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.
Epe C, Bienioschek S, Rehbein S, Schnieder T.Genomic DNA isolated from the four Dictyocaulus species D. viviparus, D. eckerti, D. filaria and D. arnfieldi was compared by random amplified polymorphic DNA polymerase chain reaction (RAPD)-PCR to get additional information whether lungworms from fallow deer belong to a separate species (D. eckerti) or have to be regarded as an isolate of D. viviparus in wild ruminants. The resulting banding patterns of the electrophoresed PCR products were compared to assess the degree of genetic differences between the different lungworms. For the two D. viviparus isolates a similarity coefficient of 93.4%...
Lichtenstein DL, Rushlow KE, Cook RF, Raabe ML, Swardson CJ, Kociba GJ, Issel CJ, Montelaro RC.As an important enzyme in DNA synthesis, dUTPase is present in a wide variety of organisms and viruses and has been identified as a component of the equine infectious anemia virus (EIAV) pol gene. The role of EIAV dUTPase, designated DU, in virus replication in vitro and in vivo was investigated with a recently described infectious molecular clone of EIAV. A deletion mutant that was deficient in dUTPase activity was constructed, and its replication kinetics was examined in fetal equine kidney (FEK) cells and primary equine bone marrow macrophage (EBMM) cells. In FEK cells, which are permissive...
Zientara S, Sailleau C, Moulay S, Wade-Evans A, Cruciere C.The development of a coupled reverse transcriptase-polymerase chain reaction assay (RT-PCR) is described for the detection of African horse sickness virus (AHSV) double-stranded RNA. Genome segments 7 and 10 were chosen as target templates for primers selected for use in the RT-PCR. Using these AHSV-specific primers all 9 serotypes were detectable. The sensitivity and specificity of the RT-PCR results were compared to those obtained by competition ELISA.
Zhao Y, Holden VR, Smith RH, O'Callaghan DJ.The UL3 protein of equine herpesvirus 1 (EHV-1) KyA strain is a homolog of the ICP27 alpha regulatory protein of herpes simplex virus type 1 (HSV-1) and the ORF 4 protein of varicella-zoster virus. To characterize the regulatory function of the UL3 gene product, a UL3 gene expression vector (pSVUL3) and a vector expressing a truncated version of the UL3 gene (pSVUL3P) were generated. These effector plasmids, in combination with an EHV-1 immediate-early (IE) gene expression vector (pSVIE) and chimeric EHV-1 promoter-chloramphenicol acetyltransferase (CAT) reporter constructs, were used in trans...
Wood JL, Chirnside ED, Mumford JA, Higgins AJ.Equine viral arteritis was diagnosed for the first time in the United Kingdom in 1993. The outbreak began on a non-thoroughbred stud in south Nottinghamshire and spread to five other premises through chilled semen used for artificial insemination and from acutely and subclinically infected mares returning home. The outbreak was contained on these six premises by means of voluntary movement restrictions. The most commonly observed clinical signs were typical: pyrexia with depression, and conjunctivitis with periorbital oedema; nasal discharge, and oedema of the distal limbs, prepuce and mammary...
Murray K, Selleck P, Hooper P, Hyatt A, Gould A, Gleeson L, Westbury H, Hiley L, Selvey L, Rodwell B.A morbillivirus has been isolated and added to an increasing list of emerging viral diseases. This virus caused an outbreak of fatal respiratory disease in horses and humans. Genetic analyses show it to be only distantly related to the classic morbilliviruses rinderpest, measles, and canine distemper. When seen by electron microscopy, viruses had 10- and 18-nanometer surface projections that gave them a "double-fringed" appearance. The virus induced syncytia that developed in the endothelium of blood vessels, particularly the lungs.
Fadok VA.Scaling and/or crusting are common clinical findings associated with equine skin diseases. Scaling and crusting may be associated with pruritic or nonpruritic dermatoses. This article focuses on those conditions that are usually nonpruritic in horses. They include the infectious dermatoses, the keratinization/seborrheic disorders, photosensitization, and the immunologic/inflammatory disorders, including pemphigus foliaceus, equine exfoliative eosinophilic dermatitis and stomatitis, and equine histiocytic dermatitis (sarcoidosis). Clinical signs that help differentiate the various disorders are...
