In situations like the ongoing concern with canine infectious respiratory disease complex (CIRDC) in the US, where we don’t have any semblance of a surveillance program, we can sometimes try to piece together the picture using different data sets and observations; insurance claims can be a valuable part of this. At our webinar on canine respiratory illness earlier this week, we were able to present some preliminary data based on pet insurance claims through Trupanion. The data are biased, since insured dogs are only a small subset of the whole dog population, but they can still be informative (especially when we don’t have much else on which to go).

The full video of the webinar, along with some other resources, is available on the Trupanion website, but I’ll give a snapshot of the of the data we presented. We’re working on more and hopefully will be able to piece together a more complete story with more data over time.

Here are few interesting slides from the webinar:

This graph shows respiratory disease claims from January 2021 to October 2023:

  • We’ve had a gradual but pretty impressive increase in respiratory disease claims over the past 2 years. Note that these data are adjusted for changes in insurance patterns, such as increasing numbers of dogs with insurance policies. This fits with my general observation from this time period that we’ve been seeing more disease, but not a sudden dramatic boom.
  • We see general ups and downs.
  • We’re at a high point now, consistent with recent concerns.

The map below is important. It shows states and provinces where there’s been an increase in respiratory disease claims year-over-year from August to October in 2022 vs 2023:

  • High rates of claims were/are present in some areas where there’s been a lot of buzz.
  • Some impressive increases have been seen in areas where we’ve had less buzz. I always get questions from Ontario veterinarians asking if we’re seeing more CIRDC cases, but I’d say it’s not much more lately than anytime over the past few years. Most often, I get asked “is that thing that’s going on in the US going to hit us here?” I think this map shows that we can’t just focus on media/social media reports to tell us what’s happening, because they can over-amplify issues and at the same time, some things might fly under the media radar.
  • Claim rates haven’t changed in most areas, though. We’re not seeing something sweeping North America, we’re seeing patchy disease. That fits with my current guess as to what’s really going on (see details below).

Oregon’s an interesting state to look at as an example. This graph shows canine respiratory-related claims in Oregon from 2021-2023, which demonstrates a typical epidemic curve with a nice increase followed by a corresponding decrease in 2023:

  • There was clearly something going on earlier this year. It didn’t seem to get much attention until it was already on the downswing, though. Talking to a few different people in Oregon, the perception seems to be that things have died down over the past month or two, and that’s consistent with the data from this graph.

This graph compares canine respiratory disease claims in California and Oregon for the last few years:

  • California has had an increase in respiratory disease claim rates too, but the pattern looks different. While Oregon had a big peak and then a return to the increasing baseline, California has had a gradual but sustained (and impressive) increase over time, eventually reaching about the same rate as Oregon overall.
  • Does California have more of a well-distributed higher rate of disease? Or, since California is a big state, have we had rotating outbreaks in different areas that end up looking like a steady increase? We’ll need to do a deeper dive on the data to figure that out. The graph shows that something’s going on in California too, but maybe in a different manner than in Oregon.

Let’s jump to some Canadian content. Here’s the graph of canine respiratory disease claims in Quebec from 2021-2023:

  • This one surprised me. I’ve been getting questions about CIRDC cases in Quebec but nothing that stood out as unusual. (Maybe there’s more in the French-language media than I’ve been seeing.)
  • The total number of claims is still relatively small, so we have to be careful not to overreact, but that’s a pretty big percentage increase.
  • The time frame is also different from the Oregon peak. There’s always a bit of a lag with insurance report data, so we can’t say whether this has hit its peak in Quebec yet, or if it’s still increasing or if it’s already on its way down.
  • Regardless, the pattern fits with something that’s been going on recently and is possibly ongoing. We’ll have to see how the numbers trend over the next few weeks.

