Questions and answers about Adenovirus Hemorrhagic Disease
Adenovirus Hemorrhagic Disease (pdf)
Adenoviruses belong to a small group of viruses that can infect a wide variety of animals, both wild and domestic. The AHD virus of deer was first identified in California in1994.
Infected deer can have clinical signs common to other diseases such as bluetongue or pneumonia. Chronic symptoms include ulcers and abscesses in the mouth and throat. Acute symptoms include rapid or open mouth breathing, foaming or drooling at the mouth, diarrhea (possibly bloody), weakness, and copius amounts of fluid in the body cavity. Death can occur within 3 — 5 days from the time the deer was exposed to the virus.
In 2001, the Oregon State University Veterinary Diagnostic Laboratory confirmed the presence of AHD in one adult black-tailed deer doe from southwest Oregon. Biologists suspect that the deaths of several dozen other deer from the same area also may have been caused by AHD. In 2002, ODFW and the Oregon State University Veterinary Diagnostic Laboratory confirmed the presence of AHD in a viral disease outbreak in Central Oregon (Deschutes, Jefferson, and Wasco counties). Between May 9 and August 1, 2002, an estimated 400 + deer have died from the virus in the Crooked River Ranch area and near Sisters, Oregon.
This family of viruses most commonly causes sporadic cases that affect a few animals in local populations. However, AHD can cause large-scale disease outbreaks under the certain conditions. AHD has been diagnosed in both mule deer and black-tailed deer in California, researchers suspect white-tailed deer also could be susceptible. There is no treatment for individual deer infected with AHD. Monitoring, proper carcass disposal, and not moving infected live deer are methods to minimize movement of the disease to new areas. ODFW staff is currently attempting to determine how widespread the disease may be. The 1993—1994 California outbreak killed several thousand deer in 17 counties.
Transmission is by direct contact between deer, contact with bodily fluids, and possibly airborne routes. High density deer populations could have a higher risk for the disease due to the ease of transmission. The time between exposure to the virus and showing signs of illness or death is commonly less than one week. It is not known if this disease has been present long-term in Oregon deer herds, or if it recently arrived. ODFW staff is encouraging people to avoid providing feed or water stations for deer because these activities may assist in spreading the disease if it is present.
Estimates from the California outbreak indicate mortality of infected fawns generally was very high, and adults much less so. Deer of all age and sex classes died in roughly the same proportions they occurred in the population during the 2002 Oregon outbreak. Future Oregon research will show how many deer in the population were exposed to AHD, but survived.
There are no known cases of humans getting sick from AHD. However, if living or hunting in an infected area, it is a good idea to wear rubber gloves when handling carcasses. People who may be sick for any reason or who have a compromised immune system should also take special precautions around these carcasses. There are no known health risks of eating meat from a deer infected with AHD. However, experts recommend thoroughly cooking any the meat from animals from an infected area.
AHD has the potential to affect deer seasons in a couple of ways. If enough deer die to significantly reduce populations in a unit, hunter success may be low in that unit during the year of the die-off. If subsequent herd inventories indicate reduced populations, low fawn recruitment, or low buck ratios, future tag numbers may be reduced until the herd recovers.