Dairy cows infected with highly pathogenic avian influenza A, or H5N1, in five U.S. states have died or been slaughtered by farmers because they did not recover, according to state officials and academics.
In South Dakota, a dairy farm with 1,700 cows sent a dozen animals to slaughter after they did not recover from the virus and killed another dozen that contracted secondary infections, said Russ Daly, a professor at South Dakota State University and a veterinarian for the state extension office who spoke with the farm. “You get sick cows from one disease, then that creates a domino effect for other things, like routine pneumonia and digestive issues,” Mr. Daly said.
A farm in Michigan culled about 10 percent of its 200 infected cows after they failed to recover from the influenza, also known as bird flu, according to Phil Durst, an educator with Michigan State University Extension who spoke with that farm. In Colorado, some dairies reported culling cows with the bird flu because they did not return to milk production, said Olga Robak, spokesperson for the state Department of Agriculture. Cows infected with the influenza typically display symptoms such as reduced milk production and lethargy.
Ohio Department of Agriculture spokesperson Meghan Harshbarger said infected cows have died in Ohio and other affected states, mostly due to secondary infections. The Texas Animal Health Commission also confirmed that cows have died from secondary infections at some dairy operations.
