Detection of members of Pasteurellaceae and Mycoplasma ovipneumoniae in lung tissues of dead bighorn sheep (Ovis canadensis) involved in pneumonia outbreaks and from the nasopharynx of healthy bighorns. The results of healthy bighorns represent the detection of the organism either in the nasal or pharyngeal swabs, or both, whereas the results of dead bighorns represent the detection of the organism in the pharyngeal swabs.