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.
Azab W, Lehmann MJ, Osterrieder N.Herpesviruses enter cells either by direct fusion at the plasma membrane or from within endosomes, depending on the cell type and receptor(s). We investigated two closely related herpesviruses of horses, equine herpesvirus type 1 (EHV-1) and EHV-4, for which the cellular and viral determinants routing virus entry are unknown. We show that EHV-1 enters equine epithelial cells via direct fusion at the plasma membrane, while EHV-4 does so via an endocytic pathway, which is dependent on dynamin II, cholesterol, caveolin 1, and tyrosine kinase activity. Exchange of glycoprotein H (gH) between EHV-1...
Johnson AL, Morrow JK, Sweeney RW.Recent research suggests that serum : CSF titer ratios could provide the most accurate antemortem diagnosis of equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona. Objective: The purpose of this study was to assess the utility of two commercially available tests, the indirect fluorescent antibody test (IFAT) and the surface antigen 2, 4/3 ELISA (SAG2, 4/3 ELISA), using archived paired serum and CSF samples. Methods: Samples were obtained from 4 types of clinical patients. Confirmed positive cases (n = 9 horses; 11 sample sets) had neurologic deficits and postmortem lesions c...
Ozkul A, Ergunay K, Koysuren A, Alkan F, Arsava EM, Tezcan S, Emekdas G, Hacioglu S, Turan M, Us D.West Nile fever is an important zoonotic infection caused by West Nile virus (WNV), a member of the Flaviviridae. Previous serological data from Turkey suggest widespread WNV circulation. This report includes cases of human and equine WNV infections occurring concurrently, and manifesting as central nervous system infections, in two neighboring provinces of Central Anatolia, Turkey. A partial phylogenetic analysis of the causative virus is given for the first time. Methods: The cases were reported in February (horses) and March (human). Symptoms of the disease were similar in the two species, ...
Evers F, Garcia JL, Navarro IT, Zulpo DL, Nino Bde S, Ewald MP, Pagliari S, Almeida JC, Freire RL.This study aimed to investigate anti-Toxoplasma gondii antibodies and to isolate the parasite from the brains of horses processed at slaughterhouses in Brazil. We collected brain and blood samples from 398 horses of various ages, from six Brazilian states. Serum samples were evaluated by indirect fluorescent antibody test (IFAT cut-off titre ≥ 1:64), and brains were submitted to mouse bioassay. Among the 398 horses, positivity for T. gondii was identified in 46 (11.6%) by IFAT and in 14 (3.5%) by mouse bioassay. In 12 of those 14 bioassays, mice were positive only by IFAT (cut-off titre ≥ ...
Ziegler U, Seidowski D, Angenvoort J, Eiden M, Müller K, Nowotny N, Groschup MH.West Nile virus (WNV) is a flavivirus that is maintained in an enzootic cycle between ornithophilic mosquitoes, mainly of the Culex genus, and certain wild bird species. Other bird species like ravens, jays and raptors are highly susceptible to the infection and may develop deadly encephalitis, while further species of birds are only going through subclinical infection. The objective of this study was to continue in years 2009-2011 the serological and molecular surveillance in wild birds in Germany (see Vector Borne Zoonotic Dis. 10, 639) and to expand these investigations for the first time a...
Chandriani S, Skewes-Cox P, Zhong W, Ganem DE, Divers TJ, Van Blaricum AJ, Tennant BC, Kistler AL.Theiler's disease is an acute hepatitis in horses that is associated with the administration of equine blood products; its etiologic agent has remained unknown for nearly a century. Here, we used massively parallel sequencing to explore samples from a recent Theiler's disease outbreak. Metatranscriptomic analysis of the short sequence reads identified a 10.5-kb sequence from a previously undescribed virus of the Flaviviridae family, which we designate "Theiler's disease-associated virus" (TDAV). Phylogenetic analysis clusters TDAV with GB viruses of the recently proposed Pegivirus genus, altho...
