Bovine Brucellosis

• • Caused by Brucella abortus
  • Eradicated in many countries including UK
  • Infection usually by ingestions but also venereal, skin abrasions, inhalation, transplacental
  • Abortion storms in susceptible herds
  • Abortion after fifth month of gestation due to placentitis
  • Brucellae excreted in foetal fluids for 2-4 weeks following abortion and at subsequent parturitions without abortion
  • Infection of mammary glands and lymph nodes persists for years
  • Excreted intermittently in milk for years
  • Seminal vesicles, ampullae, testicles and epididymus infected in bulls; necrotising orchitis
  • Decreased fertility in cows and bulls; decreased milk production

Vaccination of heifers against B. abortus in endemic regions by Strain S19, a live attenuated vaccine, stimulating a cell-mediated immune response. The vaccination of young animals interferes with serological testing. The 45/20 bacterin vaccine is less effective and the newer RB51 vaccine has no LPS O-antigen therefore not detected by serological tests and gives good protection.

Control

Test and slaughter program has eradicated bovine brucellosis in the UK.