This resource was originally published on March 29, 2024. It was most recently updated on December 17, 2024.

Check Back For Updates
This is an evolving situation. We’ll be updating this resource weekly and will indicate when it was last updated above.

Update September 16, 2024 – HPAI Detections In Humans
Infections of avian influenza in humans have been detected in countries worldwide. For a report from the World Health Organization, as well as regularly updated “situation reports,” you can check out this page. For updates specific to the United States, you can check out the Center For Disease Control’s Avian Influenza page here.

Introduction

In 2024, two years after the current outbreak of highly pathogenic avian influenza (HPAI) began in farmed bird species in the U.S., cases of HPAI began to be detected in mammalian farmed animal species. These detections have understandably worried caregivers who want to do all they can to protect their residents. This is an evolving situation, and so, unfortunately, there is still much we do not know. In this resource, we’ll do our best to answer some of the questions that are coming up as a result of these detections. We will update reports of ongoing detections in the toggle box above, and provide additional guidance as information develops. You can also keep track of ongoing detections of HPAI in mammalian farmed animal species at the USDA’s site dedicated to the subject here.

What Is Highly Pathogenic Avian Influenza?

Avian influenza refers to infection caused by avian influenza Type A viruses. Virus strains are categorized as highly pathogenic avian influenza (HPAI) or low pathogenic avian influenza (LPAI). These designations refer to how the virus affects chickens and other farmed bird species. Most Type A influenza viruses are low pathogenic, found worldwide, and can frequently be found in apparently healthy migrating waterfowl and shorebirds. In domesticated birds, low pathogenic AI viruses typically have low morbidity and mortality rates. HPAI, however, carries a high morbidity and mortality rate.

Highly pathogenic Eurasian H5 avian influenza was detected in wild birds in the U.S. in early 2022 after not being detected in a wild bird in the United States since 2016, and shortly afterward, HPAI was detected at a commercial turkeyUnless explicitly mentioned, we are referring to domesticated turkey breeds, not wild turkeys, who may have unique needs not covered by this resource. farm. Since the start of the current outbreak, all fifty states have had confirmed cases of HPAI in wild and/or domesticated birds. For more information on current cases, please refer to the USDA APHIS website.

Where Can I Find Your Existing Advice On HPAI In Birds?

You can learn more about HPAI in birds in our full resource on the subject here. If you need a quick refresher or some easily digestible information, you can find our FAQ on the subject here. For infographics that you can use at your sanctuary to remind staff and volunteers of precautions you should take, you can find those here.

What Are The Recent Developments With HPAI In Mammalian Farmed Animal Species In The U.S.?

As of this writing, there have been reports of HPAI in domesticated ruminants, camelids, and pigs. The vast majority of cases have been in cows, and all of the detections in cows have been at dairy operations. Because of this, almost all of the available information pertains to “dairy cows.” Testing indicates that the virus affecting cows is the same virus responsible for the ongoing outbreak in birds (H5N1, Eurasian lineage goose/Guangdong clade 2.3.4.4b).

While these are the first reported cases in mammalian farmed animal species in the U.S., they are not the first cases in mammals. Since 2022, the USDA has tracked hundreds of detections of HPAI in mammals (these detections have been almost entirely in wild species, but domesticated cats have also been affected). You can read more about HPAI detections in wild mammalian species here, and check out CDC guidance for veterinarians handling and evaluating potentially exposed domesticated cats here.

What Do We Know About HPAI In Cows?

As we mentioned above, almost all of the cases in mammalian farmed animal species in the U.S. have been in “dairy cows,” and therefore we know more about how HPAI seems to affect them than the other species that have been affected. Cows with HPAI may develop a poor appetite, lethargy, dehydration, fever, and abnormal feces that is tacky or loose. In lactating cows, clinical signs include a sudden drop in milk production, and more severely affected cows produced colostrum-like milk that was thick and discolored. According to the American Veterinary Medicine Association (AVMA), in affected herds, clinical signs have been reported in less than 10% of the cows, and most affected cows have reportedly recovered with supportive care. 

Affected cows shed the virus in large quantities in their milk. While it was initially believed that cow-to-cow transmission was not likely, the USDA announced evidence of cow-to-cow transmission on March 29, 2024, which the AVMA stated at the time was likely through mechanical means. As of November 11, 2024, there have been close to 500 confirmed cases in 15 states. Aside from the initial “spillover event” in which the virus spread from wild birds to cows, there is currently no genomic or epidemiologic evidence that wild birds are spreading H5N1 to cows. However, according to the USDA’s epidemiological brief updated on June 8, 2024, this possibility cannot be ruled out. 

