EM&I: Genetic evolution, phylodynamics, geographic spread of H9N2 avian influenza viruses in China from 2014 to 2025: an increasing potential zoonotic risk

   

Geographic distribution of of 1,583 H9N2 AIVs in China in 2014‒2025.

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Although pandemics are often known for their abrupt appearance and rapid spread, our understanding of how long each pandemic virus simmered - either ignored or largely unobserved - remains limited. 

• Precursors to the 2009 H1N1 pandemic virus, which emerged from North American pigs, appear to have been circulating for at least a decade before it began its world tour. 
• It has been estimated that ancestral strains of COVID-19 may have been circulating for 4 to 7 decades in bats before spilling over into humans. 

We've been watching HPAI H5Nx for 3 decades, and while it continues to improve its game, it has yet to adapt well enough to human physiology to spread efficiently.

The same could be said for many other novel viruses, including both swine and avian flu, henipaviruses like Nipah, scores of other coronaviruses, and of course `Disease X'; the placeholder for those threats yet to be discovered. 

One of the `usual suspects' we keep coming back to is LPAI H9N2, which is ubiquitous in Asian poultry, has spread to both Africa and the Middle East, and just recently turned up in Europe. 

While roughly 200 human (mostly mild) cases have been reported over the past 30 years - mostly from China - recently we've seen an uptick in cases, with 9 reported in China/Hong Kong over the past 2 months (see WHO WPRO Reporting 4 More H9N2 Cases on Chinese Mainland).

Several recent studies have found signs that LPAI H9N2 is becoming better adapted to mammals, warning of its pandemic potential; including:

• Two months ago, in Viruses: Epidemiological and Virological Characteristics of H9N2 Avian Influenza Virus in Jiangsu Province, China, 2024, researchers warned that that Jiangsu’s circulating H9N2 viruses have acquired human receptor preference and mammalian adaptation, posing silent infection and pandemic risks

• Last October, in China CDC Weekly: Epidemiological and Genetic Characterization of Three H9N2 Viruses Causing Human Infections, investigators reported a number of indicators of increased mammalian adaptation within the virus, including an enhanced ability to infect upper respiratory (α2,6-sialic acid) tract receptors, and a number of HA protein mutations, including; H191N, A198V, Q226L, and Q234L.

• The Asian Y280/G57 lineages have shown increasing signs of mammalian adaptation (see EM&I: Enhanced Replication of a Contemporary Avian Influenza A H9N2 Virus in Human Respiratory Organoids)), while the African and Middle Eastern Lineages (mostly European G1-like) are older and less evolved.

• Last summer, in Nature: Genetic diversity of H9N2 avian influenza viruses in poultry across China and implications for zoonotic transmission, researchers reported rising prevalence of key mutations associated with increased infectivity and pathogenicity in mammals.

Despite being clearly zoonotic - LPAI H9N2 is considered a `non-reportable' disease in poultry or wild birds by WOAH (see Terrestrial Animal Code). As a result, there are huge gaps in surveillance and reporting around the world.

Complicating matters, China's attempts to control LPAI H9N2 through vaccines have been less than successful. 

In 2025's NPJ Vaccines: Impact of Inactivated Vaccine on Transmission and Evolution of H9N2 Avian Influenza Virus in Chickens, we saw evidence that inactivated vaccines failed to prevent - or even reduce - H9N2 in China's poultry, and may have driven viral evolution (including mammalian adaptations).

All of which brings us to yet another Chinese study which - once again - finds that China's LPAI H9N2 continues to diversify and accrue worrisome mammalian adaptations, which they suggest increase its zoonotic risk. 

Due to its length and technical nature, I've only posted some excerpts from the abstract and narrative.  Those looking for a deeper dive will want to follow the link to read it in its entirety. 

I'll have a brief postscript after the break.

Genetic evolution, phylodynamics, geographic spread of H9N2 avian influenza viruses in China from 2014 to 2025: an increasing potential zoonotic risk

Zifeng Pang ,Peiting Zhong ,Cuishan Mai ,Junkun Fan ,Yejia Wu ,Yao Zhang , show all

Article: 2713320 | Accepted author version posted online: 03 Aug 2026
Cite this article https://doi.org/10.1080/22221751.2026.2713320 

Abstract

Subtype H9N2 of the avian influenza virus (AIV) poses a growing threat to the poultry industry and public health. However, since 2014, there has been no systematic study of its genetic evolution, genotype, spatial dynamics, and pathogenicity in China. Therefore, we performed a large-scale sequence analysis of the genome of Chinese H9N2 viruses from 2014 to 2025 using public databases and laboratory isolates. We identified 52 different genotypes in 1,591 H9N2 viruses, including 4 previously recognized genotypes (G6, G57, G58, and G68) and 48 newly defined genotypes (G118–G163) in this study. G57 and G118 were the main epidemic genotypes in China from 2014 to 2025. 

