How Cattle are Exposed to Brucellosis
- Brucellosis Main Page
- Brucellosis Surveillance Requirements
- Establishment of Designated Surveillance Area (DSA)
- Brucellosis Surveillance Requirements in DSA
- Brucellosis Symptoms in Cattle
- Brucellosis Symptoms in Humans
- Greater Yellowstone Area Risk Survey
Once a cow is infected with brucellosis, it spreads rapidly to the rest of the herd. Brucellosis is commonly transmitted to susceptible animals by direct contact with infected animals or with an environment that has been contaminated with discharges from infected animals. Aborted fetuses, placental membranes or fluids, and other vaginal discharges present after an infected animal has aborted or calved are all highly contaminated with infectious Brucella organisms. These organisms are hardy and may survive for up to 90 days in the right conditions. Cows may lick those materials or the genital area of other cows or ingest disease-causing organisms with contaminated food or water.
The Greater Yellowstone Area (GYA) houses the last known reservoir of brucellosis in the United States. The highest risk of infection occurs when livestock producers graze cattle in pastures frequented by elk during the elks’ calving season. Infected elk may abort in these pastures, creating a source of Brucella organisms that grazing cattle may feed upon. Livestock producers who avoid grazing their cattle in pastures frequented by elk during their calving season reduce the risks of suffering damages caused by a Brucellosis-infected cattle herd.
According to the Montana Department of Fish and Wildlife Department’s 2008 Brucellosis Survey, approximately 7% of elk tested were positive for Brucellosis. Click here for the full report.
The Montana Department of Livestock will help you develop a herd plan to mitigate risk. Click here for more information.