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Epizootic Hemorrhagic Disease in New York State

Map of the United States showing the distribution of Epizootic Hemorrhagic Disease 1980 - 2016
U.S Distribution of Epizootic Hemorrhagic Disease

Epizootic Hemorrhagic Disease (EHD) is an important infectious disease of white-tailed deer. It is caused by a virus. The first outbreak in the U.S. was identified in New Jersey in 1955. It occurs annually in some southeastern states and has been recently reported throughout the mid-Atlantic and Northeast. It tends to infect localized pockets of animals within a geographic area.

History of Epizootic Hemorrhagic Disease in New York

In October 2007, the first case of EHD in New York was confirmed in Albany and Rensselaer counties. In November, Niagara County was added to the list. A case history, characteristic signs and lesions, and virus isolation were used to diagnose the disease. In 2011, Rockland county reported an EHD mortality event. About 100 deer were estimated to have died. There has been no observed reoccurrence of the disease, despite surrounding states with confirmed cases.

Causes and Symptoms

The EHD virus is transmitted to deer from the bites of infected midges (Culicoides), commonly referred to as "no-see-ums" or "gnats". Outbreaks of EHD occur during late summer and early autumn due to an increase in midge numbers. Onset of a hard frost will typically kill the midges and stop the outbreak. Events can range from a few cases to significant localized impacts. Infected animals are often found near water, and multiple carcasses may be found in an area.

Map of Counties with EHD outbreaks in New York
EHD counties in NY.
New areas, where the disease has not occurred previously, are more likely to see mortalities rather than illness (morbidity). Disease can occur rapidly and kill the deer within one-three days of infection. Areas, particularly in the southeast where the disease has occurred repeatedly, are more likely to have animals that show no effects or mild symptoms. There are several serotypes (strains) of EHD: 1, 2, and 6, that occur in different areas around the country. There are no wildlife management tools or strategies to prevent or control EHD.

Common signs include:

  • swollen head, neck, tongue, or eyelids;
  • bloody discharge from the nasal cavity;
  • erosion of the dental pad or ulcers on the tongue;
  • hemorrhaging of the heart or lungs causing respiratory distress; and
  • high feverish conditions leading infected deer to sometimes be found near water sources.

For more detailed information about EHD, visit the Southeastern Cooperative Wildlife Disease Study website (leaves DEC website).

Risk to Humans

EHD is a disease of deer, although a few cases have occurred in cattle. It does not infect humans. Humans are not at risk by handling infected deer or eating venison from infected deer, although it is not recommended to eat sick animals. Wearing gloves when field dressing game and washing equipment is recommended. Hunters should also wash their hands using hot water and soap after handling wild animals. The public should report any sick animals or groups of dead deer to the nearest DEC Regional Wildlife Office or the DEC Wildlife Health Unit in Delmar.