Conservation Corner: September 16, 2002

Viral Diseases In Whitetail Deer
by James L. Cummins

Many infectious diseases affect whitetail deer. In deer management programs, the presence and impacts of diseases must be significantly considered. The most common means of deer diseases are protozoa, bacteria and viruses. Here, we will discuss the highly fatal epizootic hemorrhagic disease (EHD), or blue tongue as it is commonly called.

EHD was first reported in 1955 in New Jersey where 700 deer died. Since that outbreak, others have occurred throughout the United States in varying intensities. In 1971 scattered outbreaks of EHD occurred throughout the Southeast. In 1976, an EHD outbreak killed several thousand whitetail deer in Kansas, Nebraska, North Dakota, South Dakota and Wyoming.

EHD usually occurs from late summer to early fall. It is transmitted through blood-sucking gnats. One characteristic of this disease is its sudden attack. Whitetail deer that are infected initially loose their fear on humans. Next, they loose their appetite and, of course, grow weaker. They also salivate much more than normal and show signs of fever (136 degrees Fahrenheit). Their heart rate increases as well as breathing before the animal is finally comatosed.

Signs of EHD are characterized by extensive hemorrhaging of organs and tissues. Often, as a result, the feces, urine and saliva will contain blood. Although all organs are susceptible to hemorrhaging, those organs that are affected most often are the heart, liver, spleen, lungs and the intestines.

Other viral diseases include skin tumors. If you spend much time in pursuit of the whitetail deer, you will probably come in contact with a skin tumor, which are often called warts or fibromas. Tumors can be found on any part of the body. The carrier can be other deer, insects, or even contaminated foliage. There are no threats to humans from these tumors.

Arboviruses are another form of viral infections in whitetail deer. One of the most common arboviruses in Mississippi is viral encephalitis. Arthropods carry this disease and can infect almost any vertebrate.

The exotic foot and mouth disease was discovered in the United States in 1924. In California, where it was found, over 22,000 deer and many livestock were exterminated. This extermination program successfully eliminated the disease from the United States. However, should it reoccur, it could have serious implications on our whitetail deer herd.

Other viral diseases, such as rabies, have been found in whitetail deer populations in the United States, however, have not caused significant problems to populations.

James L. Cummins is Executive Director of the Mississippi Fish and Wildlife Foundation in Stoneville, Mississippi. Known as "Wildlife Mississippi," the Foundation is a non-profit, conservation organization founded to conserve, restore and enhance fish, wildlife and plant resources throughout Mississippi