Isolation of pathogen Leptospira sp. from preputial smegma of bull.

Bovine leptospirosis causes significant economic losses due to infertility, abortions, births of weak and premature calves, and decreased milk production. While diagnosis typically relies on clinical history and laboratory test, genital tract infection by Leptospira spp. has been increasingly reported, highlighting the need to evaluate new diagnostic strategies. This study was conducted during a leptospirosis outbreak in a naturally mated herd, and aimed to assess whether preputial smegma samples for asymptomatic bulls can be used for the detection of Leptospira spp. A total of nine bulls were testing using qPCR, culture in EMHJ, and the microscopic agglutination test. Positive serology was found in 7 out 9 animals, with Sejroe serogroup showing the highest reactivity. Pathogenic Leptospira DNA was detected in 6 bulls by qPCR, and viable Leptospira spp. were recovered from one smegma cultures. These findings support the use of preputial smegma as a reliable sample for leptospirosis diagnosis in bulls and suggest a potential novel site of Leptospira colonization. This highlights the importance of testing males in herds with natural mating programs for the diagnosis of Bovine Genital Leptospirosis.