Bayesian phylogeographic analysis showed that there were 12 obvious migration paths for the spread of H9N2 AIVs in China from 2017 to 2022. In particular, the South China region was the main transmission centre. H9N2 AIV continues to circulate in chickens and ducks in China and spreads to other hosts. 

The H9N2 AIVs with the G57 and G118 genotypes could effectively replicate in MDCK, CEF, A549, and HBE cells with titres of 0.97–8.5 lgTCID50/mL. The G57 and G118 genotypes H9N2 viruses preferentially bound to α–2,6–linked sialic acid glycopolymers (human receptors), and effectively replicate in multiple organs of mice and chickens and cause pathological changes in the lungs. Thus, it is necessary to strengthen the monitoring and prevention of H9N2 AIVs in China.

        (SNIP)

These mutations can increase the replication of H9N2 virus in mammalian cells and enhance the pathogenicity of the virus to mammals. In vitro replication experiments showed that the current H9N2 virus could replicate efficiently in MDCK, A549 and HBE cells, and the titer of CK225/22 was higher than that of the other strains.

In vivo experiments showed that the current G57 and G118 genotype H9N2 viruses replicated effectively in the turbinate and lungs of mice and caused body weight loss.

In summary, our results showed that the current H9N2 virus has obtained some mutations adapted to mammals, increasing the potential threat to public health.

       (Continue . . . )
 

Trying to predict the source of the next pandemic is a mug's game, but H9N2 constantly ranks in the top 10 zoonotic influenza A viruses the CDC has pegged as having some pandemic potential.

And many will be surprised to see that, in terms of risk of emergence, the H9N2 Y280 lineage is ranked higher than H5N1, while the G1 lineage is ranked only slightly lower.

Given the paucity of day-to-day news coming out of China regarding avian flu, it is difficult to gauge just how much of threat H9N2 currently poses.  

But based on the frequency of Chinese studies published on LPAI H9 over the past couple of years, they quite obviously take its threat seriously.

 Which suggests we should, as well.

Australia: H5N1 Positive Bird Detections (n=102) Continue to Rise

 

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The number of confirmed H5N1 detections in wild birds in Australia has more than quintupled in a little over a week, rising from 20 on July 27th to 102 today (Aug 4th). 

Most of this increase has come from the state of South Australia, where the first mass mortality event (in birds) has been confirmed.

Two quick updates this morning from the Australian Authorities, first this from DAFF.

Attributable to Australian Chief Veterinary Officer, Dr Beth Cookson:

Testing at CSIRO’s Australian Centre for Disease Preparedness (ACDP) has confirmed further positive results in South Australia, bringing the total to 81 in South Australia. This includes detections in Limestone Coast (Southend, Robe and Baudin Rocks), Kangaroo Island (Harriet River, Seal Bay, Vivonne Bay and D’Estrees Bay), Coorong, Glenelg, Troubridge Island and The Pages Islands. It also includes 6 from Baudin Rocks, comprising 5 greater crested terns and 1 silver gull.

The Baudin Rocks detection follows an investigation into over 80 sick or dead wild birds, and is the first confirmed mass mortality event in wildlife in Australia due to H5 bird flu.

In line with overseas experience and recent events within Australia, a mass mortality event is not unexpected. It follows evidence of some local transmission between a smaller number of wild birds in South Australia.

There has also been one further positive result from Portland in Victoria at this stage, through testing at its state laboratory.

There have now been 102 confirmed or presumed positive detections of H5 bird flu in Australia, based on samples tested. With the mass mortality event at Baudin Rocks, not all sick or dead wild birds were sampled as this is not necessary to determine whether the event was due to H5 bird flu.

There remain no detections in poultry or in our agricultural production system.

The risk to human health remains low.

And from SA state authorities we get:

Current bird flu detections

South Australia’s first confirmed detection of H5 bird flu was in a wild migratory bird (southern giant petrel) on Wednesday, 24 June at Knights Beach at Port Elliot on the Fleurieu Peninsula.

