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.
Ghosh M, Sharma N, Singh AK, Gera M, Pulicherla KK, Jeong DK.For more than a quarter of a century, sequencing technologies from Sanger's method to next-generation high-throughput techniques have provided fascinating opportunities in the life sciences. The continuing upward trajectory of sequencing technologies will improve livestock research and expedite the development of various new genomic and technological studies with farm animals. The use of high-throughput technologies in livestock research has increased interest in metagenomics, epigenetics, genome-wide association studies, and identification of single nucleotide polymorphisms and copy number va...
Schale S, Howe D, Yeargan M, Morrow JK, Graves A, Johnson AL.Infection by 2 or more protozoa is linked with increased severity of disease in marine mammals with protozoan encephalitis. Objective: To assess whether horses with equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona also have evidence of infection with Neospora hughesi or Toxoplasma gondii. We hypothesized that horses with EPM would be more likely than horses with cervical vertebral stenotic myelopathy (CVSM) to be positive for antibodies to multiple protozoan parasites. Methods: One hundred one horses with neurologic disease: 49 with EPM and 52 with CVSM. Methods: Case rev...
Wolny-Koładka K.The aim of this study was to assess the microbiological quality of air in three horse riding centers differing in the horse keeping systems. The air samples were collected in one facility with free-range horse keeping system and two with box stalls of different sizes. The samples were collected over a period of 3 years (2015-2017), four times per year (spring, summer, autumn, winter) to assess the effect of seasonal changes. The prevalence of aerobic mesophilic bacteria, mold fungi, actinomycetes, Staphylococcus spp., and Escherichia coli was determined by the air collision method on Petri di...
Vissani MA, Tordoya MS, Tsai YL, Lee PA, Shen YH, Lee FC, Wang HT, Parreño V, Barrandeguy M.Equine coital exanthema (ECE) is an infectious, venereally transmitted muco-cutaneous disease affecting mares and stallions, caused by equid alphaherpesvirus 3 (EHV3). Diagnostic tools for rapid identification of EHV3 are of primary importance to diminish the risk of EHV3 dissemination at the time of breeding. In the last years, it has been shown that the performance of the insulated-isothermal polymerase chain reaction (iiPCR) is comparable to virus isolation, nested PCR and real-time PCR (qPCR) in detecting pathogens of various animal species. Analytical sensitivity and specificity of the ii...
Ahlers LRH, Goodman AG.Vector-borne diseases, including arboviruses, pose a serious threat to public health worldwide. Arboviruses of the flavivirus genus, such as Zika virus (ZIKV), dengue virus, yellow fever virus (YFV), and West Nile virus (WNV), are transmitted to humans from insect vectors and can cause serious disease. In 2017, over 2,000 reported cases of WNV virus infection occurred in the United States, with two-thirds of cases classified as neuroinvasive. WNV transmission cycles through two different animal populations: birds and mosquitoes. Mammals, particularly humans and horses, can become infected thro...
Bhoora RV, Pienaar R, Cornelius F, Josemans A, Matthee O, Marumo R, Troskie C, Mans BJ.Quantitative real-time PCR assays previously developed for the detection of Theileria equi and Babesia caballi, were combined in a single multiplex TaqMan qPCR platform for the simultaneous detection of both heamoprotozoan parasites in equids. The multiplex equine piroplasmosis (M-EP) qPCR assay was shown to be efficient and specific. The detection limit was determined to be 1.4 × 10 % parasitized erythrocytes (PE) for T. equi and 2.8 × 10 % PE for B. caballi. The effect of differential DNA concentrations on the outcome of the M-EP qPCR for each target species was also investigated. ...
