Actinobacillus equuli

  • Commensal of the equine intestinal and reproductive tract
  • Pathogenesis and clinical signs:
    • Foals infected in utero or or after birth via the umbilicus
    • Infection at birth causes severe enteritis and septicaemia within 24 hours, known as sleepy foal disease
    • Foals become pyrexic and recumbent
    • Death usually occurs within 1-2 days
    • In foals that survive neonatal infection the condition progresses to cause joint infections and purulent nephritis, enteritis or pneumonia
    • A. equuli in arthritis of horses
    • Abortion, septicaemia and peritonitis in horses
  • Diagnosis:
    • Specimens cultured on blood agar and MacConkey agar and incubated aerobically for 1-3 days
    • Sticky colonies with variable haemolysis on blood agar
    • Lactose-fermenting colonies on MacConkey agar
  • Treatment and control:
    • Antimicrobials ineffective unless early in course of disease
    • Blood trasfusion and administration of colostrum
    • Good hygiene
    • Consider prophylactic antibiotics for new-born foals
    • Bacteria susceptible to streptomycin, tetracyclines and ampicillin
  • In other animals:
    • Septicaemia in piglets
    • Arthritis and enteritis in pigs
    • Enteritis in calves
    • RTX group cytotoxin present

Hepatitis

  • foals
  • bacteria from the septicaemia localise in the liver and other tissues, including the kidney