Tip Sheets

Avian flu in cattle: Cornell experts on what you need to know

Media Contact

Kaitlyn Serrao

For the first time, cows at dairy farms across the U.S. have tested positive for avian flu. The virus is believed to have spread to at least five states. The following Cornell University experts are available to discuss impacts and precautions.

Diego Diel

Associate Professor, Department of Population Medicine and Diagnostic Sciences

Diego Diel, professor of diagnostic sciences, says so far there seems to be a low transmission risk for humans.

Diel says:

We still don’t know about the ability of the virus to transmit from cow-to-cow or from cows to other animals and humans. While HPAI is a zoonotic agent, the strain of the virus that is circulating in wild birds since 2022 in North America and was now detected in cows seems to be of low risk to humans. However, this is an evolving situation, and we hope to learn more soon regarding transmission potential of the virus as public and animal health officials continue to investigate these outbreaks in dairy cows.

Sam Alcaine

Associate Professor, Food Science

Sam Alcaine, associate professor of food science, focuses on developing technologies that improve the quality, safety and potential applications of fermented dairy products and co-products.

Alcaine says: 

Several studies have demonstrated that influenza viruses, including HPAIV, are inactivated by heat. The legally required temperature and time requirements for milk pasteurization will readily inactivate HPAIV. While the risk of infection by respiratory viruses via ingestion is low, raw milk consumption is not recommended because unpasteurized milk has been associated with the contamination of other pathogenic organisms such as Salmonella, Listeria, E. coli, Campylobacter, Cryptosporidium, and Brucella.”

Aljoša Trmčić

Extension Associate, Dairy Foods Extension

Aljoša Trmčić studies the general microbiology of milk and dairy products. He explains why this virus is more sensitive than other food-borne viruses.

Trmčić says:

A virus grows and survives by hijacking the cellular machinery of a host to produce more viruses; outside of the host there is no machinery they can use. Only the virus that can effectively transfer from one host to another will survive and produce more viruses.

“To effectively transfer, a virus packs itself into a vessel; some vessels are constructed better than others. The vessel influenza virus uses has the weakest structure we know while the one food-borne viruses use has the strongest one we know; this is why influenza viruses are not as good at surviving outside of the host as food-borne viruses are.”

Robert Lynch

Dairy Herd Health and Management Specialist

Robert Lynch is part of the PRO-DAIRY team at Cornell, and a dairy herd health and management specialist.

Lynch says: 

Dairy farms experiencing this reported cows with sharp declines in appetite and milk production, depression and change in manure quality. Some have reported the cow’s milk took on a thick appearance of colostrum and fever has been reported for some but not all.  Dairies that experience a sudden increase in adult dairy cows showing these signs should contact their veterinarian.”

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