What is canine brucellosis?

Brucellosis in dogs is a serious infection caused by Brucella canis. It spreads through bodily fluids like semen, urine, and vulvar discharge during heat, birthing, or miscarriage. Though primarily contagious between dogs, it presents a minor risk to humans, with over 40 human cases recorded since 1960. In the United States, it is a reportable disease.

Clinical signs of brucellosis in dogs

• In females:
  • Abortion between day 45 and 55 of pregnancy
  • Prolonged purulent vulvar discharge
  • Stillbirth or weak puppies

• In males:
  • Epididymitis and scrotal skin infections
  • Testicular atrophy
  • Poor-quality sperm (in chronic infections)

• In both sexes:
  • Irreversible infertility

Diagnosing canine brucellosis

• AGID test (agar gel immunodiffusion): the most specific
• Three monthly serologic tests are required to confirm the diagnosis
• If all results are negative, the dog is considered uninfected

Treatment and disease control

Brucellosis is incurable, but management includes:

• Sterilization to reduce bacterial shedding (the dog remains a carrier)
• Antibiotic therapy, which cannot eliminate the infection entirely
• Hygiene precautions, especially around immunocompromised individuals

Brucellosis in breeding facilities

• Remove infected dogs from the breeding program
• Test all dogs monthly for 3 months
• Quarantine new breeding dogs for 8–12 weeks and test afterward
• Perform RSAT testing every 3–6 months

Prevention tips

• Regular brucellosis screening (RSAT)
• Spay/neuter non-breeding dogs
• Strict hygiene and isolation when needed