Nogradi N, Magdesian KG, Whitcomb MB, Church M, Spriet M.A 5-week-old foal was evaluated for fever and hematuria of 3 days duration. Cystoscopy localized the blood to be originating from the left ureter. Abdominal ultrasonography revealed left hydronephrosis, hydroureter, and omphaloarteritis of the left umbilical artery with abscess formation that communicated with an arterial structure. Computed tomography (CT) revealed a large aortic aneurysm within the center of the abscess. An exploratory celiotomy was performed and the infection was nonresectable. The prognosis for life was grave; therefore the colt was euthanized. Necropsy findings confirmed ...
Borges AM, Silva LG, Nogueira MF, Oliveira AC, Segri NJ, Ferreira F, Witter R, Aguiar DM.Serum samples collected from 547 equids in the Pantanal region of Brazil were evaluated for antibodies to Equine Infectious Anemia Virus (EIAV) by the agar gel immunodiffusion test. Risk factors associated with EIAV seropositivity were evaluated and spatial dependence investigated using a Spatial Lag Model. EIAV prevalence on farms in the Pantanal was 52.0% (13/25) with adjusted prevalence between equids of 31.5% (17.4-48.8% 95% CI). Intra-herd prevalence ranged from 5.0 to 77.0%. Statistical analysis demonstrated that farms and animals in regularly flooded areas had respectively 60 and 146 fo...
Schemann K, Lewis FI, Firestone SM, Ward MP, Toribio JA, Taylor MR, Dhand NK.On-farm biosecurity practices have been promoted in many animal industries to protect animal populations from infections. Current approaches based on regression modelling techniques for assessing biosecurity perceptions and practices are limited for analysis of the interrelationships between multivariate data. A suitable approach, which does not require background knowledge of relationships, is provided by Bayesian network modelling. Here we apply such an approach to explore the complex interrelationships between the variables representing horse managers' perceptions of effectiveness of on-far...
Wiedenheft AM, Traub-Dargatz JL, Gillette SC, O'Keefe GJ, Rao S, Salman MD.The purpose of this study was to assess the effectiveness of two different methods of online education using the knowledge base of African horse sickness (AHS) among US equine veterinarians as a model. An e-mail was sent to US veterinary members of the American Association of Equine Practitioners (AAEP), inviting them to participate in a complementary online educational opportunity. We determined participants' baseline knowledge of AHS by their responses in an AHS case scenario. Participants were then randomly assigned to either a Webinar module or a text-formatted module, followed by an educa...
Voelter-Ratson K, Pot SA, Florin M, Spiess BM.Keratomycosis is a severe disease in horses. Geographical differences in fungi causing keratomycosis and susceptibility of the organisms to antifungal drugs exist but few previous publications on this disease originate from Europe. Objective: To retrospectively compare the clinical data of 36 eyes with keratomycosis, diagnosed in 35 horses between January 2000 and August 2011 at the Vetsuisse Faculty of Switzerland. Case history, season, prior treatment, clinical appearance, surgical and medical treatment, treatment duration, and globe survival were evaluated. Methods: Retrospective case serie...
Yeo WM, Osterrieder N, Stokol T.The alphaherpesvirus, equine herpesvirus type 1 (EHV-1), is a highly prevalent cause of equine infectious abortion and encephalomyelopathy. These syndromes have been attributed to ischemic necrosis from thrombosis in placental and neural vessels, although the mechanisms underlying thrombosis are unknown. After inhalation, EHV-1 establishes a peripheral blood mononuclear cell-associated viremia, with monocytes being a target of infection. Monocytes are also the main source of tissue factor (TF) in diseased states. Since TF is the primary activator of coagulation, increased monocyte TF expressio...
Peckle M, Pires MS, Dos Santos TM, Roier EC, da Silva CB, Vilela JA, Santos HA, Massard CL.The aim of this study was to detect Theileria equi (Laveran 1901) DNA in horses and ticks using real-time PCR and to list the factors associated with infection in animals located in the Seropedica and Petropolis municipalities of the state of Rio de Janeiro. We tested blood samples from 314 horses and samples from 300 ticks, including 191 Amblyomma cajennense, 104 Dermacentor nitens, and 5 Ixodida larvae. Factors inherent to the horse, the ownership, and animal management were obtained from an epidemiological questionnaire and were evaluated in association with the presence of T. equi DNA in t...
