Multi-species Highly Pathogenic Avian Influenza Fact Sheet

Veterinarians are calling for increased transparency and surveillance in response to the HPAI outbreak


On March 25, 2024, the United States Department of Agriculture confirmed milk and oropharyngeal samples obtained from sick dairy cattle tested positive for Highly Pathogenic Avian Influenza (HPAI). Officials have been investigating a mysterious illness among dairy cattle in the past few weeks. The positive tests came from two dairy facilities in Kansas and one facility in Texas. 



Since 2022, more than 82 million commercial and backyard birds have been killed in the United States in response to HPAI outbreaks. HPAI has also infected many other species including foxes, bears, racoons, seals, mountain lions, skunks, bobcats, otters, coyotes, fishers and opossums.



In early March,10 goats tested positive for HPAI, and five died in Stevens County, Minnesota. These infections marked the first time HPAI had been found in ruminant livestock in the United States, increasing concerns about the threat to other mammalian livestock. The facility, which had 165 goats, had recently depopulated its birds due to an HPAI outbreak, and the goats who shared a pasture and water source with the birds began giving birth in the days following the depopulation.



On March 15th, reports of sick dairy cattle began circulating in agricultural media. 



On March 29th, cows in a Michigan herd tested positive for HPAI. Two cows from Texas recently joined that herd. The USDA update states, “Spread of symptoms among the Michigan herd also indicates that HPAI transmission between cattle cannot be ruled out…”



Then, dairy cattle in Idaho tested positive after cows were imported into the Cassia County herd from another state. Idaho officials added, "It is suggested the virus may be transmitted from cow-to-cow, in addition to previous reports indicating cattle were acquiring the virus from invested birds." The Idaho cattle were being quarantined, none are being allowed to leave the facility and the affected cattle are being quarantined from the rest of the herd.


By April 10th, 2024
HPAI had been confirmed in 20 diary cow herds in 6 states. 

On April 11th, 2024 that number jumped to 24 herds with South Dakota and North Carolina added to the list of states affected. An article in Reuters reported one producer who chopped down around 40 trees to stop migrating birds from nesting. 


On April 12th, Pennsylvania decided to require avian flu testing for any dairy cows coming to Pennsylvania from another state:



The PDA’s order requires the following:

  • Dairy cattle from a state where avian influenza has been confirmed in dairy cattle in the past 30 days may not be imported to, stopped off in or unloaded in Pennsylvania without testing of nasal swabs and milk.

  • At least 30 animals, or all animals in loads with fewer than 30, must be tested within five days before movement.

  • The animals must have been assembled as a group for at least 30 days with no new animals added in the 30 days before testing; otherwise, all animals must be tested.

  • Testing is not required for calves under 1 year old, and for cattle moving directly to slaughter that are not commingled with cattle not moving to slaughter.

  • Cattle from an infected farm may not be brought into Pennsylvania until the site tests negative.



Veterinarians also began seeing sick cats from dairy facilities with H5N1-positive cows. The cats developed neurological and respiratory symptoms, dying within 24-48 hours of the onset of symptoms. When tested, the cats showed high levels of H5N1. Veterinarians who might see sick cats from dairy facilities are encouraged to wear PPE.



Dead birds were found on the properties, and Animal Plant Health and Inspection Service (APHIS) said, "Based on findings from Texas, the detections appear to have been introduced by wild birds.” However, in subsequent reports, information about the presence or absence of wild birds, as well as whether the infected herds had just received new cows from affected herds or states was not reported. 



Early industry communications sought to minimize consumer concern, underestimating the virus’s transmissibility 



A key reason for depopulation of poultry was to prevent further disease spread and the infection of other animals. What kind of risk do these infected cattle pose to other animals? The National Cattlemen's Beef Association issued a statement on March 25th, 2024 saying, “USDA has confirmed that affected dairy cows do not appear to be transmitting the virus to other cattle within the same herd.” That was soon proven incorrect. 


In an interview in Science published on March 26th, when asked whether the virus was being transmitted from cow to cow, Gregory Gray, an epidemiologist at the University of Texas Medical Branch, “We don’t know. I don’t think anybody’s done those experiments. I would think that would be one of the things that people would want to investigate rather quickly.” Gray also added, “Initially, we thought we would be able to work with many farms in Texas, because they’re concerned about keeping their animals free from disease. But there’s been a real resistance to collaborating with us. There’s concern that we might find something that would damage their business.”


According to Raj Rajnarayanan, Assistant Dean of Research and Associate Professor, New York Institute of Technology College Of Osteopathic Medicine at Arkansas State University, dairy cows, blackbirds and the common grackle show a similar mutation pattern. An NPR article reports, “The USDA believes the dairy cows have been sickened by a strain called H5N1, Eurasian lineage goose/Guangdong clade 2.3.4.4b, which was likely introduced by wild birds. Pigeons, blackbirds and grackles were identified at the affected Texas farms.”