Further confirmed detections include: 

• a giant petrel (8 July at Hardwicke Bay, Yorke Peninsula)
• a southern giant petrel (10 July at Emu Bay, Kangaroo Island)
• a northern giant petrel (10 July at Port Vincent, Yorke Peninsula)
• three greater crested terns (10 July at Robe, Limestone Coast; 26 July at Semaphore, metro Adelaide; and 26 July at Robe, Limestone Coast)
• seven greater crested terns (28 July at Cape Jaffa, Port MacDonnell and Southend, Limestone Coast)
• a giant petrel (30 July at Port Lincoln, Eyre Peninsula)
• a silver gull (1 August at Robe, Limestone Coast)
• 19 greater crested terns (1 August at Beachport (3), Cape Jaffa (1), Southend (1), Port MacDonnell (2), Robe (7), Limestone Coast; and Seal Bay (5), Kangaroo Island)
• two silver gulls (2 August at Robe (1) and South End (1), Limestone Coast)
• a greater crested tern (2 August at Monarto)
• a petrel (3 August, Coorong)
• one silver gull (3 August, Glenelg)
• two greater crested terns (3 August, Troubridge Island)
• one silver gull (3 August, Southend)
• one greater crested tern (3 August, Monarto)
• six greater crested terns (3 August, Pages Island)
• five greater crested terns (3 August, Baudin Rocks)
• one silver gull (3 August, Baudin Rocks).
• 23 greater crested terns (4 August, Limestone Coast, Southend (5) and Robe (7), and Kangaroo Island, Harriet River (1), Seal Bay (4), Vivonne Bay (5) and D’Estrees Bay (1)

A further 28 suspected H5 bird flu detections are undergoing further confirmatory testing at the Australian Centre for Disease Preparedness in Victoria.

Up-to-date national information is available at birdflu.gov.au.

Given the limits of surveillance and testing, the real number is likely much higher, potentially in the thousands by now.  For now, all detections have been in migratory or native seabirds, but how long that status quo can continue remains to be seen.  

Mainland China, Taiwan & Hong Kong All Reporting Summer Surge of COVID

 
Credit China CDC  (translated by google)

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While we've enjoyed a prolonged lull in COVID activity here in the United States, the same can't be said for everyone. As we noted 3 weeks ago, both Hong Kong and Taiwan were reporting a summer uptick in COVID cases. 

Reassuringly, in their latest update (July 31st), the CDC continues to report very low respiratory illness in the United States, but indicates that - unlike with Flu and RSV - COVID activity is slowly rising.

Where COVID is Increasing (CDC 7/31/26)

By contrast, this week China is reporting 20% COVID positivity (see chart at top of blog) among influenza-like illnesses seen at sentinel hospital outpatient and emergency departments, while last week Hong Kong reported:

`The latest surveillance data showed that local COVID-19 activity is currently in an active period and remains at a relatively high level.'

Today Taiwan's CDC is reporting an additional surge in serious (and even fatal) COVID-19 cases, and is urging the public to get vaccinated and take extra precautions to avoid infection. 

With the domestic COVID-19 epidemic rising and currently in its epidemic period, we urge those who have not yet been vaccinated to get vaccinated as soon as possible and to implement self-protective measures such as frequent handwashing and wearing masks.

Release Date: 2026-08-04

The Centers for Disease Control (CDC) stated today (August 4th) that the domestic COVID-19 epidemic continues to rise and is in its epidemic period. The CDC urges the public not to let their guard down and to take good self-protection measures, including frequent handwashing; wearing masks when entering and exiting medical care facilities, taking public transportation, and going to crowded indoor places; if experiencing fever or respiratory symptoms, it is recommended to stay home as much as possible and avoid unnecessary outings, remembering to wear a mask when going out; those who have not yet been vaccinated should get vaccinated as soon as possible; and those with other risk factors for severe illness should seek medical attention immediately if they experience suspected symptoms, so that doctors can diagnose and treat them early and prescribe antiviral drugs, reducing the risk of severe complications or death after infection.

According to CDC monitoring data, the domestic COVID-19 epidemic is rising. In the 30th week (July 26th - August 1st), there were 18,990 outpatient and emergency room visits for COVID-19, an increase of 74.8% compared to the previous week (July 19th - July 25th); last week (July 28th - August 3rd), there were 62 new local severe cases and 3 local deaths.

Since October 2025, there have been a total of 265 local cases of COVID-19 complicated by severe illness, of which 28 have died. The majority of severe cases are among those aged 65 and above (74.0%) and those with a history of chronic diseases (85.3%). 89.1% of these cases have not been vaccinated this season. In the past four weeks, the predominant variant strain in local cases is PQ.16.1.1.

