Detection of bird flu in a sheep in Yorkshire is a reminder for farms to maintain tight biosecurity, particularly those with mixed poultry and livestock, experts say.
Earlier this week, Defra confirmed the case of H5N1 following repeat positive milk testing, on a farm where avian influenza had previously been confirmed in captive birds.
Although the UK's chief veterinary officer said the risk to livestock remained low, she urged all animal owners to have "scrupulous cleanliness in place".
Christine Middlemiss also encouraged farmers to report any signs of infection to the Animal Plant Health Agency (APHA) immediately.
While this is the first time this virus has been reported in a sheep, it is not the first instance of influenza of avian origin being detected in livestock, with cases of infection in dairy cows reported in the US.
However, Dr Middlemiss called on all livestock keepers to remain vigilant to the clinical signs of avian influenza following recent outbreaks.
“All keepers must maintain good biosecurity which is essential to protect the health and welfare of their animals and critical to preventing the further spread of disease in the event of an outbreak,” she said.
Nigel Bennet, manager at biosecurity specialists Roam Technology, said every farm should be reviewing and strengthening its biosecurity protocols following the case.
He said: "Prevention is our strongest defence. This means restricting unnecessary visitors, disinfecting clothing and equipment, and closely monitoring animal health.
"This case of H5N1 in sheep highlights the need for constant vigilance. Biosecurity isn’t just about responding to outbreaks; it should be a year-round priority to protect farm businesses and animal welfare.
"Farmers must remain proactive in safeguarding their livestock from potential disease threats."
What can I do?
Mr Bennet has outlined seven key areas farmers should be aware of to maximise their frontline defences:
• Develop a biosecurity plan: Work with vets to establish a clear biosecurity plan, including physical barriers, hygiene protocols, and emergency procedures.
• Cleaning and disinfection: Thoroughly clean and disinfect all vehicles, boots, equipment, and housing using Defra-approved disinfectants. Visitors should use foot baths and dedicated protective clothing.
• Monitor farm access: Restrict and track visitor access to minimise disease risks. Designate parking away from livestock, use wheel washes, and ensure tradespeople follow hygiene protocols. Mr Bennet said: "A farm should not be an open-door environment—every entry point carries risk."
• Quarantine: New or returning stock must be quarantined for at least 21 days, housed separately, and monitored for disease. Use this period for testing and vaccination before integration.
• Rodent and wildlife management: Secure feed storage and effective pest control help prevent disease transmission from wildlife. Maintain fencing to reduce contact with infected animals and minimise standing water to control disease-spreading insects.
• Optimise housing: Ensure good ventilation, clean high-traffic areas, and maintain water hygiene.
• Monitoring: Daily health checks help detect disease early and prevent outbreaks. "Knowing your animals and spotting illness early is crucial for disease control," said Mr Bennet. "Stay vigilant and keep biosecurity tight."
Avian influenza is notifiable in all poultry and other captive birds and influenza of avian origin is notifiable in both kept and wild mammals.
If you suspect your animals are infected report it immediately to the APHA by calling:
• 03000 200 301 in England
• 0300 303 8268 in Wales
• Contacting your local Field Services Office in Scotland
