Explosive and widespread abortions have occurred in the beagle canine species in the United States since 1966. A new brucella species has been defined, Brucella canis. An epidemic in the Midwest involving 178 adults and puppies was investigated. Outstanding was the severity of the epidemic, localisation of the infection in the genitourinary tract, the chronicity of the disease producing a hyperplasia of the lymphatic tissue of many organs, and isolation of pure 19 Sand 7 Sagglutinating antibody. 2 human infections in laboratory personnel were treated (and 3 other cases have been reported). Tetracycline is an effective antibiotic.