For the past year or more, we’ve been trying to track infectious upper respiratory tract disease (‘canine infectious respiratory disease syndrome’, CIRDC, or, more commonly, ‘kennel cough’). It’s a tough thing to do since testing is limited, it’s a disease that’s always present to some degree in the dog population and there’s no formal reporting system. How filled my inbox gets with enquiries seems to come in waves, but that’s probably more related to reporting (esp social media rumours). This week’s been busy so far  with a dozen or so emails so far asking about things like ‘new’ diseases or specific things like canine influenza (and it’s just Monday).

We’re still not sure what’s going on. It does seem like there’s increased disease activity over a lot of North America, and it’s been going on to some degree for quite a while. When we think about increases in respiratory disease reports, there are a few overall potential causes.

Increased disease caused by the normal suspects

  • This is my main guess at this point. Common things occur commonly and that’s particularly true for the variety of bacterial and viruses that cause CIRDC in dogs.
  • A few potential reasons can be postulated. One is there’s more dog mixing now as people start to increase activity and get together post lockdowns, and as people prioritize safer outdoor activities (often with their dogs). Combine that with a surge in new dogs and potentially decreased vaccination (overloaded vet clinics, access difficulties from earlier restrictions), and it’s easy to see how we might have more disease. Also, as more people are at home with their dogs, we probably hear more about typical mild cases because owners pay more attention when the dog is coughing beside them all day.
  • Another potential dynamic is increasing use of oral ‘kennel cough’ vaccines, as the are easier to administer to some dogs compared to intranasal vaccines. The problem is oral vaccines only protect against one cause…Bordetella bronchiseptica..while intranasal vaccines protect against that plus canine parainfluenza virus (CPIV). That’s important because CPIV is the most commonly diagnosed cause of CIRDC in many areas.

New disease

  • We’re always on the lookout for something new but nothing is apparent yet. With a new virus, we’d be more likely to see widespread transmission in exposed groups since no one would have any immunity. We’re not really seeing that. It’s more sporadic, as we’d expect with our typical causes. We can’t rule it out and there are undoubtedly various causes (mainly viral) that we simply haven’t identified yet.
  • I don’t think it’s an explanation here, though.

Increased reporting

  • This is probably part of it. There’s more social media use these days so word spreads quickly. One voice can be amplified disproportionately and unsubstantiated claims can be disseminated easily. Further, it feeds on itself. When there’s more buzz about it, more people that otherwise wouldn’t have said anything chime in. So, we probably hear about a greater percentage of infected dogs simply because people are talking about them when they otherwise wouldn’t have.

What about COVID?

  • That’s very unlikely to be playing a role. We can never say never since it’s a dynamic situation and we don’t know much about recent variants in animals. However, what we know so far is that infection of dogs and cats with SARS-CoV-2 is quite common but disease is uncommon in cats and rare in dogs.

What about canine influenza?

  • Canine flu certainly can cause large outbreaks. It spreads quickly because of limited immunity. There has been some canine flu activity in a couple places in the US in the past few months. These seem to have burned out (or at least burned down) relatively quickly.
  • There have been social media reports of canine flu outbreaks in Ontario. As far as I know, that’s false. Canine flu is reportable in Ontario and I haven’t heard of any reports (and odds are very high I’d find out very quickly). We haven’t seen canine flu in Ontario since we eradicated it in 2018. I’m always on the lookout for it, but am most concerned when there’s an outbreak that has a very high attack rate, including dogs that have had intranasal kennel cough vaccine. We’re still looking but I doubt canine flu is playing a role here.

What can people that are worried do?

  • Reduce contacts with large numbers of unknown dogs. Just like with other respiratory pathogens, the more contacts, the greater risk of encountering someone that’s infectious.
  • Reduce contact with sick dogs. This can be harder but it’s common sense…if a dog looks sick (e.g. coughing, runny noses, runny eyes), keep your dog away from it.
  • Keep sick dogs at home. (Duh…but you’d be surprised….)
  • Avoid communal things like water bowls in parks.
  • Get your dog vaccinated (ideally intranasally) against kennel cough if it tends to encounter other dogs regularly. My dog doesn’t get this routinely since we live in the country and he has a very limited number of dogs that he interacts with. If I was in town and/or going to dog parks or other places where he’d mix with lots of dogs of unknown status, I’d vaccinate him (especially as he’s getting older now).
  • Consider testing if your dog is sick. This is a tougher one since testing is useful to know what’s going on and maybe to help control things. However, it rarely tells us something that influences care for that dog (since we don’t have specific treatments). So, the cost of testing is hard to justify for some (understandably).

We’re also still tracking cases so people with sick dogs can provide info here: