Over 42,000 chickens, ducks, geese, pheasants, and turkeys are being culled across four farms in Zealand and Funen after avian influenza outbreaks, bringing the total number of birds destroyed since October 2025 to more than 500,000 as Denmark faces an extremely high infection pressure from wild birds.
The Danish Veterinary and Food Administration has begun the process of destroying more than 42,000 poultry birds across four separate farms located in Slagelse, Gislev, Ringsted, and Vordingborg. The culling comes after authorities confirmed highly pathogenic avian influenza, commonly known as bird flu, in these facilities.
Mette Kirkeskov Sie, unit chief at the Danish Veterinary and Food Administration, stated that the current infection pressure is extremely high. She emphasized the critical importance of poultry owners taking every possible precaution to protect their flocks from the deadly virus.
A Season of Unprecedented Outbreaks
Denmark has experienced a particularly severe avian influenza season. Since October 2025, authorities have recorded more than 30 separate outbreaks of the disease across the country. The scale of destruction has been enormous, with over half a million birds culled in less than five months.
Recent Escalation in Cases
The situation has deteriorated rapidly in recent weeks. In early March 2026 alone, three additional outbreaks were confirmed over just two days, affecting farms on Samsø, near Ørbæk, and at Glumsø in Zealand. These incidents resulted in the culling of approximately 70,000 chickens in addition to the 42,000 mentioned in the latest report.
The virus has struck both large commercial operations and smaller hobby farms. At Glumsø, a major facility lost 70,000 chickens in a single outbreak. Meanwhile, smaller farms near Ørbæk and on Samsø also confirmed infections, demonstrating that no type of operation is immune to the threat.
Comparison to Previous Seasons
The current outbreak season stands in stark contrast to the 2023/24 period, when Denmark recorded 12 outbreaks resulting in 239,000 culled birds. The more than 500,000 birds destroyed this season represents a dramatic escalation. October 2025 alone saw 278,000 birds culled, marking the beginning of what would become an exceptionally challenging period for Danish poultry farmers.
How the Virus Spreads
Genetic analysis has revealed that the outbreaks primarily stem from contact with wild birds carrying the H5N1 strain of avian influenza. Wild birds, particularly migratory species, have significantly increased the infection pressure in Denmark and neighboring countries since autumn 2025.
Direct and Indirect Transmission Routes
The virus can spread through multiple pathways. Direct contact between wild birds and domestic poultry represents one risk, but indirect transmission proves equally dangerous. Wild bird droppings can contaminate feed and water sources, creating infection opportunities even without physical contact between birds.
Human activity also plays a role in transmission. Visitors to poultry farms can unknowingly carry the virus on their footwear or clothing after stepping in contaminated areas. This makes biosecurity protocols essential for preventing outbreaks, particularly given the current high threat level.
Why Some Birds Are More Vulnerable
Chickens experience particularly severe symptoms when infected with avian influenza. Most infected chickens become visibly ill rapidly and the majority die shortly after infection. In contrast, ducks and geese often carry the virus without showing symptoms, which complicates early detection efforts. These asymptomatic carriers can spread the disease to other birds before farmers realize an infection has occurred.
Mandatory Restrictions for Poultry Owners
Denmark elevated its avian influenza threat level to high on October 27, 2025, triggering a comprehensive set of mandatory restrictions. These rules remain in effect as authorities battle to control the ongoing outbreaks, similar to measures taken during animal disease outbreaks affecting other livestock.
Keeping Birds Indoors or Protected
All poultry and captive birds must now be kept indoors or covered with netting that has a maximum mesh size of 20 centimeters. Alternatively, birds can be housed under solid roofing. The regulations specifically prohibit ducks and geese from having any contact with other types of poultry due to their role as potential asymptomatic carriers.
Poultry exhibitions and shows are banned without special permission from authorities. These events create opportunities for disease transmission between flocks from different locations, making them particularly risky during high threat periods.
Exceptions for Small Holders
The regulations include some exemptions for hobby farmers. Owners with fewer than 100 birds who do not sell their animals or products can receive less stringent requirements in certain cases. Small chicken coops covering less than 40 square meters may also qualify for exceptions. However, all poultry owners remain strongly encouraged to implement maximum biosecurity measures regardless of exemptions.
Protection and Surveillance Zones
Authorities establish restriction zones around every confirmed outbreak to prevent further spread. These zones impose strict limitations on the movement of birds, eggs, and poultry products.