Hicks J, Stuber T, Lantz K, Erdman M, Robbe-Austerman S, Huang X.Contagious equine metritis is a disease of worldwide concern in equids. The United States is considered to be free of the disease although sporadic outbreaks have occurred over the last few decades that were thought to be associated with the importation of horses. The objective of this study was to create finished, reference quality genomes that characterize the diversity of Taylorella equigenitalis isolates introduced into the USA, and identify their differences. Five isolates of T. equigenitalis associated with introductions into the USA from unique sources were sequenced using both short an...
de Oliveira AM, Fonseca AA, Camargos MF, Orzil LM, Laguardia-Nascimento M, Oliveira AGG, Rodrigues JG, Sales ML, de Oliveira TFP, de Melo CB.Vesicular stomatitis is an infectious disease that occurs mainly in countries of the Western Hemisphere and affects cattle, swine and horses. The clinical symptoms in cattle and swine are similar to foot-and-mouth disease and include vesicular ulceration of the tongue and mouth. The disease requires a rapid and accurate differential diagnosis, aiming for immediate implementation of control measures. The objective of the present study was to develop and perform validation tests of multiplex RT-qPCR(s) for the detection of RNA from Alagoas vesiculovirus, considering the parameters of sensitivity...
Burgess BA, Bauknecht K, Slovis NM, Morley PS.Salmonella enterica is an important cause of healthcare-associated infections in veterinary hospitals - with outbreaks of multi-drug resistant (MDR) Salmonella among equine cases resulting in high case fatality rates and substantial financial cost. Objective: Study objectives were to 1) investigate factors associated with shedding of MDR-Salmonella enterica and 2) evaluate the effect shedding may have on health outcomes of previously hospitalised horses and their stablemates. Methods: Retrospective case-control study with prospective cohort study. Methods: Analysis of medical records (N = 37...
Durham AE.Therapeutic drug monitoring and minimum inhibitory concentration (MIC) data allow more informed use of gentamicin. Objective: To measure peak and trough serum gentamicin concentrations in horses after a 6.6 mg/kg dose of gentamicin given IV and the MIC of gentamicin of bacteria for which gentamicin might be selected. Methods: Retrospective analysis of hospital records. Peak and trough plasma gentamicin concentrations were measured after 6.6 mg/kg gentamicin IV in 339 hospitalized horses. The MIC of gentamicin was measured for 503 isolates from ambulatory practice and 33 from hospital practice....
Hardefeldt LY, Gilkerson JR, Billman-Jacobe H, Stevenson MA, Thursky K, Bailey KE, Browning GF.Antimicrobial stewardship (AMS) programs are yet to be widely implemented in veterinary practice and medical programs are unlikely to be directly applicable to veterinary settings. Objective: To gain an in-depth understanding of the factors that influence effective AMS in veterinary practices in Australia. Methods: A concurrent explanatory mixed methods design was used. The quantitative phase of the study consisted of an online questionnaire to assess veterinarians' attitudes to antimicrobial resistance (AMR) and antimicrobial use in animals, and the extent to which AMS currently is implemente...
Elzinga S, Reedy S, Barker VD, Chambers TM, Adams AA.Obesity is an increasing problem in the equine population with recent reports indicating that the percentage of overweight horses may range anywhere from 20.6-51%. Obesity in horses has been linked to more serious health concerns such as equine metabolic syndrome (EMS). EMS is a serious problem in the equine industry given its defining characteristics of insulin dysregualtion and obesity, as well as the involvement of laminitis. Little research however has been conducted to determine the effects of EMS on routine healthcare of these horses, in particular how they respond to vaccination. It has...
Vaid RK, Shanmugasundaram K, Anand T, Bera BC, Tigga M, Dedar R, Riyesh T, Bardwaj S, Virmani N, Tripathi BN, Singh R. is a well-known Gram-negative bacterial pathogen causing a plethora of diseases in different animals. Although its infection has been reported from pigs and dogs in India, no report of B. bronchiseptica from horses is described. We report for the first time, isolation, identification and characterization of strains of B. bronchiseptica from respiratory infection in horses from different states in India. The antimicrobial susceptibility testing showed resistance to penicillins, ceftazidime, and chloramphanicol. The virulence capability of the strains was confirmed by sequencing genes such as a...