A scientific article published on April 7th titled Emerging Threats: Is Highly Pathogenic Avian Influenza A(H5N1) in Dairy Herds a Prelude to a New Pandemic? Says, “While the risk to public health remains categorized as low by the CDC (https://www.cdc.gov/flu/avianflu/spotlights/2023-2024/h5n1-analysis-texas.htm#print), individuals with close contact with infected animals or contaminated environments are at increased risk.”


They also say:



 “It is interesting to note that the genetic distance between groups is very small (0.002 - 0.144) for both genes, especially considering that Influenza A, along with other RNA viruses, reproduces with minimal accuracy [3]. This condition suggests that the strains affecting different hosts are similar and no spillover events have occurred yet. Indeed, the strain infecting humans is very closely related to those present in birds. A similar phenomenon occurred in Cambodia in recent years when two individuals, a father and daughter, were affected. While the father showed no symptoms, the daughter tragically passed away in a nearby hospital [4]. After a genetic evaluation emerged that the most likely scenario is that these two individuals were infected by the same reservior species [5]. Similarly, in this case, the comparison between the genetic makeup of humans, mammals, and avian species did not reflect the signature of a genetic spillover, but this does not mean that it can never happen.”



“Indeed, according to selective pressure on the HA gene, birds remain the primary host, but the virus is also accumulating genetic variability in other hosts through genetic drift phenomena. This accumulation enhances the virus's potential hazard and increases the likelihood of antigenic drift, characterized by minor mutations in the HA and NA genes, which can alter the structure of these surface proteins. We need to be vigilant as uncontrolled circulation among mammals increases the likelihood of transmission to a new host, driven by heightened variability due to unchecked circulation.



Ron Fouchier is a Dutch virologist and leading expert on H5N1 at the Erasmus Medical Center in Rotterdam. Fouchier told STAT News:



… when we see this virus in a milking farm and you see incredibly high virus load in some milk cows and their milk, that is a new risk. Because I’m not sure how familiar you are with the milking procedures, but there’s very little that people do to prevent human contact with milk. During the milking process, there’s massive generation of aerosol formation. If you have high amounts of aerosol with virus, the chances increase that you will get conjunctivitis.​​ 



….We have never seen this scale of infections in mammals, and in such diversity of mammals. We have now seen more than 40 species of mammals infected during the last outbreaks, which is unprecedented. We know that flu is unpredictable. But we also know that adaptation of virus to mammals is not a good thing.



Testing and Surveillance Protocols Severely Lacking


The April 1, 2024 version of the USDA-APHIS testing guidelines state:


"At this time, APHIS is not requiring testing. Testing may be done on a voluntary basis and is a tool producers may use to help manage this disease or reduce the risk of introducing the disease. APHIS may fund some testing as outlined below."



But this begs the questions, who determines whether testing should be required for any given disease, and when is that line drawn?


"Dairy farms and other cattle herds with an active event: cows must be exhibiting clinical signs; there may be dead/sick birds, cats, or other mammals. All would be eligible for reimbursement by APHIS through NAHLN or Unexplained Morbidity/Mortality Event (UME) funding..."



Does this just cover testing, or does it also cover a loss of productivity? 



"APHIS will fund the NAHLN laboratory influenza PCR testing for up to 20 mammals (no more than two samples per mammal) and unlimited birds per premises...samples only from clinically affected cows, or sick and dead mammals or birds on or near the premises."



On April 2nd, Princeton professor and New York Times Columnist Zeynep Tufekci commented on Twitter in response to the CDC’s recent update on the genetic sequence of the Texas H5N1 viruses that infected humans and cows, “So CDC uploads infected person’s sequence. HA clade 2.3.4.4b HPAI A(H5N1) — “closely related to viruses detected in dairy cattle in Texas”— but with PB2 E627K, a mammal adaptation. The dairy industry may resist mass testing, but it’s clearly indicated.” Tufekci also points out that we still don’t know how it is spreading and poultry byproducts are still fed to cattle in the US, which is illegal in the EU and Canada.


Tom Inglesby, MD of the Johns Hopkins Center for Health Security
said, “The testing approach to H5N1 in cattle (in the link) needs to change substantially. @USDA_APHIS may be doing what it can now with minimal resources, but testing needs to expand, get simpler, more available and transparent” adding, “The testing protocol is too complicated. It also only allows testing in cows that meet a specific profile. It only provides for limited number of tests per premises…Given the quickly increasing number of farms w/ infected cows, the number of farms that are impacted that have had minimal interaction with others, the uncertainty on mechanism of spread and extent of disease, testing for H5N1 in cattle should change in a number of ways asap.”