In addition to transmitting the virus to other cows, infected cows can spread the virus to birds and other mammals (including humans – more on this below). Cats are a species that were previously known to be susceptible to HPAI, and the CDC has reported that at affected dairies, cats who drank unpasteurized infective milk and colostrum developed fatal systemic infections. While ingestion of deceased infected wild birds cannot be ruled out as the cause of infection, evidence suggests spread between cows and cats. Researchers have also found that mice and ferrets can be infected by drinking raw milk from infected cows. Additionally, current evidence suggests that the virus has spread from premises with affected cows to premises with farmed bird species, likely due to the movement of humans, vehicles, etc.

What Do We Know About HPAI In Other Domesticated Ruminant Species?

Currently, there has only been one group of goats confirmed to have been affected in the U.S., and there have not been any reports in sheep. These goats lived on the same premises as birds who tested positive for HPAI and shared a water source with them. Newborn kids who were born just days after the birds on the property had been killed as part of regional control efforts were most severely affected. Ten goat kids, ranging from 5-9 days old, died and were confirmed to be positive for HPAI. According to the USDA, affected goat kids developed neurological signs including incoordination, seizures, blindness, inability to stand, and difficulty nursing. Only half of the kids tested for HPAI were positive, suggesting other factors may have played a role in the disease. Adult goats on the property tested negative for HPAI.

What Do We Know About HPAI In Camelids?

As with goats, currently, there has only been one group of camelids confirmed to have been affected by HPAI, and this occurred in a group of alpacas living on the same premises as infected birds. According to the Center for Infectious Disease Research & Policy (CIDRAP), only 4 of 18 alpacas tested positive for HPAI, and it appears there were no mortalities. Affected alpacas showed signs of weakness, depression, nasal discharge, and other mild respiratory signs, and also experienced abortions/stillbirths.

What Do We Know About HPAI In Pigs?

As with goats and alpacas, there has only been one group of pigs confirmed to have been affected by HPAI. These individuals were living on the same premises as birds who tested positive for HPAI, and they shared a water source with them. Current reports indicate that the pigs were not showing any signs of illness and only two of the five tested positive for HPAI. According to the USDA, the amount of virus in the samples collected from the infected pigs was low and, as a result, the lab was only able to extract partial genomic sequences from one sample. Based on genomic sequencing, the USDA says it is likely that the pigs (and farmed birds) on this property became infected after coming into contact with wild migratory birds.

Can Mammalian Farmed Animals Spread HPAI To Humans?

On April 1st, 2024, the CDC reported that a human had contracted HPAI from a cow in Texas. Currently, the CDC has reported multiple human cases related to the current outbreak in cows. To keep abreast of the CDC’s monitoring of the current HPAI situation in humans, you can check out this site. So far, all of the human HPAI cases related to the outbreak in cows have been in dairy workers who had direct contact with infected cows. While three of the first four cases presented as eye infections, one of the humans affected developed respiratory symptoms more typical with influenza. In addition to human cases from exposure to infected cows, there have been cases of bird-to-human transmission globally, with a number of cases in the U.S. in 2024 that occurred following exposure to “poultry.” In September 2024, a human case of HPAI was reported in an individual who had no known animal exposure. 

What Legal Measures Are Being Implemented To Control The Spread Of HPAI?

We Don’t Yet Know How Pigs Might Be Affected By Legal Measures To Control The Spread Of HPAI
According to the USDA, all of the five pigs in Oregon were killed “to facilitate additional diagnostic testing.” We don’t know if this will be the standard response should there be additional cases in pigs. If and when more information comes to light, we will be sure to update this section accordingly.

Thus far, in the U.S. the federal government’s policy in response to the detection of HPAI in farmed bird species has been the mandatory killing of all farmed birds on affected premises (“depopulation”). Exceptions have been made in certain cases involving “exotic” birds, often in “zooAn organization where animals, either rescued, bought, borrowed, or bred, are kept, typically for the benefit of human visitor interest.” contexts. With respect to farmed birds, there have also been some exceptions to this general federal policy in certain states based on the distinctions that a particular state may draw between “companion” birds versus “poultry.” Please note that when it comes to birds, these exceptions have been few and far between, and cannot be counted upon to protect your avian residents in the event that HPAI is detected in your area. To get an overview of the complexities of overlapping federal and state law, you can review our resource on HPAI and the law, which you can find here.

