Duck Plague (Duck Virus Enteritis)

Duck Plague, which affects only ducks, geese and swans, is caused by a herpes virus. Susceptibility varies greatly among waterfowl species: blue-winged teal, redhead ducks and wood ducks are highly susceptible, while pintails are only slightly susceptible.

Transmission of the virus can occur through direct contact with affected birds or contaminated surfaces, ingestion of food or water contaminated with infected feces or oral discharges, inhalation of viral particles and vertical transmission from female to forming egg.

Clinical/Field Signs
There is no prolonged period of illness associated with duck plague infections; death occurs rapidly in previously healthy appearing birds. Sick birds are seldom seen but may seek cover and have ruffled feathers, extreme thirst, loss of awareness, droopy head and wing, inability to fly, sensitivity to light, blood around the vent or bill, and prolapsed penis.

Lesions
Duck plague attacks the vascular system and may cause bands or disk shaped areas of hemorrhagic or yellow/tan tissue distributed in or on the esophagus, intestinal wall and cloaca; blood in the digestive tract; or small white spots on the liver and hemorrhages on the heart.

Wildlife Management Significance
The only known duck plague outbreaks in wild waterfowl occurred in Lake Andes, South Dakota in 1973 and the Finger Lakes in New York in 1993. There are no effective treatments for the disease. Once exposed, birds can become inapparent carriers which appear healthy, but shed virus into the environment via bodily secretions. The virus is hardy and can live for weeks under certain conditions. Prompt carcass collection and disposal and rigorous decontamination of areas used by infected birds reduces the amount of virus available to other waterfowl. Decontamination of personnel and equipment used in affected areas is necessary to prevent the mechanical spread of the virus to other sites. Because of the potential carrier state in exposed birds, additional actions may include euthanasia of exposed flocks and eggs that may be carriers. Recommendations are site specific; please contact the National Wildlife Health Center for assistance.

For more information on this or any other wildlife health issue, please contact the National Wildlife Health Center at 608-270-2400.