This report describes the naturally occurring atypical neuropathological manifestation of systemic canine distemper virus (CDV) infection in two 16-day-old Pit Bull pups. CDV-induced changes affected the gray and white matter of the forebrain while sparing the hindbrain. Histologically, there was necrosis with destruction of the nervous parenchyma due to an influx of inflammatory and reactive cells associated with eosinophilic intranuclear inclusion bodies within glial cells. Positive immunoreactivity against CDV antigens was predominantly observed within astrocytes and neurons. RT-PCR was used to amplify CDV-specific amplicons from brain fragments. These findings suggest the participation of CDV in the etiopathogenesis of these lesions.
Animals ; Antigens, Viral ; Central Nervous System/pathology/virology ; Distemper/*virology ; *Distemper Virus, Canine ; Dogs ; Encephalitis/pathology/*veterinary/virology ; Necrosis/pathology/*veterinary/virology

A virus strain, showing cytopathic effect in Vero cell, was isolated from plasma of a fattening pig in Gyeonggi province, Korea in October 1999. The evaluation of physicochemical/biological properties of the isolate showed that the virus, KV1899, inoculated suckling mouse showed paralysis and died within 7 days post-inoculation, the mouse brain suspension had hemagglutinating activity with goose RBC. Pathogenicity of isolate was carried out by intracranial and intraperitoneal inoculation of 3-4 weeks mice. The mice inoculated with isolate showed 10 4.5 LD50/ 0.03 ml and 10 3.0 LD50/0.5 ml according to the inoculation route. The isolate was identified as RNA and enveloped virus using IUDR and chloroform sensitivity test. The virus particles within the infected Vero cell were measured to be 40-50 nm in size by electron microscopy. The isolate was further characterized by immuno-fluorescence assay using Japanese encephalitis virus (JEV) specific monoclonal antibodies. Reverse transcription polymerase chain reaction (RT-PCR) revealed the presence of JE specific conserved sequences in this isolate. The artificially inoculated pigs had HI titer of 320 to 2,560 against JEV at 14 to 42 days post inoculation. We confirmed this isolate as Japanese encephalitis virus. It was the second isolation of JEV in pigs in Korea.
Animals ; Antibodies, Viral/analysis ; Cercopithecus aethiops ; Cytopathogenic Effect, Viral ; Encephalitis Virus, Japanese/*classification/*isolation & purification/ultrastructure ; Encephalitis, Japanese/pathology/*veterinary/virology ; Fluorescent Antibody Technique, Indirect/veterinary ; Hemagglutination Inhibition Tests/veterinary ; Hemagglutination Tests/veterinary ; Korea ; Mice ; Microscopy, Electron/veterinary ; RNA, Viral/analysis ; Reverse Transcriptase Polymerase Chain Reaction/veterinary ; Swine ; Swine Diseases/pathology/*virology ; Vero Cells/virology