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.
Information on equine infectious anaemia (EIA) in mules, including those with an equivocal reaction in agar gel immunodiffusion test (AGIDT), is scarce. For this, a study was conducted to evaluate the clinical, viral loads and pathological findings of two groups of naturally infected asymptomatic mules, respectively with a negative/equivocal and positive AGIDT reactivity, which were subjected to pharmacological immune suppression (IS). A non-infected control was included in the study that remained negative during the observation period. Throughout the whole study, even repeated episodes of rec...
Jennings JE.A 21-year-old Appaloosa mare was presented with a pigmented cutaneous mass at the base of the right side of the neck. The diagnosis of phaeohyphomycosis due to pigmented fungi, known as Pyrenophora phaeocomes and Drechslera nobleae, was made based on a histopathology report followed by polymerase chain reaction (PCR) and 18S rRNA gene sequencing. The mass was surgically excised with clean margins, which is usually curative. Une jument Appaloosa âgée de 21 ans a été présentée avec une masse cutanée pigmentée à la base du côté droit du cou. Le diagnostic de phæohyphomycose causée p...
Carfora V, Caprioli A, Grossi I, Pepe M, Alba P, Lorenzetti S, Amoruso R, Sorbara L, Franco A, Battisti A.A Methicillin-resistantStaphylococcus aureus(MRSA) was isolated in Italy from a pathological sample of a mare presenting chronic purulent sinusitis and that had undergone frontal-sinus surgery three months before. Humans, horses, dogs and environmental samples were subsequently collected at the mare's stable and at the Veterinary Hospital, where the mare was operated/hospitalized, and screened for the presence of MRSA that was detected from other horses and from the environment at both sites. All the MRSA isolates belonged to clonal complex (CC)8, ST8-t11469-SCCmec-IVa, and showed similar phen...
Terron-Canedo N, Weir W, Nicolson L, Britton C, Nasir L.Bovine papillomavirus (BPV) types 1 and 2 play an important role in the pathogenesis of equine sarcoids (ES), the most common cutaneous tumour affecting horses. MicroRNAs (miRNAs), small non-coding RNAs that regulate essential biological and cellular processes, have been found dysregulated in a wide range of tumours. The aim of this study was to identify miRNAs associated with ES. Differential expression of miRNAs was assessed in control equine fibroblasts (EqPalFs) and EqPalFs transformed with the BPV-1 genome (S6-2 cells). Using a commercially available miRNA microarray, 492 mature miRNAs we...
Monaco F, Çizmeci Ş, Polci A, Portanti O, Barut F, Deniz A, Cosseddu GM, Pişkin Ç, Savini G.In August 2014, a West Nile virus (WNV) strain belonging to lineage 2 was detected in the brain tissues of a 9 year old mare euthanised after showing severe clinical signs in Bursa region, Turkey. Phylogenetic analyses of 290 bp of NS3 coding region clustered the Turkish strain together with the 2010-2012 Greek isolates. Either IgG and IgM or IgG only WNV antibodies were detected in 2 and 11 horses, respectively, which were in the outbreak surrounding. No WNV RNA was detected in pools of 50 individuals of Culex pipiens (n = 2), Ochlerotatus caspius (n = 2), and Culex theileri (n = 1) collected...
Gressler LT, Bordin AI, McQueen CM, Cohen ND, de Vargas AC.Rhodococcus equi preferentially infects macrophages causing pyogranulomatous pneumonia in young foals. Both the vapA and rhbC genes are up-regulated in an iron (Fe)-deprived environment, such as that found within macrophages. Chloroquine (CQ) is a drug widely used against malaria that suppresses the intracellular availability of Fe in eukaryotic cells. The main objective of this study was to evaluate the ability of CQ to inhibit replication of virulent R. equi within murine (J774A.1) and foal alveolar macrophages (AMs) and to verify whether the mechanism of inhibition could be Fe-deprivation-d...
Nemoto M, Bannai H, Tsujimura K, Yamanaka T, Kondo T.A Getah virus strain isolated during an outbreak in racehorses in Japan in 2014 (14-I-605) was compared with the vaccine strain isolated in 1978 (MI-110). A comparison of the genome sequences of these strains revealed seven amino acid substitutions in non-structural protein 3, and one or two substitutions in each of other non-structural proteins. In contrast, the structural proteins were highly conserved (99.8-99.9 % amino acid sequence identity). Horse antisera raised against the MI-110 strain showed similar virus-neutralization titers against both MI-110 and 14-I-605 strains (512 and 256, r...