Greay TL, Zahedi A, Krige AS, Owens JM, Rees RL, Ryan UM, Oskam CL, Irwin PJ.Apicomplexan tick-borne pathogens that cause disease in companion animals include species of Babesia Starcovici, 1893, Cytauxzoon Neitz & Thomas, 1948, Hepatozoon Miller, 1908 and Theileria Bettencourt, Franca & Borges, 1907. The only apicomplexan tick-borne disease of companion animals that is known to occur in Australia is babesiosis, caused by Babesia canis vogeli Reichenow, 1937 and Babesia gibsoni Patton, 1910. However, no molecular investigations have widely investigated members of Apicomplexa Levine, 1980 in Australian ticks that parasitise dogs, cats or horses, until this present inves...
Loux SC, Ball BA.Placental inflammation (placentitis) is one of the leading causes of late-term abortion in mares. Although prognosis is good assuming early diagnosis and treatment, diagnostics are limited. To better characterize the disease and identify potential biomarkers, we analyzed the proteome of fetal fluids (amniotic and allantoic) in both control mares (n = 5) and mares with experimentally-induced placentitis (n = 5) using LTQ-Orbitrap mass-spectrometry. Placentitis was induced via trans-cervical inoculation of Streptococcus equi ssp. zooepidemicus. In total, 130 proteins were identified in e...
Waller A., head of bacteriology at the AHT, describes the causative agent of strangles in horses, and discusses progress with the latest research aimed at improving vaccines against this global disease.
Sumbria D, Singla LD, Kaur P.In the Indian sub-continent, equine piroplasmosis (EP) is an imperative tick-borne disease of equids predominately caused by obligatory intra-erythrocytic protozoa Theileria equi. Present exploration is the first epidemiological survey report based on Indirect Immunofluorescence Antibody test (IFAT). A total of 120 equines (98 horses and 22 donkeys/mules) from five districts of two main agro-climatic zones of Punjab were screened. The overall prevalence was 58.33%, with western plane zone at higher infection risk for T. equi (74.50%, OR = 7.45, 95% CI = 62.24-85.76); followed by wester...
Tanaka T, Otoguro T, Yamashita A, Kasai H, Fukuhara T, Matsuura Y, Moriishi K.The 5' untranslated region (UTR) of hepatitis C virus (HCV), which is composed of four domains (I, II, III, and IV) and a pseudoknot, is essential for translation and viral replication. Equine nonprimate hepacivirus (EHcV) harbors a 5' UTR consisting of a large 5'-terminal domain (I); three additional domains (I', II, and III), which are homologous to domains I, II, and III, respectively, of HCV; and a pseudoknot, in the order listed. In this study, we investigated the roles of the EHcV 5' UTR in translation and viral replication. The internal ribosome entry site (IRES) activity of the EHcV 5'...
Alphaviruses can produce febrile illness and encephalitis in dead-end hosts such as horses and humans. Within this genus, the Venezuelan Equine Encephalitis virus (VEEV) complex includes pathogenic epizootic subtypes and enzootic subtypes that are not pathogenic in horses (except subtype IE, Mexican strains), although they can cause febrile symptoms in humans. The Rio Negro virus (RNV-VEEV subtype VI) circulates in Argentina, where it was associated with undifferentiated febrile illness. Mayaro (MAYV) and Una (UNAV) viruses belong to a different group, the Semliki Forest virus complex, with co...
Tallmadge RL, Žygelytė E, Van de Walle GR, Kristie TM, Felippe MJB.Equine herpesvirus type 1 (EHV-1) is a ubiquitous and highly contagious pathogen that causes a range of disease severities with outbreaks of notable economic impact. Given the limitations in immune protection of current vaccines and the limited effectiveness of antiviral drugs on EHV-1 infections , improved treatment measures are needed to control disease. The use of drugs that alter the epigenetic state of herpes simplex virus genome has been shown to limit viral primary infection and reactivation both and . Therefore, we tested the hypothesis that maintaining a repressive epigenetic state o...
