Is milk safe to drink? Can you catch bird flu from beef? What to know about H5N1 cattle outbreaks

Confirmation that a dangerous form of bird flu is circulating among U.S. dairy cattle has raised questions among dairy producers — and consumers — on both sides of the border.

Dairy and beef farmers are implementing biosecurity measures to keep H5N1 out of their herds, while Canadians are understandably concerned about what these outbreaks could mean for food safety.

So what is the scope of these dairy cattle outbreaks, and how is Canada impacted? And is it safe to consume milk and other dairy products? 

In the last week, American officials have identified highly pathogenic avian influenza, or H5N1 bird flu, in roughly a dozen dairy cattle herds across six states: Idaho, Kansas, Michigan, New Mexico, Ohio, and Texas. 

Scientists told CBC News it appears to be the first time H5N1 has infected cows. But the outbreaks weren't entirely unexpected. Bird flu exploded globally two years ago, and numerous wild and domestic animal species have been infected, including chickens, goats, and other farmed animals. 

There have been sporadic human infections, and deaths, including a mild case in Texas in an individual who had contact with cattle — the second-ever bird flu infection reported in the U.S.

While the dairy cattle outbreaks are new and raise important questions about spread across species, outbreaks among poultry are far bigger. 

More than 80 million U.S. chickens have been affected by H5N1 across 48 states, the latest U.S. Centers for Disease Control and Prevention (CDC) data shows. 

And Canada is experiencing a similar issue, with at least 11 million birds impacted country-wide, according to federal figures.

Not that we know of, though both farmers and federal officials are watching for it.

So far, the Canadian Food Inspection Agency (CFIA) has not detected H5N1 in dairy cattle or other livestock in Canada, and is "monitoring the situation closely," the agency said in a recent statement.

But bird flu experts suspect it's heading our way — or already here.

"There's no reason to think that there would be infected birds near cattle in the U.S. and not in Canada, especially when you have multiple states infected," said Dr. Scott Weese, a veterinarian and researcher with the University of Guelph Ontario Veterinary College. 

"So it's not unreasonable to think that we've had infections in Canada."