Van den Eede A, Hermans K, Van den Abeele A, Floré K, Dewulf J, Vanderhaeghen W, Némeghaire S, Butaye P, Gasthuys F, Haesebrouck F, Martens A.The increased incidence of methicillin-resistant Staphylococcus aureus (MRSA) infection in equine hospitals highlights the need for infection control protocols based on optimal patient screening. In horses, the deep ventral meatus of the nasal cavity is the principal site sampled to detect MRSA. However, in humans, the anterior nares are the preferred sampling site. The objective of this study was to determine the optimal sampling location in the nasal chambers for MRSA in horses by comparing the results obtained from three different locations (the vestibulum, diverticulum and ventral meatus) ...
Firestone SM, Lewis FI, Schemann K, Ward MP, Toribio JA, Dhand NK.In a previous premises-level case-control study of the 2007 equine influenza outbreak in Australia, the protective effect of several variables representing on-farm biosecurity practices was identified. However, using logistic regression it was not possible to definitively identify individual effects and associations between each of the personal biosecurity measures implemented by horse premises owners and managers in the face of the outbreak. In this study we apply Bayesian network modelling to identify the complex web of associations between these variables, horse premises infection status an...
Diaz-San Segundo F, Dias CC, Moraes MP, Weiss M, Perez-Martin E, Owens G, Custer M, Kamrud K, de los Santos T, Grubman MJ.We have previously shown that delivery of the porcine type I interferon gene (poIFN-α/β) with a replication-defective human adenovirus vector (adenovirus 5 [Ad5]) can sterilely protect swine challenged with foot-and-mouth disease virus (FMDV) 1 day later. However, the need of relatively high doses of Ad5 limits the applicability of such a control strategy in the livestock industry. Venezuelan equine encephalitis virus (VEE) empty replicon particles (VRPs) can induce rapid protection of mice against either homologous or, in some cases, heterologous virus challenge. As an alternative approach ...
Rosales R, Rangel-Rivas A, Escalona A, Jordan LS, Gonzatti MI, Aso PM, Perrone T, Silva-Iturriza A, Mijares A.The focus of this study was the detection of equine piroplasmosis in Distrito Capital, Miranda, Aragua, Guárico and Apure States from Venezuela, using two methods: Competitive-Inhibition ELISA and multiplex PCR and the analysis of the possible differences in occurrence in relation to the primary purpose of the horses, which is related to varied degrees of exposure to tick. Antibody levels to Babesia caballi and Theileria equi were assessed in 694 equine serum samples using Competitive-Inhibition ELISA, while PCR assays were performed in 136 horses, using two sets of oligonucleotides to establ...
Walter J, Seeh C, Fey K, Bleul U, Osterrieder N.Latent equine herpesvirus type 1 (EHV-1) infection is common in horse populations worldwide and estimated to reach a prevalence nearing 90% in some areas. The virus causes acute outbreaks of disease that are characterized by abortion and sporadic cases of myeloencephalopathy (EHM), both severe threats to equine facilities. Different strains vary in their abortigenic and neuropathogenic potential and the simultaneous occurrence of EHM and abortion is rare. In this report, we present clinical observations collected during an EHV-1 outbreak caused by a so-called "neuropathogenic" EHV-1 G(2254)/D(...
Glass K, Barnes B.When novel disease outbreaks occur in livestock, policy makers must respond promptly to eliminate disease, and are typically called on to make control decisions before detailed analysis of disease parameters can be undertaken. We present a flexible metapopulation model of disease spread that incorporates variation in livestock density and includes occasional high-mixing locations or events, such as markets or race meetings. Using probability generating functions derived from this branching process model, we compare the likely success of reactive control strategies in eliminating disease spread...
Beltaire KA, Cheong SH, Coutinho da Silva MA.Knowledge of commonly encountered fungi infecting the mare's reproductive tract and their respective drug susceptibilities should improve treatment efficacy in mares with fungal endometritis. This is particularly important when practitioners need to start empiric treatment before culture results are complete. Objective: To report the spectrum of fungal isolates from uterine samples from mares with reproductive problems and their respective antifungal susceptibilities. Methods: Equine uterine samples submitted to the Cornell University Animal Health Diagnostic Centre for fungal culture between ...
