Acute hepatitis - leptosporosis

• Leptosporosis - diagnosis

  PCR of organism from EDTA blood (up to 5 days post infection) and urine (from 7-10 days post infection) - samples collected before antibiotic most helpful.

  Antibodu titres (MAT)

  • If high in unvaccinated dogs could be diagnostic
  • Need a rising titre in vaccinated dogs.
  • Most convincing is with rising titre (4 fold increase in 2-4 weeks)
  • Low in chronic disease therefore not helpful for carrier state.

  Dark field microscopy - difficult and low sensitivity and specificity.

  Culture is almost impossible.
• Leptosporosis - treatment

  Supportive therapy

  • IVFT
  • Potassium management; if hyperkalaemic consider calcium gluconate, dextrose/ insulin.
  • Anti-emetics
  • Anti-oxidants (SAMe)
  • Assisted nutrition.
• Leptosporosis - specific therapy

  Early antibiotic treatment is strongly recommended.

  • Penicillin G, ampicillin or amoxicillin for 2 weeks.
  • Kills circulating organisms very effectively.
  • Does not remove the carrier state.
  • Then use Doxycycline for 2 weeks
  • Elimination of carrier state
  • May cause vomiting and not always tolerated in acute cases.
• Leptosporosis - vaccination

  Inactivated organisms:

  • Serovars historically have been Icterohaemorrhagica and Canicola. Newer vaccines now include Australis and Grippotyphosa (i.e. serovars ‘L4’ vaccines).

  Duration of immunity variable in different animals - probably does not need annual vaccination unlike other vaccines.

  Serology to assess vaccination efficacy

  • Correlation between antibody levels and protection is poor.
• Leptosporosis - lifestyle management

  Reduce access to potential sources of exposure.

  Avoid drinking from or wading/ swimming in fresh or stagnant water sources and marshland.

  Control rodent sources; avoid hunting or access to wildlife.