Avian Cholera News

• Avian Cholera Confirmed on St. Lawrence Island - Alaska Department of Fish and Game Press Release
• Avian cholera, found in Alaska for first time, caused seabird die-off - Alaska Dispatch
• Hundreds of dead seabirds wash ashore on Alaska island in Bering Sea - Alaska Dispatch
• Photos: Daily life on Alaska's St. Lawrence Island - Alaska Dispatch

Avian Cholera

Most species of birds and mammals can become infected with different strains of Pasteurella multocida; however, avian cholera in wild birds is primarily caused by one strain, Type 1. The species of birds most commonly affected are ducks and geese, coots, gulls, and crows.

The bacteria can be transmitted by bird-to-bird contact, contact with secretions or feces of infected birds, or ingestion of food or water containing the bacteria. Aerosol tranmission may also occur. The bacteria may survive up to 4 months in soil and water.

Clinical Signs/Field Signs
Large die-offs are seen primarily in wild ducks and geese where the disease affects birds peracutely; that is, very rapidly. Field observations may include the sudden appearance of large numbers of dead birds in good body condition with few, if any, sick birds present. Sick birds appear lethargic, and when captured may die within minutes. Other signs include convulsions; swimming in circles; throwing the head back between the wings; erratic flight and miscalculated landing attempts; mucous discharge from the mouth; soiling or matting of the feathers around the vent, eyes, and bill; pasty, fawn-colored or yellow droppings; or blood-stained droppings or nasal discharge..

Lesions
Hemorrhages may be seen on the heart, liver, gizzard, and intestines. Areas of tissue death appear as white or yellow "spots" on the liver and spleen. The liver may appear darkened or copper in color, and may be swollen and rupture when handled. These lesions are indicative of an acute disease process and are not unique to avian cholera infection. The upper digestive tract may contain recently ingested food, while lower digestive tract may contain a thick yellowish viscous fluid that contains large numbers of P. multocida bacteria.

Wildlife Management Significance
Avian cholera is highly contagious and can spread rapidly. Prompt action is needed to prevent and minimize the spread of the disease. Careful carcass collection and disposal helps reduce the amount of bacteria in the environment. Recommendations are site specific. Contact the National Wildlife Health Center for more information.

For more information please contact: The USGS National Wildlife Health Center, at 608-270-2400.