Dysgonic fermenter 2 (DF-2) is a slow-growing gram-negative bacillus causing a zoonotic infection that is acquired through dog bites or other contact with dogs. Splenectomized patients and those with alcoholic liver disease are most susceptible to DF-2 infection. The clinical picture can be one of fulminant septicemia and disseminated intravascular coagulation in the splenectomized patient; the presentation is milder in the alcoholic patient. The overall mortality from DF-2 septicemia among the 41 cases reported in the literature is 27%. The organism is sensitive to penicillin, resistant to aminoglycosides, and not easily grown on common media. It appears to be serum-sensitive in tests with normal human serum. Penicillin prophylaxis of dog bite wounds is especially important in high-risk patients. DF-2 infection should be considered when any splenectomized patient develops fulminant septicemia, disseminated intravascular coagulation, and peripheral gangrene. Examination of a gram stain of the peripheral blood or buffy coat is of value in such cases.