Dr. Angela Rasmussen, virologist at Vaccine and Infectious Disease Organization (VIDO) said on Twitter, “Expanded testing & surveillance are an urgent need and Congress must prioritize this investment. But there is an equal need for basic virology research: susceptibility, tropism, transmission, & pathogenesis. We can’t reduce risks to cows or humans if we don’t understand them.”



Epidemiologist and health economist Dr. Eric Feigl-Ding of the New England Complex Systems Institute points out that pasteurization was not intended to kill viral particles that micelles and fat globules might protect. In seven trials, injection of the pasteurized milk sample containing Foot and Mouth Disease Virus into a naive uninfected steer resulted in the cattle becoming infected even after pasteurization.



According to the USDA, roughly 10% of the animals on impacted herds are affected by the illness. 



Texas Department of Agriculture Commissioner Sid Miller says:


Cattle impacted by HPAI exhibit flu-like symptoms including fever and thick and discolored milk accompanied by a sharp reduction in milk production averaging between 10-30 pounds per cow throughout the herd. Economic impacts to facilities are ongoing as herds that are greatly impacted may lose up to 40% of their milk production for 7 to 10 days until symptoms subside. It is vital that dairy facilities nationwide practice heightened biosecurity measures to mitigate further spread.



Poultry litter feeding



Sources of spread could be from feeding poultry litter according to an April 9th article in the Telegraph, a practice that is not legal in the EU and Canada.



“In the US, the feeding of poultry litter to beef cows is a known factor in the cause of botulism in cattle, and is a risk in the case of H5N1,” said Dr Steve Van Winden, Associate Professor in Population Medicine at the Royal Veterinary College.



“Infection of H5N1 in pigs is of particular concern – they are highly susceptible to human influenza virus strains so could act as mixing vessels for avian and human viruses to mix and generate viruses that can more efficiently infect humans,” said Dr Tom Peacock.



The FDA recently told the Telegraph that they are reviewing their decision to allow the feeding of poultry litter. 


Regarding the consumer concern over the practice, one industry article says, “ There is an apparent reluctance on the part of the public, as well as of some beef producers, to accept broiler litter as a cattle feed. However, the public readily accepts organically grown vegetables grown on composted broiler litter. The process by which a plant assimilates food into its tissues is much less complicated than the process by which a cow does the same thing; a cow’s food is broken down and processed much more completely. In fact, there is a withdrawal period when feeding broiler litter for 15 days before they can be slaughtered for beef.”



Is H5N1 shed in cattle feces? A potential threat to raw vegetable consumers



E. coli illness in humans who consumed vegetables occurred after crops were irrigated with water from a canal contaminated with cattle waste or dust from feedlots contaminated the vegetables. It is still unclear whether H5N1 could be shed in cattle feces which might then contaminate crops. 


An April 2007 WHO Report (pp. 6-7) discusses the persistence of H5N1 viruses in water:



Avian influenza viruses are known to persist for extended periods of time in water depending on environmental conditions, including temperature, pH and salinity, but information on the persistence of highly pathogenic avian influenza (HPAI) viruses, including H5N1, in water is lacking.



Persistence of avian influenza in water is most sensitive to temperature. One study showed the avian influenza subtype H3N6 resuspended in untreated Mississippi River (USA) water was detected for over 30 days at 0 °C and was undetectable after 4 days at 22°C. In a second study, which used five low- pathogenicity avian influenza viruses (H3N8, H4N6, H6N2, H12N5, and H10N7), infectivity of virus in distilled water was retained for up to 207 days at 17 °C and 102 days at 28 °C. In a study that showed a high level of positive water samples (23%) for a strain of influenza A virus in a lake where ducks were nesting, the proportion of positive samples remained high (14%) in the autumn after the ducks had left for migration, indicating that the virus is able to persist in natural waters.



Persistence of avian influenza viruses in water appears to be less sensitive to pH and salinity. In general, avian influenza virus viability in natural water (fresh, brackish, seawater) decreases with increasing salinity and pH. One modeled system predicts that infectivity is potentially greatest in cooler, freshwater habitats ranging 7.4-7.8 pH.

Due to their structure, all influenza viruses are relatively susceptible to disinfectants, including oxidizing agents such as chlorine, as well as enzymes like proteases, peptidases, neuraminidases and haemagglutinases. They are also readily inactivated by heating. Predation by bacteria and other microbes may also play a role in virus inactivation. General studies on viruses demonstrate less persistence of virus inoculated into natural waters compared to virus that is inoculated into sterilized or pasteurized waters.



