In case anyone would like a break from all the canine infectious respiratory disease (CIRDC) posts, take a moment to gawk in disbelief (as I did initially) at this human-created debacle:

Skunk purchased from Michigan breeder tests positive for rabies.

How many things are wrong with this, just based on the headline? Ugh.

For the record, breeding and sale of skunks as pets is legal in at least some parts of the US, but it is NOT legal in Ontario. In order to have a captive skunk in Ontario you need to be an authorized wildlife custodian. Animal species native to Ontario cannot be kept as pets. That is especially important when it comes to rabies reservoir species like skunks and raccoons, for reasons aptly demonstrated by this situation.

They don’t know how or when the skunk in question got infected with rabies – a very common refrain. Unfortunately even a lot of dog and cat owners don’t realize the potential for their pets to be exposed to rabies through contact with wildlife, especially bats. Bat bites can be almost impossible to find on a furry pet (sometimes they’re even hard to find on people), so if you don’t see the bat you might not realize there was an exposure. Your pet doesn’t even need to go outside to encounter a bat, because bats regularly get into houses (one way or another!). Keeping your pets vaccinated against rabies is the best way to provide protection against these potentially unseen exposures (and in Ontario, rabies vaccination is legally required for all dogs, cats and ferrets over 3 months of age – that’s 3 months, not 4 months!).

It can take months for signs of rabies to show in an animal after its been infected. Even if the animal looks perfectly healthy, it can still be incubating the virus. (The animal doesn’t become infectious to others until after the virus reaches the brain, but it may still appear normal for some time after this, before it starts to get sick). This is also part of the reason imported dogs from rabies endemic countries remain a risk for at least 6 months after their exposure risk becomes controlled (which is usually when they’re imported). There’s a great little whiteboard video from the Ontario Animal Health Network that explains more about rabies risks in imported dogs (and why just vaccinating them for rabies prior to import doesn’t solve the problem).

While efforts to control an outbreak of raccoon-variant rabies in Ontario since 2015 have pushed case numbers down to just 6 cases in skunks in 2023 (shout out to the Ministry of Natural Resources and Forestry!), they’ve had 17 rabies cases in skunks in Michigan this year, which is a good reminder for anyone who travels (especially with their pet) that the rabies risk can vary considerably by region, even within the US and Canada, and especially internationally in countries where canine-variant rabies circulates.

Also remember that even though there have only been 6 cases of raccoon-variant rabies in Ontario in 2023, we’ve identified 49 cases in bats right across the province, so keep those pets vaccinated, please!


Spoiler alert: there’s not a lot new to say about the ongoing situation with canine infectious respiratory disease in North America. Most of this I’ve said before. Talk seems to be dying down in a lot of areas, but whether that’s because there are fewer cases or people are just getting bored of talking about it is unclear. It’s probably a combination of both. Based on some data I posted last week and talking to people on the ground in different regions, it seems like most areas that have had a (real or perceived) increase in canine infectious respiratory disease complex (CIRDC) cases are returning back to baseline. Presumably, there are some other areas where disease is ramping up, as usual. However, there are still a few questions worth bearing in mind at this stage:

Is this really an outbreak?

I’d say it’s not so much an “outbreak” as a gradual increase in the incidence of CIRDC over the past couple of years, with typical periodic spikes of disease superimposed over top of it. We have fairly clear evidence of more cases in some areas, usually following the typical outbreak pattern where cases go up, then return back to baseline levels. We also have areas where there’s really nothing too different happening.

Is there a “mystery virus” causing the increase in cases?
This is commonly reported in news headlines, but there’s no evidence of that. There’s a lot of viromics work underway, where they sequence any and all viral bits present in a sample to look for anything new. Since nothing has been found (or at least reported) thus far, it’s becoming less and less likely that there’s a new virus causing any substantial number of cases. I’d also expect a bit of a different disease pattern with a new, highly transmissible virus. More time and more testing will provide more details but at this point, I don’t think we have a reasonable suspicion of a new pathogen.

