Serodiagnosis of canine leptospirosis by solid-phase enzyme-linked immunosorbent assay.

An enzyme-linked immunosorbent assay (ELISA) to detect antibodies to Leptospira interrogans serotype canicola in dogs was developed and evaluated. Comparison of the ELISA with the microscopic agglutination test (MAT) showed that, during the first two weeks after an experimental infection with serotype canicola, the ELISA detected antibody at higher dilutions than the MAT. After the second week post-infection both tests detected antibody at almost equal titres (r = 0.89). The outer envelope (OE) antigen of serotypes icterohaemorrhagiae, copenhageni and canicola was fairly serotype-specific, whereas the pellet (P) antigen showed more cross-reactivity. Both OE and P antigen of Leptospira biflexa strain Patoc I could be used as cross-reacting antigen in the ELISA. Compared to the MAT, the ELISA has some technical advantages. It is suggested that the ELISA would be useful as a screening test.