More information is needed about the inactivation of HPAI viruses in drinking water management processes and systems. Specifically, information on the effectiveness of disinfection and other treatment processes (e.g., chemical disinfectants, ozonation, thermal and thermophilic treatment processes, UV radiation, drying and desiccation, pH, biological activity, etc.) and the virus’s resistance to treatment will help to refine risk management strategies. Where such treatment processes are not available the sanitary risk assessment approach could be promoted here for both source protection and household storage.



Milk prices stable, the milk supply is safe, says the industry



Meanwhile, USDA-APHIS is emphasizing how this does not currently pose a food safety threat. 



The Meat Institute issued a statement saying that "properly prepared beef is safe to eat and is not a food safety risk to humans."



“HPAI cannot be transmitted to humans by eating meat or poultry products,” said Meat Institute President and CEO, Julie Anna Potts. The Meat Institute Statement adds, “We call on Biden Administration officials to anticipate international trade concerns and encourage our trading partners to abide by internationally recognized scientific standards as determined by the World Organisation for Animal Health (WOAH).”


The Centers for Disease Control recently updated their factsheet saying, “[the] H5N1 mammalian adaptation could represent a risk not only for diverse wild mammals but also for human health.”



Rebranding by the American Association of Bovine Practitioners Backfires


On April 7th, the AVMA-allied organization, the American Association of Bovine Practitioners, recently
issued a statement calling for highly pathogenic avian influenza in cattle to be called Bovine Influenza A Virus (BIAV). The statement says, “We believe it is important for the public to understand the difference to maintain confidence in the safety and accessibility of beef and dairy products for consumers.” T. Ryan Gregory, an evolutionary biologist at the University of Guelph, tweeted in response, “Um. Isn't there a system for formally naming viruses? And isn't that system managed by someone other than the ... *checks notes* American Association of Bovine Practitioners?”  



Matthew Hayek, Assistant Professor of Environmental Studies at New York University, tweeted, “The cattle industry must not get public license to give avian influenza a different name. It is H5N1: bird flu. It has a record of transmission between birds & mammals, and that makes it a potential danger to many more animals, including us.”



Maintaining consumer confidence is not part of the veterinarian’s oath. 



The emails sent out by the AABP are reminiscent of an email sent out by Dallas Hockman of the National Pork Producers Council after the practice of ventilation shutdown came to light. The email read, “I think it would be prudent for the 3 organizations to come out with a joint position statement relating to the current situation as well, the industries effort to address the issue, and support for the appropriate approved euthanasia processes such as Ventilation Shutdown Plus. We definitely need to come up with a new name to describe this…I am getting questions from McDonalds on this and they would like to have a response from us that they could use.”



The Program for Monitoring Emerging Diseases (ProMED), a program of the International Society for Infectious Diseases (ISID) published a April 10, 2024 post condemning AABP’s rebranding: 



It's also worth noting that the American Association of Bovine Practitioners is encouraging the use of the moniker "Bovine Influenza A virus (BIAV)" because of the perceived differing presentation in cattle per an open letter referenced here:https://www.realagriculture.com/2024/04/influenza-infection-in-cattle-gets-new-name-bovine-influenza-a-virus-biav/. This attempt to rename this or any other HPAI virus should be universally rejected. Until it is proven that no other species coming into contact with these cattle can be infected AND suffer traditional HPAI symptoms associated with that species, we should presume the virus still possesses the high mortality characteristics of HPAI strains in those at-risk species regardless of what happens in cattle. (The single case of human conjunctivitis in a dairy worker we already know about in no way supports this name change due to all the unknowns associated with it at this point).



Additionally, trying to rename the virus when it shows up in cows/cattle at this point in the outbreak only further reduces the pressure to provide those exposed to the affected cows appropriate PPE and to answer all of the questions we've covered previously to

include:

- is there cow to cow transmission?

- what are the real incidence/prevalence in cows (dairy and beef) and exposed people?

- what are the virus sources/reservoirs that are infecting these herds, etc.?

- what is being done to improve biosecurity on the affected dairies?

We don't need to say the sky is falling, but we also don't need to waste time and energy pretending an HPAI virus is now so different that it requires a name change as an urgent order of business. As noted in previous commentary, this isn't the first time Influenza A viruses have been found in cattle so we would invite the AABP to fully justify their rationale as to why now is the time to do this? As with every other time veterinarians attempt to add the species name to the virus, we're just going to regret it later because we always end up finding more strains (see swine influenza or canine influenza as prime examples of why using a species name makes no sense with the diagnostic tools we have today). Let's stick with calling it Influenza A (H5N1) and worry about dealing with real problems, not misleading the general public (or even giving anything close to the appearance of doing so). - Mod.JH



The Future

In a Wired magazine article published on April 11th, Maurice Pitesky, a researcher at UC Davis School of Veterinary Medicine said, “The impact on commercial poultry from a welfare, economic, and food security perspective is unprecedented,” says Pitesky. “We can’t seem to get this under control and we’re kind of teetering a little in terms of how far this could potentially propagate and continue to spread in farm animals throughout the world.”



