Borna disease
Borna disease is fatal neurological disease of horses and sheep caused by a virus (RNA) of the family Bornaviridae and the disease is characterized by sub acute meningoencephalitis and infiltration of mononuclear cells. The disease owes its name to the area around the town Borna in Saxony, Germany where a great number of horses died during an epidemic. The disease has not been reported in India

Clinical signs: Incubation period is 4 weeks. The clinical picture in acute disease is dominated by symptoms due to meningitis and encephalomyelitis such as severe depression, permanent standing upright in unphysiological positions, ataxia, circular movements and running against obstacles, incoordination of movement, disturbed sensory functions, lethargy, paralysis and death.

Diagnosis: Indirect immunofluorescent assay is the most suitable test for detecting BDV specific antibodies in the serum and/or CSF. In histopathology, variable degree of encephalitis is observed in brain tissue of infected horses. Lymphocytic infiltrations are usually most common in the hippocampus, the brain stem and in parts of the cerebral cortex. Virus isolation from brain tissues of infected horses is not always successful. BDV can also be detected in brain tissue by nested PCR and viral antigen by a capture ELISA.