Erol E, Jackson C, Horohov D, Locke S, Smith J, Carter C.Determination of fetal serum amyloid A (SAA) concentrations in aborted fetuses can provide valuable information regarding the infectious and/or inflammatory process of abortion in horses. To investigate the relationship between fetal SAA levels and the infectious/inflammatory disease process in feto-placental tissues, a SAA ELISA was used to test heart serum samples of 89 equine fetuses that were necropsied and diagnosed in the following groups: a multiorgan disease process diagnosed with an identified microorganism (14 cases, group 1); only placentitis diagnosed with an identified microorgan...
Giles C, Ndi O, Barton MD, Vanniasinkam T.Rhodococcus equi is a respiratory pathogen which primarily infects foals and is endemic on farms around the world with 50% mortality and 80% morbidity in affected foals. Unless detected early and treated appropriately the disease can be fatal. Currently, there is no vaccine available to prevent this disease. For decades researchers have endeavoured to develop an effective vaccine to no avail. In this study a novel human adenoviral vector vaccine for R. equi was developed and tested in the mouse model. This vaccine generated a strong antibody and cytokine response and clearance of R. equi was d...
Abrahão JS, de Souza Trindade G, Pereira-Oliveira G, de Oliveira Figueiredo P, Costa G, Moreira Franco-Luiz AP, Lopes Assis F, Bretas de Oliveira D....In August 2014, an outbreak of oral exanthematous disease in equids was reported in Brazil, affecting 11 donkeys and 3 mules. Objective: To investigate if Vaccinia virus (VACV) was the aetiological agent in this outbreak. Methods: Investigation of clinical cases using serological, molecular and phylogenetic approaches. Methods: To analyse the presence of neutralising antibodies against VACV, samples were submitted in triplicate to a plaque-reduction neutralisation test (PRNT ). On the basis of previous studies which detected VACV DNA in sera, we submitted extracted DNA samples to different pol...
Davoust B, Maquart M, Roqueplo C, Gravier P, Sambou M, Mediannikov O, Leparc-Goffart I.In Africa, infection with West Nile virus (WNV) is frequent but almost always asymptomatic in humans and equids. The aim of this study was to identify whether any other domestic animal living in the same enzootic locality may be the sentinel of WNV circulation. In northwest Senegal, blood samples were collected from 283 adult domestic animals (136 sheep, 64 horses, 29 donkeys, 29 goats, 14 cattle, and 11 dogs), in three localities near Keur Momar Sarr. Each serum was tested for WNV immunoglobulin G using enzyme-linked immunosorbent assay. The prevalence among donkeys, horses, dogs, goats, catt...
Wang Y, Mao Q, Chang H, Wu Y, Pan S, Li Y, Zhang Y.Integrins can function as receptors for foot-and-mouth disease virus (FMDV) in epithelium. Horses are believed to be insusceptible to this disease, but the mechanism of resistance remains unclear. To detect whether FMDV can use integrin to attach to equine epithelial, we compared the utilities of αvβ3 and αvβ6 between bovine and equine kidney epithelial cells (KECs). Equine KECs showed almost equal efficiency to those of bovine. Further, the integrin αv, β3, and β6 subunits from bovine and equine were cloned and vectors were transfected into SW480 cells and COS-1 cells alone or together...
Diyes GC, Rajakaruna RS.Otobius megnini is a one host, nidicolous soft tick (Family Argasidae) whose larvae and nymphs parasitize the external ear canal of many wild and domestic animals and occasionally humans. The present study was conducted to determine the seasonal dynamics of O. megnini infesting stabled horses in Nuwara Eliya racecourses. Ticks were sampled biweekly for two years from May 2013 to May 2015 from the ear canal of seven thoroughbred male horses. Weather data: temperature, rainfall and humidity for the study period were obtained from the Meteorological Department, Colombo. A total of 23, 287 ticks o...
Alves Beuttemmüller E, Woodward A, Rash A, Dos Santos Ferraz LE, Fernandes Alfieri A, Alfieri AA, Elton D.An extensive outbreak of equine influenza occurred across multiple countries in South America during 2012. The epidemic was first reported in Chile then spread to Brazil, Uruguay and Argentina, where both vaccinated and unvaccinated animals were affected. In Brazil, infections were widespread within 3months of the first reported cases. Affected horses included animals vaccinated with outdated vaccine antigens, but also with the OIE-recommended Florida clade 1 strain South Africa/4/03. Methods: Equine influenza virus strains from infected horses were isolated in eggs, then a representative stra...
