Epizootic hemorrhagic disease (EHD) is a hemorrhagic disease of white-tailed deer (Odocoileus virginianus) caused by an infection of a virus from the genus Orbivirus subsequently called Epizootic hemorrhagic disease virus (EHDV).

It is one of the most common diseases of white-tailed deer affecting deer herd in the northern United States. There have been sporadic cases in Pennsylvania as well as parts of Canada including British Columbia, Alberta and Saskatchewan. 

The EHD virus is usually found in tropical climates, wet areas, and can cause significant number of deaths within 8 to 36 hours of confirming the virus. The outbreaks usually occur in the late summer and early fall when "seasonal midge activity is at its peak." (PGC)

The signs of EHD usually begin approximately 7 days after infection of the virus and include: fever, swollen head, neck, tongue and have a loss of apetite. There is no treatment at this time.