Brucellosis is a serious infectious disease of cattle, caused by Brucella abortus, which can cause devastating economic losses to cattle industry. California has been classified a free of bovine brucellosis since 1997 and, according to a report from the USDA-APHIS 2017, all the United States are now free of brucellosis in cattle. However, brucellosis is still endemic in free ranging elk and bison populations in the Greater Yellowstone Area (GYA), which includes parts of Montana, Idaho, and Wyoming.