Brucella melitensis is a Gram-negative coccobacillus bacterium from the Brucellaceae family. The bacterium causes ovine brucellosis, along with Brucella ovis. It affects primarily sheep and goats, but cases have also been observed in cattle, yaks, water buffalo, Bactrian and dromedary camels, alpacas, dogs, horses and pigs. Humans can become infected if they have contact with an infected animal or its byproducts. Animals acquire B. melitensis by venereal transmission and contact with the placenta, fetus, fetal fluids, and vaginal discharges from infected animals. The organism is found in blood, urine, milk, and semen. It is zoonotic, unlike B. ovis, causing Malta fever or localized brucellosis in humans.