Naturally occurring herpes simplex encephalitis in a domestic rabbit (Oryctolagus cuniculus).

An approximately 1-year-old domestic rabbit showed severe neurologic signs with circling and turning somersaults. Histologically, a nonsuppurative meningoencephalitis with neuronal cell necrosis and numerous intranuclear inclusion bodies in neurons and glial cells was found. Electron microscopic examination revealed herpesvirus particles in affected cells. A human herpes simplex virus was identified by means of immunocytochemistry and in situ hybridization as the causal agent and was further classified as herpes simplex virus 1 by polymerase chain reaction analysis. Because encephalitis is easily induced in rabbits by experimental infection with herpes simplex virus, the source of infection is suspected to be a human with herpes labialis who had close contact with the rabbit.