Seroprevalence of respiratory syncytial virus in free-ranging bighorn sheep.

Sera from 187 (42%) of 447 free-ranging bighorn sheep (Ovis canadensis) in 9 western states had antibody titers to respiratory syncytial virus (RSV). Titers were from 1:5 to 1:640, as determined by the standard virus neutralization test. Results of the survey indicated that RSV is widespread in free-ranging bighorn sheep populations and that RSV may be an important factor in the bighorn sheep pneumonia-complex.