Zoll WM, Prakoso D, Dark M, Liu J, Stockdale-Walden H, Long MT.Eosinophils within the central nervous system are abnormal and are usually associated with fungal or parasitic infections in horses. Causative agents include Halicephalobus gingivalis, Sarcocystis neurona, and Neospora hughesi. Confirmation of these organisms via specific testing is typically not performed, and final diagnoses are often presumptive. With molecular technology, many of these organisms can now be confirmed. This is important for emerging and zoonotic pathogens, including Angiostrongylus cantonensis, an emerging parasite of interest in the southeastern United States. We retrospect...
Rivera-Páez FA, Martins TF, Ossa-López PA, Sampieri BR, Camargo-Mathias MI.Rickettsiosis are emerging or re-emerging diseases, with a worldwide distribution associated to transmission by arthropod vectors. Rickettsia species belong to the spotted fever group (SFG) and are transmitted by hard ticks (Acari: Ixodidae) that may act as vectors and reservoirs. This study carried out a molecular detection of Rickettsia from 7 species of the family Ixodidae collected from domestic hosts by PCR amplification of fragments of the citrate synthase "gltA" gene and outer membrane protein "ompA" gene. Of the 204 samples analyzed, 11.3% (23) were positive for rickettsial infection. ...
Borges IA, Reynolds MG, McCollum AM, Figueiredo PO, Ambrosio LLD, Vieira FN, Costa GB, Matos ACD, de Andrade Almeida VM, Ferreira PCP, Lobato ZIP....Since 1999 (VACV) outbreaks involving bovines and humans have been reported in Brazil; this zoonosis is known as Bovine Vaccinia (BV) and is mainly an occupational disease of milkers. It was only in 2008 (and then again in 2011 and 2014) however, that VACV was found causing natural infections in Brazilian equids. These reports involved only equids, no infected humans or bovines were identified, and the sources of infections remain unknown up to date. The peculiarities of Equine Vaccinia outbreaks (e.g., absence of human infection), the frequently shared environments, and fomites by equids and...
van Rijn PA, Maris-Veldhuis MA, Potgieter CA, van Gennip RGP.African horse sickness virus (AHSV) is a virus species in the genus Orbivirus of the family Reoviridae. Currently, nine serotypes have been defined showing limited cross neutralization. AHSV is transmitted by species of Culicoides biting midges and causes African Horse Sickness (AHS) in equids with a mortality up to 95% in naïve domestic horses. AHS has become a serious threat for countries outside Africa, since endemic Culicoides species in moderate climates are competent vectors of closely related bluetongue virus. AHS outbreaks cause huge economic losses in developing countries. In the dev...
Luciani M, Di Febo T, Orsini M, Krasteva I, Cattaneo A, Podaliri Vulpiani M, Di Pancrazio C, Bachi A, Tittarelli M.The diagnosis of dourine can be difficult because the clinical signs of this disease in horses are similar to those of surra, caused by . Moreover, and are closely related and, so far, they cannot be distinguished using serological tests. In a previous work, the protein pattern recognized by antibodies from dourine-infected horses and the humoral immune response kinetics were investigated by immunoblotting assay; a total of 20 sera from naturally and experimentally infected horses and from healthy animals were tested. Immunoblotting analysis showed that antibodies from infected horses speci...
Kabir A, Lamichhane B, Habib T, Adams A, El-Sheikh Ali H, Slovis NM, Troedsson MHT, Helmy YA.The equine industry holds substantial economic importance not only in the USA but worldwide. The occurrence of various infectious bacterial diseases in horses can lead to severe health issues, economic losses, and restrictions on horse movement and trade. Effective management and control of these diseases are therefore crucial for the growth and sustainability of the equine industry. While antibiotics constitute the primary treatment strategy for any bacterial infections in horses, developing resistance to clinically important antibiotics poses significant challenges to equine health and welfa...
