Experimental infection of sheep and cattle with leptospira interrogans serovar balcanica

Abstract

Eight 1-year-old ewes and 8 yearling heifers were inoculated with L. interrogans serovar balcmica. All 16 animals had seroconverted by 14 days post inoculation (pi). The only clinical signs related to infection were mild transient temperature elevations between 1 and 9 days pi which were observed in the majority of the inoculated animals. Leptospiruria was detected in 1 of the 8 sheep 18 days pi and leptospires were isolated from the kidney of this sheep at 50 days pi. Five of the 8 heifers were leptospiruric between 6 and 8 weeks pi and leptospires were isolated from kidney cultures of 3 of these heifers at 56 days pi. There was no natural transmission of balcanica infection to control animals run with these infected animals under pasture condition. Although it is possible that balcanica infection occurs sporadically in sheep and cattle in New Zealand we consider that it is unlikely to be maintained endemically in these species.