Brucellosis is a long known zoonotic disease in humans and animals which is caused by gram-negative bacteria of the Brucella genus. Brucella is classified as risk group III by the WHO. Various species of Brucella were isolated from bovines, with Brucella abortus being identified as the most frequent cause of bovine brucellosis. If cattle are held in direct vicinity of small ruminants such as sheep or goat, infections with Brucella melitensis may also occur. Dogs and cats can also be vectors of Brucella. Bovine brucellosis should generally be considered as a herd problem. Transmission of the pathogen can be oral, but also venereal, congenital or perinatal.