Australia Reports First H5N1 Case in Mammal as Fur Seal Found Dead

Australia has confirmed its first case of H5N1 bird flu in a mammal, with the virus detected in a long-nosed fur seal found dead in South Australia. The discovery marks a significant development in the country's ongoing battle against the highly pathogenic avian influenza.

The seal was located at the coastal town of Beachport, roughly 310 kilometers south of Adelaide, the state capital. Authorities reported that the animal was found dead with no visible signs of injury. The seal is one of an estimated population of 100,000 in the state's waters.

Federal Agriculture Minister Julie Collins stated that the death "does not appear to be associated with other sick or dead marine mammals." She added that once the H5 bird flu is spreading in the natural environment, significant losses are unavoidable.

Australia has been dealing with rising cases of avian influenza since the virus arrived in June. The country experienced its first mass seabird deaths from the virus this month, following its initial detection in migratory seabirds and subsequent spread to native species.

South Australia's chief veterinary officer, Skye Fruean, noted that seals are at high risk of contracting the virus because they live in close proximity to wild birds on coastal rocky outcrops. "They would be coming across, no doubt, really high levels of the virus in their environment," she said.

Australia was the last continent to report bird flu, though the virus was detected in late 2025 on the sub-Antarctic territory of Heard Island, where more than 13,000 baby seals were killed. The federal government has confirmed 297 cases nationwide, with no cases reported in poultry or agriculture so far.