In contrast to the response that the USDA mandates for birds, its response to detections of HPAI in domesticated ruminants and camelids has been very different. The USDA has stated they “do not anticipate the need to depopulate dairy herds.” Instead, policy thus far appears to involve a combination of requiring testing prior to interstate transport of “dairy cows,” as well as an opt-in program for dairy farm operators so that the USDA can learn more about the virus and how it affects “dairy cows.” 

On April 25, 2024, the USDA issued a Federal Order Requiring Testing for and Reporting of Highly Pathogenic Avian Influenza (HPAI) in Livestock. An FAQ summarizing the requirements of this order is available here. In essence, it requires testing of “lactating dairy” cows for HPAI prior to any interstate travel. If they receive a negative test result, that result is valid for seven days, and the cows may receive a Certificate of Veterinary Inspection (CVI), allowing them to travel interstate during that window.

In guidance clarifying this order, the USDA specified that “dairy cows” are those who are raised for the primary purpose of milk production. “Lactating” means that the cows are in one of the “lactation phases” (early, mid, or late) of their “production cycle.”

Testing prior to travel must be done by an approved National Animal Health Laboratory Network (NAHLN) laboratory. Any positive results must be reported by labs and by state veterinarians to the USDA, and the “owners” of these cows must also submit epidemiological and tracing information about them. Cows who have tested positive cannot be moved interstate unless they have completed a 30-day waiting period, and then been re-tested with negative results.

These requirements do NOT apply to the intrastate transport of cows, which is governed by state-specific regulations. Please note that individual states are also beginning to impose additional import requirements for cows from out-of-state which may apply to non-lactating cows. As always, we recommend checking in with state officials before conducting interstate transports to make sure you are aware of and in compliance with the current requirements.

On May 30, 2024, the USDA announced that it was also setting up a Voluntary H5N1 Dairy Herd Status Pilot Program which would offer an alternative to the mandatory testing required by the Federal Order issued in April. Under this program, “owners” with herds that tested negative for three weeks in a row are then only required to conduct weekly tests on bulk milk from their herds, and can then transport their cows as they prefer without additional individual testing. 

On October 30, 2024, the USDA announced it is planning to enhance testing and monitoring for H5N1. We will update the above information as those enhancements are announced. 

What Does All This Mean For Sanctuaries?

There is still much we do not know, but what is clear is that HPAI continues to be a major threat. While it is certainly concerning that mammalian farmed animal species are now being affected, it’s important to remember that farmed bird species face a two-pronged threat from this disease. Not only are they at risk from the disease itself (which carries a high mortality rate in birds such as chickens and turkeysUnless explicitly mentioned, we are referring to domesticated turkey breeds, not wild turkeys, who may have unique needs not covered by this resource.), but they are also at risk of regional efforts to control disease spread via the compulsory killing of birds on an affected premises (for more information on the legal implications of an HPAI detection in domesticated birds on your property, check out our comprehensive resource here, or you can find our FAQ on the subject of HPAI and the law here). Given the significant risk to farmed bird species, caregivers must continue to take appropriate steps to protect their avian residents (which you can read more about here). These recent developments indicate that we now have to also consider the possibility of newly rescued mammalian residents bringing HPAI onto sanctuary grounds, though current evidence suggests that lactating cows pose the biggest risk. In addition to the risk of the virus being spread to your avian residents and causing serious illness or the virus being spread to humans at the sanctuary, we simply don’t know what a positive detection in a mammalian sanctuary resident would mean for avian residents on the property (in terms of government response).

Epidemiological investigations in Michigan suggest that transmission between dairies and poultry facilities is likely due to the movement of people, vehicles, etc. Therefore, sanctuaries also have to consider the risk of the virus being brought into sanctuary spaces by humans, vehicles, etc. that travel to other places that house farmed animalsA species or specific breed of animal that is raised by humans for the use of their bodies or what comes from their bodies..

What Should Sanctuaries Do To Protect Their Residents?

Given that this is still a developing situation, one of the most important things to do is to stay informed. We recommend watching for updates from the USDA, AVMA, and your state’s board of animal health. Additionally, we recommend contacting your veterinarian for more information. They will likely be your best source of information and can offer more specific guidance as the situation develops based on the specifics of your sanctuary and your region. You can also pay attention to the CDC’s National Wastewater Surveillance System, which collects and displays data on detections of Influenza A in wastewater. Current monitoring methods cannot differentiate between H5N1 and other influenza A virus subtypes and also cannot determine the source of the virus, but this surveillance program might alert you to the fact that influenza A has been found in your area, in which case it might be wise to ramp up your biosecurityMerck Veterinary Manual defines biosecurity as ”the implementation of measures that reduce the risk of the introduction and spread of disease agents [pathogens].” measures.

