Epizootic Hemorrhagic Disease
DEC is currently monitoring an outbreak of EHD affecting deer in multiple counties. The outbreak started in the lower Hudson Valley in late July 2021, and has since been confirmed in Columbia, Dutchess, Greene, Nassau, Oswego, Suffolk, and Ulster counties, with suspected cases in Albany, Jefferson, Oneida, Orange, Putnam, Rensselaer, Rockland, Sullivan, and Westchester counties.
Please help DEC keep track of potential EHD cases in these and other portions of New York.
Submit reports and photos of sick or dead deer suspected of having EHD using our Online EHD Reporting Form (leaves DEC site).
Causes and Susceptible Species
Epizootic Hemorrhagic Disease (EHD) is a viral disease of white-tailed deer that is transmitted by biting midges (Culicoides spp.), also called no-see-ums or punkies. The disease is not spread directly from deer to deer and humans cannot be infected by contact with deer or bites from midges. EHD outbreaks are most common in the late summer and early fall when the midges are abundant. The dead deer do not serve as a source of infection for other animals because the virus is not long lived in dead animals. Some strains of EHD can infect cattle. EHDV-6 is the serotype (strain) of EHD virus that infected NY deer in 2020 and 2021.
Symptoms and Diagnosis
Photo by Christine Martinez
In deer, external signs of EHD include fever; small hemorrhages or bruises in the mouth and nose; and swelling of the head, neck, tongue, and lips. A deer infected with EHD may appear lame or dehydrated. Once infected with EHD, deer will begin to show signs 2 - 10 days later and usually die within 36 hours of showing signs of infection. Frequently, infected deer will seek out water sources and carcasses are often found in or near water. Deer dead from EHD infection seem to bloat and decompose rapidly. A large number of dead or sick deer may be found in a limited area.
EHD resembles other serious but rare diseases of domestic ruminants including Blue Tongue and Foot and Mouth Disease, so it is important to confirm the diagnosis when outbreaks occur. Dead deer are examined by necropsy (animal autopsy) and tissues are tested for viral DNA to confirm the disease.
Management
The first hard frost should kill midges, effectively ending EHD outbreaks. EHD is endemic (occurs yearly) in the southern U.S. and it is becoming more common in the northern parts of the U.S. In some states, large outbreaks have affected thousands of deer. Previous outbreaks in New York have occurred in 2007 (Albany, Rensselaer, and Niagara Counties), 2011 (Rockland County), 2020 (Ulster, Dutchess, Westchester, Putnam, Orange, Columbia and Albany Counties), and 2021. DEC tests and tracks deer mortalities to determine impacts on the deer population.
There is no treatment and no means of prevention for EHD. While EHD outbreaks can remove a number of deer from a local population, they generally do not have a significant long-term impact on regional deer populations.
Dead deer do not serve as a source of EHD infection to animals or people and do not need to be removed from the landscape. DEC does not remove dead deer; however, if there is a need to dispose of or move a dead deer, landowners should take routine precautions: wear gloves and wash hands afterwards. In rural and lightly populated suburban environments deer can be dragged to an area where they do not impact human activities to be scavenged and decompose. In heavily populated suburban and urban environments deer carcasses may need to go to a landfill; sometimes Nuisance Wildlife Control Operators will dispose of deer carcasses for a fee.
For hunters, thorough cooking will kill the virus, but DEC always recommends against harvesting or eating any animal that appears sick or diseased.
For more information on EHD please visit (links leave DEC's website):