Sanders RK, Martyn B, Joseph R, Peacock ML.In a two-year study of 322 conservatively treated, consecutive cases of tetanus in a rural hospital (all over twelve months old), intrathecal administration of 200 units of antitetanus serum (A.T.S.) (horse) reduced the overall mortality of 4-5% (5/110) compared with 14-5% (16/111) in the control series. 200 units intrathecal A.T.S. (horse) gave better results than 1500 units A.T.S. (horse). The results with lumbar and cisternal administration did not differ. It is suggested that tetanus is a polysystemic condition requiring polysystemic therapy. A regimen in which intrathecal A.T.S. is given ...
Xuan X, Nagai A, Battsetseg B, Fukumoto S, Makala LH, Inoue N, Igarashi I, Mikami T, Fujisaki K.Serum samples from horses in the States of Sao Paulo and Mato Grosso do Sul, Brazil were examined for diagnosis of equine piroplasmosis by both the latex agglutination test (LAT) and enzyme-linked immunosorbent assay (ELISA) with recombinant antigens. Of the 47 samples analyzed, 38 (81%) and 42 (90%) samples were positive for B. equi infection and B. caballi infection, respectively. In addition, 35 (75%) samples were positive for both B. equi and B. caballi infections. These results indicate that equine piroplasmosis is widespread and therefore a cause for serious concern in the States of Sao ...
Barros SC, Ramos F, Fagulha T, Duarte M, Henriques M, Luís T, Fevereiro M.The circulation of West Nile virus in Portugal was assessed by serological surveys conducted during 2004-2010 in horses and birds. The detection of WNV antibodies in both species in all the years covered by the study as well as the presence of anti-WNV IgM in symptomatic horses that had not traveled outside the country, support the notion that WNV circulates in Portugal.
Motoshima M, Okamatsu M, Asakura S, Kuribayashi S, Sengee S, Batchuluun D, Ito M, Maeda Y, Eto M, Sakoda Y, Sodnomdarjaa R, Kida H.A/equine/Kanazawa/1/2007 (H3N8), A/equine/Hokkaido/I828/2008 (H3N8) and A/equine/Mongolia/1/2008 (H3N8) were isolated from infected horses. A/equine/Yokohama/aq19/2009 (H3N8) and A/equine/Yokohama/aq13/2010 (H3N8) were isolated from horses imported from Canada and Belgium examined at the Animal Quarantine Service in Yokohama, Japan. In the present study, these five isolates were genetically and antigenically analyzed. Phylogenetic analysis of hemagglutinin (HA) and neuraminidase (NA) genes showed that three isolates from horses in Japan and imported from Canada belonged to the same branch, cla...
Johnstone LK, Engiles JB, Aceto H, Buechner-Maxwell V, Divers T, Gardner R, Levine R, Scherrer N, Tewari D, Tomlinson J, Johnson AL.Equine neuroborreliosis (NB), Lyme disease, is difficult to diagnose and has limited description in the literature. Objective: Provide a detailed description of clinical signs, diagnostic, and pathologic findings of horses with NB. Methods: Sixteen horses with histologically confirmed NB. Methods: Retrospective review of medical records at the University of Pennsylvania and via an ACVIM listserv query with inclusion criteria requiring possible exposure to Borrelia burgdorferi and histologic findings consistent with previous reports of NB without evidence of other disease. Results: Sixteen hors...
Dunowska M.Equid herpesvirus (EHV) type 1 is a common pathogen of horses with worldwide distribution. Infection with EHV-1 can be subclinical, or can result in sociologically and economically important outcomes such as abortion, neonatal death or neurological disease. The perceived recent increase in the reported cases of EHV-1 neurological disease in the United States of America and Europe over the past decade has caused concerns amongst veterinarians and horse owners worldwide. This review provides an update on the recent developments in our understanding of the pathogenesis and epidemiology of EHV-1 a...
