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.
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.
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 please contact: The USGS National Wildlife Health Center, at 608-270-2400.
Photo by Milton Friend
Public Health Significance
There is no evidence of human risk.
Domestic Animal Significance
Usually seen in domestic
and feral waterfowl in urban/farm pond settings during breeding season
(April to June). Many outbreaks involve Muscovy ducks. Some infected birds
may become inapparent carriers of the virus. Carriers may be a major reservoir
of disease and pose a problem for prevention and control. Occasional problem
in the domestic poultry industry. An attenuated live virus vaccine is
approved for use in domestic white Pekin ducks, but has not been proven
to work reliably in any other species.