Prevalence and pathological lesions of bovine tuberculosis assessment through routine procedures of meat inspection in infected cattle in Karachi metropolitan corporation abattoirs

Bovine tuberculosis (bTB) caused by Mycobacterium bovis is one of the most important zoonotic disease that poses huge economic losses in livestock population worldwide. A cross sectional study was therefore designed to investigate its prevalence and efficacy of meat inspection procedures for its detection in slaughtered cattle at two abattoirs of Karachi. A total 2000 were examined during March 2015 to September 2016 in which 943 animals were found suspected for bTB and necropsied from which 1170 organ samples were collected. The data collected was analyzed using Chi-square test. Results of regular and complete examination revealed that 8.12% organ samples had positive lesions of tuberculosis. The highest frequency of lesions were observed in lungs and its associated lymphnodes (64%) i.e. mediastinal lymphnodes (27%), tracheobronchial lymphnodes (26%), lungs (11%) respectively. There was a significant difference (P < 0.05) in prevalence of bTB amongst sex of cattle. Females were found at high risk of bTB. It was concluded from the results that however bTB is highly prevalent in cattle and sensitivity of inspection protocols may influence reporting positive cases. Thus it is suggested that more advanced and sensitive methods should be used for screening of tuberculosis in cattle population.