Brucellosis is caused by members of genus Brucella. These are small, non-motile, aerobic, facultative intracellular, Gram-negative coccobacilli. According to the Food and Agriculture Organization (FAO), the world Health Organization (WHO) and the world organization of animal Health (OIE), brucellosis is considered the most widespread zoonosis worldwide. Almost all domestic species can be affected with brucellosis and it is one of the most serious diseases of livestock. In the agro-based economy of Bangladesh livestock contribute 2.73% of the total GDP and 75% of the rural people are directly or indirectly involved with livestock rearing and the people usually live in very close proximity with their livestock.This book illustrates the diagnosis, seroprevalence and epidemiology of brucellosis in cattle, buffalo, sheep, goat and pig together alongside its association with reproductive diseases in Bangladesh. The exciting new study shows a new way of developing the livestock and public health policy of government as well as professionals, prevention and control of brucellosis nationally and at international level to improve livelihoods.