The study of viral infections that affect equine species assesses the relationship between viruses and horses. Infections can lead to a range of clinical symptoms and may impact the health and performance of horses. Common equine viruses include Equine Influenza Virus, Equine Herpesvirus, and West Nile Virus, among others. Understanding the mechanisms of viral transmission, pathogenesis, and host immune responses is essential for developing effective prevention and treatment strategies. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, molecular biology, and clinical management of viral infections in horses.
Lawrence WC.Autoradiographic analyses of deoxyribonucleic acid (DNA) synthesis in randomly growing KB cell cultures infected with equine abortion virus (EAV) suggested that viral DNA synthesis was initiated only at times that coincided with the entry of noninfected control cells into the S phase of the cell cycle. Synchronized cultures of KB cells were infected at different stages of the cell cycle, and rates of synthesis of cellular and viral DNA were measured. When cells were infected at different times within the S phase, viral DNA synthesis was initiated 2 to 3 hr after infection. However, when cells ...
Heydrick FP, Comer JF, Wachter RF.Phospholipid analyses of Venezuelan equine encephalitis virus showed that virus propagated in L-cell monolayers had a higher sphingomyelin content and a lower phosphatidylcholine content than virus grown in chick fibroblast monolayers. Virus of L-cell origin also was found to possess greater thermal stability than virus derived from the chick fibroblast cell.
Gruber J.Purified and concentrated Venezuelan equine encephalitis (VEE) virus derived from tissue cultures, rendered noninfectious by ionizing radiation with retention of in vitro serological activity, also retained a high level of immunogenicity. In mice, fluid vaccines afforded excellent protection against lethal challenge with homologous Trinidad strain VEE virus. A direct relationship was observed between concentration of vaccine or number of injections and survival. One intraperitoneal inoculation of undiluted vaccine protected essentially all mice challenged 21 days later with 100,000 mouse intra...
Henderson BE, Chappell WA, Johnston JG, Sudia WD.Henderson, B. E., W. A. Chappell, J. G. Johnston, Jr. and W. D. Sudia (CDC, Atlanta, Ga. 30333). Experimental Infection of horses with three strains of Venezuelan equine encephalomyelitis virus. I. Clinical and virological studies. Amer J Epidem 93: 194–205, 1971.—Clinical effect, viremias and antibody responses were compared in horses inoculated with the following strains of Venezuelan equine encephalomyelitis (VEE) virus: Fe3-7C, isolated from Culex (Melano-conion) spp. mosquitoes collected In 1963 in the Florida Everglades; TC-83, the Fort Detrick live, attenuated vaccine strain; and GJ...
Nakajima H, Ushimi C.Antigenicity of purified equine infectious anemia (EIA) virus was examined by immunodiffusion against sera obtained from horses experimentally infected with EIA virus. The purified virus reacted with the infected horse serum, and virus-specific precipitating antibody was demonstrated. Furthermore, it was found that purified EIA virus reacted against the serum of horses infected with all strains of EIA virus which were antigenically different from one another. From the result, group-specific components of the virus rather than strain-specific ones were considered to be involved in the reaction....
Marois P, Boudreault A, DiFranco E, Pavilanis V.Rhesus monkeys and ferrets were exposed to intranasal inoculation of several strains of egg-adapted avian, equine and human influenza viruses and to strains of mouse-adapted equine influenza viruses. Local replication of virus and seroconversion were observed in the majority of these animals. However, clinical infection was observed only in ferrets.
Schmidt NJ, Melnick JL, Wenner HA, Ho HH, Burkhardt MA.Immune horse sera to 42 enterovirus immunotypes were pooled according to the Lim Benyesh-Melnick and the "intersecting serum" schemes. Each serum was diluted in the pools to contain 50 antibody units. After it was established that the pools correctly neutralized prototype virus strains, they were evaluated in tests against 273 enterovirus field strains representing most of the viral types included in the pools. With test virus doses of 10-100 TCD(50), most of the poliovirus and coxsackievirus field strains were correctly identified in both schemes, but a number of the echoviruses were neutrali...