Herholz C, Kopp C, Wenger M, Mathis A, Wägeli S, Roth N.Female tabanid flies (Diptera: Tabanidae) can be a serious nuisance for horses because of their painful bites during blood feeding. They also play a primary role in mechanical transmission of a lentivirus causing Equine Infectious Anemia (EIA), a virus that has spread within Europe in recent years. According to the European law for products intended for use as a repellent on horses (recreational and sport horses), a field test is mandatory to demonstrate sufficient repellency of such a substance against the specific target fly species, but currently no agreed protocols are available for testin...
Hue ES, Fortier CI, Laurent AM, Quesnelle YF, Fortier GD, Legrand LJ, Pronost SL.The protocol describes a quantitative RT-PCR method for the detection and quantification of EHV-2 in equine respiratory fluids according to the NF U47-600 norm. After the development and first validation step, two distinct characterization steps were performed according to the AFNOR norm: (a) characterization of the qRT-PCR assay alone and (b) characterization of the whole analytical method. The validation of the whole analytical method included the portrayal of all steps between the extraction of nucleic acids and the final PCR analysis. Validation of the whole method is very important for vi...
Sergeant ES, Grewar JD, Weyer CT, Guthrie AJ.African horse sickness (AHS) is a severe, often fatal, arbovirus infection of horses, transmitted by Culicoides spp. midges. AHS occurs in most of sub-Saharan Africa and is a significant impediment to export of live horses from infected countries, such as South Africa. A stochastic risk model was developed to estimate the probability of exporting an undetected AHS-infected horse through a vector protected pre-export quarantine facility, in accordance with OIE recommendations for trade from an infected country. The model also allows for additional risk management measures, including multiple PC...
Cruz F, Fores P, Mughini-Gras L, Ireland J, Moreno MA, Newton JR.Equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4) have a worldwide distribution and cause respiratory disease, abortion, neonatal death and myeloencephalopathy in susceptible horses. Given the scarcity of serological EHV-1/EHV-4 data in Spain, the objective of this cross-sectional study was to estimate the seroprevalence of EHV-1/EHV-4 and to identify potential horse-level and stud farm-level factors associated with EHV-1/EHV-4 in the breeding Spanish Purebred (SP) horse population in central Spain. Serum samples from 334 SP unvaccinated horses, collected between September 2011 and November...
Sarkar S, Balasuriya UB, Horohov DW, Chambers TM.Equine herpesvirus-1 (EHV-1) is a major respiratory viral pathogen of horses, causing upper respiratory tract disease, abortion, neonatal death, and neurological disease that may lead to paralysis and death. EHV-1 replicates initially in the respiratory epithelium and then spreads systemically to endothelial cells lining the small blood vessels in the uterus and spinal cord leading to abortion and EHM in horses. Like other herpesviruses, EHV-1 employs a variety of mechanisms for immune evasion including suppression of type-I interferon (IFN) production in equine endothelial cells (EECs). Previ...
Field HE.Hendra virus causes acute and highly fatal infection in horses and humans. Pteropid bats (flying-foxes) are the natural host of the virus, with age and species being risk factors for infection. Urine is the primary route of excretion in flying-foxes, with viral RNA more frequently detected in Pteropus alecto and P. conspicillatus than other species. Infection prevalence in flying-foxes can vary between and within years, with a winter peak of excretion occurring in some regions. Vertical transmission and recrudescing infection has been reported in flying-foxes, but horizontal transmission is ev...
Roy Chowdhury P, DeMaere M, Chapman T, Worden P, Charles IG, Darling AE, Djordjevic SP.Clostridium difficile infections (CDI) are a significant health problem to humans and food animals. Clostridial toxins ToxA and ToxB encoded by genes tcdA and tcdB are located on a pathogenicity locus known as the PaLoc and are the major virulence factors of C. difficile. While toxin-negative strains of C. difficile are often isolated from faeces of animals and patients suffering from CDI, they are not considered to play a role in disease. Toxin-negative strains of C. difficile have been used successfully to treat recurring CDI but their propensity to acquire the PaLoc via lateral gene transfe...
Gennari SM, Pena HF, Lindsay DS, Lopes MG, Soares HS, Cabral AD, Vitaliano SN, Amaku M.Sarcocystis neurona and Neospora hughesi are coccidian protozoa that can cause neurological illness in horses in America. In this study we report seroprevalence of Neospora spp. andS. neurona in sera of 333 donkeys from the northeastern region of Brazil. Antibodies to Neospora spp. were detected in 2% (7 donkeys) of 333 sera tested by the indirect fluorescent antibody test (IFAT) with a cut-off dilution of 1:40. Antibodies to S. neurona were found in 3% (10 donkeys) of the samples tested by IFAT (cut-off ≥50) and 21% (69 donkeys) by the direct agglutination test (SAT ≥50). The SAT and IFAT...
