Brucellosis in Herds: Testing, Safety and What to Tell the Vet

Brucellosis is a herd disease that causes abortion in cows and buffaloes and can pass to people through birth fluids and raw milk. Blood antibody tests, a milk ring test and RT-PCR help a vet find it, and gloves and careful washing protect the people who handle the animals. This article is about testing and safety, and what to tell your vet.

How does brucellosis spread?

The bacterium is carried in the fluids, membranes and aborted calf of an infected animal. Other animals pick it up by licking or sniffing them, or from contaminated feed, water and bedding. The germ also appears in milk. Infected animals may abort, give birth to weak calves, retain the afterbirth, or fail to conceive, and some show no signs at all. This is why herd testing matters.

Why is it a risk to people?

People can be infected by contact with birth material, by cuts and scratches, by splashes in the eyes and by drinking raw milk. In people the illness causes long-lasting fever, sweats and body aches that can come and go. Farmers, milkers and vets are the most exposed. Wear gloves when you handle births and aborted material, wash hands and arms with soap, and keep children away. Boiling milk before drinking is widely advised. If you become unwell after contact with animals, speak to a doctor and say that you work with them.

Which tests may the lab run?

Each test looks at brucellosis in a different way.

• The Brucellosis Rose Bengal Plate Test (RBPT) is a quick screening test on serum that looks for antibodies.
• The Brucellosis Indirect ELISA (iELISA) is a more sensitive antibody test that can be run on many samples.
• The Milk Ring Test (Brucellosis Screening) screens bulk milk from a herd, to see whether any animal in it is likely to be infected.
• The Brucella abortus / melitensis RT-PCR is an RT-PCR (real-time PCR) test that looks for the genetic material of the germ itself, in samples such as milk, vaginal swabs or aborted material.

Antibody tests show that an animal has met the germ, and RT-PCR looks for the germ. A single negative result does not always clear an animal, especially soon after infection, so a registered veterinarian reads all results with the herd's history and may repeat the tests. The lab confirms the method and the sample needs when you book.

Who should be tested?

Vets usually test animals that have aborted, animals that fail to conceive, new animals before they join the herd, and bulls used for breeding. In a herd with a case, they may test more animals. The Abortion & Brucellosis Pack groups tests for brucellosis and for other common causes of abortion.

What should you tell the vet?

Give the vet a clear history:

• how many animals have aborted, and how far along each was
• whether any animal has retained its afterbirth or has repeated heats
• whether new animals have joined recently, and where they came from
• whether anyone who handles the animals has had a long fever
• whether milk is sold or drunk raw

Keep the aborted calf and membranes in a sealed bag, cool, and away from people and pets, until the vet has seen them.

What can the lab not do?

The lab gives no treatment advice and promises no control of the disease in a herd. Plans for managing a herd that has brucellosis are for your vet and the authorities. Keep reports with the breeding records. Ask your vet how to keep new animals apart until they have been tested, and how to handle calving so that birth material is kept away from people, other animals and water. If an animal tests positive, ask the vet what the result means for her calf, for the milk and for the rest of the herd, and write down the answers so that everyone who works on the farm follows the same plan.

Read next

For a look at breeding problems more generally, read Repeat Breeder Cows and Buffaloes: Lab Tests That Help. To see the other causes of abortion, see Abortion in Cattle and Buffalo: Which Samples and Tests.

Testing in Bhopal

Your vet usually takes the samples, and the lab at C-200, C Sector, Shahpura, Bhopal accepts them. Collection is free anywhere in Bhopal, and other districts can use courier, bus parcel or their vet. Call or WhatsApp +91 88175 01118; the lab confirms the method, sample needs and reporting time when you book.