Rabbit Haemorrhagic Disease

Rabbit haemorrhagic disease (RHD) is a highly contagious and acute fatal disease of the European rabbit (Oryctolagus cuniculus), caused by a calicivirus (genus Lagovirus). A similar disease, [caused by a different calicivirus and] termed European brown hare syndrome (EBHS), has been described in the hare (Lepus europaeus). Its aetiological agent is a different species of lagovirus [calicivirus], antigenically related to the RHD virus (RHDV). RHD is characterised by high morbidity and high mortality (70[40]–90%), and spreads very rapidly by direct and indirect transmission. Infection can occur by nasal, conjunctival or oral routes. Transmission of RHD is facilitated by the high stability of the virus in the environment. The incubation period varies from 1 to 3 days, and death usually occurs 12–36 hours after the onset of fever. The clinical manifestations have been described mainly in the acute infection and are nervous and respiratory signs, apathy and anorexia. Clear and specific lesions, both gross and microscopic, are present. There is primary liver necrosis and a massive disseminated intravascular coagulopathy in all organs and tissues. The most severe lesions are in the liver, trachea and lungs. Petechiae are evident in almost all organs and are accompanied by poor blood coagulation. In rabbits younger than 4–5 weeks, the RHDV infection course is subclinical.