Prevalence of erythrocytic protozoa and serologic reactivity to selected pathogens in deer in Texas

Abstract

Blood for serum and thin smears was collected from hunter-killed deer at 23 sites in 18 counties in Texas. Giemsa-stained thin blood smears were examined for hemoparasites, and serum was tested for antibody activity to bluetongue virus (BTV), epizootic hemorrhagic disease virus (EHDV), Brucella abortus and Anaplasma marginale. Of 233 smears of white-tailed deer ( Odocoileus virginianus) from across the state, Babesia odocoilei was identified from five animals (2%) at three sites and Theileria cervi was identified from 167 animals (72%) at 22 sites. Theileria species resembling T. cervi were identified in two of three axis deer ( Axis axis) and two of four sika deer ( Cervus nippon) from the Kerr Wildlife Management Area (Kerr County) and three of 16 mule deer ( Odocoileus hemionus) from Sierra Diablo Wildlife Management Area (Culbertson County). Including all species of deer tested statewide, the total prevalence of serologic reactors to BTV was 34.0% and to EHDV 32.0%, but there were significant differences among the reactor prevalence rates of different age classes. No serologic reactors to B. abortus were found. Serologic reactors to A. marginale were found in six of 20 (30.0%) mule deer in the Trans-Pecos region.