Q fever is a worldwide zoonotic infectious disease caused by Coxiella burnetii and ruminants, namely, cattle, sheep, and goats, are known to be the main reservoir for human infection. C. burnetii infection in animals can result in epizootic abortions which are often associated with vast bacteria shedding in birth fluids and placentas. Human infections mainly occur in persons handling infected animals and their products. Here the authors describe the history, bacteriology, biosafety, and epidemiology of Q fever, now known to be a serious threat to veterinary public health.