AN ABATTOIR SURVEY OF TUBERCULOSIS IN FERAL BUFFALOES

Abstract

Tuberculosis lesions were found in 193 (1.7%) of 11,322 buffaloes examined during routine post-mortem inspection at 2 export abattoirs. The prevalence of tuberculosis in buffaloes supplied from 17 separate farms ranged from 0.3%-8.22%, with the highest levels occurring on the coastal plains. Lesions were confined to 1 major body region in 50 of 72 randomly chosen cases of tuberculosis and to 2 or more regions in 22 cases. Thoracic lesions occurred in 65 of the 72 cases, abdominal lesions in 19, head lesions in 18 and carcass lesions in 9. In the thoracic cavity, lesions occurred most frequently in mediastinal and bronchial lymph nodes. In the head region, the retropharyngeal lymph node was most frequently involved; in the abdominal cavity, the liver, and in the carcass, the deep inguinal lymph node was most frequently involved. Tuberculosis lesions in buffaloes had a lardaceous consistency and were paler in color and less calcified than those normally exhibited by cattle. Mycobacteria were isolated from 30 of 31 lesion samples submitted for bacteriological examination. Of the isolates, 25 were identified as Mycobacterium bovis, 3 as M. avium-M. intracellulare-M. scrofulaceum complex, 1 as M. fortuitum and 1 as M. flavescens. The M. bovis isolates from buffaloes showed minor cultural differences to those normally characteristic of bovine isolates.