“I work on predictive models, using a combination of weather radar, satellite imagery, and machine learning, to understand how waterfowl behavior around different farms is changing,” says Pitesky. “We can use this information to understand which of the 50,000 to 60,000 commercial poultry facilities in the US are at most risk, and form strategies to protect all the birds in those facilities.”



A team of U.K. researchers published a study in Nature Communications in which they showed Crispr could be used to make chickens resistant to avian influenza. 



But Is it possible to use technology to win an ever-escalating arms race against nature? Dr. Crystal Heath has argued, we need to align our technology with our empathy instead and work to drastically scale down animal agriculture and redirect investments towards promoting slaughter-free food consumption and production. 



The disease in poultry has cost taxpayers more than $1 billion, with more than $715 million going to producers in the form of indemnity payments for the loss of their animals. The largest recipients included Jennie-O Turkey Store, receiving $89 million, and Tyson Foods, with $29 million. To ensure their interests are protected, the Poultry and Egg industry spent $1.3 million in lobbying in 2023, the dairy industry has spent more than 5 times that amount, totaling $7.6 million


Today, we consume more slaughter-based meat than ever before. In 1961, we ate 50.6 lbs per person yearly. In 2020, that number jumped to 264 lbs per year, thanks to publicly funded bailouts, subsidies, marketing, and research. What if we invested in slaughter-free methods of food production instead?



There has been an increase in the emergence of zoonotic diseases. Recent work out of the Harvard T.H. Chan School of Public Health, led by Dr. Aaron Bernstein, shows that by addressing the causes of pandemics we can not only save billions of dollars, but lives as well. “high-density livestock operations can serve as an opportune environment for spillover from wild animals into livestock or as incubators for pandemic influenza strains ... Large pig and poultry farms are where the genetic re-assortment needed to source pandemic influenza strains may most likely occur.”  



Sinel and Weis point out in a recent paper, “Infectious disease experts have long warned that the next pandemic could well emerge from a virulent new variant of avian or swine influenza spilling over into a human population and becoming transmissible through human-to-human contact.”



A recent study published in Nature says that investing in food production methods that don’t require slaughtering animals would save us $7.3 trillion globally in health burdens and ecosystem degradation.



A recent article by Plaza et al. published on the CDC’s website states:



“H5N1 has affected several mammal species since 2003, thus raising concern because H5N1 mammalian adaptation could represent a risk not only for diverse wild mammals but also for human health …. It is fundamental that we rethink the interface between humans, domestic animals, and wild animals to prevent the emergence of dangerous pathogens that affect biodiversity and human health. Governments must assume responsibility for protecting biodiversity and human health from diseases caused by human activities, particularly diseases originating from intensive production, such as this H5N1 avian influenza virus. If we hope to conserve biodiversity and protect human health, we must change the way we produce our food (poultry farming, in this specific case) and how we interact with and affect wildlife."




A recent report published on April 3, 2024 by the European Food Safety Authority warns, “Should avian A(H5N1) influenza viruses acquire the ability to spread among humans, large-scale transmission could occur, given the naïve immune status of humans to H5 viruses.” It continues, “selection pressure on virus evolution increases with different susceptible species on a farm. These can include different poultry species, but also mixed farming of poultry and fur animals or poultry and pigs which could further increase the risk.”



The document recommends:

  • Surveillance targeting humans and animals should be enhanced, together with genomic analysis and the sharing of sequence data. Animals targeted should include wild birds, poultry, captive birds and the most susceptible domestic mammals (e.g. fur animal farms, mixed farms of poultry and fur animals or poultry and pigs, and cats) as well as susceptible wild mammals, especially peri-urban and peri-domestic mammals.

  • Individuals who are occupationally exposed to animals infected with AI can be offered vaccination against seasonal influenza and/or influenza A(H5) virus for protection and to minimise the risk of reassortment between avian and human seasonal influenza strains. Specific vaccination recommendations are under the remit of national authorities. Antivirals can be used to treat infected persons or as post-exposure prophylaxis when there are contacts of human cases. 

  • Vaccination of animals is an additional prevention strategy of AI infection at farms, complementary to stamping-out policies applied to control the infection. Vaccination should be coupled with surveillance to monitor the evolution of the field virus and identify any possible antigenic changes, including possible vaccine-induced mutations.