Tatz AJ, Segev G, Steinman A, Berlin D, Milgram J, Kelmer G.There is a consensus in the veterinary literature that Parascaris equorum (ascarid) impaction carries a poor prognosis. Hence surgery is often delayed and foals are often subjected to euthanasia after diagnosis of ascarid impaction is established. Our clinical impression was that ascarid impaction carries a better prognosis than previously reported. Objective: Our expectation was that manually evacuating the impaction into the caecum, thus refraining from opening the small intestine, would improve the prognosis for survival of horses with ascarid impaction. The aim of this study was to examine...
Velez IC, Arnold C, Jacobson CC, Norris JD, Choi YH, Edwards JF, Hayden SS, Hinrichs K.Transvaginal ultrasound-guided follicle aspiration (TVA) is performed clinically but there is little information available on complications associated with this procedure. Objective: It is possible that TVA is associated with damage to the ovary and may induce peritonitis or peritoneal adhesions. This study was conducted to determine the effect of repeated TVA on mare health and ovarian status. Methods: Thirty-two mares were used for oocyte recovery via repeated TVA over a 3 year period; different mares were used each year. In Year 1, ovarian status was monitored in 11 mares by transrectal pal...
Bailey CS, Heitzman JM, Buchanan CN, Bare CA, Sper RB, Borst LB, Macpherson M, Archibald K, Whitacre M.Early, accurate diagnosis of ascending placentitis in mares remains a key challenge for successful treatment of the disease. Doppler ultrasonography has shown promise as a tool to diagnose pregnancy abnormalities and is becoming more available to equine clinicians. However, to date, no studies have prospectively compared this technique to standard B-mode measurement of the combined thickness of the uterus and placenta (CTUP). Objective: The objective of the current study was to compare Doppler and B-mode ultrasonography for the detection of experimentally-induced ascending placentitis in mares...
Finger MA, Villalobos EM, Lara Mdo C, Cunha EM, Barros Filho IR, Deconto I, Dornbusch PT, Ullmann LS, Biondo AW.Toxoplasma gondii, the agent for toxoplasmosis, has worldwide distribution. Horses normally play a secondary role in its life cycle, but movement around urban areas, feeding on grass and the increasing use of carthorses for gathering recyclable material in some urban areas of Brazil may increase their exposure to T. gondii infection. The aim of the present study was to investigate the frequency of anti-T. gondii antibodies in carthorses in the metropolitan region of Curitiba, PR. IgG antibodies against T. gondii were detected using the indirect fluorescence antibody test (IFAT) (titers ≥ 64)...
Robinson C, Steward KF, Potts N, Barker C, Hammond TA, Pierce K, Gunnarsson E, Svansson V, Slater J, Newton JR, Waller AS.The detection of anti-Streptococcus equi antibodies in the blood serum of horses can assist with the identification of apparently healthy persistently infected carriers and the prevention of strangles outbreaks. The aim of the current study was to use genome sequencing data to develop an indirect enzyme linked immunosorbent assay (iELISA) that targets two S. equi-specific protein fragments. The sensitivity and specificity of the antigen A and antigen C iELISAs were compared to an SeM-based iELISA marketed by IDvet - diagnostic Vétérinaire (IDvet). Individually, each assay compromised specifi...
Magori K, Park AW.The emergence and spread of mutant pathogens that evade the effects of prophylactic interventions, including vaccines, threatens our ability to control infectious diseases globally. Imperfect vaccines (e.g. those used against influenza), while not providing life-long immunity, confer protection by reducing a range of pathogen life-history characteristics; conversely, mutant pathogens can gain an advantage by restoring the same range of traits in vaccinated hosts. Using an SEIR model motivated by equine influenza, we investigate the evolutionary consequences of alternative types of imperfect va...
Salim B, Bakheit MA, Kamau J, Sugimoto C.This is a cross-sectional molecular epidemiological study on equine piroplasmosis (EP) affecting horses and donkeys in the Sudan. The study evaluated 499 samples from geographically distinct regions in eastern, central and western parts of the country. PCR amplification of the 18S rRNA gene of both Thelieria equi and Babesia caballi was carried out. Horses from all sampled areas were found positive to T. equi DNA but no B. caballi was detected. Absence of B. caballi infection was confirmed by another PCR targeting the B. caballi 48-kDa merozoite antigen. The overall prevalence was found to be ...