The global positivity rate is trending upward, with the US and Europe showing a slight increase from their lows, while Southeast Asia and the Western Pacific are at a plateau. The epidemic continues to rise in China, the US, and the UK; the epidemic is declining weekly in Hong Kong, Japan, and Thailand. Recently, the predominant global variant strains are NB.1.8.1, XFG, and JN.1.

The Centers for Disease Control (CDC) points out that as of August 2, 2026, approximately 1.772 million COVID-19 vaccinations have been administered this season, with vaccination rates among those aged 65 and above at 21.12% for the first dose and 0.78% for the second dose. Taiwan has approximately 165,000 doses of COVID-19 vaccine in stock. 80,550 doses were allocated to various counties and cities for vaccination on July 30th, and an additional 45,000 doses are expected to be distributed on August 6th based on demand.

(Continue . . . )

 While all remains relatively quiet here, the CDC has produced a forecast of sorts; one which suggests that a late summer surge is possible, particularly in areas which saw lower COVID activity last winter.

National Outlook

While the past several waves have shown a trend of declining hospitalizations nationally, it remains possible that there could be a larger increase this summer. There is regional variability in both the timing and magnitude of COVID-19 activity. We developed two COVID-19 modeling scenarios for the summer to demonstrate the range of possibilities for how COVID-19 activity could unfold nationally. 

One scenario assumes that no variant with significant immune-escape properties emerges; the other is based on the possible emergence of a variant with moderate immune-escape properties that achieves predominance. The latter scenario is based on the characteristics that were observed in variants that emerged in the United States in the pastA.

While not specifically modeled in this scenario, we note that since its first detection in the U.S. in 2025, there have been detections of BA.3.2 in at least 29 U.S. states and Puerto RicoB. These modeling results show that in the absence of the emergence of a variant with moderate immune-escape properties, we do not expect an increase substantially larger than that experienced this past winter (Figure 2). If such a variant does emerge, there is substantial uncertainty (Figure 2), but modeling suggests increases would likely be within the range of what has been observed in the past 3 years (Figure 1).

Whether COVID-19 will increase significantly in the short-run here in the U.S. is unknown - but given its continued evolution and proven affinity for infecting humans -  it seems unlikely that we've seen the last of this troublesome virus. 

Australia Confirms First Mass Mortality Event (Birds) on Baudin Rocks Island

Video: @abcnewsaustralia
 

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While there was little doubt of the outcome, for the past 2 days we've been waiting for test results from an apparent mass mortality event on Baudin Rocks island, South Australia.  

Overnight South Australia has reported that HPAI H5N1 was detected in a number of sampled carcasses.

Those results were announced by Agriculture Minister Julie Collins (video link), and we have the latest update from South Australia.

Current bird flu detections

South Australia’s first confirmed detection of H5 bird flu was in a wild migratory bird (southern giant petrel) on Wednesday, 24 June at Knights Beach at Port Elliot on the Fleurieu Peninsula.

• Further confirmed detections include:a giant petrel (8 July at Hardwicke Bay, Yorke Peninsula)
• a southern giant petrel (10 July at Emu Bay, Kangaroo Island)
• a northern giant petrel (10 July at Port Vincent, Yorke Peninsula)
• three greater crested terns (10 July at Robe, Limestone Coast; 26 July at Semaphore, metro Adelaide; and 26 July at Robe, Limestone Coast)
• seven greater crested terns (28 July at Cape Jaffa, Port MacDonnell and Southend, Limestone Coast)
• a giant petrel (30 July at Port Lincoln, Eyre Peninsula)
• a silver gull (1 August at Robe, Limestone Coast)
• 19 greater crested terns (1 August at Beachport (3), Cape Jaffa (1), Southend (1), Port MacDonnell (2), Robe (7), Limestone Coast; and Seal Bay (5), Kangaroo Island)
• two silver gulls (2 August at Robe (1) and South End (1), Limestone Coast)
• a greater crested tern (2 August at Monarto)
• a petrel (3 August, Coorong)
• one silver gull (3 August, Glenelg)
• two greater crested terns (3 August, Troubridge Island)
• one silver gull (3 August, Southend)
• one greater crested tern (3 August, Monarto)
• six greater crested terns (3 August, Pages Island)
• five greater crested terns (3 August, Baudin Rocks)
• one silver gull (3 August, Baudin Rocks).

