 samples from foals less than 6 months old) were collected in duplicate from nasopharyngeal tract of equines for isolation and direct PCR. A total of 12 isolates of R. equi were recovered, of which 9 were from foals and 3 from adult animals. Therefore, the present study recorded prevalence rates ...
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...
Galuppi R, Piva S, Castagnetti C, Iacono E, Tanel S, Pallaver F, Fioravanti ML, Zanoni RG, Tampieri MP, Caffara M.The present study aims to evaluate the prevalence, pattern of spread and risk factors for the transmission of cryptosporidiosis in foals and mares hospitalized in a University Equine Perinatology Unit, where a new subtype family of Cryptosporidium horse genotype was described by Caffara et al. (2013). Mares (36) and foals (37) hospitalized during the 2012 foaling season were included. Multiple sampling from each animal was performed (a total of 305 stool samples were collected). One hundred and eleven environmental samples (gauze swabs) were also collected before and after the breeding season....
Human rotavirus is the leading cause of severe gastroenteritis in infants and children under the age of 5 years in both developed and developing countries. Human lactadherin, a milk fat globule membrane glycoprotein, inhibits human rotavirus infection in vitro, whereas bovine lactadherin is not active. Moreover, it protects breastfed infants against symptomatic rotavirus infections. To explore the potential antiviral activity of lactadherin sourced by equines, we undertook a proteomic analysis of milk fat globule membrane proteins from donkey milk and elucidated its amino acid sequence. Alignm...
Dryburgh EL, Marsh AE, Dubey JP, Howe DK, Reed SM, Bolten KE, Pei W, Saville WJ.Sarcocystis neurona is considered the major etiologic agent of equine protozoal myeloencephalitis (EPM), a neurological disease in horses. Raccoon ( Procyon lotor ) is considered the most important intermediate host in the life cycle of S. neurona in the United States; S. neurona sarcocysts do mature in raccoon muscles, and raccoons also develop clinical signs simulating EPM. The focus of this study was to determine if sarcocysts would develop in raccoons experimentally inoculated with different host-derived strains of in vitro-cultivated S. neurona merozoites. Four raccoons were inoculated wi...
Ferra B, Holec-Gąsior L, Kur J.Toxoplasma gondii infects all warm-blooded animals including humans, causing serious public health problems and great economic loss in the animal husbandry. Commonly used serological tests for diagnosis of toxoplasmosis involve preparation of whole Toxoplasma lysate antigen (TLA) from tachyzoites. The production of this antigen is associated with high costs and lengthy preparation and the possibility of staff infection. There are also some difficulties in the standardization of such tests. One approach in order to improve the diagnosis of T. gondii infection is to use recombinant chimeric anti...
Martin-Alonso A, Abreu-Yanes E, Feliu C, Mas-Coma S, Bargues MD, Valladares B, Foronda P.The nematode Angiostrongylus cantonensis is the causative agent of human angiostrongyliasis, the main clinical manifestation of which is eosinophilic meningitis. Although this parasite has been found recently in its definitive rat host in Tenerife (Canary Islands, Spain), showing a widespread distribution over the north-east part of the island, there are no available data regarding which snail and/or slug species are acting as intermediate hosts on this island. Consequently, the objective of this work was to determine the possible role of three mollusc species, Plutonia lamarckii, Cornu aspers...
Sule WF, Oluwayelu DO, Adedokun RA, Rufai N, McCracken F, Mansfield KL, Johnson N.To investigate exposure of Nigerian horses to West Nile virus (WNV), we determined the seroprevalence rate of anti-WNV antibody in a cohort of 145 horses. Serum samples were collected from three locations in southwestern Nigeria between October, 2011, and July, 2012. The horses were asymptomatic and unvaccinated against WNV at the time of sampling. All sera were tested using a competition enzyme-linked immmunosorbent assay (ELISA) and by an immunoglobulin M (IgM)-specific ELISA. High rates of anti-WNV antibody prevalence were observed in all locations with a mean level of 90.3% (95% confidence...
Tavalla M, Sabaghan M, Abdizadeh R, Khademvatan S, Rafiei A, Razavi Piranshahi A.Because of the economic importance of the Arab race horses and also the role of Toxoplasma gondii and Neospora spp. in abortion and reproductive failure of these animals, we decided to perform this study. Objective: We designed this study to investigate the seroprevalence of anti-Toxoplasma gondii and anti-Neospora spp. antibodies in Arab horses from 12 cities of Khuzestan province in southwest of Iran. Methods: From October 2009 to March 2011, a total of 235 blood samples were collected from jugular veins of Arab horses of different ages and genders from 12 cities of Khuzestan province. All t...