Rosser EJ.Although there are numerous dermatoses in the horse in which the formation of crusts occurs, there are two relatively common and important infectious crusting dermatoses, namely, dermatophytosis and dermatophilosis. This article reviews the current concepts regarding the etiology and pathogenesis of each disease, as well as the more common clinical presentations, methods of diagnosis, and treatment.
Wen B, Rikihisa Y, Fuerst PA, Chaichanasiriwithaya W.Ehrlichia risticii is the causative agent of Potomac horse fever. Variations among the major antigens of different local E. risticii strains have been detected previously. To further assess genetic variability in this species or species complex, the sequences of the 16S rRNA genes of several isolates obtained from sick horses diagnosed as having Potomac horse fever were determined. The sequences of six isolates obtained from Ohio and three isolates obtained from Kentucky were amplified by PCR. Three groups of sequences were identified. The sequences of five of the Ohio isolates were identical ...
Cohen ND, Wallis DE, Neibergs HL, Hargis BM.Salmonella was identified in feces from horses, using the polymerase chain reaction (PCR) and genus-specific oligonucleotide primers. Feces from healthy horses were determined to be culture negative and PCR negative for Salmonella. Fecal samples were inoculated with known numbers of colony-forming units (CFU) of S. enteritidis. The fecal samples were enriched overnight in tetrathionate broth, and then DNA was extracted and amplified by PCR using genus-specific primers. Sensitivity of the assay extended to 10 degrees CFU Salmonella enteritidis/g feces; sensitivity of microbiologic culture with ...
Baba SS, Fagbami AH, Ojeh CK, Olaleye OD, Omilabu SA.Retrospective and prospective serological surveys to determine the prevalence of Wesslsbron (WSL) virus infections in animal populations were carried out in different vegetational zones in Nigeria. Sera from 1,492 animals comprising 292 camels, 81 horses, 4 donkeys, 320 cattle, 235 sheep, 260 goats, 114 pigs, 101 dogs and 85 domestic fowls were assayed by haemagglutination-inhibition (HI) test for presence of antibodies to WSL virus and other flavivirus antigens: Yellow Fever (YF), Potiskum (POT), Banzi (BAN), Uganda S (UGS) and West Nile (WN) viruses. Four hundred and eighty one (32%) of the ...
Long MT, Goetz TE, Whiteley HE, Kakoma I, Lock TE.Two pregnant mares diagnosed as having equine monocytic ehrlichiosis based on history, clinical signs, and high serum antibody titers to Ehrlichia risticii aborted subsequent to recovery from illness. Mare 1 and mare 2 experienced clinical illness at 120 and 143 days of gestation and aborted at 203 and 226 days of gestation, respectively. The fetuses were expelled in fresh condition, and both mares retained their placentas upon abortion. Gross findings for the fetuses included meconium staining and petechiation of external surfaces. Internally, there was increased volume of feces within the sm...
Timoney JF, Walker J, Zhou M, Ding J.Streptococcus equi subsp. zooepidemicus, a Lancefield group C streptococcus, is a frequently isolated opportunist pathogen from a variety of animal hosts, including the horse. Previous studies have indicated that equine strains carry antigens with characteristics of the antiphagocytic M proteins on the Lancefield groups A and G streptococci. We have cloned a protective M-like protein gene (SzPW60) of an equine strain of S. equi subsp. zooepidemicus W60 and determined its sequence. This gene encodes a protein with a molecular weight of 40,123 which protects mice against subsp. zooepidemicus but...
Southgate CD, Green MR.Lentivirus Tat proteins comprise a novel class of RNA-binding transcriptional activators that are essential for viral replication. In this study, we performed a series of protein fusion experiments to delineate the minimal protein domains and promoter elements required for Tat action. We show that a 15-amino-acid region of equine infectious anemia virus (EIAV) Tat protein, when fused to the GAL4 or LexA DNA binding domain, can activate transcription in appropriate promoter contexts. In the natural human immunodeficiency virus type 1 long terminal repeat, activation by Tat is dependent on multi...
