Brucellosis in Cattle: A Disease That Threatens Farm Productivity and Human Health

Brucellosis remains one of the most serious challenges facing livestock farming across Central Asia and Kazakhstan. According to WOAH (2023), Uzbekistan is classified among the high-risk countries for this disease. What makes brucellosis especially dangerous is that it is zoonotic — it can pass from animals to humans. In cattle, the disease causes not only abortions and reproductive losses, but also measurable deterioration in milk quality and production. This article examines brucellosis in full using scientific sources.

What Is Brucellosis?

Brucellosis is an infectious disease caused by bacteria of the genus Brucella. In cattle, the primary species is Brucella abortus.

How does it spread?

The disease spreads through several routes:

• Abortion materials: The aborted fetus, placenta, and birth fluids carry the highest concentration of bacteria on the farm
• Milk: Milk from an infected cow may contain Brucella
• Sexual transmission: Breeding from an infected bull
• Contaminated feed and water: Infected pasture, water sources, or feed

Impact on Milk Quality and Production

Brucellosis affects milk output and composition directly:

Source: FAO/WOAH/WHO Brucellosis Guidelines, 2023

Clinical Signs

The dominant signs of brucellosis in cattle are reproductive.

Reproductive signs (most characteristic)

• Abortion — typically in months 5–7 of pregnancy, often without any apparent prior warning
• Stillbirths
• Retained placenta (failure to expel the placenta within 12 hours of calving)
• Repeat breeding — repeated failure to hold pregnancy after service

General signs

• Elevated body temperature during the abortion episode
• Arthritis — swollen, painful joints causing lameness
• Orchitis in bulls (testicular swelling)

Latent carrier status

Many infected animals show no clinical signs at all — a carrier state that is the most dangerous situation epidemiologically, because these animals silently spread the disease within and between herds.

Diagnostic Methods

Brucellosis can only be definitively confirmed through laboratory testing.

Source: WOAH Terrestrial Manual, 2023

Brucellosis Situation in Uzbekistan

Research by FAO and IFAD (2022) identifies three main drivers of brucellosis persistence in Central Asia:

1. Uncontrolled livestock movement — purchasing cattle at markets without health verification introduces infected animals into clean herds
2. Interruptions in vaccination programs — systematic vaccination campaigns weakened significantly after the 1990s
3. Low awareness of biosecurity on smaller farms — the risks are not well understood at farm level

Uzbekistan's Ministry of Agriculture runs annual brucellosis monitoring and vaccination campaigns. In practice, however, testing and vaccination coverage on many smaller farms remains inconsistent.

Vaccination and Control

Official vaccination schedule (Uzbekistan)

• Vaccine: Brucella abortus Strain 19 (S19) or RB51
• Target animals: Heifers aged 4–8 months
• Frequency: Once a year, according to instructions from the local veterinary authority
• Critical point: Vaccination must be performed only by a certified veterinarian

Quarantine measures

• Any newly purchased animal should be quarantined for 30 days
• RBT testing should be conducted during the quarantine period
• The animal should be integrated into the main herd only after a negative test result

The Zoonotic Risk: Transmission to Humans

Brucellosis is transmitted from animals to humans through:

• Consumption of raw milk — the most common route of infection in Uzbekistan
• Contact with abortion materials — handling without gloves or protective equipment
• Undercooked meat from infected animals

Human brucellosis presents as chronic undulating fever, joint pain, and persistent fatigue. Cases in humans are reported annually in Uzbekistan (data from the Ministry of Health of Uzbekistan).

Protection for farm workers: Milk must be pasteurized. Anyone handling abortion materials must use gloves and protective clothing. This is not optional — it is basic occupational safety.

Economic Impact

The combined effect of brucellosis on a farm includes:

• Reduced milk yield — 10–25% drop in affected cows
• Calf losses — abortions and stillbirths represent direct production losses
• Reproductive inefficiency — empty cows generate no milk income and consume feed
• Forced culling — infected animals must be removed from the herd
• Trade restrictions — farms with active brucellosis cannot supply milk or cattle to buyers who require clean-herd certification

The cost of brucellosis far exceeds the cost of prevention through vaccination and testing.

Practical Herd Management Against Brucellosis

Before buying any animal

1. Request a veterinary health certificate confirming negative brucellosis status
2. Quarantine the animal for 30 days on arrival
3. Test again with RBT at the end of quarantine
4. Only integrate into the herd after a negative result

Ongoing herd management

• Maintain annual serological testing for the entire herd
• Vaccinate all heifers at 4–8 months of age
• Handle all abortion events as potentially infectious — gloves, disinfection, proper disposal of materials
• Do not allow visitors or vehicles with unknown animal contact to enter the farm without biosecurity measures

If a positive case is confirmed

• Isolate the positive animal immediately
• Report to the local veterinary authority — this is legally required in Uzbekistan
• Follow the officially prescribed control and culling protocol
• Test all remaining herd animals

Frequently Asked Questions (FAQ)

1. Can the milk of a brucellosis-positive cow be used safely after pasteurization?

Yes — pasteurized milk is safe. Brucella is destroyed at 72°C in 15 seconds. However, keeping an infected cow in the herd complicates disease control and maintains a reservoir of infection.

2. Can brucellosis be treated in cattle?

There is no practical or recommended treatment for cattle. Infected animals are removed from the herd (slaughtered). Only vaccination and prevention are effective management tools.

3. What should I do when buying a new cow?

Quarantine the animal for 30 days. Conduct an RBT test during quarantine. Request a veterinary certificate from the seller. Integrate into the herd only after a confirmed negative test.

4. Is annual brucellosis testing mandatory in Uzbekistan?

Yes. Under Uzbekistan legislation, annual serological testing is mandatory on commercial farms. Practical enforcement, however, varies across regions and farm sizes.

5. How should brucellosis cases and events be tracked?

Every abortion, repeated empty return, and laboratory test result should be recorded. FarmOps allows you to store reproductive events, abortion records, and veterinary test results directly in each cow's profile — making it faster to identify the source of an infection and track how disease dynamics change across the herd over time.

6. Can brucellosis be eradicated from a farm?

Yes, but it requires sustained effort: systematic testing of all animals, removal of all positives, consistent heifer vaccination, and strict biosecurity on animal movement. Many countries — and individual farms — have achieved and maintained brucellosis-free status.

7. How dangerous is brucellosis to farm workers?

Human brucellosis is a debilitating illness. In the farming context, the main risks are handling abortion materials without protection and drinking raw milk. These risks are entirely preventable with consistent protective measures.

Conclusion

Brucellosis remains a real and ongoing threat to farms in Uzbekistan — reducing milk yield, disrupting reproductive performance, and posing a genuine public health risk through zoonotic transmission. The most effective tools against it are consistent vaccination, rigorous quarantine of new animals, and annual laboratory testing. Every investment in prevention pays back multiple times in avoided losses.

Farms that maintain systematic records of reproductive events, test results, and animal movements — and that act quickly when a problem is identified — are farms that can control this disease. The FarmOps platform supports this kind of systematic livestock health management, linking reproductive data, veterinary records, and animal movement history in a single, searchable system.

References

1. WOAH (2023). Brucellosis (Brucella abortus, B. melitensis, B. suis). woah.int
2. FAO/WOAH/WHO (2023). Brucellosis in Humans and Animals: Guidelines. fao.org
3. FAO (2022). Brucellosis Control in Central Asia and Eastern Europe. fao.org
4. Merck Veterinary Manual (2023). Brucellosis in Cattle. merckvetmanual.com
5. IFAD (2022). Livestock Disease Management in Uzbekistan. ifad.org