A mysterious disease affecting older dairy cows in the southern United States appears to be caused by the same virus that has infected millions of domestic and wild birds over the past few years.
The U.S. Department of Agriculture said Monday that milk samples taken from sick animals at two Kansas dairy farms and one Texas dairy farm, as well as throat swabs taken from a Texas farm, showed highly pathogenic avian influenza. (HPAI) test revealed a positive result.
Federal and state authorities are investigating multiple cases of dairy cows in Texas, Kansas and New Mexico experiencing reduced milk production, decreased appetite and other symptoms.
The virus appears to have been introduced by wild birds. Genomic sequencing is underway to better understand the situation, the ministry said in a news release Monday.
U.S. dairy, beef and meat industry groups said they were not concerned about food safety. Milk from sick animals is not intended to enter the food supply, and pasteurization inactivates the influenza virus.
On dairy farms with symptomatic herds, about 10% of each affected herd appears to be affected, with little or no mortality among affected animals, according to the USDA. .
Last week, a dead baby goat at a Minnesota farm where the poultry flock had been infected with HPAI tested positive for the same virus. This is the first time it has been confirmed in domestic ruminants in the United States.
A farm owner in Stevens County, Minnesota, noticed an unusual number of newborn goats dying in early March on his property, where the backyard poultry flock had been decimated by HPAI in February.
“Spring migration is definitely the time of greatest infection risk for poultry, but the virus can also be transmitted to other animals on multispecies farms,” said Dr. Brian Hoefs, Minnesota’s state veterinarian. “This discovery is important because it highlights the possibility.” “Thankfully, previous studies have shown that mammals appear to be the definitive host, meaning they are unlikely to spread HPAI further.”
Avian influenza viruses have previously been found in other mammals, including skunks, dogs, and cats. Animals with weakened or immature immune systems are at higher risk of contracting the virus.
North of the border, the spring migration season has begun, but the Canadian Food Inspection Agency has not reported any new on-farm HPAI cases since February, when HPAI was confirmed on farms in Alberta and Quebec. .
