HELENA — The Centers for Disease Control (CDC) says nine states have seen avian influenza outbreaks in cattle since 2022.
While Montana has yet to be affected, surrounding states like Idaho, South Dakota, and Colorado have.
“There are lots of strains of avian influenza that exist in the world and a very small subset that we worry about and respond to like high path,” said the state veterinarian for Montana, Dr. Tahnee Szymanski.
According to the CDC, high-pathogenic avian influenza A, or H5N1, was first reported as a multi-state outbreak in March of this year.
The cause of the spread is not fully known, but migrating waterfowl can carry the virus and could contaminate feed or water sources for mammals.
Szymanksi said, “The most common routes of introduction would be ingestion or inhalation.”
Montana has roughly 50 licensed dairies, and thousands of ranches have beef cattle.
Szymanski says the USDA has found that milk sold commercially and properly prepared meat should inactivate the virus.
Raw milk, on the other hand, is still a question mark for researchers.
“There are other bacteria and pathogens that may be present in raw milk that people should be aware of, and I think HPAI would just kind of get lumped into that category,” said Szymanski.
Szymanski says that tracking in Montana includes local veterinarians reporting cases from ranchers who notice symptoms.
“They see a decrease in milk production, that’s probably the most substantial. The milk that they are producing will be really thick, so it looks more like colostrum,” she said.
Other symptoms include respiratory issues, abnormal feces, and fever, and transporting animals is also a concern.
Szymanski said, “If they are bringing new animals onto their farm or wanting to move animals off that would be going across state lines – there are some additional control measures.”
The CDC's current H5N1 statistics can be found here.
To find information about symptoms, prevention, and treatment visit the U.S. Department of Agriculture's website.
