Persistent Infection of Cattle with the Herpesvirus of Malignant Catarrhal Fever and Observations on the Pathogenesis of the Disease

Abstract

A case of persistent MCF virus infection is described. A steer was inoculated with attenuated virus and apparently withstood challenge with virulent MCF virus. Five months later it developed a viraemia which persisted for four weeks and the animal died after only one day's fever. Post-mortem and histological studies showed extensive ulcerative, haemorrhagic enteritis and a necrotizing polyvasculitis with mononuclear leucocyte infiltration. Experimental studies have demonstrated viraemia to preceed fever in cases of acute MCF. The pathogenesis of MCF is discussed in the light of these findings and it is concluded that MCF might be an immune complex disease.