Diagnosis of bovine genital leptospirosis in asymptomatic bulls: Comparison of methods and samples under field conditions
Juliana Pedrosa, Daiany Motta, Wilmara Gregg, André Rodrigues, Walter LilenbaumAbstract
Background
Bovine leptospirosis is a zoonosis of global importance that is associated with reproductive losses. Although diagnosis in females has advanced, genital infection in males remains poorly understood. This cross‐sectional study aimed to compare diagnostic methods and sample types for detecting bovine genital leptospirosis (BGL) in bulls under field conditions.
Methods
Blood, urine, semen and preputial cytology samples were collected from 37 unvaccinated bulls and analysed by serology (microscopic agglutination test ‐MAT) and lipL32 ‐PCR.
Results
Serology showed low seroreactivity (13.5%), whereas PCR detected infection in 80.5% of bulls. Leptospira DNA was identified in semen (70.6%), preputial cytology samples (50%) and urine (46.8%). PCR detected a higher proportion of positive animals than MAT ( p < 0.05). The genital tract had a higher frequency of Leptospira detection than the urinary tract ( p < 0.05), with no significant difference between semen and preputial cytology samples ( p > 0.05).
Limitations
The sample size was small, and the number of samples collected differed among sample types.
Conclusions
PCR using genital samples—semen and/or preputial cytology—is the method of choice for diagnosing BGL in asymptomatic bulls.