US reports first classical scrapie case since 2021, raising questions over traceability and eradication progress

The US Department of Agriculture has confirmed its first case of classical scrapie in sheep since 2021, prompting renewed calls for strict traceability measures as the country aims for OIE recognition of disease freedom by 2028.

The US Department of Agriculture’s Animal and Plant Health Inspection Service has confirmed the first US case of classical scrapie since 2021, after the disease was identified in a sheep slaughtered in Oregon, according to Brownfield Ag News. Officials said the animal was not ear-tagged, making trace-back to the source flock more difficult, and APHIS has opened an epidemiological investigation to identify the flock of origin.

Classical scrapie is a fatal, degenerative prion disease of sheep and goats that affects the central nervous system. Clinical signs can be slow to emerge, often appearing years after infection, and may include behavioural change, tremor, pruritus and ataxia before deterioration progresses to recumbency and death.

The detection comes as the United States had been working towards the World Organisation for Animal Health’s seven-year benchmark for self-declared freedom from scrapie, with January 2028 previously in sight, APHIS says. The agency has notified the OIE of the finding, but does not expect the case to affect trade.

APHIS continues to urge flock owners and veterinarians to reinforce control measures that have driven the disease’s decline, including strict ear-tagging and traceability compliance, active surveillance and prompt submission of suspect animals. The agency also highlights the value of breeding genetically resistant stock, which can reduce susceptibility and the need for depopulation in exposed flocks.

For practising veterinarians, the case is a reminder that tagging lapses still compromise disease investigation and that surveillance remains central to eradication efforts.

Image Source: American Sheep Industry