Three Kilometer Protection Zones
A protection zone extends three kilometers from each infected farm. Within this area, no poultry, eggs, meat, or related products can be moved in or out without special authorization from the Danish Veterinary and Food Administration. These restrictions typically remain in place for four to five weeks following confirmation of an outbreak.
The protection zones around the farms in Slagelse, Gislev, Ringsted, and Vordingborg now encompass significant agricultural areas. Farmers within these zones must comply with heightened monitoring and reporting requirements even if their own flocks show no signs of illness.
Ten Kilometer Surveillance Zones
An additional surveillance zone extends ten kilometers from outbreak sites. This larger area faces somewhat less restrictive measures than the core protection zone but still requires enhanced monitoring. Farm owners must report any unusual mortality or illness among their birds immediately.
Interestingly, authorities chose not to establish a restriction zone on Samsø following a recent outbreak there. The island’s geographic isolation reduces the risk of spread to other farms, making extensive land based restrictions unnecessary.
Recommended Biosecurity Measures
The Danish Veterinary and Food Administration has issued detailed guidance on protecting poultry from infection. These recommendations go beyond the mandatory requirements, offering practical steps that significantly reduce transmission risk.
Feed and Water Management
Poultry owners should provide feed and water under netting or roofing to prevent wild birds from accessing these resources. Shared feeding areas create prime opportunities for disease transmission, as infected wild birds can contaminate food and water supplies with virus laden droppings. Covering these areas eliminates direct contact between wild and domestic birds during feeding times.
Additionally, farmers should clean and disinfect feeding and watering equipment regularly. This removes any viral particles that might have been deposited by wild birds or carried into the area on contaminated footwear.
Clothing and Footwear Protocols
People entering poultry housing areas should change both clothing and footwear before approaching birds. Dedicated boots and coveralls that remain on the farm premises provide the best protection. If changing complete outfits is not practical, at minimum, footwear should be thoroughly cleaned and disinfected before entering bird housing areas.
Farm visitors should be limited whenever possible. Each additional person entering a poultry area represents another potential vector for introducing the virus. Essential visitors should follow the same hygiene protocols as regular farm workers.
Avoiding Wild Bird Contact
The Danish Veterinary and Food Administration strongly advises avoiding contact with sick or dead wild birds. People who discover dead wild birds should report them through the FugleinfluenzaTip app rather than handling the carcasses. This citizen reporting system helps authorities track the geographic spread of the virus in wild bird populations.
Dead wild birds on farm property require special handling. Farmers should contact authorities for guidance on safe removal and disposal rather than attempting to clear carcasses themselves.
Human Health Considerations
While avian influenza proves devastating to bird populations, humans face relatively low infection risk. However, the possibility of human infection cannot be entirely dismissed, particularly for people with direct exposure to infected birds.
When Humans Can Become Infected
Human infections typically occur only after close contact with sick or dead birds carrying the virus. Poultry farmers, veterinarians, and workers involved in culling operations face the highest exposure risk. The general public remains at very low risk of infection under normal circumstances.
Denmark has not reported any confirmed human cases of avian influenza during the current outbreak season. This stands in contrast to some other countries where sporadic human infections have occurred, typically among people with sustained close contact with infected poultry.
Symptoms in Humans
According to the Danish Health Authority, if a human does contract avian influenza, the symptoms closely resemble those of regular seasonal flu. Infected individuals might experience fever, cough, sore throat, muscle aches, and fatigue. In rare cases, the infection can develop into more severe respiratory illness.
People who work with poultry and develop flu like symptoms should inform their healthcare provider about their bird exposure. This allows doctors to consider avian influenza as a possible diagnosis and take appropriate testing and treatment measures.
European Context and Wild Bird Patterns
Denmark’s avian influenza crisis reflects broader patterns across Europe. Multiple countries have reported similar outbreaks driven by infected wild bird populations during the same period.
Cases in Neighboring Countries
Germany experienced notable outbreaks during this period, including an incident at a duck farm in Neuhardenberg in October 2025. Genetic analysis of virus samples from Danish and German outbreaks shows similarities, suggesting common wild bird sources spreading the infection across borders.
Wild birds do not respect national boundaries, and migratory patterns mean that infected birds can quickly spread the virus across large geographic areas. This makes international coordination essential for tracking and responding to outbreaks.
Seasonal Migration Patterns
The timing of Denmark’s outbreak wave corresponds with autumn and winter migration periods for many bird species. Waterfowl and other species pass through or overwinter in Denmark, creating repeated opportunities for virus transmission to domestic poultry. The high infection pressure observed since October 2025 reflects these seasonal patterns, with wild bird populations carrying and spreading the H5N1 strain across their migration routes.
