Malignant catarrhal fever in two California dairy herds

Abstract

Two epizootics of malignant catarrhal fever in 1976 in Southern California were characterized by the peracute and acute form of the disease. In one herd of 1000 cows, 166 (17%) were affected. Clinical signs in acute cases were fever, diarrhoea, weakness, ocular and nasal discharge, erosions of the muzzle and buccal papillae, and rapid progression of symptoms until death. Diagnosis was confirmed by history, clinical signs, gross and microscopic pathology and transmission studies.