Leptospirosis in pigs: The effectiveness of streptomycin in stopping leptospiruria

Abstract

A trial was conducted to assess the efficacy of a single intra-muscular injection of 25mg per kg of streptomycin in stopping leptospiruria in growing pigs exposed to a natural infection.

The investigation involved 54 pigs, 10–12 weeks old, that were free of serological evidence of infection with serotypes pomona or tarassovi at the start of the trial. The animals were kept in pens in a finishing house through which flowed effluent from other pens containing infected pigs. Urine samples were collected from each pig three times weekly until it was slaughtered for bacon at 20–24 weeks old.

Leptospiruria was first detected between 16 and 74 days after exposure. Twenty-one of 37 pigs which showed leptospiruria were injected with streptomycin. Leptospirae were detected in 11 of 185 (5.9%) subsequent urine samples from these 21 treated animals and serotype pomona was cultured from the kidney of 1 of the 10 animals that were examined from this group at slaughter.

Following the initial detection of leptospiruria in the 16 un-treated pigs, 179 of 211 (84.8%) subsequent urine samples con-tained leptospirae, which were also cultured from the kidneys of 4 out of 11 of these animals.