Difference between revisions of "Leptospirosis - Cats and Dogs"
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Leptospirosis can be caused by infection with a number of different serovars of the bacteria Leptospira interrogans. In general infection with a host adapted strain results in subclinical infection, intermittent shedding of the organism and the animal acts as a reservoir for infection. Infection with non host adapted strains results in clinical disease. | Leptospirosis can be caused by infection with a number of different serovars of the bacteria Leptospira interrogans. In general infection with a host adapted strain results in subclinical infection, intermittent shedding of the organism and the animal acts as a reservoir for infection. Infection with non host adapted strains results in clinical disease. | ||
| − | Vaccination against serovars ''canicola'' and ''icterohaemorrhagica'' has greatly reduced the prevalence and incidence of disease in the UK | + | Vaccination against serovars ''canicola'' and ''icterohaemorrhagica'' has greatly reduced the prevalence and incidence of disease in the UK but in some areas the disease is re-emerging as owners decide not to vaccinate due to the reduced risk. Serovars ''pomona'' and ''grippotyphosa'' are becoming important. |
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| + | Cats do not appear to be affected by clinical disease but can become subclinically infected acting as a resevoir with intermittent shedding. | ||
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***The host-adapted serovar ''canicolar'' causes acute renal failure in puppies; a chronic uraemic syndrome may follow | ***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 | ***Incidental infections with serovar ''icterohaemorrhagica'' or ''copenhagenii'' cause renal failure | ||
***''L. icterohaemorrhagiae'' may cause [[Pigmentation and Calcification - Pathology#Hepatic (Toxic) Icterus|hepatic jaundice]] | ***''L. icterohaemorrhagiae'' may cause [[Pigmentation and Calcification - Pathology#Hepatic (Toxic) Icterus|hepatic jaundice]] | ||
***Serovar ''bratislava'' causes abortion and infertility in dogs, which may be the maintenance host | ***Serovar ''bratislava'' causes abortion and infertility in dogs, which may be the maintenance host | ||
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*''Leptospirosis icterohaemorrhagica'' - a septicaemic disease which affects the [[Liver - Anatomy & Physiology|liver]] | *''Leptospirosis icterohaemorrhagica'' - a septicaemic disease which affects the [[Liver - Anatomy & Physiology|liver]] | ||
*puppies | *puppies | ||
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===Laboratory Tests=== | ===Laboratory Tests=== | ||
| − | + | Dark field microscopy on fresh urine is best | |
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===Pathology=== | ===Pathology=== | ||
Grossly- | Grossly- | ||
Revision as of 10:00, 2 September 2010
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This article is still under construction. |
Description
Leptospirosis can be caused by infection with a number of different serovars of the bacteria Leptospira interrogans. In general infection with a host adapted strain results in subclinical infection, intermittent shedding of the organism and the animal acts as a reservoir for infection. Infection with non host adapted strains results in clinical disease.
Vaccination against serovars canicola and icterohaemorrhagica has greatly reduced the prevalence and incidence of disease in the UK but in some areas the disease is re-emerging as owners decide not to vaccinate due to the reduced risk. Serovars pomona and grippotyphosa are becoming important.
Cats do not appear to be affected by clinical disease but can become subclinically infected acting as a resevoir with intermittent shedding.
- 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
- 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
Signalment
Leptospirosis can affect dogs of any age, breed or sex. Young male, adult working dogs are at greatest risk.
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
Treatment
Prognosis
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