What about that strange little bacterium reported by the lab in New Hampshire?

This bug needs to be investigated more, but it’s not looking like a leading candidate at this point. It hasn’t been found to be a potential important cause of respiratory disease elsewhere (although I’ve only heard of one place that’s said they’ve looked and failed to find it). We need to learn more about this bacterium, but I’d guess that it’s either just part of the normal bacterial microbiota in dogs or it’s a potential cause of disease that’s been around for a long time, we just didn’t know (and therefore didn’t test for it). I doubt it’s a new bug that’s just recently emerged and spread in dogs in North America.

Are the reported cases of CIRCD more severe?

I don’t think so. Concerns about severe disease in dogs are probably more of a media effect. With typical CIRDC, we expect a small percentage of dogs to get pneumonia, and an even smaller percentage to have serious disease and die. That’s always been the case. When the number of dogs with CIRDC goes up, the number of dogs with severe disease will go up proportionately. So, we’d expect to see more cases of severe disease when we have an more cases during outbreaks, not because the disease itself is more severe, but simply because there’s more overall illness. If we have 100 dogs with CIRDC, we’d expect maybe 1-2 severe cases. If we have 1000 dogs with CIRDC, our severe case numbers jump to 10-20, even if the disease itself is no different.

What about treating dogs with CIRDC with Paxlovid?

Ugh. Horrible headline writing has driven requests to use this drug in dogs with CIRDC.

Please don’t.

We have inadequate dosing data and little understanding of safety for Paxlovid in dogs, and no evidence that its use is necessary (or effective) in any of these cases

What about treating dogs with CIRDC with chloramphenicol?

UGH X2. Chloramphenicol is an antibiotic. It’s a great drug, but (as for all antimicrobials) should only be used when it’s really needed. This drug has fairly important animal and human health risks (even just handling the drug), so we should not be using it routinely; however, if I have a multidrug-resistant bacterial infection in an animal, and chloramphenicol appears to be the best option to treat it, I’ll use it. Standard treatments still apply for routine cases of CIRDC. If we start using Paxlovid and chloramphenicol routinely (be it out of fear, panic or just the desire to do “something”), I have little doubt that we’ll harm more dogs than we’ll help.

Is “kennel cough” vaccination in dogs worthwhile?

Yes. We have good vaccines against canine parainfluenza virus and Bordetella bronchiseptica, two important causes of respiratory disease in dogs. Protection is much better with “mucosal” vaccines that are given directly into the nose or mouth, so that’s the kind we want to use routinely for these pathogens. The vaccines won’t protect against all types of infectious respiratory disease, but reducing the risk of some major ones is still very helpful. Intranasal and oral vaccines are given once, then re-dosed annually. There’s currently nothing indicating we should re-vaccinate dogs more frequently than this.

Are some dogs at increased risk of infection with respiratory pathogens?

Risk of infection depends heavily on risk of (and amount of) exposure. Dogs that encounter a lot of other dogs, especially transient groups of dogs of unknown health status, are at increased risk of pathogen exposure. The more dogs encountered, the closer and more prolonged the contact, and the less certain the health status of the dogs involved, the greater the risk.

Reducing the overall number of dog contacts, particularly contacts with groups of dogs of unknown health status (e.g. random groups of dogs at an off-leash park, versus a small consistent group of known dogs at a day care or play group) is an important control measure.

Are some dogs at increased risk of severe respiratory disease?

Generally yes. We know there are some dogs that have a greater risk of severe respiratory disease or death if they get infected, so we want to be extra cautious with them, including avoiding exposure, vaccination and getting them to a veterinarian sooner if the dog gets sick. High-risk dogs include older dogs, very young puppies, dogs with pre-existing heart or lung disease, dogs with compromised immune systems, and brachycephalic breeds (i.e. flat-faced breeds like bulldogs).

