Brucellosis Disease: Clinical Signs and Prevention Methods
Although many factors affect productivity in livestock operations, certain diseases not only cause economic losses but directly threaten human health and the future of the enterprise. Foremost among these is undoubtedly Brucellosis, commonly known among the public as the "abortion disease" or "cheese disease."
What is Brucella? What Does Brucellosis Mean?
The answer to "what does Brucella mean," a term frequently heard in the sector, points to a bacterial infection. What is Brucellosis? It is a chronic, contagious, and zoonotic (transmitted from animals to humans) disease caused by bacteria of the Brucella genus, affecting domestic animals such as cattle, sheep, goats, and pigs, as well as wildlife.
Defined as brucellosis in scientific literature, this disease is one of the most widespread infections threatening livestock globally. Once the bacterium enters the body, it localizes particularly in the reproductive system, multiplying there and causing severe pathologies. In Turkey, Brucella abortus in cattle and Brucella melitensis in sheep and goats are the most frequently encountered infectious agents.
What Causes Brucellosis? Sources of Transmission
What causes an outbreak of brucellosis in farming operations? The primary source of the disease is infected animals. The bacterium is highly resilient; it can survive for months in damp environments, frozen products, and soil.
The answer to "how is brucellosis transmitted?" is critical for halting the spread of the disease:
Direct Contact: The greatest source of transmission is the aborted fetus, placenta (afterbirth), and fetal fluids shed into the environment following an abortion by an infected animal. These materials contain billions of bacteria.
Contaminated Feed and Water: Pastures, forage, and water sources contaminated with the bacterium cause healthy animals to contract the infection.
Via Milk: The milk of infected mothers is the primary transmission route for offspring (calves and lambs).
Milking Hygiene: Milking machine clusters or the milker's hands can mechanically transfer the bacteria from one animal to another.
Mating: Uncontrolled mating, other than artificial insemination, leads to the horizontal transmission of the bacteria within the herd.
What are the Clinical Signs of Brucellosis in Animals?
Diagnosing the disease early is of vital importance to avoid losing the entire herd. Brucellosis clinical signs can vary depending on the animal species and its immune status.
General Clinical Picture in Cattle and Small Ruminants (Sheep/Goats)
When discussing the clinical signs of brucellosis in animals, the first indicator that comes to mind is sudden abortions occurring in the late stages of pregnancy.
Abortion in Cattle: Abortions occurring between the 5th and 8th months of gestation are the most typical clinical sign.
Retained Placenta: The failure to expel the placenta after abortion and the subsequent development of uterine inflammation (metritis).
Drop in Milk Yield: The bacterium localizing in the udder tissue leads to a visible decrease in milk production and the deterioration of milk quality.
Infertility: Animals failing to conceive and repeatedly returning to estrus (repeatedly coming into heat).
Joint Swellings: Fluid accumulation in the knee joints (hygroma) and lameness.
Before addressing the question of whether treating brucellosis in cattle is possible, it is also necessary to look at the signs in male animals. Testicular swelling (orchitis) in bulls and rams, and the permanent infertility that develops as a result, jeopardize the genetic future of the herd.
Is Brucellosis Transmitted to Humans? (Zoonotic Risk)
The most concerning issue is the human health dimension of brucellosis. Is brucellosis transmitted to humans? Yes, brucellosis is one of the most impactful zoonotic diseases worldwide.
Transmission to humans generally occurs through the following routes:
Raw Milk and Dairy Products: Drinking unpasteurized milk or consuming fresh (white) cheeses made from such milk.
Occupational Exposure: Unprotected contact with infected animal tissues (such as fetal membranes) by veterinarians, breeders, and slaughterhouse workers.
Respiratory Route: Inhalation of the bacteria in dusty barn environments.
In humans, this disease is known as "Malta Fever" (or Undulant Fever). It manifests with night sweats, undulating fever, severe joint pain, and lethargy. In humans, just as in animals, brucellosis represents an exhausting process requiring long-term treatment.
Diagnosis and Treatment Processes
In livestock operations, no procedures should be initiated without a proper diagnosis. A producer must absolutely have a blood test (serological tests) or a milk test performed.
Treatment of Brucellosis in Animals
Many producers search for medication to treat brucellosis in animals. However, here we face a bitter truth: The treatment of brucellosis in cattle is not recommended for economic and medical reasons.
The Bacterium's Hiding Ability: The Brucella bacterium localizes intracellularly (inside the cells). Antibiotics struggle to reach and eliminate this bacterium.
Carrier Status: Even if a treated animal appears to have recovered, it continues to shed the bacteria through its milk or reproductive discharges. This represents a persistent threat to the rest of the herd.
Legal Regulations: In Turkey, as in many other countries, brucellosis is a "notifiable disease." It is generally a legal requirement that animals testing positive are sent for slaughter with compensation.
So, what is the best course of action? For humans, a long-term (at least 6 weeks) combined antibiotic therapy under a doctor's supervision is effective. However, the best solution for animals is a strict "culling and eradication" (stamping-out) strategy.
How Long Does Brucellosis Last?
If brucellosis is detected in your operation, rather than asking "how many days does it take to pass?", you should focus on the question "how do I disinfect the facility?". The bacterium can survive for 4-5 months in cool barns not exposed to direct sunlight.
Removal of the Sick Animal: The positive animal must be immediately separated from the herd.
Disposal of Tissues: The aborted fetus and placenta must be covered in quicklime and buried in deep trenches.
Disinfection: Barns must be thoroughly cleaned from top to bottom using slaked lime or potent agricultural disinfectants.
Prevention and Nutrition:
The Integro Gıda Approach
The golden rule in combating an untreatable disease is prevention. To avoid the devastating impacts of brucellosis, the following steps must be taken:
Vaccination (The Most Important Shield)
Vaccinating animals at a young age (with S19 or Rev1 vaccines) is the foundation of disease prevention. The vaccine introduces the bacterium to the animal's immune system and minimizes the risk of infection.
Biosecurity Protocols
New Animal Purchases: Animals newly entering the facility must absolutely be tested and kept in quarantine for at least 30 days.
Visitor Control: The entry of unauthorized personnel and vehicles into the barns must be strictly prevented.
Strengthening the Immune System An animal with a strong immune system can be far more resilient against low-dose bacterial challenges. In terms of nutrition, we can combat the disease pressure as follows:
Mineral Support: Copper, zinc, and selenium increase the activity of immune cells.
Vitamin Supplementation: Vitamins A, D3, and E preserve the health of the uterine mucosa, making bacterial colonization more difficult.
As Integro Gıda, the high-quality mineral blocks and vitamin supplements we offer help increase your animals' overall resistance capacity, establishing a metabolism that is more heavily shielded against infections.