  • If viruses are given opportunities to evolve under continuous selection pressure (e.g. when virus spreads in mammals that are kept in high numbers in close proximity), this could facilitate the emergence and spread of isolates with the accumulation of such mutations.”

  • In general terms, and at the global level, not only related to influenza pandemics, some of those drivers have been recognised as playing a major role through: (1) increasing human demand for animal protein; (2) agricultural and animal farming intensification; (3) increased use, trade and exploitation of wildlife; (4) unsustainable use of natural resources accelerated by urbanisation, deforestation, land use change and extractive industries; (5) increased travel and transportation; (6) changes in food supply; (7) climate change; (8) the critical health and economic situation for people living in emerging infectious disease hotspots (UNEP & ILRI, 2020; Vora et al., 2022).

  • However, it is worth noting that the susceptibility of pigs to AIV is similar to humans, with the predominant sialic acid linkage being α2-6 sialic acid. Furthermore, AIV replication is restricted in swine cells in the same manner as it is in human cells because swine acidic leucine-rich nuclear phosphoprotein 32 family member A (ANP32A) does not possess the avian-specific gene duplication necessary to facilitate the activity of avian virus polymerase (Long et al., 2019; Moncorge et  al.,  2013).Therefore, the concept of pigs as a mixing vessel hinges more on favourable circumstances, such as close interactions between infected birds, swine and humans, rather than purely physiological factors. These circumstances include dense housing on pig farms allowing for close-contact transmission events and opportunities for reassortment (Long et al., 2019).

  • Outdoor housing farming practices create the highest risk of introduction as shown for LPAIV (sixfold increase, (Bouwstra et al., 2017). This also implies that increasing the percentage of organic poultry farms – a goal in the Farm to Fork strategy of EU – may increase the number of outbreaks given the same exposure and absence of risk mitigation measures (e.g. vaccination).

  • Housing multiple poultry species on the same premises likely results in transmission between bird species and the associated selection pressure on the virus while going from one bird species to another (Health et al., 2017). The risk of virus evolution increases if poultry and potentially susceptible mammals are farmed on the same premises. From the mammals reported above, fur animals seem to have the highest risk of infection. Consequently, a combined poultry—fur animal farm could be considered a high-risk farming practice.

    • It should be noted, in the US, mink farms will feed spent hens to their mink. 


Dr. Sean Mullen, research Director at the Exercise, Technology, and Cognition Lab commented on Twitter, “Make the milk industry hurt now. Make it intentional. Because we need factory farms to FALL BY THE WAYSIDE with all of these expedited zoonotic disease transmissions. And the byproduct? We save lives.”



A 2022 article published in Science Advances called, The Infectious Disease Trap of Animal Agriculture, calls for:



  • More targeted dietary change interventions are needed; recommendations for dietary change policies across most scientific literature are general and vague (16, 55). Policies can leverage social, behavioral, and organizational sciences to change the underlying motivations and choice environments that drive consumer decisions (64, 67). Small successes should also be better communicated to decision-makers and ambitiously scaled to large populations with help from community-based advocacy and organizing (68).

  • ambitiously scaling community-based approaches to popularizing plant-rich diets.



The AVMA works against One Health and Transparency.



The total number of dairy cattle affected or at risk is still unknown. Sid Miller, Texas' agriculture commissioner, said that, unlike for poultry, he doesn’t foresee a need to depopulate cattle herds. "Cattle are expected to fully recover," he said, and on social media, he indicated that the HPAI-positive cattle will be quarantined. Trump is considering the former rodeo cowboy to head the United States Department of Agriculture if he wins the White House. 



If a disease did require mass extermination of herds, the American Veterinary Medical Association’s Guidelines for the Depopulation of Animals dictates USDA policy regarding the methods that would be used, as well as indemnity payments to producers. This document was formed via a cooperative agreement with the USDA. Regarding cattle, it says, “In some cases, it may be possible to depopulate cattle or other large ruminants using commercial or private processing facilities. (p.34)”


However, these carcasses currently could not be used for consumption. The USDA statement says, “Dairies are required to send only milk from healthy animals into processing for human consumption; milk from impacted animals is being diverted or destroyed so that it does not enter the food supply.” For the same reason, it is likely that potentially infected carcasses also could not enter the food supply. But since they plan to not cull infected cattle, at what point will the meat and milk return to the food chain? Will producers receive indemnity payments for the loss of productivity due to HPAI infections?



Whether HPAI-infected animals could be rendered if they were culled is still unknown. Regarding other disposal methods, the AVMA’s Guidelines state (p. 31):



Burial of 100,000 cattle at one time would create monumental disposal problems and possible groundwater contamination. Composting or rendering this number of cattle in a timely fashion would not be feasible. Euthanizing 50,000 to 100,000 head of cattle could be accomplished over time, but there are few viable solutions for disposal. 