Ricotti S, Garcia MI, Veaute C, Bailat A, Lucca E, Cook RF, Cook SJ, Soutullo A.Molecular and serological techniques for Equine Infectious Anemia Virus (EIAV) diagnosis were compared using samples from 59 clinically normal horses stabled on five farms in the Santa Fe Province of Argentina. Of these 26 (44.1%) were positive in official AGID tests and/or gp45/gp90-based ELISA. Surprisingly 18 of the 33 seronegative horses were positive in a PCR against viral sequences encoding gp45 (PCR-positive/AGID-negative) with all but one remaining EIAV-antibody negative throughout a two year observation period. The gp45 PCR results are supported by fact that 7/18 of these horses were ...
Liebenberg D, Piketh S, van Hamburg H.Africa horse sickness (AHS) is the most lethal infectious non-contagious horse disease and has accordingly been declared notifiable by the World Organisation for Animal Health. AHS is endemic to sub-Saharan Africa and causes considerable losses to the equestrian industry. The effect of diseases in livestock on socio-economic factors is well researched, but the effect of anthropogenic factors on the distribution of a disease is poorly understood. The purpose of the study was to assess Namibian and South African horse owners' perceptions and the effect of horse movement on AHS distribution. A cr...
Kinsley R, Scott SD, Daly JM.Serological assays provide an indirect route for the recognition of infectious agents via the detection of antibodies against the infectious agent of interest within serum. Serological assays for equine influenza A virus can be applied for different purposes: diagnosing infections; subtyping isolates; surveillance of circulating strains; and to evaluate the efficacy of vaccines before they reach the market. Haemagglutination inhibition (HI) and single radial haemolysis (SRH) assays are most commonly used in the equine field. This review outlines how both these assays together with virus neutra...
Rivero LA, Concepción JL, Quintero-Troconis E, Quiñones W, Michels PA, Acosta H.Trypanosoma evansi is a monomorphic protist that can infect horses and other animal species of economic importance for man. Like the bloodstream form of the closely related species Trypanosoma brucei, T. evansi depends exclusively on glycolysis for its free-energy generation. In T. evansi as in other kinetoplastid organisms, the enzymes of the major part of the glycolytic pathway are present within organelles called glycosomes, which are authentic but specialized peroxisomes. Since T. evansi does not undergo stage-dependent differentiations, it occurs only as bloodstream forms, it has been ...
Sanna G, Pipia AP, Tamponi C, Manca R, Varcasia A, Traversa D, Scala A.Intestinal strongyles (IS) are the most important parasites of equids, due to their high prevalence worldwide, pathogenicity and the spread of drug-resistant populations. Despite the large number of horses bred in Sardinia Island, Italy, no data are available on the efficacy of anthelmintic compounds in the control of horse strongylosis. Therefore the aim of the present study was to evaluate the efficacy of five commercial anthelmintic formulations containing fenbendazole (FBZ), pyrantel (PYR), moxidectin (MOX) and two ivermectin formulations (IVM1 and IVM2) against IS in Sardinia by performin...
Qi M, Wang R, Wang H, Jian F, Li J, Zhao J, Dong H, Zhu H, Ning C, Zhang L.In present study, 262 fecal specimens were collected from 12 groups of grazing horses in the Xinjiang Uyghur Autonomous Region of China. The specimens were subjected to PCR and sequencing analyses of the ribosomal internal transcribed spacer (ITS). The overall prevalence of E. bieneusi in horses was 30.9% (81/262). No significant differences in prevalence were observed between horses of different ages or sexes. Nineteen genotypes were identified: 15 known genotypes (BEB6, CHG19, CM6, CM7, CM8, CS-1, CS-4, D, EpbA, EbpC, G, horse1, horse2, O, and Peru8) and four new genotypes (XJH1-XJH4). Six ...
Hurley MJ, Riggs CM, Cogger N, Rosanowski SM.A 2 year prospective study was performed between February 2011 and January 2013 to determine the incidence and risk factors for shipping fever (SF) in horses transported by air to Hong Kong (HK). Using a questionnaire, data were collected from professional flying grooms regarding the journey to HK and horses in the shipment. Horses were monitored in quarantine for 2 weeks after arrival in HK, and clinical signs of SF recorded. Poisson and logistic regression models were used to identify risk factors for SF at the horse and shipment levels. The study analysed data from 869 horses on 81 flights ...
