The discovery of two cougar deaths due to H5N1 avian influenza has raised concerns about the spread of bird flu in western wildlife. The virus, which originated from domestic geese in China, has infected tens of millions of domestic chickens and wild birds since its arrival in North America in 2021.
According to Washington Department of Fish and Wildlife officials, the cougars were likely infected after eating infected birds along the Pacific Flyway or consuming prey that had eaten contaminated birds. The two deaths highlight how little is known about how bird flu spreads in wildlife.
“We don’t really know which animals are carrying and which ones have been exposed and recovering,” said Mark Elbroch, puma director of Panthera. Regular monitoring and sampling would help researchers better understand H5N1 and its spread.
Washington state has seen an uptick in cases of the virus, with reported instances in wild birds, mammals, and even domestic animals. However, public health officials say the risk to humans remains low due to the mild symptoms and lack of transmission between people.
However, experts warn that if H5N1 continues to spread among wild birds and mammals, isolated or small populations will be particularly vulnerable. “Flu is rarely considered a wildlife conservation issue,” said Justin Brown, a wildlife veterinarian. The lack of funding for state wildlife agencies and limited surveillance make it difficult to track the spread of the disease.
Researchers are working to develop better methods for detecting and monitoring H5N1 in wildlife. Blood samples from living wild animals will be tested for antibodies, indicating recovery from infection. “I think this is a disease that will be here for the foreseeable future,” said Brown.
Source: https://www.hcn.org/issues/57-4/bird-flu-finds-its-way-into-western-wildlife