Brucellosis in cattle

Brucellosis in cattle is typically associated with Brucella abortus. Infected animals can shed bacteria in birth fluids, milk, and tissues. Many regions maintain surveillance, vaccination (where authorized), and movement/testing rules.

Also known as: Bang’s disease, Brucella abortus, contagious abortion

• Abortions (often in the last third of pregnancy) or weak calves
• Retained placenta or uterine infection after calving/abortion
• Reduced fertility and milk production in some herds
• Infected animals may show few obvious signs outside reproductive events

Primarily through contact with aborted fetuses, placentas, vaginal discharges, and contaminated environments. Calves can be exposed early; wildlife reservoirs matter in some regions. People can be infected by assisting births, handling tissues, or consuming unpasteurized dairy from infected animals.

Breeding herds without a tested/closed status, operations in endemic wildlife areas, and people who handle obstetric materials without PPE. Purchasers of untested breeding stock.

• Buy from reputable, tested sources; follow interstate/international movement rules
• Isolate and investigate abortions with your veterinarian
• Dispose of aborted materials safely; limit scavenger access
• Pasteurize milk for human consumption; avoid raw dairy from unknown herds
• Use PPE when assisting calving or handling reproductive tissues

• CDC — Brucellosis
• USDA APHIS — Brucellosis

• Ranch logs (calving / events)
• Gestation calculator