Daly JM, Sindle T, Tearle J, Barquero N, Newton JR, Corning S.Surveillance of equine influenza viruses has suggested that strains included in currently licensed vaccines are a poor match for those predominantly circulating in the field. Objective: To assess the ability of Duvaxyn IE-T Plus to provide cross protection against the newly evolved South Africa/4/03 (H3N8) strain of equine influenza virus. Methods: The vaccine efficacy was evaluated by challenge infection with influenza strain A/eq/South Africa/4/03 (H3N8) 2 weeks after a primary course of 2 vaccinations with Duvaxyn IE-T Plus given at a 4-week interval. The outcome of challenge in vaccinated ...
Yang N, Mu MY, Yuan GM, Zhang GX, Li HK, He JB.Toxoplasma gondii is an important zoonotic pathogen infecting humans and almost all warm-blooded animals. The most common sources of human infection are ingestion of tissue cysts in raw or undercooked meat. However, limited information is available about T. gondii infection in horses and donkeys in China. In the present study, we report the seroprevalence of T. gondii infection in horses and donkeys in Liaoning province, northeastern China. Methods: Serum samples were collected from 711 and 738 slaughtered horses and donkeys, respectively, in 13 regions of Liaoning province. The modified agglu...
Yaniv A, Dahlberg J, Gazit A, Sherman L, Chiu IM, Tronick SR, Aaronson SA.Molecular clones of the integrated form of the genome of equine infectious anemia virus (EIAV), the etiologic agent of a naturally occurring, worldwide disease of horses, were obtained. The restriction map of a full-length genome was determined. Additional evidence for the close evolutionary relationship between EIAV and a prototype lentivirus (caprine arthritis encephalitis virus) was acquired by Southern blotting and immunological analyses. An interspecies radioimmunoassay was developed in which EIAV and ovine and caprine lentiviruses could be detected equally well. These studies make availa...
Söderlund R, Bölske G, Holst BS, Aspán A.Infection by Mycoplasma felis is associated with ocular and respiratory disease in cats and respiratory disease in horses. A correct diagnosis is beneficial since the use of specific antimycoplasmal treatment can lead to resolution. The objective of the present study was to develop a real-time polymerase chain reaction (PCR) method based on dual-labeled fluorogenic probe technology, targeting the gene encoding elongation factor Tu (tuf ), for the fast and specific detection of M. felis. Specificity was achieved by basing the assay design on partial sequencing of the tuf gene in strains and cli...
Boschwitz JS, Timoney JF.The antiphagocytic property of equine fibrinogen for Streptococcus equi subsp. equi strain CF32 was examined in vitro. The results of bactericidal assays demonstrated that the presence of fibrinogen enhanced the ability of overnight and early log-phase cultures of strain CF32 to resist killing by equine neutrophils by 12-fold and seven-fold, respectively (p > 0.01). In addition, fibrinogen-coated bacteria treated with fibrinogen specific F(ab')2 fragments were 32% more susceptible to killing by equine neutrophils after opsonization in serum (p > 0.05), indicating that specific epitopes o...
Laroucau K, Colaneri C, Jaÿ M, Corde Y, Drapeau A, Durand B, Zientara S, Beck C.To evaluate the routine complement fixation test (CFT) used to detect Burkholderia mallei antibodies in equine sera, an interlaboratory proficiency test was held with 24 European laboratories, including 22 National Reference Laboratories for glanders. The panels sent to participants were composed of sera with or without B mallei antibodies. This study confirmed the reliability of CFT and highlighted its intralaboratory reproducibility. However, the sensitivity of glanders serodiagnosis and laboratory proficiency may be improved by standardising critical reagents, including antigens, and by dev...
Kainzbauer C, Rushton J, Tober R, Scase T, Nell B, Sykora S, Brandt S.In January 2010, 18 months after excision of an ocular squamous cell carcinoma (SCC), a Connemara mare presented with anorexia and periorbital/parotideal lesions. Post mortem examination revealed these lesions as forming one entity, with 2 additional growths in the retropharyngeal region and the left jugular groove, respectively. The lesions were confirmed histopathologically as SCCs. Using PCR, peripheral blood mononuclear cells (PBMCs) from 2008 and 2010, tumour tissue, intact skin and vulval mucosa were screened for Equus caballus papillomavirus type 2 (EcPV-2) and bovine papillomavirus typ...
