Bird Flu Found in Tissue Samples of US Dairy Cow Sent to Slaughter, USDA Reports

By Tom Polansek and Manas Mishra

Bird flu virus particles have been detected in tissue samples from a dairy cow that was sent for slaughter at a U.S. meat processing facility. However, no virus was found in samples from 95 other cattle, according to the U.S. Department of Agriculture (USDA). As a precaution, the meat from these animals was kept out of the nation’s food supply.

In response to an expanding outbreak of bird flu affecting dairy cattle, agriculture and health officials have intensified testing of meat, dairy products, and livestock. Since the virus was first identified in cattle in late March, two dairy workers in the U.S. have also tested positive for the virus.

Older dairy cows are commonly processed into hamburger meat, and USDA’s findings coincide with the onset of the peak grilling season leading up to the U.S. Memorial Day weekend. The agency has conducted testing on beef tissue from 96 out of 109 muscle samples as part of a meat safety study.

The USDA collected tissue samples from dairy cattle that were culled due to systemic diseases at slaughter facilities, analyzing them through PCR testing. It’s worth noting that this testing method cannot differentiate between live virus and virus fragments.

The U.S. Food and Drug Administration (FDA) previously reported the detection of viral particles in pasteurized milk samples from retail stores, though these samples did not contain live virus. The FDA has issued warnings against consuming raw, unpasteurized milk.

During a routine post-mortem inspection, USDA personnel identified signs of illness in the affected cow, ensuring that its meat did not enter the food supply. The agency emphasized that such measures reinforce confidence in the effectiveness of the food safety system in place.

USDA has confirmed cases of bird flu in 58 dairy herds across nine states. The department has also reported no detection of viral particles in samples of ground beef collected from retail locations, and that cooking ground beef to medium or well-done temperatures eliminated the virus after it had been artificially introduced for experimental purposes.