This study was done to investigate the infection rates of leptospirosis in different Veterinary Clinics in Dakahlia Province during the period from September 2016 to December 2017, The study was applied on a total of 115 urine samples, collected from suspected cattle (97) and their in-contact dogs (18), which suffered from different clinical signs of leptospirosis. The collected samples were examined for Leptospira spp. by different methods as Dark Field Microscopy (DFM) and staining by Silver Impregnation Method “Fontana Method".
The results of DFM showed that, 28 out of 97 (28.9%) cattle urine samples were positive, and eight out of 18 (44.4%) dogs' urine samples were positive. Additionally, the results of Fontana Method revealed that, 44 out of 97 (45.4%) cattle urine samples were positive, and 13 out of 18 (72.2%) dogs' urine samples were positive. To confirm these results, conventional polymerase chain reaction (PCR) targeting (23S rDNA) gene of Leptospira, was done on 6 urine samples, included 3 cattle urine samples and 3 dogs' urine samples (one sample was positive, and two samples were negative in each species). PCR result confirmed the DFM and Fontana method results. In addition, a treatment trial for three groups of cattle infected with leptospirosis was performed by Dihydrostreptomycin, Oxytetracycline and Amoxicillin, respectively for 3 days. This study showed higher prevalence of leptospirosis in Dakahlia by DFM and Fontana methods. Moreover, Dihydrostreptomycin, Oxytetracycline and Amoxicillin have been successfully affecting on leptospirosis.