Four more cats have tested positive for H5N1 avian influenza in connection with a growing dairy cow outbreak in the United States, bringing the number of cases in the current outbreak to a new level, according to state and federal officials. The total number was 7.
Sonya Olsen, associate director for preparedness and response in the CDC’s influenza division, reported three new cat cases on Thursday, and state officials reported a fourth case on Friday.
“The reports we heard were that the cat developed neurological symptoms, rapidly weakened and died,” Olsen told BNO News.
Three of the new cases were found at two dairy farms in Curry County, New Mexico, and all have died, according to the state Department of Agriculture. The fourth case was found at a dairy farm in Wood County, Ohio.
This follows the recent deaths of three other cats at a dairy farm in Texas.
The global prevalence of H5N1 clade 2.3.4.4b, and its recent increase in prevalence in mammals, has raised concerns about the possibility of future variants capable of causing human-to-human transmission. So far, only a few cases of human infection have been found through contact with infected birds or cattle.
In late March, the U.S. Department of Agriculture (USDA) announced that avian influenza had been detected in unpasteurized milk from sick cows in Kansas and Texas, marking the first known case of infection in cows. The number of dairy farm outbreaks has since increased to 34 in nine states, and a Texas farm worker also tested positive.
Earlier this week, authorities confirmed that viral fragments of H5N1 avian influenza were found in samples of commercial milk. Experts say milk is still considered safe due to pasteurization and tests are currently underway to confirm this.
“The risk of avian influenza is evolving with the virus and requires real-time monitoring,” the World Health Organization said in a statement Friday. “WHO and our partners are calling on countries to quickly share information to make this possible.”
Cats are known to be vulnerable to this new strain of H5N1 avian influenza. The first case of a cat infected with this variant was reported near a duck farm in southern France in December 2022 and was euthanized.
A few months later, in 2023, nearly 40 cats died at two animal shelters in South Korea after eating contaminated cat food. And in Poland, more than a dozen cats died in an outbreak likely caused by contaminated raw meat.
At least 20 cats have been infected with H5N1 avian influenza in the United States, including seven cases reported this month. The remaining 13 cases occurred last year involving infected poultry or wild birds.
