Avian flu may be spreading between cattle in USA
Remnants of the virus have been found in samples of pasteurised milk.
The H5N1 strain of highly pathogenic avian influenza may be spreading between cattle, the United States Department of Agriculture has warned.
Since March, the virus has been detected in cattle herds in eight states, including Texas and New Mexico in the south, North Carolina on the east coast, and Idaho in the west. Affected cattle have displayed clinical signs including decreased lactation, low appetite, lethargy, fever, and dehydration.
In a statement answering frequently asked questions, the department said that while it is believed that cattle first caught the virus from wild migratory birds, ‘the investigation to date also includes some cases where the virus spread was associated with cattle movements between herds.’
The department also said that there is evidence that in some cases the virus may have spread from dairy cattle premises into nearby poultry premises ‘through an unknown route’.
The United States Food and Drug Administration has revealed that remnants of the virus have been found in samples of pasteurised milk. However, it has said that there is not believed to be any risk to humans, stating: ‘To date, we have seen nothing that would change our assessment that the commercial milk supply is safe.’
Since the outbreak in cattle began, there has been one confirmed case in a human. A dairy worker in Texas who had been in contact with infected cattle tested positive and is recovering after being treated with an antiviral drug.
The World Organisation for Animal Health (WOAH) has said that it is closely monitoring the recent cases in cattle. In a statement, WOAH said: ‘Timely and transparent reporting is crucial to maintain a good understanding of the disease situation and prevent any type of misinformation or disinformation.’
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The BSAVA has opened submissions for the BSAVA Clinical Research Abstracts 2026.
