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.
Lancaster WD, Olson C, Meinke W.Four of five spontaneous benign equine connective tissue tumors of unknown etiology and a bovine papilloma virus (BPV)-induced equine tumor contained BPV-specific DNA sequences as determined by DNA-DNA hybridization of DNA from tumors with BPV DNA labeled in vitro. Analysis of the kinetics of reassociation indicated that 20-75% of the BPV genome was present in the various tumors. The number of partial BPV genome equivalents ranged from 60 to 500 copies per diploid quantity of cellular DNA. Thermal denaturation profiles of duplexes formed between labeled BPV DNA and DNA from tumor cells indicat...
Berezin VV.Virologic and serological surveys of wild vertebrates carried out in various provinces of Cuba demonstrated definitely that birds were the main hosts of eastern equine encephalomyelitis (EEE) virus in this territory. Fifteen strains of this virus were isolated from 8 species of birds belonging to 5 orders. Isolation of EEE virus from the blood of the endemic genus of iguanas indicates a certain role of cold-blooded animals in the ecology of this agent. Active EEE virus foci have been found in 4 provinces of the Republic of Cuba: Pinar del Rio, Havana, Matanzas and Las Villas. Isolation of a nu...
Allen GP, O'Callaghan DJ, Randall CC.Infection of cells with equine herpesvirus type 1 (EHV-1) or type 3 (EHV-3) resulted in the induction of a DNA polymerase activity distinguishable from host cell DNA polymerases by its high salt requirement for maximal activity. By column chromatography on DEAE-cellulose, DNA-cellulose, phosphocellulose, and hydroxyapatite, the EHV-1-induced polymerase was purified 500-fold with 1–2% recovery of total activity from the nuclei of infected hamster livers. The final enzyme preparation was homogeneous as judged by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels. Calculations based ...
Wilks CR.The immune response in horses following experimental infection with equine herpesvirus type 1 (EHV-1) was assessed by measuring cytotoxicity for EHV-1-infected target cells. A technique was developed, using [125I]5-iodo-2'-deoxyuridine ([125I]IUDR)-labeled equine fetal kidney cells infected with EHV-1 as the target cells. It was shown that peripheral blood leukocytes from a recovered horse were capable of lysing target cells, as measured by the loss of radio-active label. Following the experimental infection of specific-pathogen-free ponies with EHV-1, cytotoxicity was obtained with fresh auto...
Weiland F, Matheka HD, Coggins L, Hatner D.Morphological studies of EIAV reveal knobs on the surface of the particles, conically and tubularly shaped cores, budding particles with dense crescents directly underlying the plasma membrane, and distinct intracytoplasmic structures in infected cells.
Benmansour A, Benelmouffok A, Bouguermouh A.During an epizootic of equine acute respiratory disease in Algeria, a strain of equine influenza virus was isolated. Sera examination by hemagglutinin inhibition test and complement fixation test confirmed the etiology of the disease. The first and second outbreak of the disease remained localised. The third outbreak spread within few months to all parts of the country. Horses vaccinated with a commercial equine influenza vaccine remained healthy.
Melnick JL, Schmidt NJ, Hampil B, Ho HH.This paper describes the preparation of seven combination pools of equine antisera, designated J though P, for identification of 19 coxsackievirus A immunotypes. Each pool is composed of 4 to 6 antisera; the serotypes included are A1-6, 8, 10-15, and 17-22. These pools, unlike the previously prepared A-H enterovirus pools, were lyophilized from volumes of 0.5 ml dispensed into 5-ml vials, and when rehydrated with 5 ml of diluent provide 50-antibody-unit material ready for use in identification tests without further dilution. Procedures for using the antiserum pools are given, and guidance is p...
Verberne LR, Mirck MH.A comparative study of the literature of the past ten years showed that vaccination of horses and ponies against influenza is best done using adjuvant-containing vaccines. Comparable results may probably be obtained by twice inoculating an aquenous vaccine. There are no drawbacks to the use of aluminium-hydroxide as an adjuvant when mineral oil is used as an adjuvant, the first and second vaccinations do not present any problems.
Bigler WJ, Lassing EB, Buff EE, Prather EC, Beck EC, Hoff GL.Research and surveillance programs relating to the circulation of eastern equine encephalomyelitis (EEE) virus in Florida between 1955 and 1974 are summarized. All available data suggest that EEE virus is 1) endemic in many Florida fresh water swamps and waterways, 2) active in a continuous cycle throughout the year with a peak between May and August, and 3) circulating in Culiseta melanura. It has been isolated also from eight other mosquito species.
Thompson DB, Spradborw PB, Studdert M.Some details of the clinical and postmortem findings of an Arab foal that died as a consequence of adenoviral pneumonia superimposed on a combined immunodeficiency disease are provided. The foal was the 17th in a series of similar deaths that occurred on a farm since 1959. An adenovirus, which by haemagglutination inhibition and serum neutralisation tests was antigenically similar to 2 other equine adenoviruses isolated in Australia, was isolated from a nasal swab taken from the foal when it was 23 days of age.