Why might CIRDC rates be increasing?

It’s just a guess, but we could have a pandemic-associated confluence of factors that have led to more dogs with greater susceptibility to respiratory infection.

Changes in how we have interacted over the past few years, and how often dogs go to kennels or daycare (which is often the trigger for getting a kennel cough vaccine) could plausibly have reduced overall vaccination coverage in the dog population. Also, if fewer dogs were exposed to respiratory viruses over the past few years, there may be more dogs that are susceptible to them now. I try to stay away from the “immunity debt” discussion, since that’s more political than scientific, and it’s triggering for some people (my inbox is a testament to that). Nonetheless it’s quite logical that less immune protection from less vaccination and less infection over the past couple years could mean more susceptible dogs. It’s not “debt,” it’s just deferred exposure.

From a severe disease standpoint, changes in the popularity of different dog types could be playing a role too. The French bulldog, a higher risk breed, is now the most popular dog in the US. That’s plausibly going to increase the number of cases of severe disease just based on numbers.

What should the average dog owner do?

  • Breathe. This is not a doggie plague sweeping across the nation.
  • Consider your dog’s risk of exposure and whether you can do things to reduce it, while not being unnecessarily disruptive to life in general (e.g. if your dog needs to go to day care for you to work, send your dog to day care).
  • Consider your dog’s risk of severe disease when deciding whether to change your behaviours and how much to change.
  • Talk to your veterinarian about respiratory disease vaccines.

This wasn’t on my bingo card for 2023, but it looks like I need to comment on the use of Paxlovid in dogs with respiratory disease. I guess I shouldn’t be surprised, but there’s been a lot of buzz about a single report of a veterinarian using Paxlovid to treat one dog with respiratory disease – in the absence of any definitive diagnosis as to what was making the dog sick.

Some media reports are claiming Paxlovid cured the dog. Did it?

Probably not. I suspect the dog got better on its own despite Paxlovid (not because of it), but can’t say for sure. However, I can say that I don’t see any evidence that we should be using this drug in dogs, and I have a variety of concerns about its use in this manner.

Concerns about Paxlovid use in dogs (quick version)

Paxlovid is an antiviral that we know basically nothing about in dogs. We don’t have dosing or safety info in dogs, and we don’t have evidence that the respiratory disease we’re currently seeing in dogs in North America is caused by a virus that’s susceptible to Paxlovid. So, I don’t think its use is appropriate in such cases, and I suspect widespread use of Paxlovid in dogs would result in harming more dogs than it would help.

Concerns about Paxlovid use in dogs (longer version)

Using a human drug in a pet isn’t rare in veterinary medicine, and often it can be appropriate. Veterinarians often need to use drugs in an extra-label manner, since many important drugs are not licensed for use in animals. When we know how to use the drug, its safety and that it’s likely to work in an animal, this kind of extra-label use can be appropriate.

  • The less we know about things like dosing and safety in animals (which can be very different across species), the greater the risk.
  • The less we know about efficacy, the lower the value.

Treatment is typically a cost-benefit decision, based on assessing potential risks, potential unknowns and potential beneficial effects.

Paxlovid is a combination of two antiviral drugs, nirmatrelvir and ritonavir, which are both protease inhibitors, neither of which are used in dogs. The combination has been shown to be beneficial for treating COVID-19 in some types of people, in some circumstances, with the right timing. That’s based mainly on study of Paxlovid use in unvaccinated people. In Canada, it’s licensed for use in people with mild to moderate COVID-19 who are at increased risk of severe disease. It’s not meant for everyone, and it’s meant for early treatment. There are different opinions about whether it’s really of much use at this point in the pandemic, but I won’t get into that.

What do we know about Paxlovid in dogs?

