Epidemiology and diagnosis of the European brown hare syndrome in Scandinavian countries: a review.

Outbreaks among European brown hares (Lepus europaeus, Pallas) of a fatal disease associated with severe liver damage have occurred in Sweden since the beginning of the 1980s. The disease, called the European brown hare syndrome (EBHS), was recognised in Denmark in 1982 and is today widespread in Denmark and southern Sweden. It has not been reported in Norway or Finland. Two species of hares are affected in Sweden, the European brown hare and the varying hare (Lepus timidus, Linnaeus). EBHS occurs both in free living and farmed hares. The disease is clearly seasonal, occurring most frequently in October, November and December. A virus related to the viral haemorrhagic disease of rabbits virus has been shown to cause EBHS. All attempts to isolate the virus in cell culture have been unsuccessful. Diagnosis can be made by histopathology and detection of the virus in organ homogenates by haemagglutination, negative staining electron microscopy and enzyme-linked immunosorbent assay (ELISA). Antibodies can be detected early by haemagglutination inhibition and ELISA.