Blue tongue disease reported in Kentucky deer

A white-tailed deer from western Kentucky is the state’s first confirmed case of hemorrhagic disease this year.

Murray State University’s Breathitt Veterinary Center recently confirmed to the Kentucky Department of Fish and Wildlife Resources that a deceased female deer recovered from Graves County tested positive for hemorrhagic disease, sometimes referred to as “blue tongue” or EHD. 

Kentucky Fish and Wildlife is investigating other possible cases involving 22 deer in 11 counties and expects the number could grow in the coming weeks.

“Hemorrhagic disease cannot be transmitted to people or pets,” said Dr. Christine Casey, state wildlife veterinarian for Kentucky Fish and Wildlife. “It is caused by two different viruses: epizootic hemorrhagic disease virus (EHD) and bluetongue virus. These viruses are transmitted to deer by small biting flies, also called no-see-ums.”

Kentucky experiences localized hemorrhagic disease outbreaks each year. More regionally widespread and statewide outbreaks can occur in cycles of five years or longer. A significant regional outbreak of hemorrhagic disease affected many east Kentucky counties two years ago. Far western Kentucky endured an outbreak in 2012, and the last statewide outbreak occurred in 2007.

Outbreaks of hemorrhagic disease generally last from late summer until the first hard frost of the year kills the virus-carrying flies.

Hemorrhagic disease has been present in the United States for more than 60 years. It is not the same as chronic wasting disease (CWD), an always fatal neurological disease that affects white-tailed deer, elk and other members of the deer family. Chronic wasting disease has never been detected in Kentucky.

One main difference between the diseases is that some deer do survive hemorrhagic disease outbreaks and produce protective antibodies, which can be passed to their young. Protective antibodies are major contributors to herd immunity and one reason why Kentucky sees cyclic outbreaks of hemorrhagic disease, rather than a higher prevalence every year.

In Kentucky and across the Midwest, deer that die from hemorrhagic disease typically die within 24 to 36 hours after being bitten by an infected insect. People often find carcasses of deer that have died from the disease around water, and because they died rapidly these animals can appear well fed or otherwise normal. Sometimes there are several carcasses in one area.

While elk in Appalachian Kentucky also contract hemorrhagic disease from insect bites, they usually show no outward signs of illness and death does not occur.

Suspected cases of hemorrhagic disease in dead or dying deer on fw.ky.gov