Pretty much nothing. I’m not aware of any dosing or safety information.  The only thing I can find is a study that looked at Paxlovid in serum of different animal species, including dogs (i.e. they added the drug to serum in a tube, but they did not give the drug to the live animals) and did a pharmacokinetic study on just two healthy research dogs (Greenfield et al 2023). That’s a start, but the small number of dogs (2) means it still doesn’t tell us too much. The researchers reported some pretty major differences between species, including between dogs and people. They concluded that “Some species (rabbit,dog) demonstrated high plasma protein binding (PPB) that was concentration-dependent, whereas others (human, monkey, rat) did not. This can have a major impact on understanding concentration-effect relationships for both efficacy and safety endpoints. As such, it is important to consider PPB when selecting animal species for studies aimed towards understanding efficacy and safety in humans.

My take home message from that study is it can’t tell us anything about how/if we can and should use Paxlovid in dogs, and we can’t assume safety and efficacy data in people apply to dogs.

Sometimes we use the same doses in people and dogs for a specific drug, but sometimes, the doses are quite different.

Some drugs that are useful in people also work in dogs, but some drugs do not.

Some drugs that are relatively safe in humans are relatively safe in dogs, but some human drugs are highly toxic to dogs.

If we don’t know dosing and safety in a particular species, it’s really hard to consider use of a particular drug if there isn’t a huge potential upside, e.g. because we need to treat a severe disease and we have no other options, and where the drug has a strong chance of working. That’s not the case here with canine respiratory disease and Paxlovid.

Could Paxlovid work in dogs?

Paxlovid could have an impact on some viral causes of canine infectious respiratory disease complex (CIRDC), such as canine respiratory coronavirus (which is a completely different virus than SARS-CoV-2, despite the similarity in name). However, even IF Paxlovid has effects on canine respiratory coronavirus, or other relevant viruses, that may not really mean a lot clinically. It might shorten disease and/or might reduce the risk that secondary complications developing, but that would probably still be dependent on very early treatment, something that is not likely to happen in a lot of dogs when illness is still mild, particularly given the cost of Paxlovid.

Could use of Paxlovid in dogs hurt?

Absolutely. We have no idea if the drug is safe in dogs. There are various known side effects in people, and the drug interacts with a lot of other medications. If we’re going to apply a cliché, it should be “above all, do not harm” vs “it can’t hurt.” The latter is not likely true.

What about developing resistance to Paxlovid?

There’s probably very little risk of viral resistance to Paxlovid increasing due to use in dogs. The concern would mainly be about development of resistance in viruses that can affect people, since that’s where the drug is most often used and where resistance is most likely to have a significant impact. Dogs can be infected with SARS-CoV-2, but for resistance to be a risk, a dog would have to be infected with SARS-CoV-2 at the time it had respiratory disease (likely unrelated, since SARS-CoV-2 is unlikely to cause clinical respiratory disease in dogs based on what we know) AND resistance would have to develop while the dog was infected AND that resistant virus would have to be transmitted back to a person. Dogs seem to pose very limited risk for transmission of SARS-CoV-2 to humans, so it’s fair to assume that the health risks posed to humans from use of Paxlovid in dogs are very low to negligible.

However, we understand little about antivirals and antiviral resistance in animals, and the precautionary principle would have us remain pretty conservative with their use, and to only do so after a thorough risk assessment.

At this point, my assumption is that widespread use of Paxlovid in dogs would harm more dogs that it would help.

In contrast, there’s a different story about another COVID-19 drug in cats. We have some good data about the antiviral drug Remdesivir in terms of dosing, safety and efficacy for feline infectious peritonitis, which is otherwise a pretty much invariably fatal disease. This is a drug we should be using in cats, but we still can’t get (legal) access to it in North America. We’re working on that, so it will probably be the topic of a post in the near future. Good or bad news? I don’t know yet.

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).


There’s a lot of concern about respiratory disease in dogs at the moment, so it’s a opportunity time to revisit some routine preventive measures that we really should be using all the time (but unfortunately sometimes fall by the wayside). This post focuses on precautions for dog groomers, but really it applies to a broad range of places where dogs go.

