Canine Leptospira IgM Antibody Test Card (Colloidal Gold Method)

Target and Hazard: Leptospirosis, caused by pathogenic serovars of Leptospira interrogans (e.g. the icterohaemorrhagiae and canicola groups), is a zoonotic infectious disease. Dogs become infected by contact with water or soil contaminated by the urine of carrier animals; the organism enters through mucous membranes or broken skin and, once established in the kidney, is shed in urine for long periods. Affected dogs show fever, jaundice, haemoglobinuria, hepatic and renal damage and a bleeding tendency, and acute severe cases may be fatal. Because infected dogs shed the organism into the environment and can infect humans, the public-health significance is significant.

Significance of Testing: IgM is the first antibody to appear after infection, so its presence indicates recent or acute infection, in contrast to IgG, which reflects past exposure. The card detects canine Leptospira IgM antibodies in serum for early supportive diagnosis of suspected acute cases and aetiological investigation of acute jaundice or renal cases, helping initiate antibacterial treatment early, isolate shedders and disinfect the environment, thereby reducing transmission to people and other dogs. Where necessary, results should be interpreted together with pathogen detection and convalescent sera.

Principle: Colloidal gold immunochromatographic assay (indirect format): the test line (T) is coated with Leptospira-specific antigen; IgM antibodies in the sample bind to gold-labelled anti-dog IgM, migrate along the membrane and are captured by the antigen at the T line, producing a visible line; the control line (C) confirms reagent and procedure validity.

Performance and Applications: No instrument required; serum or plasma samples; visual reading within 5–10 minutes; stored and shipped at room temperature — suitable for rapid on-site screening in veterinary clinics, primary veterinary stations and animal disease control institutions. Method: colloidal gold immunochromatographic assay (indirect format) | Samples: serum, plasma | Time to result: 5–10 min | Reading: visual assessment of T/C lines — a coloured T line indicates a positive result, C line is the procedural control | Format: tests/box (as stated on the label) | Storage: 2–30 °C, cool and dry; shelf life 18 months | Note: sensitivity, specificity, limit of detection, intra-/inter-assay CV and agreement with MAT (microscopic agglutination test)/pathogen detection are subject to our internal QC report.