Ellis JA, Bogdan JR, Kanara EW, Morley PS, Haines DM.The ability of monovalent and bivalent equine herpesvirus (EHV) vaccines to stimulate cellular and antibody responses to EHV-1 and EHV-4 was compared in healthy horses. Comparison of data from lymphocyte blastogenesis tests in which live viruses were used as antigens and that were conducted prior to vaccination and after 2 vaccinations revealed that horses given modified-live EHV-1 had significant increases in proliferative responses to EHV-1 (P = 0.03) and EHV-4 (P = 0.04). Responses to EHV-1 and EHV-4 in horses given the inactivated-virus bivalent vaccine were less; however, significant diff...
Stiller D, Coan ME.This brief review focuses first on several epidemiologically relevant aspects of anaplasmosis, including: (1) the role of male ticks as intrastadial, biological vectors of Anaplasma through interhost transfer; (2) the application of molecular diagnostic assays in assessing tick vector competence and evaluating the role of chronically infected carrier cattle as sources of Anaplasma marginale infection in vector ticks; (3) opportunities provided by a recently developed in vitro tick feeding system in quantitating studies of tick-hemoparasite-host interactions. Lastly, current knowledge of the st...
Campbell AJ, Gasser RB, Chilton NB.In the current study, molecular techniques were evaluated for the species identification of individual strongyle eggs. Adult worms of Strongylus edentatus, S. equinus and S. vulgaris were collected at necropsy from horses from Australia and the U.S.A. Genomic DNA was isolated and a ribosomal transcribed spacer (ITS-2) amplified and sequenced using polymerase chain reaction (PCR) techniques. The length of the ITS-2 sequence of S. edentatus, S. equinus and S. vulgaris ranged between 217 and 235 nucleotides. Extensive sequence analysis demonstrated a low degree (0-0.9%) of intraspecific variation...
van Rensburg IB, Jardine JE, Carstens JH, van der Walt ML.Specimens from the ileum, colon and rectum were aseptically collected from 50 consecutive horse carcases submitted for necropsy to the Department of Pathology, Faculty of Veterinary Science, University of Pretoria. These were bacteriologically examined for the presence of Salmonella. Seventeen of these were positive for Salmonella at one or more sites. Serotyping of the isolates revealed a dominance of Salmonella Hayindogo in these horses.
McCann SH, Mumford JA, Binns MM.A search for variable restriction sites has been carried out for equine herpesvirus-1 (EHV-1) in an attempt to develop markers which can be used to group epidemiologically related viruses into groups, and to learn more about the dynamics of EHV-1 disease. Crude viral DNA extracts of EHV-1, prepared by Hirt extraction, were digested with AluI, HaeIII, or RsaI, and Southern blotted following electrophoresis. DNA fingerprints, produced by probing the Southern blots with the EHV-1 EcoR1-I fragment, separated 56 isolates into 16 groups. The variable sites within the EcoR1-I fragment were mapped app...
Morley PS, Bogdan JR, Townsend HG, Haines DM.The Directigen Flu A assay (Becton Dickinson, Microbiology Systems, Mississauga, Ontario, Canada) is a commercially available immunoassay designed for rapid in vitro recognition of influenza A nucleoprotein. The purpose of this study was to evaluate this assay for detection of influenza virus in nasal secretions of naturally infected horses. The assay was shown to react with representative strains of influenza virus which cause disease in horses and did not react with nasal secretions from uninfected horses kept in isolation. Between 33% and 45% of nasal secretions specimens obtained from clin...
Johansson KE, Pettersson B, Uhlén M, Gunnarsson A, Malmqvist M, Olsson E.Seven Swedish isolates of Ehrlichia species from the blood of four dogs and three horses with clinical granulocytic ehrlichiosis, were identified by direct solid phase DNA sequencing of polymerase chain reaction (PCR) products from the 16S rRNA gene. The amplified DNA fragments were produced with primers complementary to the universal regions, U1, U2, U5 and U8 of the 16S rRNA molecule. Identical sequences were obtained from all seven isolates. This nucleotide sequence was similar to the sequences deposited in GenBank for Ehrlichia phagocytophila and E equi. The sequence of the Swedish ehrlich...
