HPAI Found in Kansas, Texas Dairy Herds

WASHINGTON, March 25, 2024 – The U.S. Department of Agriculture (USDA), Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC), as well as state veterinary and public health officials, are investigating an illness among primarily older dairy cows in Texas, Kansas, and New Mexico that is causing decreased lactation, low appetite, and other symptoms.

As of Monday, March 25, unpasteurized, clinical samples of milk from sick cattle collected from two dairy farms in Kansas and one in Texas, as well as an oropharyngeal swab from another dairy in Texas, have tested positive for highly pathogenic avian influenza (HPAI). Additional testing was initiated on Friday, March 22, and over the weekend because farms have also reported finding deceased wild birds on their properties. Based on findings from Texas, the detections appear to have been introduced by wild birds. Initial testing by the National Veterinary Services Laboratories has not found changes to the virus that would make it more transmissible to humans, which would indicate that the current risk to the public remains low.

Federal and state agencies are moving quickly to conduct additional testing for HPAI, as well as viral genome sequencing, so that we can better understand the situation, including characterization of the HPAI strain or strains associated with these detections.

At this stage, there is no concern about the safety of the commercial milk supply or that this circumstance poses a risk to consumer health. 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. In addition, pasteurization has continually proven to inactivate bacteria and viruses, like influenza, in milk. Pasteurization is required for any milk entering interstate commerce.

Federal agencies are also working with state and industry partners to encourage farmers and veterinarians to report cattle illnesses quickly so that we can monitor potential additional cases and minimize the impact to farmers, consumers and other animals. For the dairies whose herds are exhibiting symptoms, on average about ten percent of each affected herd appears to be impacted, with little to no associated mortality reported among the animals. Milk loss resulting from symptomatic cattle to date is too limited to have a major impact on supply and there should be no impact on the price of milk or other dairy products.

This is a rapidly evolving situation, and USDA and federal and state partners will continue to share additional updates as soon as information becomes available. More information on biosecurity measures can be found here.

Below, you can read a joint statement of all the dairy organizations on the news of HPAI in Kansas and Texas dairy herds:

Joint Dairy Organization Statement on Highly Pathogenic Avian Influenza in Cows

ARLINGTON, VA  Statement from the National Milk Producers Federation (NMPF), the International Dairy Foods Association (IDFA), the U.S. Dairy Export Council (USDEC) and Dairy Management Inc. (DMI)

Earlier today, the U.S. Department of Agriculture confirmed highly pathogenic avian influenza (HPAI) in two dairy cattle herds in Texas and two herds in Kansas.

Importantly, USDA confirmed that there is no threat to human health and milk and dairy products remain safe to consume. Pasteurization (high heat treatment) kills harmful microbes and pathogens in milk, including the influenza virus.

Also, routine testing and well-established protocols for U.S. dairy will continue to ensure that only safe milk enters the food supply. In keeping with the federal Grade “A” Pasteurized Milk Ordinance (PMO), milk from sick cows must be collected separately and is not allowed to enter the food supply chain. This means affected dairy cows are segregated, as is normal practice with any animal health concern, and their milk does not enter the food supply.

Consumers in the United States and around the world can remain confident in the safety and quality of U.S. dairy.

Enhanced Biosecurity Protocols Underway on U.S. Dairy Farms

As information related to an illness affecting dairy cows in several states began to circulate over the past two weeks, USDA’s Animal and Plant Health Inspection Service (APHIS) worked with state veterinary authorities as well as federal partners including the FDA to swiftly identify and respond to detections and mitigate the virus’ impact on U.S. dairy production. Dairy farmers also have begun implementing enhanced biosecurity protocols on their farms, limiting the amount of traffic into and out of their properties and restricting visits to employees and essential personnel. Avian influenza is an animal health issue, not a human health concern. Importantly, mammals including cows do not spread avian influenza—it requires birds as the vector of transmission and it’s extremely rare for the virus to affect humans because most people will never have direct and prolonged contact with an infected bird, especially on a dairy farm. As a precaution, dairy farmers are taking important measures to protect their workers.

The National Dairy FARM Program (NDFP) offers several valuable biosecurity resources providing dairy farmers with tools to keep their cattle and dairy businesses safe, including:
Everyday Biosecurity Reference Manual
Enhanced Biosecurity Prep Guide 
Herd Health Plan Protocol Template – Biosecurity
Animal Movement Log
People Entry Log

Biosecurity practices guidance is available here.

Dairy farmers who observe clinical signs in their herd consistent with this outbreak, such as a significant loss of animal appetite and rumination or an acute drop in milk production, should immediately contact their veterinarian. Veterinarians who observe these clinical signs and have ruled out other diagnoses on a client’s farm should contact the state veterinarian and plan to submit a complete set of samples to be tested at a diagnostic laboratory.

What is Pasteurization? 

Pasteurization is a process that kills harmful bacteria and pathogens, including viruses, by heating milk to a specific temperature for a set period of time. The processing of milk products involves pasteurization of the raw milk to a minimum of 161.5?F for 15 seconds and then immediately cooling it. Ultra pasteurization is a process that heats milk at a higher temperature for specified times to extend a product’s shelf life.

What is Avian Influenza? 

Detections of avian influenza in birds, including chickens, are common in the United States in the spring and fall due to wild birds spreading the virus as they migrate to and from their seasonal homes. While it is uncommon for Highly Pathogenic Avian Influenza to affect dairy cows, USDA APHIS has been tracking detections of HPAI in mammals for many years in the United States, leading dairy farmers and veterinarians in the United States to prepare for this eventuality. As a result, dairy farmers have taken immediate measures to enhance biosecurity measures in and around dairy farms to keep the food supply safe.

About the Illness in Cows

Dairy producers with affected cows are reporting a rapid onset illness in herds, specifically among older, lactating cows. Clinical signs include:

  • Decreased herd level milk production
  • Acute sudden drop in production
  • Decrease in feed consumption
  • Abnormal feces and some fever
  • Older cows may be more likely to be severely impacted than younger cows

According to dairy farmers and veterinarians reporting on affected herds, most affected cows recover within two to three weeks.

Information for Affected Producers 

Producers who believe dairy cattle within their herd are showing the clinical signs described above should report these signs immediately to state veterinarians. Animals may also be reported to APHIS’ toll-free number at 1-866-536-7593.

Trade and Exports

The U.S. dairy industry will continue to work with the U.S. federal government, trading partners and the World Organization for Animal Health (WOAH) to encourage adherence to WOAH standards and minimize all unnecessary or unfair trade impacts. It is essential that trading partners do not impose bans or restrictions on the international trade of dairy commodities in response to these and future notifications and rely on the science-based food safety steps taken in U.S. dairy processing, namely pasteurization, in preserving market access.

Additional Information

  • To provide context on the overall size of the U.S. dairy herd, there are more 9.3 million dairy cows in the United States.
  • U.S. dairy export value was $8.11 billion in 2023, the second largest value on record.