Two bulls on a Beaverhead County, Mont. ranch have tested positive for brucellosis.
The Department of Livestock says the bulls were euthanized and all other animals on the ranch have tested negative for exposure to the bacteria that causes cattle to abort.
The ranch is within Montana's brucellosis Designated Surveillance Area. The infected bulls were identified during a voluntary whole-herd test and the ranch has been placed under quarantine.
State Veterinarian Dr. Marty Zaluski said Tuesday the early discovery shows the DSA program is working to protect the state and its trading partners.
Officials have determined elk to be the likely source of the brucellosis infections in livestock in the Greater Yellowstone Area.
Livestock officials say this is the eighth brucellosis infected herd found since the creation of the DSA in 2010.