Agencies Respond To Questions About Wildlife Diseases

Two diseases mostly affecting wild birds have been detected recently in Montana.

These include pigeon paramyxovirus, which has become more widespread in the past month, and highly pathogenic avian influenza, which has been detected in Montana since 2022. Mortality in wild birds from HPAI tends to cycle with waterfowl migrations, and detections of HPAI in Montana have increased recently due to seasonal migrations.

Hunters, livestock and pet owners and other residents may have questions about these pathogens and what precautionary steps they can take. Here are some answers to common questions related to these diseases.

What is avian influenza virus? Avian influenza virus is a naturally occurring virus of birds. AI viruses are classified into two groups, based on the severity of disease they cause in infected poultry. Low pathogenic avian influenza viruses generally cause no clinical illness, or only minor symptoms in birds. Highly pathogenic avian influenza viruses are extremely infectious and fatal to poultry and some species of wild birds. It has also been known to infect mammals in limited cases, likely from consuming infected waterfowl.

Does HPAI infect humans?

Different HPAI viruses have different levels of infectivity for humans and cause symptoms of varying degrees of severity. Twelve human cases with the current H5N1 bird flu virus have been reported worldwide since 2021. Current studies suggest that the type of H5N1 virus circulating worldwide does not easily infect humans. Other H5N1 viruses, which sometimes circulate and cause outbreaks in several different countries, have caused serious illness and death. Although the Centers for Disease Control and Prevention considers risk of HPAI spread to humans to be very low, Montanans, including hunters, should take precautions when handling game birds or any sick or dead bird they find. Whenever possible, avoid contact with sick or dead wildlife. Even if a bird is not suspected to have died from a contagious disease, gloves should always be worn if a dead animal must be handled for disposal. If you develop flulike symptoms within 10 days of contact with a wild bird or ill domestic fowl, contact your primary care provider to notify them of your symptoms and recent bird contact. HPAI testing can be arranged through your local or state health department.

What about HPAI transmission to pets? The risk of HPAI transmission to domestic mammals continues to be low. However, mammals such as dogs and cats are at increased risk if they ingest infected domestic or wild birds or their bodily fluids. Stray or feral cats and dogs, hunting dogs, and outdoor pets may be at increased risk given the possibility of finding and ingesting dead or sick birds. Limiting pet exposure to domestic poultry and wild birds, especially if the birds are sick or dead, can help reduce the risk of transmission.

What is pigeon paramyxovirus?

Paramyxoviruses are also naturally occurring viruses in birds. Montana Fish, Wildlife and Parks recently detected PPMV-1 in Montana. This strain of PPMV is not known to affect most mammals and usually does not affect avian species aside from doves and pigeons. While there have been no confirmed cases of PPMV-1 causing disease in poultry in the U.S., some other avian paramyxoviruses can affect poultry and other avian species.

Does PPMV infect humans?

PPMV infection in humans is extremely rare, often following direct, extended contact with infected birds. PPMV in humans typically results in very mild symptoms. However, fatal and severe cases of PPMV have also been observed in humans and is a concern for immunocompromised individuals. Montanans should take precautions when handling game birds or any sick or dead bird they find. Whenever possible, avoid contact with sick or dead wildlife. Even if a bird is not suspected to have died from a contagious disease, gloves should always be worn if a dead animal must be handled for disposal.

What about PPMV transmission to domestic animals?

PPMV-1 usually does not affect avian species aside from doves and pigeons. Limiting domestic animals’ exposure to wild birds, especially if the birds are sick or dead, can help reduce the risk of illness in domestic animals.

I’ve found a dead bird. What should I do? If dead wild birds need to be collected for disposal, wear disposable gloves and scoop the bird into a plastic bag, then seal or tie the bag and place it in a garbage receptacle. If you suspect an outbreak of HPAI in your own poultry/ domestic animals, or if your flock experiences sudden die off, follow the collection procedure above and contact the Montana Department of Livestock at 406-444-2976.

When should I report dead wild birds to FWP? Montana Fish, Wildlife & Parks is interested in reports about certain situations of sick or dead wild birds where disease testing may be warranted. These include reports of five or more sick or dead wild birds in the same location, sick or dead wild birds found in proximity to domestic poultry, or sick or dead wild birds that have had prolonged or close contact with people.