The testing program will examine approximately 800 muscle tissue samples from asymptomatic dairy cows and test them for H5N1. Carcasses that test positive for H5N1 will not be released into commerce and will be saved for research purposes. USDA's Animal and Plant Health Inspection Service (APHIS) may also conduct additional traceback activities to gather epidemiological data and prevent the spread of H5N1.

Federal Milk Testing Programs

USDA-FSIS also began testing milk samples for H5N1 in December 2024 under its National Milk Testing Strategy (NMTS) with the issuance of a Federal Order and accompanying guidance requiring that raw milk samples nationwide be collected and shared with USDA for testing.

Separately, the U.S. Food and Drug Administration (FDA) conducted its own milk testing program, which tentatively concluded that avian flu does not pose a food safety risk in pasteurized dairy products. However, traces of H5N1 have been found in raw milk and raw dairy products, and FDA considers these products to pose a food safety hazard. The National Environmental Health Association has also reinforced the hazards of raw milk consumption.

The FDA's milk testing program was suspended in late April amid massive workforce reductions at the Department of Health and Human Services instigated by the Trump administration.

North Carolina Takes Action Against Raw Milk

While several U.S. states have been passing legislation allowing the intra-state sale of raw milk and dairy products, North Carolina's 2025 Farm Act (SB 639) is anticipated to close "loopholes" in state law banning the sale of raw milk. Under current North Carolina law, raw milk can be sold if labeled for pet consumption and not human consumption, or traded within a herd-share agreement. The Farm Act, which is up for final vote by the North Carolina House of Representatives, would eliminate the "pet milk" sale option for raw milk.

European Commission Releases New Guidance on Avian Flu Prevention

In Europe, the European Commission (EC) continues to monitor the spread of H5N1 in U.S. dairy cattle. It released a new guidance document on June 24 describing prevention, preparedness, and response for zoonotic avian flu in animals other than birds, as well as practical actions that can be taken to prepare for and respond to avian flu detection in EU mammals or food. The guidance reinforces the EU's robust animal health framework already in place under its One Health framework.

The document notes, "Even if the EU is not currently affected by this virus genotype [B3.13, affecting dairy cattle in the U.S.], some other circulating strains in the EU have proven capacity to infect other mammal species and there are already measures in place to mitigate risks posed by HPAI in the EU, it is prudent to consider various potential options of action in animals, notably in dairy cows, ahead of a potential introduction of this virus."

With regard to food safety, the guidance specifies that preparedness and initial prevention actions will be triggered in the case of "indication of new, riskier, transmission pathways of this virus among animals, beyond the movement of lactating cows," "indication of new, riskier, transmission pathways of this virus to humans, such as wide food-related transmission," or "indications that there is human-to-human transmission."

The document also notes that "…support from EFSA [the European Food Safety Authority] has been already requested to analyze the situation in the U.S. and obtain scientific advice assessing animal health and veterinary public health, including food safety, risks linked with this particular HPAI strain, addressing in particular its likely evolution, its likelihood of spread to the EU or Europe in particular with the migratory wild birds and if likely, the estimated expected time for this spread, its potential impact on the EU and possible risk mitigation measures," including emergency measures addressing the import of high-risk products (including food) and animals into the EU.

The full guidance document can be read here.