Table: Comparison of Tests Used to Diagnose Leptospirosis in Dogs

Comparison of Tests Used to Diagnose Leptospirosis in Dogs

Diagnostic Test	Pros	Cons	False Positives	False Negatives	Comments
Microscopic agglutination test (MAT)	Widely available	Commercial laboratory only Requires live organisms Cross-reactions may confuse interpretation	Vaccination Exposure without disease	Early in the course of acute disease	Acute and convalescent titers recommended
Point-of-care immunochromatographic test for IgM antibodies^a	Patient-side test Rapid results	No numerical titer	Recent vaccination	Uncommon	Positive at low MAT titers
Point-of-care ELISA for antibodies against LipL32^b	Patient-side test Rapid results	No numerical titer	Vaccination	Early in the course of acute disease	Often negative with low MAT titers
Laboratory ELISA^c	Does not require live organisms	No numerical titer	Vaccination	Early in the course of acute disease	--
PCR assay	Rapid results Available at veterinary laboratories Validated for use in dogs	Not serogroup specific	Subclinical carriers Dead organisms Contamination	Low leptospire numbers Intermittent shedding	Most useful when combined with serological testing
Bacterial culture	Directly demonstrates presence of the organism	Technically demanding Not widely available Long turnaround time	Organisms can be isolated from body fluids of healthy animals	Antimicrobial therapy Timing of sampling Technical difficulties	Not often used clinically
^aZoetis WITNESS® Lepto ^bIDEXX SNAP® Lepto Test ^cDetects same antibodies as the SNAP® test