The view from the Director’s office

As we learned from the COVID pandemic, new diseases – particularly viral diseases – can arise and spread rapidly over wide geographical areas. Sometimes, other viruses that we believe we had under control can shift unexpectedly and cause new diseases or affect different species. This is the case with the B3.13 genotype variant of highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b. No one anticipated this virus’s recent jump into cattle this year, causing systemic illness and mastitis in lactating dairy cattle in 13 US states at last count, 3 of which (Michigan, Minnesota, Idaho) border Canada: https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/hpai-confirmed-cases-livestock [1].

This variant also causes high mortality in poultry flocks and cats linked to affected dairy herds. Bovine veterinarians, diagnostic labs, animal health regulatory agencies and public health officials in Canada and the US have been meeting and sharing information frequently since the outbreak was confirmed, to understand how this viral variant spreads, and which species and animals are affected. The Canadian Animal Health Surveillance System (CAHSS) has done superb work in bringing together people from the aforementioned organizations, and in developing informational tools for people in the field. Bovine veterinarians who are attending cattle with compatible clinical signs are encouraged to contact their CFIA District Office and to submit samples (milk, urine, nasopharyngeal swabs) for HPAI testing to the closest CAHSN network laboratory. Companion animal veterinarians should consider HPAI on their list of differential diagnoses for cats with neurologic signs or sudden death, particularly those that live on or near dairy or poultry farms. CAHSS has developed an excellent fact sheet for HPAI testing in cats: https://cahss.ca/cahss-tools/document-library/highly-pathogenic-avian-influenza-A-H5N1-and-cats [2].

Let’s hope for a quiet fall – but we should all be watchful nonetheless, so we can detect and limit the spread of significant disease outbreaks.

Maria Spinato, Director

Animal Health Laboratory, University of Guelph, Guelph, ON.