Cook RF, Berger SL, Rushlow KE, McManus JM, Cook SJ, Harrold S, Raabe ML, Montelaro RC, Issel CJ.Serial passage of the prototype (PR) cell-adapted Wyoming strain of equine infectious anemia virus (EIAV) in fetal donkey dermal (FDD) rather than fetal horse (designated fetal equine kidney [FEK]) cell cultures resulted in the generation of a variant virus strain which produced accelerated cytopathic effects in FDD cells and was 100- to 1,000-fold more sensitive to neutralizing antibodies than its parent. This neutralization-sensitive variant was designated the FDD strain. Although there were differences in glycosylation between the PR and FDD strains, passage of the FDD virus in FEK cells di...
Pavlásek I, Hess L, Stehlík I, Stika V.The first occurrence of Giardia spp. in horses in the Czech Republic is reported. During preventive examination of 360 five-month up to 14-year horses from various parts of the region of Central Bohemia carried out from January 1993 to June 1994 in the parasitological laboratory of the State Veterinary Institute in Prague, the Giardia cysts were detected in the excrements of 18 (5%) horses, mostly 2-4 years of age, and in two foals 3 and 6 weeks old. During the period between March 1993 and June 1994, systematic and repeated observation was aimed at a group of 38 racing horses two up to four y...
Joost RE.Acremonium coenophialum Morgan-Jones and Gams, an endophytic fungus commonly found in tall fescue (Festuca arundinacea Schreb.), has been identified as the cause of poor performance of beef cattle and horses on tall fescue. Ryegrass staggers, a neurological disorder of sheep, has been linked to the presence of a similar fungus, A. lolii Latch, Christensen and Samuels, in perennial ryegrass (Lolium perenne L.). Renovation of endophyte-infected (E+) pastures with endophyte-free (E-) cultivars of tall fescue or perennial ryegrass has resulted in improved animal performance, but productivity and s...
Plumlee Q, Meason-Smith C, Dieterly A, Gomez G, Porter BF, Rodrigues Hoffmann A.Many previously unrecognized fungi are emerging as potential pathogens. One such group is dematiaceous fungi of the Chaetomiaceae family (phylum Ascomycota, class Sordariomycetes). These fungi are rare causes of opportunistic, neurotropic phaeohyphomycosis in humans but are not known to cause similar infections in animals. The aims of this study were to investigate equine hyphal mycotic encephalitis, characterize key histopathologic features, and classify causative organisms with molecular diagnostic techniques. Seven cases were evaluated by histopathology. Panfungal PCR targeting the ribosoma...
Loublier C, Cerri S, Gryspeerdt A, Amory H, Bauwens C, Cesarini C.Lawsonia intracellularis (LI) is an obligate intracellular gram-negative rod causing equine proliferative enteropathy (EPE). Occasional cases of EPE have been reported in foals living in Belgium, but the seroprevalence of equine LI in this country is unknown. The target population included clinically healthy adult horses, whose blood samples were collected and analyzed for specific IgG antibodies against LI using a blocking enzyme-linked immunosorbent assay test. The results were expressed as percentage of inhibition (PI). Samples that had a PI <20% were judged as negative, those between 20 an...
Sajid M, Ahmad MU, Khan MA, Anjum MA, Mushtaq MH.The present study was an attempt to elucidate the seroprevalence of equine influenza virus (H3N8) in two geographically distinct regions of Pakistan where vaccination is not routinely practiced. Methods: A total number of 315 animals of family Equidae were included in the survey. Blood samples and nasal swabs were collected from the same animal and analyzed through ELISA and Hemagglutination Inhibition. Results: The seroprevalence for EIV was 10 and 8.39 in districts under study. Out of 29 ELISA positive sera, 7 (24.1 %) showed antibodies against H1 and 22 (75.9 %) showed against H3 of influen...
