Pathogen Prevalence in Domestic Sheep in Western Nebraska: Implications for Bighorn Sheep Conservation and Coexistence on a Multi-Use Landscape

Bighorn sheep (Ovis canadensis) and domestic sheep (Ovis aries) are members of the same genus and thus share multiple pathogens that can be spread between them. One specific respiratory pathogen of concern is Mycoplasma ovipneumoniae (M. ovipneumoniae), which has been linked to pneumonia epizootics in bighorn sheep that are often characterized by all age die offs upon initial exposure followed by years of low lamb recruitment. Domestic sheep have been identified as one carrier of M. ovipneumoniae with transmission between sheep species occurring when there is close contact on the landscape. To prevent this cross-species transmission, importance has been placed on keeping bighorn sheep and domestic sheep spatially and/or temporally separate. On a landscape of multiple uses that is comprised mainly of privately owned land, this is a difficult goal to achieve. To understand the challenges that arise with having both domestic and wild sheep species in the same landscape, I sent a survey to domestic sheep producers. To understand the perceptions and attitudes of ranchers and hobby farmers about bighorn sheep and their potential to participate in conservation initiatives. Survey results revealed a positive response from domestic sheep producers in support of a wild and domestic sheep advisory committee working toward healthy coexistence of domestic and wild sheep on a shared landscape. Using a Risk of Contact (ROC) tool, we also identified areas on the landscape where domestic and bighorn sheep are at greatest risk of contact and therefore management focus should be placed on investigating pathogen and disease prevalence while working towards prevention of pathogen spread. Lastly, we examined different strain types of M. ovipneumoniae found in domestic and bighorn sheep in western Nebraska to estimate spatial prevalence and possible transmission events of M. ovipneumoniae. Through reducing disease prevalence and/or potential for disease transfer from domestic sheep to bighorn sheep and small management changes, we aim to promote coexistence of healthy domestic sheep and bighorn sheep on the western Nebraska landscape