A further 49 suspected H5 bird flu detections are undergoing further confirmatory testing at the Australian Centre for Disease Preparedness in Victoria.

The current national tally sits at 78 confirmed detections, but that undoubtedly underrepresents the current situation.  There are literally thousands of citizen reports of bird deaths that have not been investigated. 

This update from https://www.agriculture.gov.au/campaigns/birdflu

Detection of H5 bird flu 

As of 3pm AEST, 3 August 2026, Australia has 78 confirmed detections of H5 bird flu in wild seabirds.

• 10 in Western Australia (WA)
• 58 in South Australia (SA) 
• 2 in New South Wales (NSW)
• 1 in Queensland (QLD)
• 7 in Victoria (VIC).

This is the serious H5 bird flu strain that has been circulating globally.

There have been no detections in poultry or the wider agriculture industry. There is no evidence of any large scale deaths. 

The Consultative Committee for Emergency Animal Disease (CCEAD) has reviewed its previous advice and endorsed a framework on national poultry biosecurity measures that will commence from 31 July. Under this framework, state and territory governments are responsible for issuing advice on biosecurity measures using a risk-based approach.

State and territory governments are responsible for surveillance and response activities on the ground. They are actively working with industry to provide guidance on implementation of enhanced biosecurity measures, as appropriate. Find out more about bird flu in your state or territory.

National coordination is being led by the Department of Agriculture, Fisheries and Forestry (DAFF).

The risk to human health remains low.

Australia is well prepared to respond quickly.

While Australian national and local governments continue to stress the lack of outbreaks in poultry or other livestock, and still maintain `There is no evidence of any large scale deaths', the recent history of H5N1 suggests those types of reassurances are likely to be short-lived. 

Australia: Updated H5N1 Detections In Wild Birds (n=62)

 

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While we are still awaiting results from the mass mortality event on Baudin rocks, CSIRO has confirmed 3 more South Australian birds positive for H5N1, and Victoria's total has jumped to 7. 

These are just confirmed cases, and likely represent just a fraction of HPAIs spread throughout the nation.  Due to the logistics of recovering bird carcasses, and limited testing capacity, the backlog of uninvestigated citizen reports on dead birds has grown well into the thousands. 

As we discussed a little over 2 weeks ago, the number of daily reports were already far outpacing their ability to investigate and test carcasses.

 Graphic generated by Gemini

 Yesterday SA Chief Veterinary Officer Skye Fruean was quoted as saying:

"At some point in time and we're not there yet, we will stop testing in areas where we know it [bird flu] is well established … because there is nothing we can do to stop the spread, we don't need to continue testing in an area that we know it is present."

Since it is a weekend, reporting is sparse. But we do have the following update from https://www.agriculture.gov.au/campaigns/birdflu.

 

Detection of H5 bird flu 

As of 5pm AEST, 2 August 2026, Australia has 62 confirmed detections of H5 bird flu in wild seabirds.

• 10 in Western Australia (WA)
• 42 in South Australia (SA) 
• 2 in New South Wales (NSW)
• 1 in Queensland (QLD)
• 7 in Victoria (VIC).

This is the serious H5 bird flu strain that has been circulating globally.

There have been no detections in poultry or the wider agriculture industry. There is no evidence of any large scale deaths. 

The Consultative Committee for Emergency Animal Disease (CCEAD) has reviewed its previous advice and endorsed a framework on national poultry biosecurity measures that will commence from 31 July. Under this framework, state and territory governments are responsible for issuing advice on biosecurity measures using a risk-based approach.

State and territory governments are responsible for surveillance and response activities on the ground. They are actively working with industry to provide guidance on implementation of enhanced biosecurity measures, as appropriate. Find out more about bird flu in your state or territory.

National coordination is being led by the Department of Agriculture, Fisheries and Forestry (DAFF).

The risk to human health remains low.

Australia is well prepared to respond quickly.

Finland Reports 1st ASF Detection - Switzerland Investigating Unidentified Bovine Disease

Note: Many countries are slow or reluctant to report outbreaks.

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Although we spend most of our time looking at zoonotic diseases in this blog, over the years we've also followed a number of emerging and reemerging agricultural diseases, including: 

African Swine Fever In China: Epizootic or An EpicZootic?