Joncas JH, Gilker JC, Chagnon A.The relative value of heterophil agglutinins (HA) and of specific EBV antibodies in the diagnosis of infectious mononucleosis (IM) was assessed in 108 cases of the disease and in 280 controls. Among the 108 cases 93 were HA-positive by sheep cells in at least one of their sera, while 15 were HA-negative by the same test. Among the 280 controls false-positive HA tests were not encountered except in eight cases with the horse cell microtitre tests. With one of the two slide tests at least two false-positive tests and 12 false-negative tests were also found but these sera had low titres in microt...
Nakamura Y, Nishi H, Katayama Y, Niwa H, Matsumura T, Anzai T, Ohtsu Y, Tsukano K, Shimizu N, Takai S.An eight-year-old thoroughbred mare with no previous history of illness aborted a fetus at 196 days of gestation, and its internal tissues were examined immunohistologically and bacteriologically. The placenta was not examined, but specimens of the intrauterine fluids and the dam's faeces were collected four days after the abortion and examined bacteriologically. No significant histological lesions were found in the fetus but the amnion and the umbilical cord were oedematous and had petechial haemorrhages. Rhodococcus equi was isolated in pure culture from the lung, heart and stomach contents ...
Bird J, Herd RP.The ability of two species of nematophagous fungi, Arthrobotrys oligospora and Arthrobotrys flagrans (syn. Trichothecium flagrans, Duddingtonia flagrans), to control the development of infective larvae in feces from naturally infected horses was assessed in vitro. The horses were from a farm where it had been previously established that cyathostomes accounted for 100% of the strongyle egg output. The feces from these naturally infected horses were mixed with spores of each fungal species at four concentrations: 0 (control), 1, 10, and 100 spores per egg. Five replicates for each group were inc...
Schemann K, Gillespie JA, Toribio JA, Ward MP, Dhand NK.Rapid, evidence-based decision-making is critical during a disease outbreak response; however, compliance by stakeholders is necessary to ensure that such decisions are effective - especially if the response depends on voluntary action. This mixed method study evaluated technical policy decision-making processes during the 2007 outbreak of equine influenza in Australia by identifying and analysing the stakeholder network involved and the factors driving policy decision-making. The study started with a review of the outbreak literature and published policy documents. This identified six policy ...
Sellers RF, Maarouf AR.Cases of western equine encephalitis in horses in 1987 in western USA and Manitoba, Canada were examined by backward trajectory analysis of winds. Culex tarsalis mosquitoes infected with western equine encephalitis virus could have been carried on southerly winds from Texas and Oklahoma to northern USA and from there to Manitoba. The presence of the Polar front over North Dakota and Minnesota at the end of July would have led to the landing of Cx. tarsalis in Montana and Wisconsin and prevented further carriage into Manitoba. Temperatures in southern Texas during the winter months (average dai...
Velineni S, Breathnach CC, Timoney JF.Streptococcus zooepidemicus (Sz) is a tonsillar commensal of healthy horses but with potential to opportunistically invade the lower respiratory tract. Sz is genetically variable and recombinogenic based on analysis of gene sequences including szp, szm and MLST data. Although a variety of serovars of the protective SzP are commonly harbored in the tonsils of the same horse, lower respiratory infections usually involve a single clone. Nevertheless, isolation of specific clones from epizootics of respiratory disease has been recently reported in horses and dogs in N. America, Europe and Asia. In...
Archambault D, St-Laurent G.Equine arteritis virus (EAV) is the etiological agent of equine viral arteritis, a contagious viral disease of equids. EAV is the prototype virus of the arteriviruses, a group of small enveloped viruses with positive single-stranded RNA genomes. Because apoptosis or programmed cell death is believed to play an important role in the biogenesis of several cytopathogenic viruses, we examined whether EAV was able to induce cell apoptosis in vitro. To do this, Vero cells were infected with EAV at a multiplicity of infection of 0.1 tissue culture infectious dose (TCID50) per cell, and analyzed at va...
Rossi TM, Milwid RM, Moore A, O'Sullivan TL, Greer AL.Infectious respiratory disease is a common cause of morbidity among racehorses. Quantification of contact patterns in training facilities could help inform disease prevention strategies. The study objectives were to: i) describe the contact network among horses, locations, and humans at a Standardbred horse training facility in Ontario; ii) describe the characteristics of highly influential individuals; and iii) investigate how management changes alter the network metrics and discuss the potential implications for disease transmission. Proximity loggers detected contacts among horses, staff, a...
