Duck Plague

	Caused by A herpes virus.
Host	Only ducks, geese, and swans. There is variation in species susceptibility to this virus. For example, blue-winged teal are most susceptible, while pintails are least.
Transmission	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 Signs/Field Signs	Rapid death 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	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. 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.
Public Health Significance	None.
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.