Recovery of multireassortant bluetongue virus serotype 6 sequences from a mule deer (Odocoileus hemionus) and Dorset sheep (Ovis aries) in Colorado.

We report the discovery of two bluetongue virus serotype 6 (BTV-6) reassortants recovered from a domestic sheep and a free-ranging mule deer in northern Colorado. At the time of this publication, whole-genome sequencing of BTV-6 isolates in the Western U.S. have not been undertaken. These findings reflect the incursive movement of geographically distinct BTV serotypes into important agricultural areas of the U.S. and demonstrate reassortment with regionally circulating serotypes.