The New York State Department of Environmental Conservation (DEC) reported on Tuesday that three deer in Southampton tested positive for bluetongue, which is closely related to the Epizootic Hemorrhagic Disease (EHD) virus and is transmitted in the same way.
According to the DEC message sent out Tuesday morning, this is the first time the bluetongue (BT) virus was detected in New York deer, let alone deer on the East End, but it was found in several other mid-Atlantic coast states this year.
The NY DEC also reported that a white-tailed deer in Southampton tested positive for EHD and two deer were found dead in the town of Schodack upstate in Rensselaer County in late August. These are in addition to two deer in the town of Dover Plains, Dutchess County, that died from EHD in mid-August.
EHD virus and BT virus are often fatal to deer. They are transmitted by biting midges, small bugs often called “no-see-ums.” EHD and BT outbreaks are most common in late summer and early fall when midges are abundant. Diseases caused by the viruses are usually not spread directly from deer to deer, and humans cannot be infected by deer or bites from midges.
Both EHD and BT cause similar symptoms in deer including fever, difficulty breathing, dehydration, swelling of the head neck and tongue, attraction to water, and rapid death. Infected deer will frequently seek out water sources and many succumb in or near a water source. Once clinical signs of EHD or BT infection are apparent, deer usually die within 36 hours.
There is no treatment or means to prevent EHD or BT in free-ranging deer. The dead deer do not serve as a source of infection for other animals.
Both illnesses can infect cattle and sheep. Cattle seldom exhibit signs of disease, but sheep can suffer severe disease and death from BT infection.
The EHD virus was first confirmed in New York in 2007 with relatively small outbreaks in Albany, Rensselaer, and Niagara counties, and in Rockland County in 2011.
In 2020, a large EHD outbreak occurred in New York’s lower Hudson Valley, centered in Putnam and Orange counties, with the public reporting approximately 1,500 dead deer. In 2021, the outbreak shifted and DEC received more than 2,000 reports of dead deer primarily in Ulster, Dutchess, Columbia, Oswego, and Jefferson counties.
EHD and BT outbreaks do not have a significant long-term effect on deer populations, but deer mortality can be intense in small geographic areas. EHD is endemic (occurs yearly) in the southern states where there are annual outbreaks, so some southern deer have developed immunity.
In the northeast, EHD outbreaks occur sporadically and deer in New York have little or no immunity to this virus. Consequently, most EHD-infected deer in New York are expected to die.
The good news, however, is here in the north, the first hard frost kills the midges that transmit the disease, ending the EHD and BT outbreak.
Reporting Deer with BT or EHD
The DEC is asking the public to report sightings of sick or dying deer online or to the nearest DEC Regional Office or Environmental Conservation police officer by checking the online list or calling the DEC Law Enforcement Dispatch Center at 1-844-DEC-ECOs (1-844-332-3267).
More information about EHD and an online EHD reporting form for deer with EHD symptoms, is available at the DEC’s website, dec.ny.gov/animals/123773.html. The DEC may collect samples from deer and analyze data from deer reports to determine the extent of the outbreak.
For more information, visit Cornell University’s Wildlife Health Lab website, cwhl.vet.cornell.edu.