#Netherlands: #Antibodies to {#H5N1} #birdflu virus found in dairy #cow (Min. Agriculture, Jan. 24 '26)

{Automatic translation from Dutch to English}

Date: January 23, 2026 

Regarding: Dairy cow with antibodies against bird flu 

Dear Chair, Through this letter, I am informing the House, also on behalf of the Minister of Health, Welfare and Sport, about the situation surrounding a dairy cow with antibodies against bird flu (highly pathogenic avian influenza, HPAI). 

No evidence has been found of active virus circulation of bird flu among the dairy cows on this farm in the municipality of Noardeast-Fryslân (province of Friesland). 

There are also no signs of bird flu spreading at other dairy farms. 

I am currently conducting follow-up investigations and have asked all involved parties to be alert to any potential signs. 

Situation: 

The Netherlands Food and Consumer Product Safety Authority (NVWA) received a report on December 24, 2025, about two sick cats. 

One of these cats tested positive for bird flu. 

The cat in question died on December 26, 2025. 

The second cat tested negative and has fully recovered. 

I informed your House of this in my letter of January 13th, including Parliamentary Document 28807, no. 322. 

Following this report, the Netherlands Food and Consumer Product Safety Authority (NVWA) conducted source and contact tracing. 

This revealed a relevant contact with a dairy farm; the cat in question originated from this dairy farm. 

On January 15th, the dairy cattle on this farm were screened. 

Milk samples were taken from several of the cows present, and a sample was also taken from the bulk milk. 

At the time of sampling, no animals showing symptoms of the disease were present on the farm. 

The samples were sent to Wageningen Bioveterinary Research (WBVR) for analysis. 

The results of the PCR tests, which can detect the virus in milk, were negative for both the individual samples and the bulk milk sample. 

This confirmed that no virus was present among the dairy cattle on the farm. 

In addition, the samples were tested for the presence of antibodies. 

On January 20, the WBVR reported that one cow had antibodies to H5N1 avian influenza. 

The presence of antibodies indicates a previous infection with the virus. 

The cow in question had suffered from mastitis and respiratory problems in December. 

These are Symptoms that can be observed in a dairy cow infected with avian influenza. 

At the time of sampling, this cow had recovered. 

Following this positive antibody test, the NVWA (Netherlands Food and Consumer Product Safety Authority) revisited the farm on January 22nd. 

During this visit, blood and milk samples were taken from all cattle present. 

A bulk milk sample was also taken again. 

Today, January 23rd, 2026, the PCR results from these tests were received. 

All but five samples were negative. 

The bulk milk was also PCR negative. 

The five remaining individual milk samples resulted in a test error in the laboratory and will be retested this weekend. 

Based on the PCR results known so far, from last week and today, there is no indication of active circulation of avian influenza virus among the dairy cattle on the farm. 

The five final PCR results will be available this weekend. 

If a positive result is unexpectedly obtained, I will inform Parliament immediately. 

In addition, the results of the antibody testing will follow later next week. 

Antibody testing is important to determine whether more animals have been exposed to the virus, which could indicate past virus circulation. 

Other mammals on the farm (such as dogs, cats, and horses) are currently showing no symptoms. 

Avian influenza in dairy cattle: 

As far as we know, antibodies against avian influenza have not previously been demonstrated in dairy cattle in Europe. 

However, since March 2024, there have been numerous avian influenza outbreaks among dairy cattle in the United States (Parliamentary Document 28807, No. 298). 

The virus causing these outbreaks in dairy cattle in America has not been found in Europe to our knowledge. 

The symptoms exhibited by cows with avian influenza are primarily reduced milk production, fever, loss of appetite, and thick, discolored milk. 

The avian influenza virus is primarily excreted in cows' milk. 

Most dairy cows recover from infection and eventually return to their previous milk production levels. 

It is also possible for a cow infected with avian influenza to show no symptoms; even in that case, the cow often sheds the virus. 

An infected cow sheds infectious virus for about two weeks after infection. 