Acosta-Jamett G, Cleaveland S, Cunningham AA, Bronsvoort BM, Craig PS.Cyst echinococcosis (CE) is one of the most important zoonosis in Chile, where studies have focussed mainly in moist southern regions. The present study was conducted to determine the prevalence of cystic echinococcosis (CE) in livestock and humans in the semiarid Coquimbo region in north-central Chile. A review of all surgical cases of CE in humans reported in the Elqui, Limarí and Choapa provinces in Coquimbo region for the period comprising 1995-2006 was obtained. In addition, a retrospective study of CE covering condemnation records from slaughterhouses of these provinces from the same pe...
Gildea S, Sanchez Higgins MJ, Johnson G, Walsh C, Cullinane A.There is a lack of information concerning concurrent administration of vaccines against equine influenza virus (EIV) and equine herpesvirus 1 and 4 (EHV-1/4). The primary objective of this study was to determine the impact of the concurrent use of EIV and EHV-1/4 vaccines in Thoroughbred racehorses on their humoral immune response to EIV. This study was carried out on a population of 30 horses using an inactivated whole-virus EIV vaccine and an inactivated EHV-1/4 vaccine. Horses were randomly allocated to vaccination group A or B. Horses in group A were vaccinated against EIV and EHV-1/4 2 we...
Damiani AM, Scicluna MT, Ciabatti I, Cardeti G, Sala M, Vulcano G, Cordioli P, Martella V, Amaddeo D, Autorino GL.During local respiratory disease outbreaks, occurring in 2003 and 2004 in horse training stables within race-tracks in Rome, and on a stud horse farm in Bari in 2005, four strains of equine influenza (EI) virus were isolated. All outbreaks occurred in flu-vaccinated horses. Here, we are reporting the results of the genetic characterization of these isolates, together with that of another EI virus strain isolated in 1999 from a dead foal presenting pulmonary lesions. Alignment and phylogenetic analyses were carried out using the haemagglutinin amino acid sequences. The Rome and Bari isolates we...
Webster WR.In August 2007 equine influenza (EI) was diagnosed in Australia's horse population following the failure to contain infection in quarantine after the importation of one or more infected horses. The response had many unique features, and addressed financial, social, economic, human and animal health, trade and recovery issues. The outbreak and the associated control measures had a vast impact on individual horse owners, the horse industry and associated sectors in both infected and uninfected states.
Dutra F, Schuch LF, Delucchi E, Curcio BR, Coimbra H, Raffi MB, Dellagostin O, Riet-Correa F.A disease named locally as churrío or churrido equino (i.e., equine scours) has occurred for at least 100 years in Uruguay and southern Brazil in farms along both shores of the Merín lake. This report describes cases of churrido equino and provides serologic, pathologic, and DNA-based evidence indicating that the disease is in fact equine monocytic ehrlichiosis (Potomac horse fever). Results of an epidemiological investigation conducted on an endemic farm are also presented. Clinical signs in 12 horses were fever, depression, diarrhea, dehydration, and sometimes colic and distal hind limb ed...
Reinisch AI.Six recent cases of animal hoarding in Manitoba were compared to the relevant literature. Cases were similar to previous reports in age and demographics of hoarders. Five cases involved small mammals and 1 case involved horses. Understanding this phenomenon would be enhanced by consistent investigative format and reporting and closer working relationships with public health. Six cas récents d’amassement d’animaux au Manitoba ont été comparés à la documentation pertinente. Les cas étaient semblables à des rapports antérieurs relativement à l’âge et aux données démographiques ...
Madison JB, Sommer M, Spencer PA.A retrospective evaluation of 64 cases of suspected infectious arthritis in horses was undertaken to determine the relations among histopathologic findings in synovial membrane specimens, cytologic findings in synovial fluid samples, and bacterial culture results. Positive cultures were obtained from 55% of the joints, and 18 different bacterial organisms were cultured. Culturing of synovial fluid yielded bacterial growth more often than did culturing of synovial membrane. Histologic evaluation (H&E and Gram stain) of synovial membrane specimens provided little information to help distingu...
Misra KK, Roy S, Choudhury A.Trypanosoma (Trypanozoon) evansi is a causative agent of the dreadful mammalian disease trypanosomiasis or 'Surra' and carried as a latent parasite in domestic cattle but occasionally proves fatal when transmitted to horses and camel. Sporadic outbreak of 'Surra' to different animals (beside their natural hosts) reminds that T. evansi may be zoonotic, as their close relative cause sleeping sickness to human being. This haemoflagellate is mechanically transmitted by horse fly and its effect on different host varies depending on certain factors including the effectiveness of transmission by mech...
