• Journal of Practical Agriculture & Fisheries Research
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• v.16 no.1
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• pp.105-113
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• 2014

Equine herpesvirus type 1 (EHV-1) is an economically important pathogen of horses and exerts its major impact by inducing abortion storms and sporadic abortions in pregnant mares, early neonatal death in foals, and respiratory disease in young horses. Although equine herpesvirus type 4 (EHV-4) rarely causes clinical manifestations of disease in organs other than the respiratory track, isolated cases of myeloencephalopathy and sporadic abortions have been reported in EHV-4 infections. Here, we report an abortion storm in Thoroughbred breeding farms in Jeju island, South Korea. It occurred for 16 days from first abortion to last one. There were no clinical signs prior to abortion and stillbirth in broodmares. Two PCR-primers were made on glycoprotein B gene of EHV-1 and EHV-4 to amplify specific common regions of the viruses. We could detect the virus specific genes in aborted samples by PCR, and concluded that the cause of abortion storm was EHV infection. This report describes the first abortion storm case caused by EHV in Thoroughbred breeding farms in South Korea.

• Journal of Microbiology
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• v.40 no.3
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• pp.183-192
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• 2002

Cells infected With equine herpesvirus type-1 (EHV-1) Produced both infectious and non-infectious Virus-related particles. Compared to the whole virion, non-infectious particles termed L-particles were deter-mined to lack 150 kDa protein, commonly known as nucleocapsid protein. The potential of L-particles to induce immune responses was studied in mice and foals. Intranasal immunization with L-particles or whole virions induced poor IgG antibody responses in mice. Interestingly, despite the poor antibody response, the conferred immunity protected the host from challenge infections. This was indicated by a significant reduction in virus titers in line with recovery towards normal body weight. Subsequently, the test on the usefulness of L-particles as immunizing agents was extended to foals. Immunization of specific-pathogen-free (SPF) foals resulted in similar results. As determined by a complement-fixing-antibody test (CFT), foals seroconverted when they were immunized either with inactivated L-particles or whole virions via intramuscular (i.m.) injections. The presence of the antibody correlated with the degree of protection. Beyond day 1 post challenge infection (p.i.), there was no virus shedding in the nasal mucus of foals immunized with whole EHV-1 virions. Virus shedding was observed in foals Immunized with L-particles but limited to days 6 to 8 p.i. only. In contrast, extended vim shedding was observed in non-immunized foals and it was well beyond day 14 p.i. Viremia was not detected for more than four days except in non-immunized foals. Immunization in mice via intranasal (i.n.) conferred good protection. However, compared to the i.n. route, a greater degree of protection was obtained in foals following immunization via i.m. route. Despite variation in the degree of protection due to different routes of immunization in the two animal species, our results have established significant evidence that immunization with L-particles confers protection in the natural host. It is suggested that non-infectious L-particles should be used as immunizing agents for vaccination of horses against EHV-1 infection.

• Korean Journal of Veterinary Service
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• v.34 no.2
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• pp.187-190
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• 2011

The Thoroughbred horse was an approximately 4-years-old castrated male with highly emaciation, nasal epistaxis and subsequently died. Gross necropsy revealed epistaxis and hyperemia on the lung, multiple hemorrhage in muscle, and liver was focally attached to the peritoneum with fibrin. According to polymerase chain reaction (PCR), Equine herpes virus type 1 and 4 (EHV type 1, 4) was detected in the lung and trachea. In bacterial culture from kidney, liver, spleen, muscle and blood, Streptococcus equi subsp. zooepidemicus was isolated. Based on the gross lesion and PCR, this horse was diagnosed as EHV type 1, 4 and S. zooepidemicus coinfection.

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.743-752
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• 1995

The study was carried out to characterize the properties of Korean isolates of EHV from aborted fetuses and determine envelope protein profiles. The results obtained were summarized as follows; 1. Two strains of EHV was isolated from 2 liver samples among 10 aborted fetuses from which the virus isolation was attempted. 2. Morphological and some enzymatic properties of the Korean isolates of EHV which was designated as $LC_1$ and $LC_2$ was identical to those of a reference strain of Australia-N of EHV-1. The Korean isolates of EHV could be propagated on ED cell culture and they formed typical plaques 1 to 2 days after infection in the ED cells from which typical cuboidal particles of 150~170 nm diameter herpesvirus were observed. The virus could be detected specifically from neucleus and cytoplasm of infected cells by flourescent antibody technique using FITC labelled anti-Aust IV(EHV-1) antiserum. The Korean isolates, $LC_1$ and $LC_2$ were specifically neutralized by anti Aust IV antiserum and reacted positively to CELISA. 3. The structural polypeptides of purified enveloped virions of $LC_1$ and $LC_2$ isolates of EHV were determined by SDS-polyacrylamide gel electrophoresis to identify the envelope glycoproteins. $LC_1$ and $LC_2$ strains revealed 14 glycoproteins ranging in molecular weight from 190 kD to 31 kD while 17 structural proteins of Aust IV(EHV-1), of which 14 were identical to those of $LC_1$ and $LC_2$, were identified. Upon immunoblotting by rabbit antiserum against EHV isolates and EHV-1(Aust IV), 4 immunogenic proteins of $LC_1$ and $LC_2$ were 135 kD, 88 kD, 64 kD and 59 kD, of which 135 kD, 88 kD and 64 kD proteins were also found in Aust IV(EHV-1).

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.753-758
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• 1995

The study was carried out to investigate the pathogenicity of EHV isolate to hamsters and mice and immunogenicity of experimentally produced. vaccine were evaluated in the horses. Hamsters infected. intranasally with $LC_1$ isolate showed symptoms of nasal discharge, conjunctivitis and body weight loss during the observation period of 12 days after infection, while only slight depression and body weight loss were noticed with mice infected with $LC_1$ indicating that hamsters are more susceptible to the virus. Antibody titer of mice and hamsters were gradually increased to highest level of 1:2560~10240, 1:640~1280, respectively, at 7~12 days post vaccination. Horses immunized against $LC_1$ killed vaccine reached to maximum antibody titer of 1:20480 around 4 weeks after 1st vaccination and declined after 12 weeks post vaccination. No significant antibody increase were detected after 2nd vaccination. Mean body temperature and mean total leukocyte counts remained within normal range and no adverse reaction were noticed after vaccination.