A line of Holstein dairy cows feed through a fence at a dairy farm in Idaho on March 11, 2009.Charlie Litchfield/The Associated Press
After cases of avian flu were found in dairy cattle in eight U.S. states, Canada’s agricultural industry is taking steps to monitor its herds.
According to the U.S. Centers for Disease Control and Prevention, the highly pathogenic H5N1 virus has been detected in cows, marking the first time that avian flu has infected bovines. Earlier this month – in likely the first instance of mammal-to-human transmission of the virus – a dairy worker in Texas was diagnosed with the bird flu after having contact with cattle and was presumed to be infected.
No bovines in Canada have contracted avian influenza, the Canadian Food Inspection Agency said. And while the virus has been detected in both farmed and wild birds, as well as mammalian species such as domestic dogs, it has not yet been found in humans here, according to the agency.
Martin Appelt, CIFA’s senior director, said H5N1 was likely introduced to cattle in the U.S. through wild birds and poultry and is now considered an evolving influenza virus.
Since late March, avian influenza has been found in dairy herds in Idaho, Kansas, Michigan, New Mexico, North Carolina, Ohio, Texas and South Dakota. Seventeen U.S. states have imposed new restrictions on cattle imports from states with infections, according to the American Veterinary Medical Association.
Avian flu has been present in wild bird populations for years, but the most prevalent H5N1 strain circulating is highly contagious and deadly to birds. Since 2022, there has been an explosion of outbreaks among domestic poultry and other animals, including minks, seals and sea otters.
According to recent observations in the U.S., Dr. Appelt said there is no evidence of a severe spread of fatal disease among cattle, putting the infection rate at around 10 per cent in the affected herds.
“Most of those animals appear to be recovering just fine with some supportive care, which really does not tick the boxes for a dramatic foreign animal disease that requires drastic measures to tackle,” Dr. Appelt said.
He added: “I think it would be unfair and very premature to fall into any sort of panic mode at this point.”
Canadian consumers should also not be concerned about reports of the virus being detected in the milk of infected cows in the U.S. since pasteurization kills it, Dr. Appelt said.
In a written statement to The Globe, Dairy Farmers of Canada said Canadian dairy producers adhere to some of the highest biosecurity standards in the world and only milk from healthy animals is authorized for distribution and human consumption.
Wietze Dykstra, a dairy farmer in Woodstock, N.B., said DFC has sent numerous updates on the situation. Still, he worries about animal welfare, consumer concerns and economic repercussions.
“As a farmer, our first line of support is our herd veterinarian,” Mr. Dykstra said. “At least we know the symptoms now so if we see it here we can contact our support.”
Under Canada’s Health of Animals Act, the CFIA may order the destruction of animals affected by a disease such as bird flu. Agriculture and Agri-Food Canada spokesperson Bronwyn Goodman said farmers registered under AgriStability are eligible for financial support in cases of destructive outbreaks.
Officials across the country are monitoring the situation. Both the Ontario and Alberta ministries of agriculture said they are co-ordinating with CIFA.
“We have sent a notice to the veterinary community in Alberta advising them to be diligent when monitoring and ensuring investigation support and laboratory diagnostics for testing suspect situations,” Jeanna Friedley, a spokesperson for the Alberta ministry, said in a statement.
Ontario veterinarian Jeff Wilson said the current avian flu outbreak and its spread into cattle populations could be used as an opportunity to improve best practices.
Dr. Wilson, who specializes in avian pathology and dairy cattle epidemiology, conducted surveillance and responded to several outbreaks during previous work with the University of Guelph and the Public Health Agency of Canada.
He advises creating a team that represents all stakeholders to collect and centralize data, ensuring transparent communication. This would allow outbreak responders to develop co-ordinated, strategic responses rather than disjointed or reactive measures, he said.
“Whether it’s poultry influenza or poultry influenza in cattle, I would say let’s return to the basics,” Dr. Wilson said.