Methods of mass killing cattle listed in the AVMA’s Guidelines on Depopulation include firearm (gunshot) and penetrating captive bolt gun directed at the poll or top of the head directed towards the tongue, vs the more preferred frontal shot (p.35). Other methods include injectable euthanasia solution, which would require large quantities and would pose a risk to wildlife. Methods permitted in constrained circumstances include electrocution. 



Disturbingly, the cattle industry has codified, via the AVMA’s Guidelines, limiting consumer transparency around depopulation events, even using law enforcement if needed, stating (p. 33):



Efforts should be made to shield depopulation activities from being easily observed by the public. When appropriate, especially for large-scale depopulation events, the use of law enforcement to protect boundaries and maintain public safety is advisable. When possible, trained communicators such as designated public information officers should be tasked with leading communication with the media and general public.



During poultry facility outbreaks, the need for rapid mass killing of birds to prevent disease spread was cited as a major reason ventilation shutdown plus (VSD+) became an increasingly common method of mass killing. The killing method involves sealing up buildings and pumping in heat until the birds inside die and usually takes several hours



The AVMA listed VSD+ as a method of killing in “constrained circumstances,” under industry pressure, which allowed corporations to receive taxpayer-subsidized indemnity payments when their animals were killed using this method. This policy meant companies had no financial incentive to put plans in place to end the lives of their animals in less cruel ways—these less cruel methods are compiled in this table by the Animal Welfare Institute. 



In 2022, the National Association of State Departments of Agriculture (NASDA) urged "APHIS to conduct [a] scientific review on VSD+ as one of the preferred depopulation methods to rapidly eradicate highly contagious diseases," which would make heatstroke-based killing even more prevalent than it already is. 


More than 2,000 veterinarians have signed onto
Veterinarians Against Ventilation Shutdown to ask the American Veterinary Medical Association to reclassify heatstroke-based killing as a “not recommended” form of depopulation. Unfortunately, the AVMA has failed to act with a sense of urgency, and three years later, there has been no change. The AVMA retaliated against member veterinarians advocating to reclassify VSD+, banning them from attending the AVMA’s Cargill-sponsored Humane Endings Symposium and even implying they posed a threat. A Veterinary Information News article states:


Dr. Gail Golab, AVMA associate executive vice president and chief veterinary officer, said some outspoken critics were refused admission so that attendees, including those who raise livestock (known as producers), could share their experiences using depopulation methods without fear of reprisal. "It is absolutely critical that people feel very comfortable and that they're able to have candid and open conversations about the methods and about their application," Golab said in an interview during the three-day meeting. 



Meanwhile, non-veterinarian and self-proclaimed “bacon-activist” Jeff Pigott of the National Pork Producers Council was able to attend



Timeline of events:



On March 16th, 2024 the Texas State Veterinarian sent out the following letter:



To whom it may concern,


The Texas Animal Health Commission (TAHC) is aware of an animal health situation affecting dairy cattle. TAHC is working closely with the U.S. Department of Agriculture (USDA) to further monitor and evaluate reported cases.



Clinical signs include decreased herd level milk production; acute sudden drop in production with some severely impacted cows experiencing thicker, concentrated, colostrum like milk; decrease in feed consumption with a simultaneous drop in rumen motility; abnormal tacky or loose feces, and some fever.



Impacted herds have reported older cows in mid-lactation may be more likely to be severely impacted than younger cows and fresh cows or heifers. Dry cows and heifers do not appear to be affected. In addition, some herds have reported pneumonia and clinical mastitis cases as secondary sequelae.



The TAHC, USDA, Texas A&M Veterinary Diagnostic Laboratory (TVMDL), and dairy veterinarians, along with other partners, are working closely to coordinate an efficient plan to monitor and evaluate affected dairy cattle, develop a case definition, and conduct additional diagnostics.



A strong emphasis on enhanced biosecurity measures is encouraged. As monitoring and evaluation is underway, limiting people on and off premises and prioritizing diligent biosecurity practices is critical. When more information is available, additional guidance regarding preventative measures at the dairy level will be shared.



As outlined within the Pasteurized Milk Ordinance, normal and best practice dictates that milk appearing to be abnormal should be diverted from the salable milk supply. Additionally, the federal meat inspection act requires an antemortem and postmortem examination of every animal presented for slaughter to ensure safe and wholesome products enter the food chain.



