The intermittent treatment with isoniazid was adopted in 240 bovines from a naturally infected herd. At the beginning of the treatment, 36.6% of the animals were positive reactors and 2.9% inconclusive reactors. The drug was administered orally at a dose of 25mg/kg of live weight, three times a week (on Mondays, Wednesdays and Fridays) during 10 months in a total of 120 doses. The cure of 98.9% of the treated animals was verified by the allergic desensitization demonstrated through the tuberculin test and the bacteriological control of 39 slaughtered animals. The treatment in this herd did not cause selection of isoniazid-resistant strains as demonstrated by the isoniazid sensitivity test carried out in M. bovis culture isolated from a non-cured animal.
bovine; tuberculosis; intermittent treatment; isoniazid