Mycobacterium avium Complex Serovar 8 Infection in a Japanese Brown Calf

Abstract

A 3-month-old female calf of Japanese brown suffering from chronic dearrhea was euthanatised at 8 months of age and showed gross finding similar to Johne's disease. Histopathology revealed the edematous thickening of ileal lamina propria with infiltration of monocytes, and the swelling of mesenteric lymph nodes. From affected mesenteric lymph nodes Mycobacterium avium complex serovar 8 was isolated, and the isolates were susceptible to cycloserine but not to ethambutol and other 8 drugs tested. It was suggested that it might be important to distinguish this disease from the Johne's disease.