Charman HP, Bladen S, Gilden RV, Coggins L.Equine infectious anemia virus (EIAV) has a density of 1.154 g/cm3 in sucrose a high-molecular-weight RNA similar in size to Rauscher murine leukemia virus, and an internal virion reverse transcriptase that utilizes the synthetic RNA template poly(rA) but not the synthetic DNA template poly(dA), both with (dT)12 as primer. Although capable of utilizing manganese at low concentrations (approximately 0.1 mM), EIAV reverse transcriptase showed highest activity in the presence of 9 mM magnesium. The major protein of EIAV has a slightly lower molecular weight than the comparable protein of type C v...
Breaud TP, Steelman CD, Roth EE, Adams WV.A tissue culture of Culex pipiens quinquefasciatus Say ovarian cells appeared to support the growth of equine infectious anemia (EIA) virus. Shetland ponies inoculated with 2nd, 7th, 9th, and 11th passages of mediums harvested from infected tissue culture had clinical signs of the disease and became EIA positive on 11, 19, 23, and 43 days after inoculation, respectively.
Sentsui H, Kono Y.Equine infectious anemia (EIA) virus which was propagated on an equine dermal cell line agglutinated guinea pig erythrocytes. Viral fluids containing about 10(7.5) mean tissue culture infective doses/ml showed hemagglutinating (HA) titers ranging from 16 to 32 units/0.05 ml. Results of cesium chloride equilibrium density gradient centrifugation revealed that the hemagglutinin was inseparable from the virus particles. The hemagglutination reaction persisted over a wide range of temperature and pH, and the absence of divalent cations did not decrease its activity. The HA activity was stable at 4...
Gleeson LJ, Sullivan ND, Studdert MJ.The inoculation of equine herpesvirus type 3 (EHV3) strain 65/61 into the amniotic cavity of a mare 6-7 months pregnant resulted in abortion 11 days later. Following abortion typical lesions of coital exanthema were not observed in the genital tract of the mare, nor was EHV3 isolated from her. Serological evidence, however, indicated that the mare was infected with EHV3 following inoculation. Grossly the foetal disease was characterised by placentitis, focal ulcerative dermatitis, focal necrosis of the lungs and a striking diptheritic gastritis. Histological findings were interstitial pneumoni...
Goto H, Shimizu K, Abe T, Kanamitsu M.A serological survey was conducted on horse sera collected for 7 years just before the first outbreak of equine influenza (EI) infection in Japan in 1971. No antibodies against the A/Equi-1/Prague/56 (equi-1) and A/Equi-2/Miami/63 (equi-2) strains of EI virus were detected in any of the sera of 452 native horses when employing hemagglutination inhibition (HI) and complement fixation (CF) tests against viral (V) antigen. On the contrary, of the 80 imported horses, 48 (60.0%) had HI titers of 1:8 or higher against equi-1 and 23 (28.8%) against equi-2. In the CF-V test 42.6% of the horses showed ...
Dinter Z, Klingeborn B.Six cases of paresis occurred in a Swedish stud with 48 mares and a stallion. Complement-fixation tests revealed a recent infection with EHV-1 in most horses of the stud. Serumneutralisation tests showed rapid antibody-titre increases during the course of the disease. This type of antibody response was interpreted as induced by reinfection or, possibly, recurrent infection. Two diseased mares were sacrificed. No virus could be isolated from their central nervous system (CNS), liver or spleen, but there is a presumptive evidence for the presence of an antigen specific to EHV-1 in the CNS and li...
Scherer WF, Ordonez JV, Dickerman RW, Navarro JE.Evidence was sought during 1970-1975 of persistence of equine-virulent Venezuelan encephalitis (VE) virus in regions of Central America that were heavily involved in the epidemic-equine epizootic of 1969. (a) Four sentinel horses were exposed in an arid, upland region of the Atlantic drainage of Guatemala during August-October 1970, but no horse became infected. (b) The epicenter region of the 1969 outbreak, in southwestern Guatemala and southwestern El Salvador, was studied during July 1970-February 1974; no antibody developed in sentinel horses, sentinel hamsters did not die, mosquitoes yiel...
Zientara S.After a brief historical account of the outbreak of infectious arteritis of horses which occurred in 1984 in Kentucky (United States of America), the author reports on the present state of knowledge concerning the organisation of the genome of the virus. Clinical signs of the disease are described, as well as modes and routes of transmission. Finally, currently-available vaccination procedures are discussed and their value is assessed.
Strang C.Camilla Strang of the Animal Health Trust provides an overview of the diagnosis and control of conditions associated with infection by equine herpesvirus.