Obvious clinical signs may be apparent in only about 5% to 10% of dogs infected with B. burgdorferi. So the harder question is, how should we manage the vast majority of infected dogs that show no clinical signs?

To help confirm a diagnosis of canine leptospirosis, veterinarians today must rely on serologic testing with the microscopic agglutination test. Interpreting the test can be problematic, though, especially early on in the disease or in a recently vaccinated dog.