Brucellosis neurobrucellosis. Brucellosis in humans is usually associated with consumption of unpasteurized milk and soft cheeses made from the milk of infected animals—primarily goats, infected with "Brucella melitensis" and with occupational exposure of laboratory workers, veterinarians, and slaughterhouse workers. Some vaccines used in livestock, most notably "B. abortus" strain 19, also cause disease in humans if accidentally injected. Brucellosis induces inconstant fevers, miscarriage, sweating, weakness, anaemia, headaches, depression, and muscular and bodily pain. The other strains, "B. suis" and "B. canis", cause infection in pigs and dogs, respectively. Definite diagnosis of brucellosis requires the isolation of the organism from the blood,
Brucellosis (goats and sheep), "B. ovis" (sheep), and "B. suis" (caribou and pigs). "Brucella" species have also been isolated from several marine mammal species (cetaceans and pinnipeds). "B. abortus" is the principal cause of brucellosis in cattle. The bacteria are shed from an infected animal at or around the time of calving or abortion. Once exposed, the likelihood of an animal becoming infected is variable, depending on age, pregnancy status, and other intrinsic factors of the animal, as well as the number of bacteria to which the animal was exposed. The most common clinical signs of cattle infected with "B. abortus"