Niczyporuk JS, Samorek-Salamonowicz E, Lecollinet S, Pancewicz SA, Kozdruń W, Czekaj H.Serum samples of 474 wild birds, 378 horses, and 42 humans with meningitis and lymphocytic meningitis were collected between 2010 and 2014 from different areas of Poland. West Nile virus (WNV) antibodies were detected using competition enzyme linked immunosorbent assays: ELISA-1 ID Screen West Nile Competition, IDvet, ELISA-2 ID Screen West Nile IgM Capture, and ELISA-3 Ingezim West Nile Compac. The antibodies were found in 63 (13.29%) out of 474 wild bird serum samples and in one (0.26%) out of 378 horse serum samples. Fourteen (33.33%) out of 42 sera from patients were positive against WNV a...
Woodward A, Rash AS, Medcalf E, Bryant NA, Elton DM.Equine influenza is a major cause of respiratory infections in horses and causes widespread epidemics, despite the availability of commercial vaccines. Antigenic drift within the haemagglutinin (HA) glycoprotein is thought to play a part in vaccination breakdown. Here, we carried out a detailed investigation of the 1989 UK outbreak, using reverse genetics and site-directed mutagenesis, to determine the individual contribution of amino acid substitutions within HA. Mutations at positions 159, 189 and 227 all altered antigenicity, as measured by haemagglutination-inhibition assays. We also compa...
Sapsutthipas S, Leong PK, Akesowan S, Pratanaphon R, Tan NH, Ratanabanangkoon K.Snake envenomation has been estimated to affect 1.8 million people annually with about 94,000 deaths mostly in poor tropical countries. Specific antivenoms are the only rational and effective therapy for these cases. Efforts are being made to produce effective, affordable and sufficient antivenoms for these victims. The immunization process, which has rarely been described in detail, is one step that needs to be rigorously studied and improved especially with regard to the production of polyspecific antisera. The polyspecific nature of therapeutic antivenom could obviate the need to identify t...
Wilkins PA, Lascola KM.Interstitial pneumonias encompass a wide variety of acute and chronic respiratory diseases and include the specific diseases equine multinodular pulmonary fibrosis and acute lung injury and acute respiratory distress. These diseases have been diagnosed in all age groups of horses, and numerous agents have been identified as potential causes of interstitial pneumonia. Despite the varied causes, interstitial pneumonia is uniformly recognized by the severity of respiratory disease and often poor clinical outcome. This article reviews the causal agents that have been associated with the developmen...
Legrand LJ, Pitel PH, Cullinane AA, Fortier GD, Pronost SL.REASON FOR PERFORMING THIS STUDY: Equine influenza virus (EIV) is considered the most economically important equine respiratory pathogen worldwide. The H3N8 subtype, responsible for all outbreaks of equine influenza globally, evolves perpetually. Mutations in the genome of these viruses have the potential to modify their antigenic properties and recognition by pre-existing antibodies. Objective: The aim of this study was to determine the genetic evolution of EIV strains in France and to compare it with the evolution of strains isolated globally. Analysis of the sequence data was performed to i...
Abe N, Matsubara K.The Cryptosporidium horse genotype, a zoonotic protozoan parasite first found in a Prezewalski wild horse, has not been found in any other mammal but calves, horses, and humans. Hedgehogs, popular exotic pet animals in Japan, are a reservoir of two zoonotic Cryptosporidum: C. parvum and C. erinacei (previously known as the hedgehog genotype). Recently, after finding Cryptosporidium infection in a four-toed hedgehog (Atelerix albiventris), we identified the isolate genetically as the Cryptosporidium horse genotype. Its subtype (VIbA13) was the same as that of an isolate from a pet shop employee...
Wang T, Xi C, Yu Y, Liu W, Akhtar MF, Li Y, Wang C, Li L.Equid herpesvirus 8 (EHV-8), also known as asinine herpesvirus type 3 (AHV-3), can cause severe respiratory disease, abortion in mares, and neurological disorders. There is limited information on the prevalence of EHV-8 in donkeys in China. In this study, we investigated EHV-8 infection in donkeys using PCR, resulting in the identification of a field strain, termed EHV-8 SD2020113, which was isolated using RK-13 cells and characterized by high-throughput sequencing and transmission electron microscopy. Our data indicated that 38.7% (457/1180) of donkeys showed the presence of EHV-8 in blood sa...