Rola J, Socha W, Zmudzinski JF.Nucleotide and amino acid sequences of ORFs 5, 6 and 7 of EAV during persistent infection in the stallion of the Malopolska breed were analysed in the study. A total of 11 blood and semen samples were collected between 2004 and 2011. The titre of specific EAV antibodies in this carrier stallion was maintained at a high level throughout the study and was equal approximately 1:128. The sequence analysis of ORF5 showed 16 variable sites including 12 with synonymous substitutions and 4 with non-synonymous substitutions. The degree of nucleotide sequence identity among the strains ranged from 98.92...
Wagner B, Goodman LB, Rollins A, Freer HS.Lyme disease is caused by Borrelia burgdorferi, which is transmitted by infected ticks (Ixodes spp.). Reports on Lyme disease in horses have increased in recent years. Nevertheless, the diagnosis of Lyme disease in horses is still challenging owing to its vague clinical presentation and the limitations of diagnostic tests. Objective: This study used a new serological Lyme multiplex assay to examine antibody responses to 3 antigens of B. burgdorferi, outer surface protein (Osp) C, OspF and C6, and to verify their use as markers for early and late infection stages in horses. Methods: Multiplex...
Spence KL, O'Sullivan TL, Poljak Z, Greer AL.Horses are a highly mobile population, with many travelling locally, nationally, and internationally to participate in shows and sporting events. However, the nature and extent of these movements, as well as the potential impact they may have on disease introduction and spread, is not well documented. The objective of this study was to characterise the movement network of a sample of horses in Ontario, Canada, over a 7-month equestrian season. Horse owners (n = 141) documented their travel patterns with their horse(s) (n = 330) by completing monthly online questionnaires between May and Novemb...
Freestone JF, Carlson GR.Case records of horses with muscle disorders presenting to the Veterinary Medical Teaching Hospital of the University of California, Davis, over a nine year period were evaluated. The objectives of the review were to identify the common myogenic muscle problems and their clinical features. Muscle disease of idiopathic aetiology following exercise was by far the most common condition noted. Other causes of myogenic muscle disorders included congenital, infectious, immune-mediated and nutritional factors.
Banks KL.The monocytes of horses infected with equine infectious anemia virus were shown by their failure to migrate from capillary tubes and their increased adherence to erythrocytes to be activated.
Vercruysse EM, Narinx FP, Rives ACM, Sauvage AC, Grauwels MF, Monclin SJ.To describe bacterial isolates and associated antibiotic resistance from horses with ulcerative keratitis in Belgium. Methods: Medical records from horses with ulcerative keratitis presented to the ophthalmology service of the Veterinary teaching hospital of Liege, Belgium, between 2014 and 2021 were evaluated. Bacterial isolates were identified and VITEK® 2 (Biomérieux) provided antimicrobial susceptibility testing and resistance detection. Results: Two hundred eyes of 196 horses were sampled. Ninety-seven eyes had a positive bacterial culture (48.5%) and 139 bacterial isolates were identif...
Begg AP, Johnston KG, Hutchins DR, Edwards DJ.A survey of 2 horse populations was done to detect the number of asymptomatic faecal excretors of Salmonella sp. 1201 faecal samples from 250 horses hospitalised at the University of Sydney were cultured. Three serotypes, S. typhimurium (4 horses), S. anatum (2) and S. tennessee (1) were isolated from 7 horses (2.8%). None was detected in 75 mares similarly examined at a thoroughbred stud farm. In retrospect, S. typhimurium was also the most common (70%) of the 19 serotypes recovered from 171 horses with clinical salmonellosis seen at Camden, 1969 to 1986. Forty cases occurring since 1983 were...
Hines R, Maury W.In vivo, tissue macrophages have been implicated as an important cell for the replication of equine infectious anemia virus (EIAV). Laboratory investigations of EIAV/macrophage interactions, however, have been hampered by the laborious blood monocyte isolation procedures. In addition, adherent equine macrophage cultures generally have poor long-term viability and are resistant to transfection. This report describes an adherent canine macrophage-like cell line, DH82, that supports the replication of EIAV. This cell line was easily transfectable and supported EIAV Tat transactivation of the LTR....
