Leptospirosis is one of the most important and costly contributors to reproductive losses in the beef and dairy industries. Regional presence of leptospirosis in dairy herds ranged from 36% of herds in the Midwest to 91% in California, with an overall average of 59%.1 A 6 state study conducted with a cross section of environmental and management conditions representative of the U.S. beef cattle industry found overall prevalence of Lepto hardjo-bovis in cattle herds to be 42 percent.21 Bolin CA., Bovine leptospirosis prevalent in U.S. dairy herds. Bovine Veterinarian. 2003; February. pgs. 14-152 Wikse SE, Rogers GM, et al. Herd prevalence and risk factors of Leptospira infection in beef cow/calf operations in the United States: Leptospira borgpetersenii Serovar Hardjo. Bov Pract 2007;41(1):15-23.