NASHVILLE — White-tailed deer populations in portions of Middle and West Tennessee are currently experiencing an increase in hemorrhagic disease (HD) activity based on TWRA monitoring efforts. HD is a naturally occurring disease in deer, typical of southeastern states, that can be caused by epizootic hemorrhagic disease (EHD) and bluetongue (BT) viruses. These viruses are transmitted by a biting midge (known as no-see-ums), not directly between deer. HD is not known to cause disease in humans either through insect bites or through handling or consuming meat from infected deer.

HD occurs seasonally, but the severity is highly variable year-to-year, ranging from a few infrequent cases to highly visible outbreaks. Outbreaks are known to be linked to environmental conditions that impact the midge life cycle. Midges breed in the mud around water sources such as stump holes and small puddles. Years of excessive rain in the spring and early summer, followed by dry conditions in the late summer (as much of Tennessee has experienced this year), create favorable conditions for midge reproduction and elevated abundance, increasing the risk of HD outbreaks.

The disease can cause fatigue, respiratory distress, swollen tongue, sores in the mouth, fever, and sloughing of hooves that may cause lameness in deer. The deer may become thin, the tongue may hang from the mouth, accompanied by drooling, a lack of fear, and the whites of the eye may appear red. Usually, sick, dying, or dead deer are found in or near water as they try to relieve fever symptoms. However, not all deer that succumb to HD will look sick. Midges will die off with the first hard frost, but already infected deer may exhibit symptoms for several weeks after.

Deer can recover from this disease and develop immunity that can be passed on to the next generation. Therefore, the severity of outbreaks also depends on the level of herd immunity to circulating viruses. Some of these survivors may look thin and could suffer from lameness until their condition improves. Deer populations in the Southeast have evolved with these viruses and show long-term resiliency. Developed immunity often prevents consecutive outbreaks, allowing time for natural population recovery.

Thus far, HD has been lab confirmed in eight white-tailed deer in Franklin, Giles, Humphreys, Lewis, Shelby, Sumner, Wayne, and Williamson counties, with additional sick and dead deer reports coming in that are consistent with HD. TWRA officials will continue to monitor the situation and provide updates as necessary. If you find a sick or dead deer, please submit a report at https://www.tn.gov/content/tn/twra/sickdeer.html. TWRA staff may reach out to you if there is an opportunity to collect a viable sample for HD testing. Testing can only occur within 24 hours of death.

The Tennessee Wildlife Resources Agency is responsible for protecting, managing, and conserving fish and wildlife species for the benefit of Tennesseans and visitors. The Agency also maintains public safety through law enforcement and safety education on waterways.