We encourage sanctuaries to revisit their biosecurity plan (or to create one if they haven’t already). If you care for birds, you absolutely need to be taking steps to protect your residents. If your animal sanctuary is located in an area where avian influenza is currently a concern (in birds or other species), keeping detailed, accurate records of the steps you’re taking to prevent its spread at your organization is critical, should the virus be detected nearby. To help organizations stay organized in their HPAI recordkeeping, we’ve developed a simple spreadsheet with sections for some of the key tasks caregivers must perform to keep their avian residents safe. Check out our HPAI biosecurity plan and checklist for more information on these strategies!

In addition to preventing direct and indirect contact between wild and domesticated birds, if you currently house avian and mammal species together (or if you give them separate access to the same spaces), we recommend you take immediate steps to house them separately. As mentioned above, the cases in goats, alpacas, and pigs all occurred at premises in which these species shared space with affected birds.

While there is currently no evidence that wild birds are spreading H5N1 to cows (aside from the initial “spillover event”), it does appear likely that the case in pigs was due to contact with infected migratory birds. While it’s unlikely that sanctuaries can prevent all direct and indirect contact between their mammalian residents and wild birds, it’s a good idea to look at your current practices and see if there are things you can do to lessen this exposure. For example, consider if there are ways you can protect drinking water and food from possible contamination from wild birds. Even if you can’t fully exclude wild birds, perhaps you can take steps to lessen the risk. For example, if you have a water trough under a tree, perhaps you can move it to another area where wild birds are less likely to congregate (and possibly defecate in the water). Ponds and other natural bodies of water are potential sources of exposure, so it’s wise to restrict your residents’ access to these water sources. If your area sees a lot of migratory birds coming through at certain times, you may want to take additional measures to protect your residents during these higher-risk times.

To reduce the risk of a new resident bringing HPAI to your sanctuary, we recommend reviewing your intake and quarantine protocols with your veterinarian to see if you need to make any changes. Depending on where you are located, this may mean seriously considering temporarily suspending intake. 

The case in goats suggests that very young neonates may be most vulnerable, but without knowing more about the care these goat kids received (for example, did they receive colostrum, were they born into a clean environment, did they receive immediate veterinary care, etc.), it’s hard to know what other factors may have contributed to the development of disease. That said, when it comes to resident health, we always suggest erring on the side of caution, so if you rescue a neonatal mammalian resident or are caring for pregnant individuals, we recommend talking to your veterinarian about additional measures you can implement to reduce the chance of vulnerable babies being exposed to HPAI. Because milk from infected cows contains HPAI virus, it’s important to think carefully about the milk/milk replacer you feed babies at your sanctuary to avoid potential exposure. Current evidence indicates that pasteurization inactivates the virus.

What Can Sanctuaries Do To Protect Humans?

The CDC continues to say that the risk to humans is low but acknowledges that folks who work closely with “poultry” and “livestockAnother term for farmed animals; different regions of the world specify different species of farmed animals as “livestock”.” may be at an increased risk of exposure to HPAI. We recommend sanctuaries consult with their veterinarian regarding measures to implement to protect their personnel and other humans coming into sanctuary spaces. At a minimum, folks should observe careful hygiene (including handwashing) and should wear PPE when working with residents who are showing signs of illness, as well as when working with newly rescued residents. We always recommend keeping visitors away from sick and quarantined residents, but this is even more critical now. 

You can review the CDC’s interim recommendations for preventing exposure here and their updated guidance for worker protection here.

Pertinent Resources From The Open Sanctuary Project:

Advanced Topics In Resident Health: Avian Influenza (Vet Reviewed)

Avian Influenza FAQ 

Avian Influenza Infographic

Highly Pathogenic Avian Influenza: Your Sanctuary And The Law

Highly Pathogenic Avian Influenza And The Law: FAQ For Animal Sanctuaries And Rescues

HPAI Record-Keeping Template

HPAI Biosecurity Plan & Checklist

Biosecurity Part 2: Creating And Implementing A Biosecurity Plan

Establishing Safe And Effective QuarantineThe policy or space in which an individual is separately housed away from others as a preventative measure to protect other residents from potentially contagious health conditions, such as in the case of new residents or residents who may have been exposed to certain diseases. And IsolationIn medical and health-related circumstances, isolation represents the act or policy of separating an individual with a contagious health condition from other residents in order to prevent the spread of disease.  In non-medical circumstances, isolation represents the act of preventing an individual from being near their companions due to forced separation. Forcibly isolating an individual to live alone and apart from their companions can result in boredom, loneliness, anxiety, and distress. Protocols For Your Animal Sanctuary

