In this article. Brucellosis is an infectious disease caused by a type of bacteria called Brucella. The bacteria can spread from animals to humans. There are several different strains of Brucella bacteria. Some types are seen in cows. Others occur in dogs, pigs, sheep, goats, and camels.Recently, scientists have seen new strains in the red fox and certain marine animals, including seals.Brucella in animals cannot be cured.here are several different strains of Brucella bacteria. Some types are seen in cows. Others occur in dogs, pigs, sheep, goats, and camels. Recently, scientists have seen new strains in the red fox and certain marine animals, including seals. Brucella in animals cannot be cured.