We encourage veterinary practitioners to report affected animals to the TAHC Amarillo region office, 806-354-9335, or TVMDL-Canyon, 806-651-7478. Data driven diagnostics are key to the etiological and epidemiological evaluations, in turn unveiling crucial understandings of prevention methods. Veterinarians may call Dr. Alexis Thompson at TVMDL-Canyon, 806-651-7478, to make case specific diagnostic plans and receive guidance on sample collection. Collection of EDTA whole blood, serum, feces, urine, and milk from sick and paired healthy animals from the same herd may be advised. Veterinarians should collect and document detailed production information on the affected dairy cattle.

Updated information regarding the situation and case definition will be provided along with next steps. We encourage checking the TAHC website, https://www.tahc.texas.gov/, for situational updates and additional guidance as more information becomes available.


On March 17th, 2024 the American Veterinary Medical Association sent the following email to members of the House of Delegates:

We are providing information about a situation that has occurred on dairy farms in Texas and potentially other parts of the southwest. AABP leadership is currently engaged in discussions with local veterinarians and diagnostic laboratories. We will do our best to keep all of you updated. We very much appreciate our collaboration with the AABP as we work together to gather and disseminate good information. 



Unfortunately, there is a significant amount of misinformation being circulated.  It is important that veterinarians not become part of disseminating this misinformation and that we rely on official statements from diagnostic laboratories and individuals directly involved in managing this disease event. 



Veterinarians are on the front-lines of preventing the spread of disease, so we ask that each of you please review this email in the event that you observe, or your clients report, these clinical signs. The clinical case presentation that has been reported is: 



1. Sudden reduction in feed intake with decreased ruminations evident on physical exam and rumination monitors.



2. Sudden decrease in milk production on a herd level. Individual cows that are more severely affected have milk that is yellow and concentrated with the appearance of colostrum.


3. Variations in manure consistency with the most common finding being tacky to dry manure, although some cows appear to have diarrhea



4. Secondary infections such as pneumonia and mastitis.

The affected cases appear to be in lactation 2 or greater animals that are more than 150 days in milk. Calves, heifers, and dry cows appear not to be affected. Morbidity is around 10% of the animals. Cases present over a 7-10 day time period and the first herds report a return to near normal production in 3 weeks. Mortality is very low, however individual cows who do not return to production are being culled. Diagnostic labs that have received submissions have not identified an etiology.  Investigations are ongoing. 



We are making all of you are aware so that you have correct information and not misinformation. If you happen to see cattle fitting the above case description, we encourage you to immediately address it with your clients and submit samples to your diagnostic laboratory. The American Association of Veterinary Laboratory Diagnosticians (AAVLD) has been notified, and the AABP and diagnosticians are working together closely, with AVMA also supporting this effort. 



It is important to submit a complete set of samples to the laboratory. This should include red top and purple top blood, feces, urine and milk from at least 10 affected and 10 non-affected animals. The negative control samples are critically important to be able to identify a causative agent. If there are any animals that can be sacrificed, a complete necropsy should be performed with submission of all tissues to the diagnostic laboratory, both fixed and fresh, along with a complete case description. Please contact your veterinary diagnostic laboratory prior to sample collection to make sure that there are no additional samples recommended and for assistance with collection of samples, preservation, and shipping.


We will continue to provide timely updates regarding this disease event as new information surfaces.  Please be vigilant for these signs and perform the appropriate diagnostics if these signs are observed.”


On March 20, 2024 The American Association of Bovine Practitioners (AABP) sent to its membership a description of an unknown cause of increased morbidity on dairies in Texas, with the Panhandle region most severely affected.



Case definition that has been reported:



**Please be advised that there are variables to these clinical signs, and more information is still being collected.**



1. Increased dairy cattle morbidity in affected herds has been going on for several weeks and seems to be clustered in the Texas Panhandle. There have been no cases reported in Wisconsin at the time of this post release.



2. The signalment of affected cattle has a strong link to 2nd lactation and older animals with cattle in the >150 days in lactation to be most affected. Practitioners working with these herds are estimating that 5-10% of the herd is affected. Fresh heifers and transition cows are not affected, low but not zero prevalence in these groups. Dry cows, steers, and young stock are not reported to have morbidity. There are NO reports of high mortality events, but the cows that do not recover in milk production are reported to be culled.



3. Affected sick cattle present with anorexia and poor rumen motility as noted on physical examination or with rumination monitors. This is followed by a significant milk drop. Evaluation of milk is described as thicker in viscosity (visually consistent with the appearance of colostrum) and is trace CMT positive, but there are no other signs of mastitis. No etiological agents have been detected at this time on milk evaluation. Cattle are also presenting with hypomotility of the rumen and GI tract, fecal consistency is variable, and the most common report is not diarrhea, but rather constipation. There are also reports of secondary infections including pneumonia and mastitis. Diagnostic labs that have received submissions have not identified an etiology. Investigations are ongoing to attempt to identify the etiology.


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