SYSTEMIC ADENOVIRUS INFECTION ASSOCIATED WITH HIGH MORTALITY IN MULE DEER (ODOCOILEUS-HEMIONUS) IN CALIFORNIA

Seventeen counties in northern California experienced epizootics of hi gh mortality in the mule deer (Odocoileus hemionus) population during the latter half of 1993. Thirteen deer submitted to the California Vet erinary Diagnostic Laboratory System as part of this natural die-off h ad systemic adenovirus infection. Pulmonary edema was present in all 1 3 deer. Erosions, ulceration, and abscessation of the upper alimentary tract occurred in 7/13 deer. Four of 13 deer had hemorrhagic enteriti s. All 13 deer had widespread systemic vasculitis with endothelial int ranuclear inclusions. Fluorescein isothiocyanate-labeled antibody dire cted against bovine adenovirus type 5 bound to antigen in endothelial cells. Adenovirus was identified by transmission electron microscopy w ithin the nuclei of endothelial cells in 6/6 deer examined. An adenovi rus was isolated from lung homogenates of one deer that were cultured on black-tailed deer pulmonary artery endothelial cells. With the exce ption of the intranuclear inclusions evident on histologic evaluation, gross and histologic changes were similar to those described for blue tongue virus infection and epizootic hemorrhagic disease virus infecti on in white-tailed deer. Nine additional deer were emaciated and had p haryngeal abscesses with focal vasculitis, which may represent the chr onic affects of previous nonfatal adenovirus infection.