Stull CL, Spier SJ, Aldridge BM, Blanchard M, Stott JL.Little information exists on the immunological effects of transport or the use of supplements to minimise transport stress. Objective: To establish baseline ranges and evaluate immunophenotypic and functional changes associated with transport and a nutritional 'adaptogen' supplement. Methods: Horses received either supplement (n = 10) or placebos (n = 9) during the 30 day study. After 28 days in stalls, 12 horses (6 supplement; 6 placebo) were transported for 24 h, then unloaded and recovered. Venous blood samples were collected on Days 1, 14 and 28 to establish baselines, and on Days 28, 29 a...
Dubey JP, Venturini MC, Venturini L, McKinney J, Pecoraro M.Sera from 76 horses from Argentina were examined for antibodies to Sarcocystis neurona, Toxoplasma gondii and Neospora caninum. Antibodies to S. neurona were found in 27 (35.5%) of 76 horses using immunoblots with culture derived merozoites as antigen. Antibodies to T. gondii were found in 10 (13.1%) of 76 horses by using the modified agglutination test with formalin-fixed tachyzoites and mercaptoethanol; titers were 1:25 (two horses), 1:50 (six horses), 1:100 (two horses), and 1:200 (one horse). Antibodies to N. caninum were not found in any of the 76 horses by the use of N. caninum agglutina...
Lang A, de Vries M, Feineis S, Müller E, Osterrieder N, Damiani AM.A peptide-based enzyme-linked immunosorbent assay (ELISA) for discrimination between serological responses to equine herpesvirus type 1 (EHV-1) and 4 (EHV-4) was developed. Three and four peptides for EHV-1 and EHV-4, respectively, were designed and studied initially in the ELISA using sera from foals infected experimentally. The most promising peptide pair, derived from EHV-1 glycoprotein E and EHV-4 glycoprotein G, was evaluated further using acute and convalescent sera from horses infected experimentally and naturally as well as a panel of horse field sera. Ten pre- and post-vaccination ser...
Allen GP.To evaluate a technique for identifying horses latently infected with neuropathogenic strains of equine herpesvirus-1 (EHV-1). Methods: 36 adult mares, 24 of which were experimentally infected as weanlings with neuropathogenic or nonneuropathogenic EHV-1. Methods: Mandibular lymph node (MLN) tissue was obtained from each horse via biopsy during general anesthesia. Purified DNA from MLNs was tested for EHV-1 DNA by use of a magnetic bead, sequencecapture, nested PCR assay. For MLNs that contained EHV-1 DNA, the 256-bp DNA fragments amplified via sequence-capture nested PCR were sequenced to det...
Nasisse MP, Nelms S.Ulcerative keratitis is one of the most common vision-threatening diseases of the horse. Successful therapy, however, can be achieved in the majority of cases provided the diagnosis is made early and the treatment is specific for the disease. This article reviews the pathophysiology, clinical signs, and contemporary medical and surgical approaches to bacterial and fungal ulcerative keratitis in the horse.
Pagamjav O, Kobayashi K, Murakami H, Tabata Y, Miura Y, Boldbaatar B, Sentsui H.Three hundred sera were collected from horses in various parts of Mongolia in 2007 and seroepidemiological surveys for several equine viruses performed on them. Equid herpesvirus 1 and equine rhinitis A virus were prevalent, and equine arteritis virus and equid herpesvirus 3 were detected over a wide area though their rates of antibody-positivity were not high. Equine infectious anemia was distributed locally. The rates of horses antibody-positive for Japanese encephalitis virus and equine influenza virus were low, but these were detected. Bovine coronavirus antibodies were detected at a high ...
