State of tuberculosis in sheep bred with dairy cattle in the southwest region of Maranhão

Abstract

In order to know the situation of ovine tuberculosis in Maranhão, Brazil, we evaluated 343 sheep in the southwest region of the state, of both sexes (247 females and 96 males), aged over six months, through the comparative cervical test (TCC), with tuberculin inoculation in the right cervical region. Cranially, avian purified protein derivate (PPD) was injected; and caudally, beef PPD was injected, in individual doses of 0.1 mL. All animals were negative for tuberculosis; however, 65 sheep had higher reactions to bovine tuberculin than to the avian one. To investigate the possibility of low awareness or anergy in animals with advanced tuberculosis, one cachectic sheep was necropsied, aged four years, with negative results for TCC, but with reaction to avian tuberculin and enlarged hardened lymph nodes. The results indicated C. pseudotuberculosis, Actinomyces pyogenes, Staphylococcus aureus and Mycobacterium sp infections. Culture and isolation resulted in Pseudomonas aeruginosa and Bacillus sp. No bacterial structures compatible with acid-fast bacteria were found. The results confirmed the absence of animals reactive to M. bovis, assuming no tuberculosis in sheep in the study area.