Epizootiology of hemorrhagic disease in mule deer in central Arizona

We report two male mule deer (Odocoileus hemionus) mortalities that occurred near Prescott, Arizona (USA) in September 2001. Necropsy lesions were compatible with those described for hemorrhagic disease (HD). Bluetongue (BTV) and epizootic hemorrhagic disease (EHDV) viral RNA were identified in tissues from one deer and EHDV viral RNA was identified in the other via reverse transcription-polymerase chain reaction (RT-PCR). Virus isolation attempts were unsuccessful in both cases. To determine geographic range and viral serotypes involved, we collected blood samples from healthy hunter-harvested male mule deer in three game management units near Prescott in October 2001. Forty-one blood samples were collected and antibodies against EHDW and/or BTV were found in 21/41 (51%) samples as determined by agar immunodiffusion. Serum neutralization test results suggest that multiple EHDV and BTV serotypes are present in Arizona.