Wildlife Diseases

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Disease Issues in Mammals

Deer Diseases

Moose Diseases

Furbearer Diseases

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Bird Diseases

Avian Influenza

Avian Influenza (AI) is a type A influenza virus that is naturally found in certain species of waterfowl and shorebirds. However, the occurrence of highly pathogenic avian influenza (HPAI) subtype highly pathogenic H5N1 avian influenza had raised concern regarding the potential impact on wild birds, domestic poultry, and human health should it be introduced into the United States (U.S.). Numerous potential routes for introduction of the virus into the U.S. exist including illegal movement of domestic or wild birds, contaminated products, via an infected traveler, as a bioterrorism event, and the migration of infected wild birds.

In 2007, the Maine Department of Inland Fisheries and Wildlife (MDIFW) continued to work with USDA/APHIS/Wildlife Services (WS) and US Fish and Wildlife Service (USFWS) to develop and implement an early detection surveillance program for highly pathogenic H5N1 avian influenza in wild migratory birds. Following guidelines in the US Interagency Strategic Plan for Early Detection of Highly Pathogenic H5N1 Avian Influenza in Wild Migratory Birds three of the five collection strategies were implemented by cooperating agencies in Maine. The collection strategies included: investigation of morbidity and mortality events, and surveillance in live wild birds, surveillance in hunter-harvested birds. MDIFW contributed by collecting samples during waterbird banding operations and from hunter harvested waterfowl.

Although naturally occurring low pathogenic avian influenzas have been found in wild birds in Maine, H5N1 has not been found in any of Maine’s samples.

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 transmission may also occur. The bacteria may survive up to 4 months in soil and water.

Large die-offs are seen primarily in wild ducks and geese where the disease affects birds peracutely. The sudden appearance of large numbers of dead birds in good body condition with few if any sick birds is observed. Death may be so rapid that birds literally fall out of the sky or die while eating with no previous signs of disease. 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, such as flying upside down or trying to land a foot or more above the water; 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.

Wellfleet Bay Virus

New Virus Discovered in Eider Ducks

For the past six years scientists have focused on finding out why common eider ducks (Somateria mollissima) were dying in the fall by the hundreds, sometimes thousands, along the shore of Wellfleet Bay, Massachusetts. Now named the Wellfleet Bay virus, the virus is loosely related to flu virus, attacks the liver and gallbladder, and seems to work very fast. Eider ducks collected from these mass die-offs appear healthy and are not emaciated from long illness; they die from liver disease. So far, Wellfleet Bay is the only place in the world known to harbor the virus, although scientists believe it is related to an equally mysterious Quarjavirus family that is distributed around the world. Wellfleet virus is an Orthomyxovirus, an RNA virus like the influenzas. Now researchers are trying to discern whether ticks in the summer breeding grounds are infecting the eiders, as in other Orthomyxoviruses, or if the virus is spread by another route.

Lymphoproliferative Disease Virus (LPDV)

In 2012, wildlife disease researchers from the southeastern United States announced that they had identified, for the first time, Lymphoproliferative Disease Virus (LPDV) in wild turkeys from 4 southeastern states (Arkansas, West Virginia, Georgia and South Carolina). During Maine’s spring 2012 wild turkey hunting season, 3 wild turkeys tested positive for exposure to LPDV. Prior to this, the virus had not been detected in the U.S. It had been detected in domestic turkeys in Great Britain. Researchers believe that some turkeys carry the virus without becoming ill, while other turkeys can develop tumors on the head and feet and can ultimately die from it. These tumors look very similar to those of a disease referred to as avian pox. Avian pox virus is quite common in a number of species of birds, including wild turkeys. Birds showing mild outbreaks of avian pox can be consumed, and hunters are encouraged to thoroughly cook the meat of harvested birds. Additionally, birds with LPDV can be consumed, and hunters are encouraged to thoroughly cook the meat as well. Although these diseases are not transferable to humans, a hunter can turn in a bird and hunt for another one, as long as the bird is not tagged first. Once a turkey is tagged it is now in your possession and considered part of your bag limit.

High Mercury Levels

Waterfowl Hunters Warned Of High Mercury Levels

The Maine Department of Inland Fisheries and Wildlife is warning waterfowl hunters in and around the lower Penobscot River that high levels of toxic mercury have been found in the breast meat of black ducks and mallards taken from the area.

Especially high levels were found in black ducks at the Mendall Marsh Wildlife Management Area in Frankfort.

Waterfowl taken from the immediate vicinity of Mendall Marsh and from Orrington south to the southern tip of Verona Island may contain high levels of mercury.

The safe eating guidelines for waterfowl meat in the area are:

  • Children under the age of 8 and pregnant or nursing women should not eat any waterfowl meat taken from this area.
  • All others should not eat more than two waterfowl meals per month. One 8-ounce duck breast is considered one meal.

Also see: West Nile Virus Facts (PDF)

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