Viruses: Novel Rodent Coronavirus-like Virus Detected Among Beef Cattle with Respiratory Disease in Mexico

Viruses: Influenza D in Domestic and Wild Animals 

There are also agricultural diseases that inhabit the middle ground, in that they can infect humans - but do so only rarely or have little or no epidemic or pandemic potential - such as the NWS screwworm, Newcastle disease, and Orf Virus (to name a few).

And sometimes, as was the case of 2024's Curious Reports of Unknown Disease In Dairy Cows (Texas, Kansas & New Mexico) - which was later confirmed to be HPAI H5N1 - an outbreak in livestock can pose a risk to humans.  

But even without a zoonotic component, these diseases can pose substantial economic and public health risks, including raising food insecurity issues (see COCA Call: Diseases of Food Animals Threaten Global Food Security).

Arguably, one of the most devastating non-zoonotic diseases is African Swine Fever (ASF), which has spreading across Europe for the past 2 decades, and reached China/Asia in 2018-2019 causing the loss of tens of millions of pigs. 

This week Finland reported their first detection of ASF in wild boars near the Russian border. This from the Finnish Food Authority:

African swine fever detected in Eastern Finland

July 31/2026

Preliminary tests have confirmed African swine fever (ASF) in wild boars in Virolahti, Eastern Finland. The Finnish Food Authority will verify the result with the EU’s reference laboratory for African swine fever in Spain. Measures to limit the spreading of the disease will be taken immediately. This is the first time that the disease has been detected in Finland. This disease is not contagious to humans.

The Finnish Food Authority has established an infection zone around the area where the finding was made, and the movement of pigs in the zone is restricted. The goal is to determine the prevalence of the disease in wild boars in the area and to prevent the disease from spreading elsewhere in Finland. You can find a map of the infection zone and the content of the current restrictions on the Finnish Food Authority’s website.

The virus causing African swine fever was detected in wild piglets that were found dead. The remains of three dead piglets were found by a local who delivered them to the Finnish Food Authority. The carcasses were found close to each other in Vaalimaa, Virolahti. A preliminary ASF virus finding was made in the Finnish Food Authority’s tests on Thursday 30 July.

The press release will be expanded

For more information, contact the Finnish Food Authority:
Sirpa Kiviruusu
Head of Unit
Animal Health and Medication Unit
tel. +358 40 092 0503
sirpa.kiviruusu@ruokavirasto.fi

Yesterday Pathfinder on FluTrackers posted an AFP report on a unidentified disease being reported in Swiss dairy cows, which led me to the following statement by the Swiss FSVO (Federal Office for Food Safety and Veterinary Affairs):

(translation)

Announcement published on July 31, 2026
Diseases in dairy cows: BLV is monitoring the development

Reports of fever, diarrhea, and significant drops in milk production are increasing in dairy cows. Investigations are underway with veterinarians, industry representatives, universities, laboratories, and veterinary authorities.

The Federal Food Safety and Veterinary Office (FSVO) is aware of reports of an increase in illnesses among dairy cows. Several farmers are reporting symptoms, particularly fever and diarrhea, often accompanied by a significant drop in milk production. The cause has not yet been identified. Investigations are underway into both metabolic and potential infectious causes. These investigations are being conducted in collaboration between practicing veterinarians, Cattle Health Switzerland, veterinary universities and laboratories, and the veterinary authorities.

So far, no pathogen has been identified as the infectious cause. A direct link between the current heat wave and the reported cases of diarrhea has not yet been established. However, high temperatures pose a significant stress, especially for high-yielding dairy cows, and can make the animals more susceptible to disease.

During heat waves, the animals must therefore be consistently protected from heat stress, especially through sufficient water, shade and suitable cooling measures.

Nonspecific symptoms such as fever, diarrhea, or decreased performance can also indicate a highly contagious animal disease. Animal owners should therefore inform their veterinarian immediately so that the necessary examinations can be initiated if required.

The Federal Food Safety and Veterinary Office (FSVO) is monitoring the situation together with the relevant specialist agencies and is continuously assessing it. Should further action be required, the necessary measures will be examined.

While this may turn out to be a heat-induced illness, or something common like Bovine Viral Diarrhea Virus (BVDV), the fact that no cause has been immediately determined makes this worth watching. 

Six weeks ago, in FAO calls for stronger prevention and global action as transboundary animal diseases spread across regions, we looked at the growing risks from the spread of agricultural diseases. 

Our health, and in many ways our fate, is inexorably intertwined with the global biosphere - making what happens in a Fruit bat in Bangladesh, a Shrew in China - or a cattle herd in Europe - something that that has the potential to change our world overnight.