ABSTRACT
Brucellosis, an infectious disease of many mammalian species including humans, is caused by bacteria of the genus Brucella. These bacteria are Gram negative, small (0.5-1.5 µm in length), and rod shaped. They exist alone or in small clusters and are not capable of movement (Figure 3.1). There are several species of Brucella. B. abortus causes mainly a disease of cattle, but in North America, it also infects elk and bison. B. melitensis is found in sheep and goats; B. suis is found in domestic and feral hogs; B. ovis infects sheep; B. canis occurs in dogs; B. neotomae infects woodrats; B. pinnipediae is found in seals, sea lions, and walruses; and B. cetaceae infects whales and porpoises (Table 3.1).