Aklilu N, Batten C, Gelaye E, Jenberie S, Ayelet G, Wilson A, Belay A, Asfaw Y, Oura C, Maan S, Bachanek-Bankowska K, Mertens PP.African horse sickness (AHS) is associated with high morbidity and mortality in equids, especially horses. A retrospective analysis was carried out concerning 737 AHS outbreaks that occurred during 2007-2010 in Ethiopia. A total of ten outbreaks were investigated in the study period. All four forms of the disease (pulmonary, cardiac, horse sickness fever and the combined form) were observed, with the cardiac form being the most prevalent. Multiple African horse sickness virus serotypes (AHSV-2, AHSV-4, AHSV-6, AHSV-8 and AHSV-9) were detected by molecular methods (type-specific real-time RT-PC...
Cole JR, Hall RF, Gosser HS, Hendricks JB, Pursell AR, Senne DA, Pearson JE, Gipson CA.A group of 14 pregnant mares was exposed via contact to 4 mares bred to stallions infected with equine viral arteritis virus. There was a demonstrable febrile response in each donor mare and in 12 of the pregnant mares. All 18 mares became seropositive after exposure. Equine viral arteritis virus was isolated from the nasopharynx of 5 pregnant mares, but not from the donor mares. Ten of the pregnant mares aborted, and virus was isolated from fetal specimens or placenta of 8.
Lin C, Holland RE, Williams NM, Chambers TM.Equine nasal turbinate epithelial cells and tracheal rafts were maintained with sustained viability in culture. Both types of culture supported productive replication of equine influenza virus (equine-2, subtype H3N8) and cell death occurred through apoptosis following viral infection. Thus, primary respiratory epithelial cell and organ cultures of equine origin may be valuable as alternatives to the intact animal for studying the virus-host interaction of equine respiratory viruses including influenza.
Esparza J.Mystery surrounds the extent to which horsepox virus may have contributed to the vaccinia virus used to eradicate smallpox. With few documented cases of horsepox in recent years it may never be solved, says José Esparza, who seeks to raise awareness of the potential historical and scientific importance of identifying new cases.
Taouji S, Collobert C, Gicquel B, Sailleau C, Brisseau N, Moussu C, Breuil MF, Pronost S, Borchers K, Zientara S.Equine herpesviruses type 1 and 4 (EHV-1 and EHV-4) are ubiquitous in the equine population. One of their main properties is their ability to establish life-long latent infections in their hosts even in those with natural or vaccine-induced immunity. However, effect of vaccination status on prevalence and tissue tropism was not established. In this study, EHV-1 and EHV-4 were detected by polymerase chain reaction and by classical virus isolation from neural, epithelial and lymphoid tissues collected from unvaccinated (33) or vaccinated (23) horses. The percentage of EHV-1- and EHV-4-positive h...
Cabre O, Durand JP, Prangé A, Gomez J, Maurizi L, Tolou H, Davoust B.This study was carried out in 2003 to detected serological evidence of West Nile virus infection in 190 Army horses kept nearby French troops stationed in Southeast France and in Africa (Chad, Côte d'Ivoire and Senegal). Both IgG and IgM antibodies were searched for using an ELISA assay. Specifiity of IgG antibodies was determined by western blot and plaque reduction seroneutraization. Finding showed that 79% of the Army horses (n=96) tested in Africa presented specific IgG antibodies. All horses that were seropositive for IgG were seronegative for IgM. None of the Army horses (n=94) tested i...
Hooper PT, Williamson MM.The most important clinical and pathological manifestation of Hendra virus infection in horses and humans is that of severe interstitial pneumonia caused by viral infection of small blood vessels. The virus is also capable of causing nervous disease. Hendra virus is not contagious in horses and is spread by close contact with body fluids, such as froth from infected lungs. Diagnosis should be based on the laboratory examination of blood, lung, kidney, spleen, and, if nervous signs are present, also of the brain. Evidence of infection with the more recently identified and related Nipah virus wa...
Campos JR, Breheny P, Araujo RR, Troedsson MH, Squires EL, Timoney PJ, Balasuriya UB.Equine arteritis virus (EAV) is the causal agent of equine viral arteritis (EVA), a respiratory and reproductive disease of equids. Some strains of EAV can cause fever, leukopenia, and dependent edema of the limbs, scrotum, and preputium in the acutely infected stallion. We hypothesized that fever and scrotal edema observed during the acute phase of the infection, but not the presence of EAV, have an adverse effect on semen quality. A group of seven stallions were intranasally inoculated with the Kentucky 84 (KY84) strain of EAV. Stallions were monitored for clinical signs of EVA until 42 days...
