Amid the spread of avian flu in U.S. dairy cattle, the Canadian Food Inspection Agency (CFIA) has announced the results of its proactive monitoring of dairy products in Canada, indicating that “commercially sold milk and milk products remain safe to consume.”
All milk sold in Canada must be pasteurized, a process that kills harmful bacteria and viruses, including the highly pathogenic avian influenza (HPAI) spreading in the United States, the agency added in a June 18
press release.
While avian influenza, often called bird flu, has been around for decades, it only jumped to cows in recent months, with HPAI
first detected in U.S. dairy cows on March 25. As of June 21,
112 cases of the HPAI virus have been detected in dairy cattle across 12 states, including 25 cases each in Idaho and Michigan, 17 in Texas, and 12 in Colorado, according to the U.S. Department of Agriculture (USDA). Other states reported fewer than 10 cases each.
Avian influenza, often called bird flu, is caused by a virus that affects several species of food-producing birds, such as chickens and turkeys, as well as pet and wild birds.
The virus can be broadly classified into two types. Most of these viruses are “low pathogenic,” typically causing little or no signs of illness. However, HPAI viruses can cause severe illness and death in infected birds.
The strain of avian influenza virus that affects cows, H5N1, has also caused illness in
three people in the United States. Two of those patients experienced inflamed eyes, while the most recent case also exhibited respiratory symptoms. The
USDA warned earlier in June that the avian flu virus is
likely spreading through people who work on multiple farms and through equipment sharing.
In response to the situation south of the border, the CFIA tested 600 retail milk samples from across Canada for HPAI.
“All samples have tested negative for HPAI fragments, with no evidence of disease in dairy cattle detected in milk,” the CFIA press release said.
In addition to testing retail milk samples, the CFIA said it conducted a study under Health Canada’s leadership in May and June this year to assess how well pasteurization neutralizes the HPAI virus in milk. Completed in June, the study confirmed that pasteurization effectively eliminates the virus, even at high concentrations of the virus.
These findings are consistent with similar studies conducted by international researchers earlier this year, which the CFIA said suggest that Canada’s milk supply remains safe even if HPAI were to be detected in the country.
A recent study has
highlighted the risks associated with consuming raw cow milk contaminated by HPAI. Mice showed signs of illness within 24 hours after consuming unpasteurized cow milk containing the virus, according to a
study by the Texas A&M Veterinary Medical Diagnostic Laboratory. The affected mice exhibited symptoms such as ruffled fur and lethargy, with high levels of the virus detected in their respiratory and several other organs.
Avian influenza is designated a
“reportable disease” in Canada, meaning it is a disease that can impact human well-being, animal health, and the Canadian economy. Although government agencies have not received any suspected cases of HPAI, any cases must be reported to the CFIA.
Bird flu has also affected farms in Australia, with outbreaks reported in the states of
New South Wales and Victoria in May and June. These outbreaks, which have resulted in
lockdowns of some affected farms, were caused by H7N8, a strain distinct from the H5N1 strain reported in other parts of the world.
Amie Dahnke and Zachary Stieber contributed to this report.
