U.S. official report that dairy cows in Texas and Kansas have tested positive for the bird flu. A concerning development in the spread of the Type A H5N1 strain. [Source]
This strain, notorious for causing outbreaks among birds and occasionally infecting humans, is now affecting older dairy cows in these states, as well as New Mexico, leading to decreased lactation and reduced appetite among the cattle.
The confirmation of this strain in dairy cattle comes on the heels of a report from Minnesota, where goats were diagnosed with the virus following an outbreak among poultry.
This instance is believed to represent the first time bird flu—also known as highly pathogenic avian influenza—has been found in U.S. livestock.
Despite the alarming nature of this discovery, officials from the U.S. Department of Agriculture have reassured the public that the commercial milk supply remains safe and that the risk to human health is low.
Dairies have stringent protocols to prevent milk from sick animals from entering the food supply, and all milk sold through interstate commerce undergoes pasteurization—a process that effectively kills viruses and other bacteria.
“At this stage, there is no concern about the safety of the commercial milk supply or that this circumstance poses a risk to consumer health,” reassures the USDA in a recent statement.
Federal testing has found no mutations in the virus that would facilitate its transmission to humans.
The emergence of what Texas Department of Agriculture Commissioner Sid Miller referred to as “mystery dairy cow disease” prompted a swift response from local officials.
“We hadn’t seen anything like it before,” Miller stated, describing the affected cows as appearing to have a cold due to their lethargy and lack of appetite. This led to an investigation by the state’s animal health commission, which included testing for bird flu.
According to Erin Robinson, a spokeswoman for the commission, it is believed the cattle contracted the virus from infected wild birds.
Unlike bird flu outbreaks in poultry—which often necessitate the culling of affected flocks—livestock appear capable of recovering on their own within seven to ten days.
This situation has ignited a rapid response from both state and federal health officials, including the Food and Drug Administration and the Centers for Disease Control and Prevention.
Michael Payne, a food animal veterinarian and biosecurity expert with the University of California-Davis Western Institute for Food Safety and Security, noted that the virus seems to infect about 10% of lactating dairy cows in the affected herds, explaining that this does not mirror the severity seen in bird flu outbreaks among poultry flocks.
To combat the spread of the virus and protect the nation’s dairy supply, industry officials have initiated enhanced biosecurity measures on farms across the U.S. These include limiting access to farm properties and restricting visits to employees and essential personnel only.
The detection of bird flu in dairy cattle serves as a stark reminder of the virus’s ability to cross species barriers. With bird flu having been reported in 48 different mammal species previously, Payne remarked, “It was probably only a matter of time before avian influenza made its way to ruminants.”
As this situation continues to evolve, dairy-heavy states like Iowa have announced they are closely monitoring developments.