Ovary: abscess

Etiology

• Infection of the reproductive tract with bacteria, most commonly Pasteurella multocida.

Predisposing factors

General

• Poor environmental hygiene.
• Overcrowding.
• Exposure to rabbits carrying Pasteurella multocida.

Specific

• Increasing age.
• Positive Pasteurella multocida carrier status.
• Mating with a carrier or symptomatic male.

Pathophysiology

• Transmission of Pasteurella multocida from carrier animal to naïve rabbit occurs via several routes:
  • Feco-oral via coprophagy or cecotrophy.
  • Ingestion of bacteria via mutual grooming.
  • Transmission to young during birth.
  • Venereal transmission.
  • Aerosol transmission.
• Ascending infection tends to occur in breeding females mated with a carrier male:
  • Can occur with or without successful copulation.
  • Bacteria ascend up the reproductive tract.
  • May induce metritis, pyometra or pyosalpingitis before reaching the ovary to form an abscess Abscess.
• Hematogenous spread:
  • Can occur in unmated females.
  • Initial entry via wound or respiratory tract colonization.
  • Invasion into the blood stream.
  • Spread to internal organs with potential for abscessation including the liver, kidneys and reproductive tract.
  • May occur many weeks or months after initial infection.

Timecourse

• Incubation varies from 2-3 weeks in acute cases and respiratory disease to prolonged periods for hematogenous forms of disease.
• Abscessation may be acute, subacute or chronic.
• Infection with Pasteurella may be lifelong.

Epidemiology

• Pasteurella multocida Pasteurella multocida is the primary respiratory pathogen reported in rabbits but ovarian abscessation appears to be extremely rare.