Case Report
Domestic sheep can carry the bacterium in their upper respiratory tract, often with little effect on health and productivity. However, for bighorn sheep populations, there is a link between infection and pneumonia, poor lamb recruitment, and high fatality rate. Because of these outcomes, preventing transmission of to free-ranging wild sheep has garnered interest from both the livestock and wildlife sectors. We hypothesized that treatment with intranasal and systemic enrofloxacin would reduce the prevalence of -positive animals in a flock of domestic sheep. Initially, the prevalence decreased in the treated group; but by 34 d post-treatment, the number of -positive sheep returned to near pretreatment prevalence. Key clinical message: Test-and-slaughter is a method used to reduce the risk of transmission of pneumonia-causing from domestic sheep and goats to free-ranging wild sheep. In an effort to find an alternative, we used enrofloxacin to treat a flock of -positive domestic sheep; however, long-term reduction of prevalence in the flock was not achieved.