The Lancet. Global healthMay 14, 2022
Volume 10, Issue 6 e862-e872 doi: 10.1016/S2214-109X(22)00117-6
Van Hao N, Loan HT, Yen LM, Kestelyn E, Hong DD, Thuy DB, Nguyen NT, Duong HTH, Thuy TTD, Nhat PTH, Khanh PNQ, Dung NTP, Phu NH, Phong NT, Lieu PT....Intramuscular antitoxin is recommended in tetanus treatment, but there are few data comparing human and equine preparations. Tetanus toxin acts within the CNS, where there is limited penetration of peripherally administered antitoxin; thus, intrathecal antitoxin administration might improve clinical outcomes compared with intramuscular injection. In a 2 × 2 factorial trial, all patients aged 16 years or older with a clinical diagnosis of generalised tetanus admitted to the intensive care unit of the Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam, were eligible for study entr...
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...
Soboll G, Breathnach CC, Kydd JH, Hussey SB, Mealey RM, Lunn DP.The control of EHV-1 infection by cytotoxic T-cell responses (CTL) via a reduction in cell associated viremia remains an important goal in horses. Unfortunately, current vaccines are inefficient at inducing these responses. We have identified the immediate early (IE) gene of EHV-1 as a potent stimulator of virus-specific CTL responses in ponies expressing a specific MHC class I serological haplotype (A3/B2). This study was designed to determine if vaccination of A3/B2 MHC I positive ponies with the IE gene could induce protection and immune responses associated with cell mediated immunity. Pon...
Steel CM, Hunt AR, Adams PL, Robertson ID, Chicken C, Yovich JV, Stick JA.To identify factors affecting the prognosis for survival and athletic use in foals with septic arthritis. Methods: Retrospective study. Methods: 93 foals with septic arthritis. Methods: Medical records were reviewed to obtain clinical findings, laboratory test results, radiographic findings, treatment method, and outcome. Race records for Thoroughbreds and Standardbreds were evaluated to determine whether foals subsequently raced and whether they raced successfully. Results: 43 foals had 1 affected joint, 44 foals had multiple affected joints, and number of affected joints was not recorded for...
Sreenivasan CC, Jandhyala SS, Luo S, Hause BM, Thomas M, Knudsen DEB, Leslie-Steen P, Clement T, Reedy SE, Chambers TM, Christopher-Hennings J....Equine influenza, caused by the H3N8 subtype, is a highly contagious respiratory disease affecting equid populations worldwide and has led to serious epidemics and transboundary pandemics. This study describes the phylogenetic characterization and replication kinetics of recently-isolated H3N8 virus from a nasal swab obtained from a sporadic case of natural infection in an unvaccinated horse from Montana, USA. The nasal swab tested positive for equine influenza by Real-Time Quantitative Reverse Transcription Polymerase Chain Reaction (RT-PCR). Further, the whole genome sequencing of the virus ...
Kleiboeker SB, Chapman RK.During a recent breeding season, ulcerative, pustular skin lesions were observed on the external genitalia of 2 mares and 1 stallion within a small herd. Based on the location and description of the skin lesions plus the clinical history, equine coital exanthema, caused by equine herpesvirus 3 (EHV3), was the primary differential diagnosis. Scrapings of skin lesions from the perineum of 2 mares were submitted for diagnostic evaluation. Virus isolation was attempted by inoculation of several cell lines of equine origin, but no cytopathic agent was detected. The skin scrapings were processed for...
Saqib M, Muhammad G, Naureen A, Hussain MH, Asi MN, Mansoor MK, Toufeer M, Khan I, Neubauer H, Sprague LD.Glanders is a contagious and fatal zoonotic disease of solipeds caused by the Gram-negative bacterium Burkholderia (B.) mallei. Although regulations call for culling of diseased animals, certain situations e.g. wild life conservation, highly valuable breeding stock, could benefit from effective treatment schemes and post-exposure prophylaxis. Results: Twenty three culture positive glanderous horses were successfully treated during a confined outbreak by applying a treatment protocol of 12 weeks duration based on the parenteral administration of enrofloxacin and trimethoprim plus sulfadiazine, ...
Gibson KE, Pastenkos G, Moesta S, Rikihisa Y.Neorickettsia risticii is the Gram-negative, obligate, and intracellular bacterial pathogen responsible for Potomac horse fever (PHF): an important acute systemic disease of horses. N. risticii surface proteins, critical for immune recognition, have not been thoroughly characterized. In this paper, we identified the 51-kDa antigen (P51) as a major surface-exposed outer membrane protein of older and contemporary strains of N. risticii through mass spectrometry of streptavidin-purified biotinylated surface-labeled proteins. Western blot analysis of sera from naturally-infected horses demonstrate...
