Illinois Department of Natural Resources

September 9, 2007

Virus Detected in Illinois’ White Tailed Deer Population

Animal Health Officials Say Epizootic Hemorrhagic Disease is Deadly to Deer, but Poses no Risk to Humans

SPRINGFIELD, Ill. – An outbreak of an acute, infectious virus that kills white-tailed deer has been detected in Illinois, the state Departments of Agriculture and Natural Resources reported today.
Epizootic Hemorrhagic Disease (EHD), an often-fatal virus that causes high fever and severe internal bleeding, has been confirmed in captive deer herds in Franklin and Randolph counties. It also is the suspected cause of death in wild deer in at least 28 counties throughout central and southern Illinois.

“One farm, in particular, has been devastated,” Dr. Colleen O’Keefe, IDOA division manager of Food Safety and Animal Protection, said. “The farm, located in Franklin County, has lost 16 of its 20 deer.”

EHD poses no risk to humans, according to Dr. O’Keefe. Other wild ruminants also are susceptible, including elk, mule deer, pronghorn antelope and bighorn sheep. Domestic animals such as livestock may become infected, but rarely exhibit signs of the disease or develop serious illness.

EHD is spread by biting midges, or gnats. The midges transmit the virus from infected to uninfected animals as they feed. There currently is neither a vaccine nor an effective treatment for the disease. “The only viable way to control the virus is to control the insect population,” Dr. O’Keefe said. “Short of spraying for insects, there’s nothing much a landowner can do to prevent the disease other than wait for cold weather.”

EHD outbreaks typically begin in late summer or early fall and end with an insect-killing frost. The deaths this year were first reported in late August. Officials believe the dry summer in central and southern Illinois, where the cases are concentrated, has contributed to the current outbreak. “When shallow ponds and creek beds dry up, conditions are good for hatches of disease-carrying insects,” Dr. Paul Shelton, Illinois Department of Natural Resources Forest Wildlife Program manager, said. “Then, as summer progresses, deer tend to become more concentrated around watering holes, facilitating the spread of the disease.”

EHD was first identified in 1955 when several hundred white-tailed deer died in both Michigan and New Jersey. Since then, cases have been documented throughout much of the United States and southern Canada. The last significant outbreak in Illinois occurred in 2004, although a few cases normally are observed in any given year.

Symptoms develop about seven days after exposure to the virus and include loss of appetite, excessive salivation, muscle weakness, lameness, depression and a rapid pulse and respiration rate. In very acute cases of the disease, animals enter a “shock-like” state, become prostrate and die within eight to 36 hours after the onset of symptoms.

Farmers with ill deer should not assume the animals are infected with EHD, even if they are exhibiting classic symptoms. A veterinarian should be called to give the deer a check-up. If the animal dies, the Illinois Department of Agriculture’s animal disease laboratories in Centralia and Galesburg will perform a post-mortem exam to determine the cause of death. The fee for this exam ranges from $40 to $100, depending upon the level of testing that is required.

Landowners or hunters who witness a deer exhibiting signs of EHD, especially near a creek or pond, can assist agency efforts to monitor the extent of the disease by reporting it to IDNR Deer Project Manager Tom Micetich at (309) 543-3316, extension 231.