Northern Ireland is witnessing the “largest ever” outbreak of avian flu in the UK after two additional suspected cases were discovered.
The cases have been identified in a commercial poultry flock near Markethill in Co Armagh and a commercial duck flock in Coagh, Co Tyrone.
Disease control measures have been put in place, including the humane culling of the affected birds, some 14,000 in Armagh and 22,000 in Tyrone.
It follows confirmation of two positive cases in each of those counties earlier this month, in Aughnacloy and Broughshane.
Chief veterinary officer Dr Robert Huey has called on flock keepers to “urgently review” their biosecurity measures.
“Unfortunately notifiable avian influenza is strongly suspected in two further commercial flocks in Northern Ireland,” he said.
“This is now not only the largest ever outbreak of HPAI in the UK but also in Northern Ireland and we must do all we can to protect our flocks, protect our businesses and protect the economy.
“I cannot stress enough how important it is that flock keepers reassess all of their biosecurity measures immediately.
“Are they stringent enough? Are you reviewing them every day? What else can you do to prevent an incursion?
“You can also complete our biosecurity checklist at http://daera-ni.gov.uk/publications/daera-ai-biosecurity-self-assessment
“Do it today, do not wait.”
Agriculture Minister Edwin Poots warned that we have reached a “critical point” in the management of the outbreak.
He added: “This strain of H5N1 spreads quickly and could wipe out an entire flock in a matter of days.
“Keep your flock housed, change your boots, wash your hands, wear disposable boiler suits, keep surrounding areas clean and only have essential vehicles coming on site – simple, repetitive steps will help protect your flock from avian flu.
“We have also received confirmation from the National Reference Lab that the cases in the commercial duck farm in Aughnacloy and the backyard flock keeper in Broughshane were both positive for HPAI H5N1.
“We cannot afford to be complacent and must act now to protect our flocks.”
Temporary control zones (TCZs) have been introduced at the sites of the suspected cases to mitigate onwards disease spread.
Samples have been sent to the National Reference Laboratory for testing, and should avian flu be confirmed, the TCZs will be replaced with a three-kilometre protection zone and 10km surveillance zone around the affected premises.
The cases discovered at Aughnacloy earlier this month led to the culling of 22,100 ducks, while the same measures were applied to the “small backyard flock” found at Broughshane.
The flock owners are to receive compensation for the lost livestock. A valuation at the Aughnacloy site has been described as ongoing.