1. Clinical Medicine 3 Neal Villanueva, DVM
Leptospirosis
Clinical Medicine 3
Neal Villanueva, DVM

2. Definition Gram negative spirochete (helical) 200 serovars
Most common serovars affecting dogs
L. canicola- Dog is the reservoir host
L. icterohemorrhagiae
L. grippotyphosa
L. pomona
L. bratislava
Rare in cats

4. Pathophysiology
Penetrate skin or mucous membranes and enters the bloodstream (4-7 days)
Spreads systemically (2-4 days)
Transitory fever, leukocytosis and anemia.
Capillary and endothelial cell damage  petechial hemorrhages
Liver-
hepatic necrosis
Kidney-
damages renal tubules and replicates in the tubular epithelial cells
Death
Secondary to renal failure
Acute septicemia and/or DIC

6. Transmission Direct Indirect Host to host
Contact with infective urine
Postabortion discharge
Sexual contact
Indirect
Exposure to infective urine to a contaminated environment where the organism can survive.
Vegetation
Soil
Food, water
bedding

8. Environmental factors
Warm and moist environment
Wet season/high rainfall areas of temperate regions
Low-lying areas (marsh, muddy, irrigated)
Tropical and subtropical
T°- 7-10°C ( °F) to 34-36°C (93-96°F)
Water
↑ survival in stagnant water
Slightly alkaline pH
Can survive 180 days in wet soil, longer in standing water.

10. Signalment Species Age Dogs Cats- rare
Young dogs without passive maternal antibodies
Severe disease
Old dogs with adequate antibody titer levels seldom exhibit clinical disease unless exposed to a serovar not in the vaccine
No cross immunity between serovars

11. Clinical Signs History Peracute to subacute disease Fever
Sore muscles, stiffness
Weakness
Anorexia
Depression
Vomiting
Dehydration
Diarrhea +/- blood
Death

12. Chronic Sub-clinical illness Fever of unknown origin PU/PD
Chronic renal failure

13. Physical Exam- peracute to acute
Tachypnea
Rapid, irregular pulse
Poor capillary perfusion
Hematemesis
Hematochezia
Melena
Epistaxis
Injected mucous membranes
Petechial/ecchymotic hemorrhages
Reluctance to move, hyperesthesia and stiff gait
Hematuria
Conjuctivitis,rhiniteis

14. Diagnosis Suggestive history Increased risk factors
Exposure to stagnant water, host animals and wooded areas
Lack of prior vaccination
Fever and renal and/or hepatic involvement are suggestive.
Increased risk factors
Middle-aged dogs
Large breed, mixed breed, hound dogs
Dogs living in urban areas
Terriers, toy breeds

15. Laboratory findings CBC Serum chemistry
Leukopenia during leptospiremia  leukocytosis +/- left shift.
Thrombocytopemia
Normocytic normochromic anemia
Serum chemistry
Azotemia, hyperphosphatemia, hypercalcemia
Hyponatremia, hypochloremia, hypokalemia if vomiting
Hyperkalemia w/ oliguria or anuria
+/- elevated hepatic values (AALT, AST, ALKPhos, Tbil)

16. Specific Tests Microscopic Agglutination Test (MAT)
4 fold increase in titers over a 2-4 week period
Or a single test result of 1:800 + is diagnostic
Unable to differentiate b/t infection and vaccination
Polymerase Chain Reaction test (PCR)
Positive before seroconversion  earlier diagnosis
100% sensitivity, 83% specificity
Sensitivity may result in false positives

17. Treatment Supportive care and fluid therapy
Elimination of leptospiremia
Ampicillin
Amoxicillin
Penicillin
Elimination of carrier state
Doxcycline
Tetracycline
azithromycin

18. Prevention Vaccination L. canicola L. icterohaemorrhagiae L. pomona
L. gryppotyphosa
Only lasts 6-8 months, recommend booster q6m.
No cross protection from other serovars

20. Zoonotic potential Recreational water sources, floods Occupational
Keep lepto suspect animals separate
Handle urine/urine contaminated items with latex gloves
Facemasks and goggles when hosing contaminated areas

21. Questions?