California’s coordinated response to a virulent strain of bird flu that spilled into the state’s dairy herds drew praise from animal health officials, researchers and industry leaders at a recent Cal/OSHA Occupational Safety and Health Standards Board hearing. But worker advocates reiterated ongoing concerns over perceived safety violations and claims of inconsistent enforcement, warning the disease remains a high-risk threat for vulnerable dairy workers.
The informational hearing focused on lessons learned from last year’s devastating outbreak of highly pathogenic avian influenza among dairies and poultry operations. The virus was first detected in a California dairy last August and has since spread to more than 700 herds across the state, with about 170 active cases, and triggered the euthanasia of over 166 million birds.
Michael Payne, a veterinarian and academic coordinator at the University of California, Davis, described California’s response to the outbreak as “one of the best examples I can think of for a disease that affects both wildlife and humans and livestock” and that could serve as a template for other states.
The response — led by the California Department of Food and Agriculture, the California Department of Public Health and the Division of Occupational Safety and Health, or Cal/OSHA — rolled out rapidly last fall through a one health model, coordinating human, animal and environmental health interventions.
The centerpiece of the effort was an expansive public health campaign in Tulare County launched in October at the World Ag Expo pavilion. The training event focused on dairy herdsmen and featured presentations on disease transmission, personal protective equipment usage and paid sick leave rights.
“Workers were also informed at this meeting of their rights, their available testing sites and paid sick time,” said Anja Raudabaugh, CEO of Western United Dairies.
The outreach initiative resulted in the distribution of more than 4.6 million pieces of PPE statewide — including 800,000 respirators, 3.5 million gloves, 234,000 goggles and 230,000 face shields. PPE was distributed not only to dairy farms, but to poultry processors, dead animal haulers, milk truck drivers and feed mills. Western United Dairies said it delivered more than 2,400 PPE kits, with CDFA providing an additional 1,000 kits under the governor’s emergency order.
Virus circulation and spillover confirmed
According to Payne, the outbreak was traced to migratory waterfowl in Texas, where mutations allowed the virus to jump from birds to cattle in early 2024.
“Cattle that had the disease, that were not demonstrating symptoms, were transported from one state to another,” he said. “That's also the way that California received it from Idaho.”
While most infected cows showed symptoms like fever, loss of appetite and reduced milk production, some herds experienced mortality rates as high as 2.5% — especially during a severe October heat wave.
The virus eventually completed a transmission loop: “Originally, waterfowl gave it to cows, cows spread it to other cows, then cows gave it back to some flocks,” he said. “This is old news now, because more than 80% of all of those herds have been released from quarantine, and those few herds remaining are rapidly moving towards being released.”
Infected animals have been found across several species. Local sparrows, starlings and crows tested positive, and the virus was detected in houseflies, airborne dust and even in cats that drank raw milk. Thirty-eight human cases were confirmed in California — most leading to conjunctivitis or mild flu-like symptoms among dairy and poultry workers.
Anja Raudabaugh, Western United Dairies (photo: Brad Hooker/Agri-Pulse)“That's more than half of the total cases inside the United States,” said Payne, crediting CDPH for rigorous testing. “The reason for that is not because we have more people getting sick. It's because we look harder.”
Workers say PPE and safety protections were inconsistent
Despite the interagency campaign, labor advocates testified that many dairy workers lacked basic PPE or proper training during the outbreak.
Speaking through a Spanish translator, one Kings County dairy worker named Javier said he was tasked with cleaning milk tanks using acid without gloves, masks or safety gear and did not have a ladder to get out of the tank. He also described being shocked while fixing a water pump and told only to rest after regaining consciousness.
“Failing conditions not only put workers at daily risk but also create perfect environments for viruses like avian flu to thrive and spread,” said Lizbeth Vasquez, a representative from Valley Voices, a community-based organization that provided PPE and outreach to more than 100 dairies in Tulare and Kings counties.
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Jorge Luna Monterey, the worker rights program director at the organization, added that employers only provided the state-mandated five days of sick leave and did not offer time off for medical monitoring or testing.
Anne Katten, a policy advocate at the California Rural Legal Assistance Foundation, urged Cal/OSHA to acquire direct access to quarantine data to better target enforcement.
Cal/OSHA reported it conducted 54 random inspections at dairy facilities during the outbreak and found just two violations under its zoonotic disease standard. Board member Nola Kennedy expressed concern over the disconnect.
“We often hear comments from one side that will say, ‘We're doing a great job. Everything's good. We've got all these training programs in place and outreach efforts.’ Then we'll hear from another side that ‘We're not getting any protection,’” said Kennedy. “I'd like to understand the industry [viewpoint] a little better.”
Industry pushes back, emphasizes outreach
Raudabaugh responded to the testimony by calling the reported conditions “unacceptable.”
“I would like to know which dairy it is so I can root it out and fix it,” she said. “That is not an industry standard.”
She explained that Western United Dairies represents 86% of California’s dairy farms and worked with CDPH to conduct PPE distributions at public venues — such as churches, swap meets and libraries — to avoid biosecurity risks and immigration fears.
“We really tried to avoid going onto individual farms so that we did not contribute to the raid impression that is happening right now,” she said.
Bryan Little, senior director of policy advocacy at the California Farm Bureau, emphasized the industry’s extensive outreach.
“I've spent a lot of time on the phone talking with Anya about what they're doing,” said Little, noting that the farm bureau also held webinars with Cal/OSHA consultation and distributed H5N1 information through its Farm Employers Labor Service. “It's fair to say that if the need arises, we're prepared to do it again.”
Cal/OSHA Board Chair Joseph Alioto encouraged both Valley Voices and Western United Dairies to collaborate.
“There's obviously a disconnect,” said Alioto. “Maybe you all could have some discussion and try really hard to really understand each other's position, so that you might be able to work together to go after those folks who you both dislike.”
Federal cuts threaten disease surveillance and worker safety
While California agencies have maintained a robust response, experts warned that federal pullbacks could erode long-term preparedness.
Rachael Jones, director of the Center for Occupational and Environmental Health at the University of California, Los Angeles, told the board that the Centers for Disease Control has gutted the extramural research program at the National Institute for Occupational Safety and Health — cutting staff from 23 previously to one by July.
“It's extremely difficult to rebuild,” said Jones. “We are anticipating that … we will be laying off staff and possibly faculty in Southern California.”
Jay Smith, a corporate safety consultant, testified that NIOSH has been the backbone of national worker safety and “did an enormous amount of stuff,” with only 1,100 employees at the institute, making them “tremendously efficient — no waste, fraud and abuse there.”
What’s next?
CDFA has released most infected herds from quarantine, and officials say pasteurization protocols have largely stopped transmission through milk. CDPH continues statewide testing.
But advocates urged the board to strengthen Cal/OSHA’s oversight powers, require additional paid leave during outbreaks, and expand multilingual hotlines for anonymous worker complaints.
Alioto suggested the board’s new state response subcommittee may explore future regulatory changes.
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