A highly fatal infectious disease was obtained in adult rabbits in Assiut area during winter of 1992. Many outbreaks of the disease occurred in domestic rabbit colonies. The mortality rate was 100% among a rabbit colony of 26 rabbits and it was 96.5% in another colony of 29 adult rabbits. The course of the disease was drastic and the clinical symptoms ranged between peracute and acute picture. Infected rabbit died suddenly without any observed clinical manifestations. Haemorrhagic foamy discharge from the nostrils and vagina was observed in few cases. Post mortem findings included bloody mucous in the trachea, discoloured liver. The diagnosis of the disease was relied on the epidemiological observation and by detec tion of the virus particles in hepatic cells by electron microscopy. Experi mental infection of adult rabbits was carried out by organ suspensions.
Infected rabbit died within 42 to 66 hours, with the same post mortem lesions as those observed in natural outbreaks. The organ suspensions of the diseased and experimentally infected animals showed a haemagglutin ation titer using type 0 human and chicken erythrocytes. Convalescent rabbit serum completely abolished haemagglutination in haemagglutination inhibition test, whereas normal rabbit serum had no inhibitory effect.