Sato W, Sukmawinata E, Uemura R, Kanda T, Kusano K, Kambayashi Y, Sato T, Ishikawa Y, Toya R, Sueyoshi M.In this study, we investigated the occurrence of antimicrobial resistance in commensal Escherichia coli isolated from healthy Thoroughbred (TB) racehorses in Japan. A total of 212 fecal samples were individually collected from TB racehorses from March 2017 to August 2018 at Japan Racing Association training centers. E. coli was isolated by using selective agar media, deoxycholate-hydrogen sulfide-lactose (DHL) and eosin methylene blue (EMB). A total of 417 E. coli isolates were examined against 10 antimicrobial agents by using the broth microdilution method. The 417 E. coli isolates were phylo...
Phumoonna T, Muscatello G, Chicken C, Gilkerson JR, Browning GF, Barton MD, Heuzenroeder MW.A total of 227 field samples from naturally exposed foals aged between 3 weeks and 6 months were used in an evaluation of a peptide-based enzyme-linked immunosorbent assay (ELISA) for diagnosis of Rhodococcus equi infection. A biotinylated peptide derived from the virulence-associated protein A (VapA) of R. equi, a horse pathogen, was synthesized and designated as PN11-14. The peptide corresponds to the N-terminal B-cell epitope TSLNLQKDEPNGRASDTAGQ of the VapA protein. Based upon a serum immunoglobulin (Ig)G titre of 512 as a positive cut-off value for the R. equi infection, the ELISA provide...
Black P, Douglas I, Field H.Hendra virus was first described in 1994 in Australia, causally associated with a cluster of fatal equine and human cases at a thoroughbred racing stable in the Brisbane suburb of Hendra. This year marks the twentieth anniversary of the identification of pteropid bats (flying-foxes) as the natural host of the virus, and it is timely to reflect on a pivotal meeting of an eclectic group of scientists in that process. They included animal and public health experts, environmental scientists, veterinary and horse industry representatives, and wildlife experts. The task was to review and prioritise ...
Hifumi T, Akioka K, Tanaka T, Miyoshi N.Alveolar echinococcosis, which is caused by a larval-stage infection of Echinococcus multilocularis, is a zoonosis with public health importance. Recently, alveolar echinococcosis in slaughtered horses has been reported in Japan and Poland. In terms of public health, a highly sensitive and specific diagnostic method is essential for early detection during meat inspection. In this study, the loop-mediated isothermal amplification (LAMP) assay was developed and validated to target the mitochondrial cytochrome b (cob) gene of E. multilocularis. Forty-one hepatic solid nodules obtained from each h...
Archer RM, Knight CG, Bishop WJ.Six horses from several geographical locations in New Zealand presented with signs of guttural pouch mycosis. All horses had experienced epistaxis within 14 days of presentation. Results: In five horses with epistaxis, a diagnosis of guttural pouch mycosis was made on endoscopic observation of fungal plaques in the affected guttural pouches. One of these cases died before surgery was attempted. The remaining four cases underwent ligation and balloon catheter occlusion of the internal carotid artery of the affected pouch. Three of these horses survived and were reported to be healthy 1 year aft...
Paweska JT, Binns MM, Woods PS, Chirnside ED.A seroepidemiological survey of donkeys in South Africa (n = 4300) indicated a wide distribution and increasing prevalence of antibodies to equine arteritis virus (EAV). Donkey sera inhibited equine arteritis virus infection in virus neutralisation (VN) tests and in ELISA specifically bound to a recombinant antigen derived from the Bucyrus isolate of EAV. These results suggest that donkeys have been exposed to the same serotype of this virus as circulates among horses. A good correlation existed between EAV neutralising antibody titres and ELISA absorbance values (0.8631); the ELISA was sensit...