Li XY, Chen YO, Wang QK, Li K, Pape T, Zhang D.Species of Gasterophilus are obligate parasites of equids and may induce severe, even lethal myiasis. However, identification of the third instar Gasterophilus larva at the species level is still problematic predominantly due to a shortage of diagnostic morphological features and incomplete molecular libraries. Testing the suitability of three different molecular markers showed that the traditional 650 bp barcode region near the 5' terminus of the cytochrome c oxidase subunit I (COI) served as a better tool for species-level identification than a 663 bp region near the 3' terminus of COI and a...
Mead DG, Ramberg FB, Maré CJ.In previous experiments we have demonstrated that colonized and wild black flies are competent laboratory vectors of different Mexican and Western USA isolates of vesicular stomatitis virus, serotype New Jersey (VSV-NJ). We have recently demonstrated biological VSV-NJ transmission by black flies using animal models. In the study described here, we tested the vector competence of colonized and wild black flies for the vesicular stomatitis virus, serotype Indiana (VSV-IN). A 1998 equine isolate was used. After a 10 day incubation period, saliva from experimentally infected Simulium vittatum and ...
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...
Hemida MG, Perera RAPM, Chu DKW, Ko RLW, Alnaeem AA, Peiris M.West Nile virus (WNV) is an important emerging zoonotic arbovirus giving rise to clinical syndromes of varying severity in humans and horses. Culex mosquitoes are the main vector. Although WNV has been reported in many countries in the Middle East and Asia, little is known about its prevalence in equine populations in the Arabian Peninsula. We have carried out a serological study on 200 horses to assess WNV infection in the Eastern and Central regions of Saudi Arabia in 2013-2015. Sera were tested for the presence of WNV antibodies in parallel using a commercial enzyme-linked immunosorbent ass...
de Moraes MVDS, Salgado CRS, Godoi TLOS, de Almeida FQ, Chalhoub FLL, de Filippis AMB, de Souza AM, de Oliveira JM, Figueiredo AS.The equine parvovirus-hepatitis (EqPV-H), recently identified in association with serum hepatitis in horses (also known as Theiler's disease), has been so far described in horses from North America, Asia and Europe. There is no information regarding its circulation in South America. Our retrospective study (2013-2016) screened by EqPV-H nested-PCR a total of 96 Brazilian horses grouped according to previous status of infection: Known to be positive for one or more horse "hepatitis viruses" (equine hepacivirus, equine pegivirus-EPgV and Theiler's disease-associated virus) and known to be negati...
Takai S, Fujimori T, Katsuzaki K, Tsubaki S.Quantitative culture of R. equi in the feces of dams and foals, in the air of the stalls and in the soil of the paddocks was carried out on three horse-breeding farms during the foaling season. The isolation rates of R. equi from the feces of dams from the 3 farms suddenly increased to approximately 80% at the end of March, when the snow in the paddocks finished melting, and remained at that level during April and May. The mean number of R. equi and the isolation rate of R. equi from the feces of dams on the farms were investigated for 5 weeks before and 5 weeks after delivery. During the 10 w...
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...
Peters J, Block W, Oswald S, Freyer J, Grube M, Kroemer HK, Lämmer M, Lütjohann D, Venner M, Siegmund W.The delivery of clarithromycin (CRL) to its site of action in bronchial/alveolar epithelial cells (EC), bronchial epithelial lining fluid (ELF), and bronchoalveolar lavage cells (BALC) may be influenced by CYP3A4 and the drug transporters, ATP-binding cassette (ABC) B1 and ABCC2 and organic anion-transporting polypeptides (OATPs), which can be modulated and/or up-regulated via the nuclear pregnane X receptor (PXR) by rifampicin (RIF). Therefore, we evaluated the disposition and pulmonary distribution of CLR (7.5 mg/kg b.i.d., 21 days) and expression of ABCB1, ABCC2, OATP1A2, and OATP2B1 in EC ...
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...
