I’ve been behind on posts so here’s a quick update: things seem to be going well in the latest Canadian H3N2 canine influenza outbreak. Here’s the rundown:
- After eradicating the last outbreak in the spring, cases were identified again in mid-October, associated with more importation of dogs from Asia.
- The last new positive dog was identified October 30th.
- All infected dogs that have been identified in the latest cluster have close ties to the index site and have been from one area. One of these dogs left the region but has (hopefully) been kept quarantined for 28 days (as have the rest of the infected dogs).
- Most of the infected dogs that we have been able to follow serially (i.e. test multiple times) are no longer shedding the virus.
We can’t call this over yet, since our last new case was October 30. Dogs can shed the virus for a few weeks after infection (even if they look healthy). Currently, we use 28 days as the potential shedding period. So, we’re looking at ~November 26 as the end of the window for the last known case. I tack on a week or so to give us time to find any cases that might have been infected at end of that period. Odds are quite low at this point that there will be more transmission from this outbreak, but we need a bit more time and testing to be sure. By early December, we can hopefully declare this over.
This is hopefully another example of our ability to eradicate this highly infectious virus with astute primary care veterinarians, quick testing, good communication and responsible owners who will quarantine infected animals. I’m always wary of speaking to soon (or jinxing it), but it’s important to know this approach can be successful. It’s not often done (explaining why flu continues to spread in some regions) but with some effort, diseases like this can be contained.
At the same time, the effort required and the potential for such a virus to spread beyond our control can’t be ignored. That’s why we need to be careful when importing dogs from areas where canine influenza is widespread.