Akiba M, Uchida I, Nishimori K, Tanaka K, Anzai T, Kuwamoto Y, Wada R, Ohya T, Ito H.Equine paratyphoid is caused by Salmonella enterica serovar Abortusequi, and manifests mainly as abortion in the mare. We compared S. Abortusequi strains isolated in Japan and other countries using pulsed-field gel electrophoresis (PFGE) and fluorescent amplified-fragment length polymorphism (FAFLP) analysis. PFGE analysis of S. Abortusequi strains gave 21-27 fragments ranging in size from 33 to 602kb. Although two PFGE profiles were observed among the 20 S. Abortusequi isolates in Japan, the restriction fragments originating from the chromosome were common between the two profiles. The simila...
Meng Q, Lin Y, Ma J, Ma Y, Zhao L, Li S, Liang H, Zhou J, Shen R, Zhang X, Shao Y.The attenuated Chinese equine infectious anemia virus (EIAV) vaccine has successfully protected millions of equine animals from EIA disease in China. In this pilot study, to determine whether this attenuated vaccine can induce broadly neutralizing antibodies, we immunized four horses with the attenuated Chinese vaccine strain EIAVFDDV and then observed the evolution of neutralizing antibodies against different EIAV strains. During the vaccination phase, all vaccinees rapidly developed high levels of neutralizing antibodies against the homologous vaccine strain (pLGFD3V), and 3 out of 4 horses ...
Magdesian KG, Leutenegger CM.Clostridium difficile infection can occur in the dams of sick foals, but it is unknown if mares and foals share the same isolates. In this study, C. difficile isolates from fecal samples of 11 mares paired with 11 foals were genotyped by arbitrarily primed PCR; two mares and three foals in five mare-foal pairs had diarrhea. Fecal immunoassays were utilized to detect C. difficile common antigen and toxin A. Quantitative real-time PCR (qPCR) systems were developed to detect genes for toxins A and B, as well as for binary toxin B. Sequences of all toxins were present in all isolates, although onl...
Littler E, Yeo J, Killington RA, Purifoy DJ, Powell KL.Previously, we have shown a common antigen of several herpesviruses (pseudorabies virus, equine abortion virus and bovine mammillitis virus) to be antigenically related to the major DNA-binding proteins of herpes simplex virus types 1 and 2. In this study we have purified the cross-reacting polypeptide from cells infected with pseudorabies virus, equine abortion virus and bovine mammillitis virus and shown the cross-reacting protein to be a major DNA-binding protein for each virus. Tryptic peptide analysis of the cross-reacting DNA-binding proteins of all five viruses has shown structural simi...
Renshaw RW, Wise AG, Maes RK, Dubovi EJ.A polyomavirus was isolated from the eyes of horses, and the sequence was determined. A nearly identical VP1 sequence was amplified from the kidney of another animal. We report the complete genome sequence of the first polyomavirus to be isolated from a horse. Analysis shows it to be most closely related overall to human and nonhuman primate polyomaviruses.
de Carvalho Filho MB, Ramos RM, Fonseca AA, de Lima Orzil L, Sales ML, de Assis Santana VL, de Souza MM, Dos Reis Machado E, Filho PR, Leite RC....The allergic test of mallein is one of the most frequently used tests, together with the Complement Fixation Test (CFT), for the diagnosis of glanders in endemic areas. Mallein, a purified protein derivative (PPD), is produced similarly to PPD tuberculin and the end product is a primarily proteic antigen, which is only poorly purified. The immuno-allergic activity of mallein is believed to be due to a high molecular weight group of proteins present in the antigen. To improve the quality of the antigen, in terms of sensitivity and specificity, a new method of mallein production was developed, i...
Judson R, Songer JG.The minimal inhibitory concentrations of 39 antimicrobial agents for 54 isolates of Corynebacterium pseudotuberculosis in vitro have been determined. The most active agents were penicillins, macrolides, tetracyclines, cephalosporins, lincomycin, chloramphenicol, and rifampicin. Most isolates were resistant to aminoglycosides, nitrofurans, polymyxins, nalidixic acid, and cycloheximide.