Mahmoud MS, Kandil OM, Abu El-Ezz NT, Hendawy SHM, Elsawy BSM, Knowles DP, Bastos RG, Kappmeyer LS, Laughery JM, Alzan HF, Suarez CE.The tick-borne intra-erythrocytic apicomplexan Babesia caballi is one of the etiological agents of equine babesiosis, an economically important disease of equids in most tropical and subtropical areas of the world. Discovering candidate antigens for improved diagnostic tools and vaccines remains needed for controlling equine babesiosis. This study describes the B. caballi sbp4 (Bcsbp4) gene and protein (BcSBP4) and analyzes its antigenicity in infected equids. Methods: BLAST searches of an uncurated B. caballi assembly genome using the B. bovis SBP4 as a query were carried out, followed by PCR...
de Waal T, Liebenberg D, Venter GJ, Mienie CM, van Hamburg H.African horse sickness (AHS) is an infectious, non-contagious arthropod-borne disease of equids, caused by the African horse sickness virus (AHSV), an orbivirus of the Reoviridae family. It is endemic in sub-Saharan Africa and thought to be the most lethal viral disease of horses. This study focused on detection of AHSV in Culicoides imicola (Diptera: Ceratopogonidae) pools by the application of a RT-qPCR. Midges were fed on AHSV-infected blood. A single blood-engorged female was allocated to pools of unfed nulliparous female midges. Pool sizes varied from 1 to 200. RNA was extracted and prepa...
Castillo-Olivares J, Wieringa R, Bakonyi T, de Vries AA, Davis-Poynter NJ, Rottier PJ.Equine arteritis virus (EAV) is an enveloped plus-strand RNA virus of the family Arteriviridae (order Nidovirales) that causes respiratory and reproductive disease in equids. Protective, virus-neutralizing antibodies (VNAb) elicited by infection are directed predominantly against an immunodominant region in the membrane-proximal domain of the viral envelope glycoprotein G(L), allowing recently the establishment of a sensitive peptide enzyme-linked immunosorbent assay (ELISA) based on this particular domain (J. Nugent et al., J. Virol. Methods 90:167-183, 2000). By using an infectious cDNA we h...
Hodgkinson JE, Lichtenfels JR, Mair TS, Cripps P, Freeman KL, Ramsey YH, Love S, Matthews JB.We report the use of six oligoprobes designed from intergenic spacer region sequences to identify fourth-stage larvae (L4) of the tribe Cyathostominae. Oligoprobes were designed for identification of the following species: Cylicocyclus ashworthi, Cylicocyclus nassatus, Cylicocyclus insigne, Cyathostomum catinatum, Cylicostephanus goldi, and Cylicostephanus longibursatus. A seventh probe was designed as a positive control to identify all these members of the Cyathostominae. The intergenic spacer region was amplified by PCR using conserved primers. Initially, three oligoprobes were used in South...
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...
Bykovsky AF, Yershov FI, Zhdanov VM.Morphogenesis of Venezuelan equine encephalomyelitis virus was studied by means of electron microscopy. Virus-specific structures (factories, viroplasts) were found at early stages of infection; these structures were composed of fibrillar and cylindrical formations, aggregates of ribosomes, and viral nucleoids. The latter emerged from fibrillar and cylindrical structures. Aggregates of viral nucleoids were found in the cytoplasm and occasionally in the nuclei of virus-infected cells. Viral envelopes and mature virions were formed on the cell membranes and on the membranes of intracellular vacu...
Sugahara Y, Matsumura T, Kono Y, Honda E, Kida H, Okazaki K.Heparin extensively inhibited infection of MDBK cells by equine herpesvirus 1 (EHV-1) strains adapted to bovine cells or hamsters, while the reagent merely reduced infectivity of strains passaged only in equine cells. The gC of two strains adapted to non-equine cells seemed to have higher affinity for heparin, although the reagent bound to both the gC and gB of all strains tested. Amino acid substitutions of the gC of the EHV-1 strains adapted to non-equine cells converged on the hydrophilic regions, amino acid residues 92 to 175, resulting in the glycoprotein becoming more cationic. These res...
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...
Lassen B, Peltola SM.There is evidence of resistance in horses to anthelmintic treatment using ivermectin and pyrantel. However, little information is available about the parasites, treatment practices or anthelmintic resistance in the horse population in Estonia. In the present study, we examined 41 trotting and riding horses aged < 3 years from four stables in Estonia. Faecal samples were collected, and horses were selected for treatment if the nematode egg count per gram faeces exceeded 200. Horses (n= 32) that shed strongyle-type eggs were treated with pyrantel, whereas Parascaris equorum-positive animals...
MacDonald DG, Morley PS, Bailey JV, Barber SM, Fretz PB.Post operative surgical wound infection rates were determined 452 cases of equine orthopaedic surgery performed at the Western College of Veterinary Medicine, Saskatoon, Saskatchewan, between January 1, 1981 and December 31, 1990. Only surgical procedures classified as clean or clean-contaminated by the National Research Council were included in this study. The overall post operative infection rate was 10.0% (45 of 452). Clean surgeries (n = 433) had an 8.1% infection rate while clean-contaminated surgeries (n = 19) had a 52.6% infection rate. Information collected from the medical records was...