Rakhshandehroo E, Sharifiyazdi H, Shayegh H, Ahmadi A.Habronema muscae is a spirurid nematode that undergoes developmental stages in the stomach of equids, causing chronic catarrhal gastritis. Despite preceding investigations have developed polymerase chain reaction (PCR)-based assays for molecular diagnosis, we aimed to assess the applicability of cytochrome c oxidase subunit 1 (cox1) sequences to identify the H. muscae infection and to assess the level of intraspecific variations in this parasite obtained from affected horses in Southern Iran. According to the morphological characterizations, two different isolates of H. muscae were identified....
Gaíva e Silva L, Borges AM, Villalobos EM, Lara Mdo C, Cunha EM, de Oliveira AC, Braga IA, Aguiar DM.The prevalence of antibodies against Equine Influenza Virus (EIV) was determined in 529 equines living on ranches in the municipality of Poconé, Pantanal area of Brazil, by means of the hemagglutination inhibition test, using subtype H3N8 as antigen. The distribution and possible association among positive animal and ranches were evaluated by the chi-square test, spatial autoregressive and multiple linear regression models. The prevalence of antibodies against EIV was estimated at 45.2% (95% CI 30.2 - 61.1%) with titers ranging from 20 to 1,280 HAU. Seropositive equines were found on 92.0% of...
Kumar J, Chaudhury A, Bera BC, Kumar R, Kumar R, Tatu U, Yadav SC.The present immuno-diagnostic method using soluble antigens from whole cell lysate antigen for trypanosomosis have certain inherent problems like lack of standardized and reproducible antigens, as well as ethical issues due to in vivo production, that could be alleviated by in vitro production. In the present study we have identified heat shock protein 70 (HSP70) from T. evansi proteome. The nucleotide sequence of T. evansi HSP70 was 2116 bp, which encodes 690 amino acid residues. The phylogenetic analysis of T. evansi HSP70 showed that T. evansi occurred within Trypanosoma clade and is most c...
Takeishi M, Kuwata R, Ono T, Sasaki A, Ogata M, Iwata E, Taji S, Koike M, Nemoto M, Bannai H, Isawa H, Maeda K, Morikawa S, Kitagawa H, Yoshikawa Y.Getah virus (GETV), an arthropod-borne virus transmitted by mosquitoes, has been isolated from several animals. GETV infection in horses shows clinical signs such as fever, rash, and edema in the leg. Noma horses are one of the eight Japanese native horses. The present study aimed to clarify the occurrence of GETV infection in Noma horses. Serum samples collected from Noma horses were analyzed using a virus neutralization test and enzyme-linked immunosorbent assay and showed that the anti-GETV antibody titers in the samples collected in 2017 were significantly higher than those collected in 20...
McFarlane BL, Embree JE, Embil JA, Rozee KR, Weste JB, Artsob H, Spence L.A large number of North American equine samples were tested for the California group of arboviruses (CAL). Of 861 equine sera tested by hemagglutination inhibition using the snowshoe hare virus as an antigen, 106 (12.3%) were positive. Neutralization tests confirmed antibodies to this virus in 72 of the positive sera. This study provides evidence of CAL activity in the domestic animal population of Nova Scotia.
Glaser AL, Renshaw RW, Trock SC, Brady RC, Dubovi EJ.Salem virus (SalV) is a recently identified equine virus belonging to the family Paramyxoviridae. The only known isolate was obtained from a horse that was involved in a disease outbreak of undetermined nature and the circumstances of its isolation suggested an etiologic role. However, the experimental infection of a colostrum-deprived foal failed to reproduce the disease; only mild neutropenia and temperature elevation were recorded. An additional attempt to establish an etiological relationship with the disease was made by conducting a retrospective evaluation of the serological profiles of ...