Kumar D, Antiya SP, Patel SS, Pandit R, Joshi M, Mishra AK, Joshi CG, Patel AC.Since December 2019, Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has been spreading worldwide, triggering one of the most challenging pandemics in the human population. In light of the reporting of this virus in domestic and wild animals from several parts of the world, a systematic surveillance study was conceptualized to detect SARS-CoV-2 among species of veterinary importance. Nasal and/or rectal samples of 413 animals (dogs n= 195, cattle n = 64, horses n = 42, goats n = 41, buffaloes n = 39, sheep n = 19, cats n = 6, camels n = 6, and a monkey n = 1) were collected from d...
Nicholson VM, Prescott JF.Restriction enzyme digestion patterns of the large virulence plasmids of 8 human and 37 foal isolates of virulence-associated protein (VapA)-positive Rhodococcus equi strains from different sources were compared. Foal isolates came from five continents. Digestion with EcoRI divided these plasmids into three closely related types, and digestion with BamHI divided them into three major types which corresponded to the EcoRI types. The only EcoRI and BamHI type 3 plasmid was from a single foal isolate obtained from Japan. There are thus two major but related virulence plasmids in isolates from foa...
Guo PF, Chen TT, Tsaihong JC, Ho GD, Cheng PC, Tseng YC, Peng SY.Cryptosporidiosis is a zoonotic disease caused by the protozoan parasite Cryptosporidium. A total of 436 horse fecal samples were collected from 19 farms, and acid-fast staining method was used for primary screening. Cryptosporidium oocysts were found in 161 samples, among which 33 positive sample were selected for nested PCR, restriction fragment length polymorphism analysis and DNA sequencing of 18 S rDNA, showing 31 samples to be bovine C. parvum and 2 C. felis. The methods employed in this study should be useful as tools to identify cryptosporidiosis genotypes and species of livestock.
Val-Calvo J, Darcy J, Gibbons J, Creighton A, Egan C, Buckley T, Schmalenberger A, Fogarty U, Scortti M, Vázquez-Boland JA.A multidrug-resistant clone of the animal and human pathogen Rhodococcus equi, MDR-RE 2287, has been circulating among equine farms in the United States since the 2000s. We report the detection of MDR-RE 2287 outside the United States. Our finding highlights the risk for MDR-RE spreading internationally with horse movements.
Liu GH, Li JY, Zhu XQ.Setaria digitata is a filarial parasite that causes fatal cerebrospinal nematodiasis in goats, horses and sheep, resulting in substantial economic losses to livestock farmers. In the present study, the complete mitochondrial (mt) genome of S. digitata from China was determined, characterized and compared with that of S. digitata from Sri Lanka. The identity of the mt genomes was 98.3% between S. digitata from China and Sri Lanka, and the complete mt genome sequence of S. digitata from China was slightly shorter (25 bp) than that from Sri Lanka. For the 12 protein genes, this comparison reveal...
Klevjer-Anderson P, Cheevers WP, Crawford TB.Equine dermal fibroblasts persistently infected with equine infectious anemia virus (EIAV) show no alterations in cell morphology or growth kinetics when compared to uninfected cells. The percentage of cells immunofluorescent positive for viral proteins fluctuated, depending upon the stage of the cell cycle, while production of extracellular virus was uniform throughout the cell cycle, increasing only as the cell number increased. This was shown in log versus stationary phase cultures as well as in cultures synchronized by sterum starvation. The establishment of productive infection did not re...
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...
Bjöersdorff A, Bagert B, Massung RF, Gusa A, Eliasson I.We report the isolation and partial genetic characterization of two equine strains of granulocytic Ehrlichia of the genogroup Ehrlichia phagocytophila. Frozen whole-blood samples from two Swedish horses with laboratory-verified granulocytic ehrlichiosis were inoculated into HL-60 cell cultures. Granulocytic Ehrlichia was isolated and propagated from both horses. DNA extracts from the respective strains were amplified by PCR using primers directed towards the 16S rRNA gene, the groESL heat shock operon gene, and the ank gene. The amplified gene fragments were sequenced and compared to known seq...