Scott GR.Twelve DNA viruses and forty‐three RNA viruses are known to infect horses. In addition, there are three unclassified viruses and, at least, three alleged viruses infecting horses. Differential diagnosis is difficult. At least twenty‐eight of the fifty‐eight viruses induce clinical disease but the range of syndromes is limited; eleven provoke respiratory symptoms and eleven cause encephalitis. Thirty‐four equine viruses with a limited geographical distribution are transmitted by arthropod vectors. Twenty viruses are spread by contact and their distribution, in general, is global. The ve...
Balasuriya UBR.The primary goals of this chapter are to discuss common viral RNA isolation and purification methods that are routinely used by various diagnostic laboratories and to highlight the advantages and drawbacks of each method and to identify the most suitable and reliable method to increase the sensitivity and specificity of RT-PCR assays for the detection of equine influenza virus (EIV) in clinical specimens. Our experiences and review of literature show that magnetic bead-based nucleic extraction methods (manual and automatic) work well for isolation and purification of EIV RNA from nasal swab sp...
Kim L, Morley PS, McCluskey BJ, Mumford EL, Swenson SL, Salman MD.To report clinical and serologic findings in horses with oral vesicular lesions that were consistent with vesicular stomatitis (VS) but apparently were not associated with VS virus (VSV) infection. Methods: Serial case study. Methods: 8 horses. Methods: Horses were quarantined after appearance of oral lesions typical of VS. Severity of clinical signs was scored every 2 to 5 days for 3 months. Serum samples were tested for antibodies by use of competitive ELISA (cELISA), capture ELISA for IgM, serum neutralization, and complement fixation (CF). Virus isolation was attempted from swab specimens ...
Neill JD, Kelling CL, Rhodes MB.Pigs experimentally inoculated with bovine herpesvirus-1 or equine herpesvirus-1 developed mild clinical disease signs. Regression of clinical disease was accompanied by development of specific virus-neutralizing antibodies. These antibodies did not react positively with pseudorabies antigens in the serum-virus neutralization test, an indirect radioimmunoassay, or a microimmunodiffusion test.
Alstad AD, Sahu SP, Pedersen DD, Saari DA, Kawaoka Y, Webster RG.An influenza virus, A/equine/Alaska/1/91 (H3N8), was isolated from horses from Alaska with an acute respiratory infection. Pathogenic and serologic studies revealed that this virus is similar to previously isolated equine H3N8 influenza viruses. Antigenic analyses utilizing hemagglutination inhibition and neuraminidase inhibition assays indicated an antigenic drift from the prototype equine H3N8 influenza virus, A/equine/Miami/1/63. Partial sequence analysis of the A/equine/Alaska influenza virus indicated that each of 8 gene sequences are of equine origin.
Horner GW.To review laboratory aspects of the equine viral arteritis (EVA) control scheme in New Zealand between 1989 and 2002. Methods: The optimisation and performance of the virus neutralisation test (VNT) for equine arteritis virus (EAV) antibody, and the cell culture test to detect EAV in semen were analysed. Laboratory data and control scheme results were reviewed. Results: Using optimised tests, it has been shown that antibody prevalence in Standardbred horses has steadily declined from 54% to <20%. Prevalences in Thoroughbred horses have remained at a low level of around 3%. The number of horses...
Hoffmann B, Joseph S, Patteril NAG, Caveney MR, Elizabeth SK, Muhammed R, Wernery R, Wernery U.African horse sickness (AHS) is a viral disease of equids, caused by a virus of the genus Orbivirus, family Reoviridae. The African horse sickness virus (AHSV) genome is made up of ten double-stranded RNA (dsRNA) segments that together code for seven structural and four nonstructural proteins. AHS is endemic in sub-Saharan countries. The efficacy and safety of inactivated AHS vaccines containing all nine serotypes, produced at the Central Veterinary Research Laboratory (CVRL) in Dubai, United Arab Emirates have been proven in the past. All nine AHSV serotypes were isolated from 102 samples col...