Shepard JJ, Andreadis TG, Thomas MC, Molaei G.Eastern equine encephalitis virus (EEEV) is a highly pathogenic mosquito-borne arbovirus, with active transmission foci in freshwater hardwood swamps in eastern North America, where enzootic transmission is maintained between the ornithophilic mosquito, Culiseta melanura, and wild passerine birds. The role of other locally abundant mosquito species in virus transmission and their associations with vertebrate hosts as sources of blood meals within these foci are largely unknown but are of importance in clarifying the dynamics of enzootic and epidemic/epizootic transmission. Blood-engorged mosqu...
Covaleda L, Fuller FJ, Payne SL.Equine infectious anemia virus (EIAV) infection is distinctive in that it causes a rapid onset of clinical disease relative to other retroviruses. In order to understand the interaction dynamics between EIAV and the host immune response, we explored the effects of EIAV and its S2 protein in the regulation of the cytokine and chemokine response in macrophages. EIAV infection markedly altered the expression pattern of a variety of pro-inflammatory cytokines and chemokines monitored in the study. Comparative studies in the cytokine response between EIAV(17) and EIAV(17DeltaS2) infection revealed ...
Johansen CA, Williams SH, Melville LF, Nicholson J, Hall RA, Bielefeldt-Ohmann H, Prow NA, Chidlow GR, Wong S, Sinha R, Williams DT, Lipkin WI....In northern Western Australia in 2011 and 2012, surveillance detected a novel arbovirus in mosquitoes. Genetic and phenotypic analyses confirmed that the new flavivirus, named Fitzroy River virus, is related to Sepik virus and Wesselsbron virus, in the yellow fever virus group. Most (81%) isolates came from Aedes normanensis mosquitoes, providing circumstantial evidence of the probable vector. In cell culture, Fitzroy River virus replicated in mosquito (C6/36), mammalian (Vero, PSEK, and BSR), and avian (DF-1) cells. It also infected intraperitoneally inoculated weanling mice and caused mild c...
Zheng YH, Sentsui H, Kono Y, Ikuta K.An attenuated equine infectious anemia virus (EIAV), named V26, was previously obtained after 50 passages of the Japanese virulent strain V70 in primary macrophage culture. To clarify the differences between both viruses, their full-length sequences were determined. There were higher mutations in S2 (6.15% amino acid difference) and LTR (10.7% nucleotide difference). The presumed initiation codon of the S2 gene was absent from the sequence of V26. There was a large insertion within the long-terminal repeat (LTR) U3 hypervariable region of V26. In addition, there were minor mutations in gag (1....
Coleman M, Kuskie K, Liu M, Chaffin K, Libal M, Giguère S, Bernstein L, Cohen N.The objective of this study was to determine the in vitro antimicrobial activity of gallium maltolate (GaM) against Rhodococcus equi. A total of 98 virulent bacterial isolates from equine clinical cases were examined, of which 19 isolates were known to be resistant to macrolides and rifampin. Isolates were cultured with various concentrations of GaM and minimal inhibitory concentration (MIC) values were determined after 24 and 48 h. Both the MIC(50) and the MIC(90) after 24h of growth were 558 ng/mL (8 μM) and after 48 h of growth were 2230 ng/mL (32 μM). There were no apparent differences b...
Scoles GA, Ueti MW.The apicomplexan hemoprotozoan parasite Theileria equi is one of the etiologic agents causing equine piroplasmosis, a disease of equines that is endemic throughout large parts of the world. Before 2009 the United States had been considered to be free of this parasite. Occasional cases had occurred but there was no evidence for endemic vector-borne transmission in the U.S. until a 2009 outbreak in Texas in which Dermacentor variabilis and Amblyomma cajennense were implicated as vectors. Although D. variabilis has previously been shown to be a competent laboratory vector, studies suggested A. ca...
Tözsér J, Friedman D, Weber IT, Bláha I, Oroszlan S.The proteinase of the equine infectious anemia virus (EIAV), a lentivirus closely related to human immunodeficiency virus (HIV), was purified from concentrated virus. The specificity of the enzyme was characterized using oligopeptides representing naturally occurring cleavage sites in the Gag and Gag-Pol polyproteins. The length of the substrate binding pocket was found to be 1-2 residues longer than that of HIV proteinases. Although the EIAV and HIV proteinases cleaved most of the peptides at the same bond, some were hydrolyzed by only the EIAV enzyme. Oligopeptides representing cleavage site...
