Brucellosis in Cattle
Brucellosis is a reportable disease in Idaho.
Highest risk of brucellosis in Idaho is in the Designated Surveillance Area (DSA), which is an outlined region near the Greater Yellowstone Area where there is enhanced surveillance through a cooperative state and federal program. In our national park, wild cervids such as elk can carry the disease, and interaction between cattle and elk is a risk factor.
What is brucellosis?
Brucellosis is an infectious disease of animals and humans caused by bacteria of the genus Brucella. Cattle brucellosis can cause abortion, infertility, and sterility, resulting in economic loss to the producer. The state has rules administered by the Department of Agriculture, IDAPA 02.04.20, “Rules Governing Brucellosis,” which address brucellosis in cattle and bison specifically.
How is brucellosis transmitted?
The major sources of infection are reproductive (mainly fetal and placental) secretions and mammary secretions (milk) from infected animals. Brucellosis can be transmitted through ingestion of or contact with aborted fetuses and contact with infected calves. Brucellosis can also be transmitted from bull to cow through natural mating; however, this is very rare.
What are the signs of infection in cattle and domestic bison?
Most of the time there are no signs. Cattle may abort late in pregnancy, or give birth to weak or sick calves. In extreme cases, brucellosis can cause arthritis in the joints.
Can brucellosis infect humans?
The main risk for humans to become infected with brucellosis is through contact with reproductive fluids – placental and fetal fluids – from infected animals. Although there is a possibility for brucellosis to be transmitted through milk or meat, the pasteurization of milk and the cooking of meat destroy the bacteria. Raw milk, which hasn’t gone through the pasteurization process, does retain the possibility of transmission. Other than that, any infection risk in humans is primarily in people who work with cattle and are exposed to potentially infected fluids.
Am I required to vaccinate for brucellosis?
All intact female cattle and domestic bison must be vaccinated against brucellosis between the ages of 4 and 12 months unless being fed for slaughter in an Idaho approved feedlot. If your Idaho-origin animal is over 12 months and has not been vaccinated for brucellosis, contact us at (208) 332-8540 for information on adult vaccination.
How do I get my animals vaccinated?
Any federally accredited veterinarian can perform vaccination for brucellosis. Contact your veterinarian to set up an appointment for vaccination.
Am I required to test for brucellosis?
Cattle and domestic bison leaving the Designated Surveillance Area (DSA) are required to test for brucellosis. Some states may require testing of animals moving to their state from anywhere in Idaho.
If you are requesting permission for adult vaccination of your Idaho-native adult cattle, a negative brucellosis test will be required.
Previously, producers who participate in the ISDA Raw Milk Program were required to have regular milk testing. Unfortunately, each single test result does not account for all risk throughout the rest of the year. Raw milk continues to be an option for consumers.
Who do I contact for brucellosis testing?
Any federally accredited veterinarian can draw blood to test for brucellosis. Contact your veterinarian to set up an appointment.
What are “test eligible” animals?
Test eligible animals are all sexually intact cattle and domestic bison 12 months of age and over, and all parturient and post-parturient cattle and domestic bison, regardless of age.
What will testing cost me?
The costs for tests run at the state laboratory are not charged to producers. However, the costs associated with collecting samples for testing will vary. Contact your veterinarian for a list of fees associated with brucellosis sample collection. Through a USDA grant, veterinarians can be reimbursed for testing of cattle within the DSA.
What can I do to prevent brucellosis in my cattle and domestic bison?
The best way to prevent brucellosis from infecting your herd is to ensure that your herd is 100% vaccinated, as required by state law, and do not allow any contact between wild elk and your cattle or domestic bison during the winter. This is especially important in eastern Idaho, where brucellosis-infected elk could be aborting and leaving infected fluids in a cattle winter feeding area.
If you have a question that is not covered here, please contact Animal Industries by email or at (208) 332-8540.