Gao X, Jiang CG, Han XE, Zhao LP, Shen RX, Xiang WH, Zhou JH.To elucidate the function of the S2 gene in equine infectious anemia virus (EIAV) and its role in the attenuation of the Chinese attenuated EIAV vaccine strains, the S2 in the EIAV vaccine strain EIAV (FDDV) was reverse-mutated and the in vitro replication character of the resultant virus was evaluated. Based on the sequence variation of the S2 gene between the EIAV virulent strains and vaccine strains, all the four vaccine-specific sites in the S2 of an EIAV(FDDV) infectious clone, pFDDV3-8, were reverse-mutated to the sequences of the virulent strain EIAV(DV115). The reverse-mutated molecula...
de Vries C, Vanhaesebrouck E, Govaere J, Hoogewijs M, Bosseler L, Chiers K, Ducatelle R.A premature dead equine fetus with excessive fluctuating distension of the abdomen was delivered by extraction. Post-mortem examination revealed ascites and a solitary, irregular, bulging, multinodular, firm, yellow mass of 25 cm in diameter in the right liver lobe. Extensive peritoneal implantation metastases were present. The masses were composed of polygonal embryonal cells arranged in sheets and nests. Based on the immunohistochemical expression of Ki67, low molecular weight cytokeratin and alpha-1 fetoprotein, a diagnosis of hepatoblastoma with peritoneal implantation metastases was made....
Peckle M, Pires MS, Dos Santos TM, Roier ECR, da Silva CB, Vilela JAR, Paulino PG, Santos HA, Massard CL.The epidemiological aspects of Babesia caballi infection were evaluated in 516 horse samples from Rio de Janeiro, Brazil. The presence and infestation level of ticks on horses, breed conditions, and animal management were evaluated on each farm through an epidemiological questionnaire. The gene that codes for rhoptry-associated protein-1 (RAP-1) of B. caballi was amplified by nested PCR (nPCR). Among the horses sampled, 17.2% (n = 89/516) presented B. caballi DNA. The characterized samples showed 99-100% similarity with other isolates of B. caballi based on the RAP-1 gene, available in GenBa...
Ellis JA, Bogdan JR, Kanara EW, Morley PS, Haines DM.The ability of monovalent and bivalent equine herpesvirus (EHV) vaccines to stimulate cellular and antibody responses to EHV-1 and EHV-4 was compared in healthy horses. Comparison of data from lymphocyte blastogenesis tests in which live viruses were used as antigens and that were conducted prior to vaccination and after 2 vaccinations revealed that horses given modified-live EHV-1 had significant increases in proliferative responses to EHV-1 (P = 0.03) and EHV-4 (P = 0.04). Responses to EHV-1 and EHV-4 in horses given the inactivated-virus bivalent vaccine were less; however, significant diff...
Vengust M, Baird JD, van Dreumel T, Ackerley C, Bienzle D.A case of a 1-month-old Thoroughbred foal with dysphagia, salivation, pyrexia, oral mucosal pustules, and esophageal ulceration is reported. Swabs from the ulcerated lesions yielded Equid herpesvirus 2 (EHV-2) in virus isolation assays, and histopathology of a biopsy from the esophageal lesion identified nuclear inclusions suggestive of herpesviruses. Immunohistochemical staining with antibodies specific for EHV-2 was positive for epithelial cells in the vicinity of the ulcer but not in more distant mucosa. Electron microscopic evaluation of the biopsy showed herpesviral particles in epithelia...
Cho SN, Collins MT, Reif JS.The indirect fluorescent antibody test was used to examine 109 samples of equine sera randomly selected from serum pools. Results were compared with titers obtained by the microagglutination (MA) test. A high correlation (r = 0.89) was found between titers measured by the 2 tests. Blood samples were obtained serially from a total of 156 horses at a research farm and the sera were tested against Legionella pneumophila serogroups 1 through 4 using the MA test; 29 horses (19%) seroconverted to at least 1 serogroup of L pneumophila. The indirect fluorescent antibody test substantiated the results ...
Stephenson N, Hodzic E, Mapes S, Rejmanek D, Foley J.Anaplasma phagocytophilum is a tick-transmitted bacterial pathogen of humans and animals comprising strains that cause clinical disease in people, dogs and horses (the pathogenic A. phagocytophilum "genospecies") and more distantly related strains. A rodent-adapted genospecies named DU1, found primarily in woodrats, is unable to infect horses. We developed a real-time PCR (RT-PCR) assay, which targets an 85 base pair region of the ank gene and is specific for the pathogenic genospecies of A. phagocytophilum from North America. Thirty DNA samples from A. phagocytophilum RT-PCR-positive rodents ...