Elia G, Lanave G, Lorusso E, Parisi A, Trotta A, Buono R, Martella V, Decaro N, Buonavoglia C.Equine hepacivirus is the closest homologue of hepatitis C virus. Limited data on the clinical features of this infection are available. We report the identification of a horse with high-titre viremia by equine hepacivirus. Over a 15-month follow-up, the clinical signs and the viremic status persisted, suggesting a chronic evolution.
Suzuki K, Matsui Y, Miura Y, Sentsui H.Equine coronavirus (ECoV) was first isolated from a diarrheic foal and was found genetically similar to group II coronaviruses. However, its pathological characteristics were not adequately investigated. In our preliminary in vitro investigation, ECoV-induced cell death was observed in bovine kidney-derived MDBK cells. Based on this finding, we investigated whether the ECoV-induced CPE was apoptosis. Following ECoV infection, MDBK cells showed morphological changes such as cell rounding and detachment from the culture surface. Moreover, syncytium formation was observed as the other type of cyt...
PLUMMER G.Experiments involving the intranasal inoculation of monkeys, rabbits and guinea pigs with an equine respiratory virus were carried out. The animals were killed at various intervals after inoculation and attempts made to isolate virus in tissue culture from extracts of homogenized tissues and organs. All three species were susceptible, virus reproduction occurring in the respiratory tract and associated lymph glands. Of the three species virus was least readily isolated from the guinea pig tissues. There was a viraemia in monkeys and rabbits, but virus was less readily detected in the blood of ...
Hawkins JA, Adams WV, Wilson BH, Issel CJ, Roth EE.The mechanical transmission of equine infectious anemia (EIA) virus by Tabanus fuscicostatus was investigated. In 1 of 7 transmission trials, a single horsefly transmitted EIA virus from an acutely infected pony to a susceptible pony. Groups of horseflies isolated for 3, 10, or 30 minutes before refeeding transmitted EIA virus, whereas those isolated for 4 or 24 hours did not. Data from field studies indicate that the home range or flight distance of horseflies may exceed 4 miles. That information together with our observations suggest that segregation of infected horses (usually defined as at...
Castillo-Olivares J, Mansfield KL, Phipps LP, Johnson N, Tearle J, Fooks AR.West Nile virus (WNV) has re-emerged as an important pathogen for humans and horses, which are considered to be incidental 'dead-end' hosts. We have demonstrated that horses are susceptible to experimental infection with WNV and that horses infected with either WNV lineage 1 or lineage 2 elicit a similar antibody profile in serum samples. These data suggest that virus-neutralizing antibody responses persist for longer than WNV-specific IgM levels in serum and that there are not any notable differences in the antibody profile following experimental infection of horses with either WNV lineage 1 ...
McBrearty KA, Murray A, Dunowska M.To determine which viruses circulate among selected populations of New Zealand horses and whether or not viral infections were associated with development of respiratory disease. Methods: Nasal swabs were collected from 33 healthy horses and 52 horses with respiratory disease and tested by virus isolation and/or PCR for the presence of equine herpesviruses (EHV) and equine rhinitis viruses. Results: Herpesviruses were the only viruses detected in nasal swab samples. When both the results of nasal swab PCR and virus isolation were considered together, a total of 41/52 (79%) horses with respirat...
Ribeiro MG, Seki I, Yasuoka K, Kakuda T, Sasaki Y, Tsubaki S, Takai S.We investigated the prevalence of virulent Rhodococcus equi in clinical isolates from 41 foals (19 sporadic and seven endemic cases) in Brazil between 1991 and 2003. Of the 41 virulent isolates, six contained an 85-kb type I plasmid, 33 contained an 87-kb type I plasmid, both of which have been found in isolates from the Americas, and the remaining two contained a new variant, which did not display the EcoRI, EcoT22I and BamHI digestion patterns of the 11 representative plasmids already reported (85-kb types I-IV; 87-kb types I and II; 90-kb types I-V). We tentatively designated the new varian...