Epizootic hemorrhagic disease (EHD) is a vector-borne viral disease that affects cattle and white-tailed deer. Deaths are uncommon however it can cause severe dehydration in affected animals, leading to high mortalities during high temperatures. Most infections with the North American strains of EHD appear to be subclinical and seropositive cattle may be common in some regions. Evidence also suggests that pregnant cows may experience reproductive problems (such as abortions and fetal resorptions).
It is transmitted mainly through bites from infected biting midges, gnats, and mosquitoes.