Objective—To estimate serovar-specific prevalence
of leptospirosis by use of veterinary teaching hospital
and laboratory submission data; describe annual and
seasonal patterns of leptospirosis; and identify risk
factors for age, sex, and breed.
Animals—90 dogs with leptospirosis.
Procedures—Hospital records of dogs examined at
Purdue University Veterinary Teaching Hospital with a
diagnosis of leptospirosis and laboratory records of
dogs from which sera were tested for antibodies
against Leptospira spp at Purdue University Animal
Disease Diagnostic Laboratory from 1997 through 2002
were reviewed. The likely infecting Leptospira serovar
was identified. Seasonal and annual prevalences were
calculated by use of hospital population at risk (hospital
cases) or serologic testing submissions (diagnostic laboratory
cases). Age-, sex-, and breed-specific risk factors
for hospital cases were estimated by odds ratios.
Results—Of the 39 hospitalized dogs identified, 34
had been serologically tested, and 22 of those were
infected with Leptospira kirschneri serovar grippotyphosa.
Of the 51 diagnostic laboratory cases, 59%
had a reciprocal titer ≥ 800 against serovar grippotyphosa.
Diagnostic laboratory cases were more common
in summer, whereas hospital cases of leptospirosis
were more common in fall. Male dogs were
at significantly greater risk of leptospirosis than
female dogs; and dogs 4 to 6.9 years old were at significantly
greater risk than dogs < 1 year old.
Conclusions and Clinical Relevance—L kirschneri
serovar grippotyphosa infection was associated with
most cases of leptospirosis in dogs. Use of an effective
vaccine that includes this serovar is advisable for
dogs at risk of leptospirosis. (J Am Vet Med Assoc 2004;224:1958–1963)