SOURCES:

Highly Pathogenic Avian Influenza (HPAI) Detections in Livestock | United States Department Of Agriculture (Non-Compassionate Source)

Detections of Highly Pathogenic Avian Influenza | USDA APHIS (Non-Compassionate Source)

Avian Influenza | World Organisation For Animal Health (Non-Compassionate Source)

Detection Of Highly Pathogenic Avian Influenza In Dairy Herds: Frequently Asked Questions | U.S. Department of Agriculture (Non-Compassionate Source)

Avian Influenza Virus Type A (H5N1) In U.S. Dairy Cattle | American Veterinary Medical Association (Non-Compassionate Source)

Avian Flu Detected For First Time In US Livestock | Center for Infectious Disease Research & Policy  (Non-Compassionate Source)

Current H5N1 Bird Flu Situation in Dairy Cows | Centers For Disease Control And Prevention (Non-Compassionate Source)

Federal Order Requiring Testing for and Reporting of Highly Pathogenic Avian Influenza (HPAI) in Livestock | USDA/APHIS (Non-Compassionate Source)

Federal Order to Assist with Developing a Baseline of Critical Information and Limiting the Spread of H5N1 in Dairy Cattle: Frequently Asked Questions  | USDA/APHIS (Non-Compassionate Source)

Clarification to Inquiries Received on April 24 Federal Order | USDA/APHIS (Non-Compassionate Source)

USDA Announces $824 Million in New Funding to Protect Livestock Health; Launches Voluntary H5N1 Dairy Herd Status Pilot Program | USDA/APHIS (Non-Compassionate Source)

U.S. Case of Human Avian Influenza A(H5) Virus Reported | Centers For Disease Control And Prevention (Non-Compassionate Source)

Highly Pathogenic Avian Influenza A (H5N1) Virus Infection Reported in a Person in the U.S. | Centers For Disease Control And Prevention (Non-Compassionate Source)

Technical Report: Highly Pathogenic Avian Influenza A(H5N1) Viruses | Centers For Disease Control And Prevention (Non-Compassionate Source)

Updated as of June 8, 2024 1 Highly Pathogenic Avian Influenza H5N1 Genotype B3.13 in Dairy Cattle: National Epidemiologic Brief | USDA APHIS (Non-Compassionate Source)

Page 1 of 10 2024 Highly Pathogenic Avian Influenza (H5N1) – Michigan Dairy Herd and Poultry Flock Summary | USDA APHIS (Non-Compassionate Source)

Delegates Updated On HPAI Response | AVMA News (Non-Compassionate Source)

H5N1 Highly Pathogenic Avian Influenza (HPAI) In Livestock Information For Small Ruminant (Sheep And Goat) And Camelid Stakeholders | USDA APHIS (Non-Compassionate Source)

More Evidence Pasteurization Inactivates H5N1 Avian Flu Virus In Milk | CIDRAP (Non-Compassionate Source)

CDC Reports Fourth Human Case of H5 Bird Flu Tied to Dairy Cow Outbreak | CDC News Room (Non-Compassionate Source)

Colorado Reports Three Presumptive Positive H5 Cases in Poultry Workers | CDC News (Non-Compassionate Source)

Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Virus Infection In Domestic Dairy Cattle And Cats, United States, 2024  | Emerging Infectious Diseases, Volume 30 (Non-Compassionate Source)

How CDC Is Monitoring Influenza Data Among People To Better Understand The Current Avian Influenza A (H5N1) Situation | CDC (Non-Compassionate Source)

Testing Transmission And Infection Of H5N1 From Cows | National Institutes Of Health (Non-Compassionate Source)

USDA Announced First U.S. H5N1 Avian Flu Detection In US Pigs | CIDRAP (Non-Compassionate Source)

USDA Builds on Actions to Protect Livestock and Public Health from H5N1 Avian Influenza | USDA (Non-Compassionate Source)

USDA Animal And Plant Health Inspection Service Shares Update On H5N1 Detection In Oregon Swine, Bovine Vaccine Candidate Progression | USDA APHIS (Non-Compassionate Source) 

Non-Compassionate Source?
If a source includes the (Non-Compassionate Source) tag, it means that we do not endorse that particular source’s views about animals, even if some of their insights are valuable from a care perspective. See a more detailed explanation here.