Urinary shedding of leptospires and presence of Leptospira antibodies in healthy dogs from Upper Bavaria.

Leptospirosis is classified as a re-emerging zoonotic disease with global importance. The aim of this study was to determine urinary shedding of leptospires in healthy dogs and to identify the shedded leptospire species. Furthermore, antibody presence against leptospires was evaluated. In a prospective study urine samples of 200 healthy dogs from Upper Bavaria were randomly collected and evaluated by real-time polymerase chain reaction (PCR) specific for the lipL32 gene of pathogenic Leprospira (L.) spp. Positive samples were further characterized via multilocus sequence typing (MLST) to identify the Leptospira species. Microagglutination test (MAT) was performed to determine serum antibody titers. Three of 200 urine samples were found to be PCR-positive resulting in a urinary shedding prevalence of 1.5% (95% confidence interval 0.3-4.5%). All three dogs had been vaccinated before with a bivalent vaccine, covering the serogroups Canicola and Icterohaemorrhagiae. One dog shed leptospires of the species L. borgpetersenii, and two of the species L. interrogans. Of all dogs, 17.0% had antibody titers >= 1:100, and 3.5% titers >= 1:400 to serovars of non-vaccinal serogroups. Healthy dogs that shed leptospires represent a possible risk for humans and other animals. The study emphasizes the importance of general hygiene measures in veterinary practice while handling urine of all dogs, and the use of vaccines that protect against a broader range of serogroups and that prevent urinary shedding.