This dead-head was found at Big Oaks, it is suspected to have died from EHD. BOCS Photo Hemorrhagic Disease (HD) is caused by one of two viruses, epizootic hemorrhagic disease (EHD) virus or blue-tongue (BT) virus. Although the two viruses have non-distinguishable symptoms, they differ genetically. HD is a viral disease that infects all ungulates, most commonly White-Tailed Deer, as well as cattle and domestic sheep. In Indiana, the disease was first detected in the 1890s as