Tirosh-Levy S, Gottlieb Y, Arieli O, Mazuz ML, King R, Horowitz I, Steinman A.Equine piroplasmosis (EP) is an important tick-borne disease of equids, caused by Theileria equi and Babesia caballi. It is endemic in most parts of the world, including Israel, and has clinical and economic consequences. This study was set to evaluate the presence of EP parasites in domestic donkeys and in wild equids in Israel and the Palestinian Authority (PA). To assess subclinical EP infection in 98 domestic donkeys (Equus africanus asinus), 9 Asiatic wild donkeys (Equus hemionus), 8 zebras (Equus quagga), 7 African wild donkeys (Equus africanus) and 5 mules, were tested using PCR and qPC...
Turell MJ.Experimental studies were undertaken to evaluate the vector competence of selected mosquito species [Aedes taeniorhynchus (Wiedemann), Culex declarator Dyar and Knab, and Mansonia titillans (Walker)] from northwestern Venezuela for the epizootic (IC) strain of Venezuelan equine encephalitis (VEE) virus that was responsible for the 1995 outbreak of VEE in this area. Ae. taeniorhynchus was highly susceptible to infection (94% of 35), and 89% had a disseminated infection. Virus-exposed Ae. taeniorhynchus that refed on susceptible hamsters readily transmitted virus, confirming that this species wa...
Pusterla N, Gebhart C.Equine proliferative enteropathy (EPE) is a disease of foals caused by the obligate intracellular organism Lawsonia intracellularis. This organism is unique in that it causes proliferation of infected enterocytes, resulting in thickening of the intestinal epithelium, most often the small intestine. This disease affects mainly weanling foals and causes fever, lethargy, peripheral edema, diarrhea, colic and weight loss. The diagnosis of EPE may be challenging and relies on the presence of hypoproteinemia, thickening of segments of the small intestinal wall observed on abdominal ultrasonography, ...
Saxena A, Pal V, Tripathi NK, Goel AK.Burkholderia mallei, a potential biothreat agent is the aetiological agent of glanders, a zoonotic disease primarily affecting equines. B. mallei shares close genetic proximity with B. pseudomallei, the aetiological agent of melioidosis. Hence, molecular detection of B. mallei and its differentiation from B. pseudomallei has always been challenging. Early diagnosis of glanders is critical for timely treatment in humans and disease containment in animals. In this study a recombinase polymerase amplification-lateral flow (RPA-LF) assay has been developed for early and accurate detection of B. ma...
Gray WL, Yalamanchili R, Raengsakulrach B, Baumann RP, Staczek J, O'Callaghan DJ.Equine herpesvirus type 1 (EHV-1) preparations enriched in defective interfering particles (DIPs) have previously been demonstrated to mediate the coestablishment of persistent infection and oncogenic transformation in primary hamster embryo fibroblasts. In this study, it was demonstrated that infection of a rabbit kidney (RK) cell line with EHV-1 DIP-enriched preparations also results in the establishment of persistent infection. Viral transcription was characterized in RK cells infected with DIP-enriched stocks and compared to viral transcription in RK cells infected with standard (STD) EHV-...
Żychska M, Witkowski L, Klementowska A, Rzewuska M, Kwiecień E, Stefańska I, Czopowicz M, Szaluś-Jordanow O, Mickiewicz M, Moroz A, Bonecka J.... infection is commonly known in equine medicine to cause frequently fatal rhodococcosis. Infections in other species and people are also reported. Clinical manifestation in goats is relatively similar to horses and humans, but data regarding bacterium prevalence are scarce. Thus, the study aimed to estimate the occurrence of in goats. Methods: During post mortem examination, submandibular, mediastinal, and mesenteric lymph nodes were collected. Standard methods were used for bacteria isolation and identification. Results: A total of 134 goats were examined, and 272 lymph node samples were col...
Egberink H, Horzinek MC.Feline immunodeficiency virus (FIV) has morphological, physical and biochemical characteristics similar to human immunodeficiency virus (HIV), the cause of AIDS in man. However, it is antigenically and genetically distinct from HIV; an antigenic relatedness with equine infectious anaemia virus has been demonstrated. FIV has been molecularly cloned and sequenced. Diagnostic tests are commercially available and attempts at preparing inactivated, subunit and molecularly engineered vaccines are being made in different laboratories. During FIV infection a transient primary illness can be recognized...
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...
