Leptospirosis - Cats and Dogs

Description

• • Dogs and cats
    • Serovars canicola and icterohaemorrhagica cause leptospirosis in dogs, but are vaccinated against
    • Serovars pomona and grippotyphosa are becoming important
    • The host-adapted serovar canicolar causes acute renal failure in puppies; a chronic uraemic syndrome may follow
    • Incidental infections with serovar icterohaemorrhagica or copenhagenii cause renal failure
    • L. icterohaemorrhagiae may cause hepatic jaundice
    • Serovar bratislava causes abortion and infertility in dogs, which may be the maintenance host
    • Infections uncommon in cats

• Leptospirosis icterohaemorrhagica - a septicaemic disease which affects the liver
• puppies
• Leptospirosis is an important spirochaetal group of diseases causing disease in animals and humans (zoonotic)
• Transmission
  • via urine of affected animals
  • organisms can remain viable for weeks in damp conditions
• method of action
  • cause anaemia via intravascular haemolysis

Diagnosis

Clinical Signs

• fever
• dehydration
• haemorrhaging from the mucous membranes of the body

Laboratory Tests

• dark field microscopy on fresh urine is best

Pathology

Grossly-

• widespread hameorrhages
• icterus
• pale foci in the liver (not always a constant finding)
• subcapsular and cortical renal haemorrhages

Microscopically-

• foci of necrosis
• dissociation of hepatocytes form each other (similar to post mortem change)
• substantial haemosiderin in the Kuppfer cells (from the haemolysis)
• need to use a silver stain or immunofluorescence to demonstrate the organisms in tissues

References

• Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition) Merial
• Nelson, R.W. and Couto, C.G. (2009) Small Animal Internal Medicine (Fourth Edition) Mosby Elsevier