Australia has confirmed its first case of H5N1 bird flu in a mammal after the virus was detected in a dead long-nosed fur seal in South Australia.
South Australian authorities said the seal was found dead near Beachport, about 310km south of Adelaide, with no visible signs of injury. It is the first confirmed detection of H5N1 in an Australian mammal.
The development comes as Australia battles a growing outbreak of highly pathogenic avian influenza, which was first detected in migratory seabirds before spreading to native species.
The country recorded its first mass seabird deaths from the virus this month, marking a further escalation of the outbreak.
Federal Agriculture Minister Julie Collins said the seal’s death did not appear to be linked to other sick or dead marine mammals.
“Once the H5 bird flu is spreading in the natural environment it is not possible to avoid significant losses,” Collins said in televised remarks.
Australia’s chief veterinary officer for South Australia, Skye Fruean, said seals face a high risk of contracting the virus because they live close to wild birds along rocky coastal areas.
“They would be coming across, no doubt, really high levels of the virus in their environment,” Fruean said.
The seal came from an estimated population of about 100,000 in South Australia’s waters.
Australia was the last continent to report bird flu, although H5N1 was detected on the sub-Antarctic Heard Island in late 2025. More than 13,000 baby seals were reportedly killed by the virus on the island, according to local media.
Despite the latest mammalian detection, the Australian government said H5N1 has not been detected in the country’s poultry or agricultural sectors. As of Friday, 297 cases had been confirmed nationwide.
