Hemorrhagic disease impacting Tennessee deer herds
Tennessee Wildlife Resources Agency (TWRA) offices are receiving reports of dead deer in scattered areas of the state. The timing and details of many of the reports are indicative of hemorrhagic disease (HD). This disease is totally different form Chronic Wasting Disease which has been detected in West Tennessee and has been much in the news for the last year.
Hemorrhagic disease occurs in whitetail deer almost every year in Tennessee at varying levels of severity. So far this year, reports are predominantly coming from Middle Tennessee, and based on the volume of reports it appears to be above average in severity.
Reports to TWRA offices indicate mortality of deer in at least 20 counties with more expected as the season progresses. The last substantial outbreak of HD in Tennessee was in 2017 and was predominantly in East Tennessee. The last major statewide outbreak of HD was in 2007.
“Reports are coming in daily as TWRA continues to monitor the situation,” said James Kelly, Deer Management Program Leader for TWRA. “If hunters or the public find sick or dead deer they are encouraged to report these animals to their local TWRA regional office.”
HD is caused by viruses in one of two groups of vector borne viruses belonging to either the epizootic hemorrhagic disease virus (EHDV) group or bluetongue virus (BTV) group. HD is transmitted to deer from biting midges or “no-seeums.” Unlike CWD it is not transmitted from deer to deer by contact. The virus causes fever, respiratory distress, and swelling of the neck or tongue. Not all deer exposed to the virus will die, but those that do usually do so within 3 to 10 days of exposure in or near water as they seek to cool their bodies from the fever. Incidence of HD usually peaks around mid-September and activity slows down mid-October with the onset of cold weather.
“Although some of the clinical symptoms are similar, it is important to not confuse HD with CWD (Chronic Wasting Disease),” said University of Tennessee Wildlife Veterinarian, Dr. Dan Grove. “Unlike CWD, HD is a virus and deer can survive infection and populations will eventually rebound following an outbreak. Incidence of HD tends to cycle up and down as the environmental conditions are right for the biting midge to breed. CWD, on the other hand, is actually a much greater concern because the causative agent known as prions persist in the environment for decades and in deer populations indefinitely.”
For more information on Hemorrhagic Disease, please visit the Southeastern Cooperative Wildlife Disease Study website.
For more information about CWD, please visit CWDinTennessee.com.