Tuberculosis in apparently healthy milch cows.

Screening for mycobacteria was carried out on samples of normal milk, supramammary lymph nodes (SLNS) and udder tissue from apparently healthy milch cows, including the milk from those suspected of tuberculous mastitis. Milk samples from the slaughtered and live Fulani cows which were apparently healthy yielded 5% and 7% of tubercle bacilli, respectively, while suspected tuberculous milk from slaughtered cows and live cows yielded 8% and 10% of the bacilli, respectively. Tubercle bacilli were isolated both from SLNS with and without lesions. The udder tissue was positive for mycobacteria even though visible lesions were absent.