These symptoms are based on experiences in the US.1 

In response to the large number of avian influenza outbreaks among dairy cows in the US, a policy manual for HPAI in dairy cows2 was developed in early 2025. 

Milk Safety 

Previously, the NVWA's Bureau for Risk Assessment and Research (BuRO) conducted research at the request of the Ministry of Health, Welfare and Sport (VWS) into the management of food and feed safety risks of HPAI virus in milk3. 

In this research It is confirmed that pasteurizing milk completely inactivates the avian influenza virus present. 

The milk is then safe for human consumption and poses no risk to public health or the spread of the virus. 

It is important that raw milk and raw-milk dairy products from cows infected with avian influenza are not consumed. 

Monitoring dairy cattle: 

Individual infection of a dairy cow with the avian influenza virus can occur. 

It is important to know whether this leads to spread within and between farms. 

There are currently no indications that this is the case. 

The basic animal health monitoring program conducts a so-called syndrome surveillance, which involves weekly national and regional monitoring of bulk milk deliveries to determine whether there are any animal health problems in dairy cattle. 

This is a sensitive tool that is particularly valuable when new conditions arise that do not produce specific or noticeable symptoms. 

In addition, the basic monitoring program utilizes pathological examination, and unexplained problems can be reported to the Veekijker (cattle watcher). 

This also makes it possible to identify individual suspected cases of avian influenza infection. 

To date, the basic monitoring has not found any indications that suggest avian influenza infection in dairy cows. 

Naturally, I am closely monitoring the situation and have asked all stakeholders to do so. 

In the short term, I will ask the experts to provide a risk assessment. 

I will also ask experts to analyze possible infection routes and to assess the effectiveness of the monitoring options for HPAI in cattle. 

Furthermore, I have informed stakeholders about this new situation and asked them to report any notable findings. 

Public Health Risk: 

Based on the currently available data, the RIVM (National Institute for Public Health and the Environment) estimates the risk to public health to be very low. 

Because the other cows on the farm also tested negative in the PCR test, it seems unlikely that the virus could have spread from the cow to the other cows. 

Due to the cat that previously tested positive near the farm, individuals working or living on the farm were already known to the Municipal Health Service (GGD). 

These individuals have not shown any symptoms consistent with (avian) influenza since then. 

To be on the safe side, all persons exposed to the cow will still be offered testing for an active or past infection. 

Milk on this farm is used only for pasteurized products, meaning any virus present is inactivated and poses no risk of external contamination. 

Furthermore, the milk from the previously infected cow was not processed for human consumption due to the existing mastitis pattern. 

Therefore, the chance that virus from the infected cow has ended up in the milk for human consumption is very small. 

Given the new situation, the RIVM will soon organize a Zoonosis Response Team (RT-Z) in line with the existing zoonosis structure, in which Experts from human and veterinary health will conduct a risk assessment based on the new situation and share it online. 

Finally, the avian influenza situation in our country remains worrying. 

Unfortunately, outbreaks have occurred in recent weeks on both commercial poultry farms and hobby farms. 

Wild birds are also regularly found with avian influenza. 

The fact that a dairy cow has been infected with the avian influenza virus is therefore consistent with these times of high infection pressure. 

Nevertheless, this is a worrying development. I will therefore continue to closely monitor this situation and will conduct further research. I will inform you, together with the Minister of Health, Welfare and Sport, of relevant developments regarding avian influenza and this case. 

Sincerely, Femke Marije Wiersma, Minister of Agriculture, Fisheries, Food Security and Nature

Source: 

Links: Press Release, https://www.rijksoverheid.nl/onderwerpen/vogelgriep/nieuws/2026/01/23/antistoffen-vogelgriepvirus-gevonden-bij-melkkoe ; Parliamentary Document: https://www.rijksoverheid.nl/onderwerpen/vogelgriep/documenten/kamerstukken/2026/01/23/melkkoe-met-antistoffen-tegen-vogelgriep

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