Diseases and Parasites of Maryland Deer

Q & A Fact Sheet Hemorrhagic Disease in White-tailed Deer

Q. What is Hemorrhagic Disease (HD)?

A. Hemorrhagic disease is an acute, infectious, often fatal viral disease of deer and elk that is caused by Epizootic Hemorrhagic Disease virus. This disease is characterized by extensive hemorrhages and has been responsible for significant disease outbreaks in portions of the northern United States and parts of southern Canada. It is the most important endemic infectious disease of white-tailed deer in the southeastern US.

Q. Has HD occurred before?

A. The occurrence and identification of HD was first reported in 1955 in white-tailed deer in New Jersey where approximately 700 deer succumbed. Since the initial confirmation of HD, outbreaks have occurred in white-tailed deer throughout portions of the United States and southern Canada.

Q. Does HD occur every year?

A. The disease occurs annually, but its distribution and severity of occurrence are highly variable. Occurrence may involve only a very few scattered, mild cases or may appear as dramatic, highly visible outbreaks.

Q. Why is it called Hemorrhagic Disease?

A. The viruses attack and derange the blood clotting mechanism and cause degenerative changes in blood vessel walls leading to extensive hemorrhaging in organs and tissues throughout the animal's body.

Q. Can farm animals get HD?

A. Cattle seldom exhibit clinical signs and usually any signs are very mild. Sheep are not affected.

Q. Can People get HD?

A. No. It is not infectious to humans, dogs, or cats.

Q. How is HD spread?

A. Transmission does not occur by direct contact, it is spread through biting midges, otherwise known as no-see-ums.

Q. What are the clinical signs of HD?

A. White-tailed deer exhibit signs of illness 5-10 days after being exposed to the virus. Deer initially lose their appetite and fear of man, grow progressively weaker, often salivate excessively, exhibit shortness of breath, and finally become comatose. Hemorrhaging or lesions on the mucosa of the mouth and tongue can be seen. Severe emaciation is seen in animals recovering from severe disease. The disease is roughly categorized according to location and severity of lesions if they are present:

  • Peracute - (rapid progression): severe swelling, respiratory distress
  • Classical acute - (not so rapid): swelling, bleeding in and around the heart and gut, erosions of the mouth and stomach
  • Chronic - (slow progression): sloughing of the hoof wall or toe and severe rumen ulcers

Any deer found dead with no visible injuries during the late summer and early fall should be considered a potential Hemorrhagic Disease case. These cases should be reported to your local Wildlife and Heritage Service office.

Q. How is HD diagnosed?

A. A confirmed diagnosis requires isolation of the virus from sick or freshly dead deer with clinical signs or lesions typical of hemorrhagic disease. Preferred specimens for virus isolation are unclotted whole blood in EDTA or heparin and refrigerated samples of spleen and lymph node.

Q. What can be done to prevent HD?

A. There is no known effective treatment or control for HD.

Q. What is DNR doing about it?

A. The Wildlife and Heritage Service of Maryland DNR monitors the occurrence of Hemorrhagic Disease in all twenty-three counties. Deer are examined at meat processors during the muzzleloader and firearm seasons. Wildlife and Heritage participates in the nationwide monitoring program with the Southeastern Cooperative Wildlife Disease Study (SCWDS). Fresh deer carcasses are delivered to state health labs when a Hemorrhagic Disease outbreak is suspected.

Q. Is HD a danger to the health of Maryland's overall deer population?

A. No, outbreaks of HD are localized, not widespread, and do not have a major effect on the statewide deer population.

Q. What do I do if I find a dead deer and suspect HD?

A. Deer deaths from HD occur in the late summer or early fall. If you find a deer you suspect has died from HD, contact the DNR Wildlife and Heritage Service Field Office closest to you: Bel Air (410) 836-4557, Annapolis (410) 260-8540, Cumberland (301) 777-2136, and Wye Mills 410-827-8612.

Q. Can I eat a deer that exhibits signs of HD?

A. The presence of HD in a deer that does not exhibit outward signs of the disease does not affect the safety of the meat. Deer with chronic HD can often have visible sores and secondary infections. The Department of Natural Resources recommends not eating deer which have large, open sores.

Q. Will HD effect the hunting season or bag limit?

A. Deer deaths are usually not widespread but in small pockets. ( Not over an entire county). Since deer mortality is geographically limited there is no reason to adjust hunting seasons or bag limits.


Davidson, William R., and Victor F. Nettles. Field Manual of Wildlife Diseases in the Southeastern United States. Second Edition. 24-33. 1997.

Trainer, Daniel O., and Lars H. Karstad. Epizootic Hemorrhagic Disease. Infectious Diseases of Wild Mammals. 50-53. 1970.

Developed by:

The Maryland Department of Natural Resources Fish and Wildlife Health Program, DNR Wildlife and Heritage Service, and the Epidemiology Department of the Virginia-Maryland Regional College of Veterinary Medicine at College Park

Updated October 12, 2007

Diseases and Parasites of Maryland Deer