Oregon dairy farmers, scientists keeping an eye on nationwide bird flu outbreak

CORVALLIS, Ore. — Oregon dairy farmers and scientists are keeping a close eye on their cows as avian flu spreads across the U.S. 

"The virus in cattle has been diagnosed in 9 states, one of which is on our border to the east in Idaho," said Doctor Kurt Williams, director of the Oregon Veterinary Diagnostic Laboratory at Oregon State University.

The USDA reports avian flu has infected 51 herds in 9 states. While the virus hasn't been detected in Oregon or Washington, dairy farmers are still required by the federal agency to test their cows before moving them across state lines. 

Williams runs the only lab in Oregon qualified to test cows for avian flu. They're part of The National Animal Health Laboratory Network. His lab conducted tests for avian flu over the last few years as it swept through poultry flocks and wild birds. 

"In especially domestic poultry, it's a devastating disease that can lead to the deaths — and has led to the deaths of tens of millions of poultry in the United States," Williams says. 

Avian flu was detected for the first time in a herd of cows in March. But Williams says the symptoms are different, and not as lethal. 

"People working with the cows noticed that the cows — their appetites were suppressed; milk production had dropped; that the character, both visual characteristics and the consistency of the milk, had changed," Williams explained. 

The FDA says traces of bird flu have been found in milk across the U.S. but that the virus is not live or infectious. 

"There's no reason to be alarmed at this juncture," Williams said. "We have great food safety systems in the United States. Pasteurization inactivates the virus, and so to me, I think that [consumers] need to feel very confident in picking up ice cream or a gallon of milk."

So far, all of the milk samples Williams and his team have tested came back negative for avian flu. But he adds he wouldn't be surprised to get a positive test in the future as the virus continues to spread and adapt. 

"If this issue with dairy cattle evolves in such a way that it becomes much more fluid, it's possible that we could end up having to test thousands and thousands of samples of milk," he said.

Williams says the diagnostic lab can conduct testing at a high volume. During the pandemic, technicians ran over 300,000 COVID-19 tests. 

"Knowledge is power, and we need to be tracking this virus and understanding its impact on the dairy industry but also the potential for other species, including our own and the public health implications," Williams said. 

Meanwhile, the Oregon Health Authority (OHA) is reminding people to not consume raw (unpasteurized) milk consumption amid the outbreak, saying there is risk for a variety of illnesses, such as E. coli and salmonella, and that raw milk can be easily contaminated. Pasteurization, OHA added, kills the H5N1 virus.