Brucellosis in Cattle and Buffalo: Why Herd Testing Matters

Brucellosis is a bacterial disease that causes abortion in cows and buffaloes, and it can spread from animals to people. Blood tests such as RBPT and ELISA can help find infected animals, even ones that look healthy, so that the herd and the family can be protected.

What is brucellosis?

Brucellosis is caused by germs called Brucella. In cattle and buffalo it is mostly Brucella abortus. The disease is also called contagious abortion.

The germ is found in large numbers in the aborted calf, the afterbirth (placenta) and the birth fluids. It can also be present in milk. It spreads to other animals through:

• feed, water and bedding soiled by birth fluids or an aborted calf
• licking or sniffing aborted material
• sometimes, breeding

Many infected animals look completely healthy. That is why the disease can spread quietly through a herd.

Brucellosis can spread to people

Brucellosis is a zoonotic disease. This means it can pass from animals to humans. In plain words, people can catch brucellosis from infected cows and buffaloes.

People mostly catch it by:

• drinking raw or unboiled milk, or eating dairy foods made from raw milk
• touching an aborted calf, afterbirth or birth fluids with bare hands, especially through cuts, or touching the mouth or eyes with soiled hands

In people it causes fever that comes and goes, night sweats, body and joint pain, headache and weakness. It can last for weeks or longer. Anyone with these signs who works with animals or drinks raw milk should see a doctor and mention the animal contact.

To stay safe, boil milk well before use, because boiling or pasteurising kills the germ. Wear gloves for calving and for any abortion. Wash hands and arms with soap and water afterwards. Keep children away from aborted calves and afterbirth.

Signs in cows and buffaloes

Watch for:

• abortion, usually in the later months of pregnancy
• afterbirth that does not come out
• weak calves, or calves born dead
• less milk
• repeated breeding failure
• in bulls, swollen testicles and poor fertility

Many infected animals show none of these. A cow may abort once, calve normally the next time, and still carry and spread the germ. Abortion also has other causes, such as other infections, poor feed and injury. Only a test and a vet's examination can sort this out.

How the blood tests work

Blood is collected by your vet or a trained person. The clear liquid that separates from clotted blood is called serum, and the lab tests the serum. Label each sample with the animal's ear tag number or name, because results are given for each animal. In Bhopal, sample collection at your door is free. From other districts, read Sending Samples to a Bhopal Vet Lab from Other MP Districts.

The Brucellosis Test (RBPT / ELISA) looks for antibodies. Antibodies are proteins the body makes when it meets a germ.

• RBPT (Rose Bengal Plate Test) is a quick screening test. Serum is mixed with a pink-stained liquid that contains killed Brucella germs. If antibodies are present, visible clumps form.
• ELISA is a laboratory antibody test that shows its result by colour change. It is often used to look more closely at a screening result.

No single test is perfect. A very recent infection may not show antibodies yet, and past vaccination can matter when the result is read, so tell your vet about any vaccination. Your vet may repeat a test or use two tests together. Reporting time is confirmed when you book.

Your vet may suggest testing:

• animals that have aborted
• bulls used for breeding
• animals that keep failing to conceive
• new animals, before they join the herd

Why herd testing matters

One sick-looking animal is not the whole picture. Infected animals that look healthy can still spread the germ at calving and through milk. Brucellosis can mean fewer calves and less milk, so finding it early protects the herd as well as the family.

• Ask for a test report before you buy an animal, and keep new animals apart until your vet agrees.
• Test again when your vet advises, because one result is only a snapshot in time.
• Ask your vet or the local animal husbandry department about vaccination programmes in your area.
• If an animal tests positive, your vet will guide the next steps to protect people and other animals.

The Herd Screening Pack and the Breeding & Pregnancy Pack bring brucellosis testing together with other herd and breeding checks.

When to talk to your vet

Speak to your vet if you see:

• an abortion, a stillbirth or a very weak calf
• an afterbirth that is not passed
• an animal that keeps failing to conceive
• a bull with swollen testicles

After an abortion, keep the animal apart from the herd and wear gloves. Do not touch the calf or afterbirth with bare hands. Ask your vet how to dispose of it safely.

If anyone in your family has a long fever with joint pain, see a doctor and mention your animals.

Test results are interpreted by a registered veterinarian together with the animal's signs and history.