When it comes to other factors that might increase insurance claims, we have to consider the influence of recent media attention. If a dog had mild respiratory disease (e.g. cough, runny eyes but eating well and otherwise pretty healthy), it might not normally be taken to a veterinarian. However, if the owner is freaked out because of all the news coverage about CIRDC, they’re more likely to take that dog to a veterinarian now versus in previous years. Those cases then end up in an insurance dataset like this (or in a testing dataset from a laboratory) because of owner factors, not dog or disease factors. One way to help tease this out is to look atmore expensive claims, or claims that involve things that would only be done on sicker dogs (eg. oxygen therapy). Our preliminary look at those data showed similar but more blunted trends in terms of increases in some areas, gradual increases over time overall, and no change in most regions. So, the increases we’re seeing in overall claims are probably pretty reflective of true changes, though likely with some fear-driven (vs disease-driven) increases.

Other things we need to consider are what types of dogs seem to be over-represented, beyond regional effects. Preliminarily, claims involving brachycephalics (squish-nosed breeds) seem to be significantly more common, which isn’t overly surprising as these dogs may have less tolerance of any form of respiratory disease. More to come on that.

What’s driving severe disease is also really important. Mild respiratory disease isn’t ideal, but we’re more worried about pneumonia and severe illness that can make dogs really sick, result in high veterinary bills, and kill a small percentage of dogs. Brachycephalics, senior dogs and dogs with pre-existing heart or lung disease are probably at higher risk for severe disease, but we need to look at the data more to confirm that.

Where does this take us?

As we get more data, look at disease patterns over time and locations, and talk to more people about what they are seeing, I’m increasingly convinced that this is a situation of the usual suspects (our normal CIRDC pathogens) doing their usual thing (mild disease in most dogs with a small subset that get pneumonia and a small subset that get really sick), but at a higher rate. I think the rate has been increasing for a while, which makes the normal ups that we see with waxing and waning disease more obvious. I think it’s clear that we’ve had true increases in disease in some areas, but not all, and that clusters are following the typical course of “what goes up, comes down.” Media attention is amplifying the concern, so that we’re hearing more about a lot of things we wouldn’t normally, but there’s a true disease underpinning to those reports.

Why? What is driving the increase in disease rates?

The “why” is unclear, since we still don’t really know the “what” well. When I think about what drives increased disease, I focus on dog factors and bug factors. We have various logical reasons why this increase could be driven largely by dog factors. For example, in the past few years, we’ve seen:

  • More dogs
  • Disrupted veterinary care (less vaccination)
  • Changes in human activities (e.g. more remote work, maybe leading to fewer dogs at day care and therefore less kennel cough vaccination)
  • Other changes in human activities that alter how dogs interact
  • Changes in the types of canine respiratory disease vaccines we use
  • Earlier pandemic restrictions reducing the normal level of exposure to kennel cough pathogens and vaccination

The net result would be an increase in dogs with less immunity from vaccination or previous infection.

For bug factors, I think about the possibility of:

  • A new pathogen
  • An existing pathogen that’s changed

We don’t currently have any clear evidence of either of these bug factors. The story about a previously unknown small bacterium that has been found by the New Hampshire veterinary diagnostic laboratory is still worth investigating, but at this point it’s not clear that it’s driving anything. If this bug turns out to be a pathogen in dogs, most likely it will be a “new to us pathogen” versus a “new pathogen” scenario. By that, I mean that it’s more likely that it’s a longstanding cause of disease that we’ve never diagnosed before, versus a new bug that’s recently emerged and is starting to spread. The current disease patterns don’t really fit with emergence of a new highly transmissible pathogen.

I’m open to new evidence and other opinions, but at this point, if I had to make a somewhat informed guess, I’d go with the assumption that we have patchy but significant increases in disease in some areas across parts of North America, but driven by our normal bacterial and viral causes.

We also have to avoid over-interpreting the insurance claim data, since it’s just one piece of the puzzle, albeit a potentially important one. Everyone always wants definitive answers “now,” but that’s not how outbreaks or outbreak investigations go (especially outbreaks in dogs where we have almost no funding for formal surveillance or analysis of any kind).