We already have an update on the Michigan dog disease outbreak that I wrote about yesterday which has attracted a lot of attention.
An update (August 24) from the Michigan State Veterinarian indicates this appears to be an outbreak of parvovirus. I’m not overly surprised. As I wrote yesterday:
An outbreak of our typical canine parvovirus?
- This is probably the most likely explanation, or at least the one to rule out first. That will require confirmation that parvovirus is actually the cause in most cases, and investigation of the vaccination status of those dogs.
Further investigation identified canine parvovirus in affected dogs. Initial point-of-care (i.e. in-clinic) tests for parvovirus were negative and while we rely on these tests a lot (and they’re generally quite good), we know they are not 100% sensitive. The report says those tests were consistently negative, which suggests a reasonable number were performed. That’s interesting since with severe disease and a lot of tests, I’d expect a positive. However, knowing that the tests aren’t perfect and that parvovirus is very common, we still shouldn’t jump to ruling it out too quickly, even with negative screening tests in multiple dogs. More sensitive tests performed at the Michigan State University Veterinary Diagnostic Laboratory were used to confirm the dogs were indeed infected with parvovirus.
The other key factor here was vaccination history. Affected dogs were incompletely vaccinated. This likely means the dogs were young and not fully vaccinated yet, or hadn’t been properly vaccinated when they were puppies. I covered parvovirus vaccination issues in yesterday’s post as well.
So, from a population standpoint this is encouraging, because it means the cause of the outbreak is not likely something new, and our current preventive measures should be effective… they just need to be used.