Infection control is typically pretty straightforward and boring (which is why it often gets neglected). There’s nothing really fancy and it’s mostly pretty low tech – mainly a matter of using some good general practices and a solid dose of common sense.

With canine infectious respiratory disease complex (CIRDC), the main transmission concerns are from direct contact between dogs, contact with oral/nasal secretions (e.g. shared bowls, licking the same spot soon after another dog) and respiratory aerosols (from coughing, sneezing, heavy panting etc.). There is always a risk of disease transmission at dog grooming facilities, regardless of whether there’s an outbreak going on in the area or not. Various diseases are always circulating in the dog population, and sometimes we can’t tell when an animal is infectious to others, so we apply routine infection control practices in all situations, and increase those when we identify increased risk.

Some routine, every day infection control practices include:

  • Communication so owners know not to bring sick dogs to the groomer. If clients are being called or emailed with appointment reminders, add a statement about cancelling if the dog is sick. (Sound familiar? Lots of what we did for people during the pandemic can also be applied for control of disease transmission in dogs).
  • Business practices that don’t encourage owners to bring sick dogs (e.g. no charge if someone cancels at the last minute because their dog is sick. Yes, a policy like that can be abused, but we don’t want incentives for people to bring in a sick dog).
  • A housing setup that keeps dogs separated. At a minimum, we want no (or very limited) direct contact between dogs.
  • Good ventilation, such as having an in-room HEPA filter or two, especially in dog housing areas.
  • Routine use of personal protective equipment. Ideally, groomers should wear something over their street clothes that’s easy to change if it gets contaminated. If street clothing or scrubs are the only layer they’re wearing, it’s important to have a change of clothes handy. However, it’s easier and better to immediately take off a lab coat, smock or gown than it is to go go somewhere to change clothes completely.
  • Hand hygiene, such as washing hands or using a hand sanitizer between animals.
  • Cleaning and disinfection of areas and shared equipment between animals. Any routine disinfectant should work against typical canine respiratory pathogens, but I always like to use as good a disinfectant as possible. If you can get it, I’d use an accelerated hydrogen peroxide (AHP) product.

Routine stuff is, well, routine. It’s not rocket science (and pretty boring in the end) but it’s the core of good infection control. However, we also need to have a plan for higher risk situations. Ideally, this plan is written out and communicated to everyone in the facility before a situation happens, so it can be implemented by everyone without delay or confusion. Human factors are usually the biggest problem when we see infection control breakdowns.

How to respond to a dog with respiratory disease at a grooming facility

Even with good use of routine practices, it’s possible for a sick dog to get in once in a while. Sometimes people don’t realize or don’t care that their dog may be infectious, and it’s not always obvious as they walk in the door. There are generally two main scenarios:

1. Sick dog is identified as it arrives

 This one’s easy. Ask the owner to take the dog home right away. If there’s a need to discuss anything, ideally the dog should be removed from the facility and the discussion is done by phone. Otherwise, the discussion could take place outside, or inside after the owner puts the dog in a vehicle (if it’s safe to do so). While this is happening, attention should be paid to any other dogs in the vicinity, to keep them away from the sick dog.

There’s not a lot to do with the airspace by the time this happens. Aerosol transmission is the main concern here, and that’s only for a short period of time and over short distances. The risk of something wafting around the building in the air for a long time is low. The pandemic taught us the importance of good ventilation and air filtering, so it would be ideal if there was already a well-ventilated space and a HEPA filter running to further reduce the risk.

Any personnel that had direct contact with the dog before it was removed should change their outerwear and wash their hands.

The general environment is probably fairly low risk but it’s not zero, especially surfaces the dog may have licked, nosed or coughed/sneezed on. Disinfecting those surfaces ASAP would be wise. Having a spray bottle with disinfectant handy is good for many things, and would help speed up the process here too.

If the owner wants to reschedule, we don’t have a good handle on how long to wait, since we won’t likely have a diagnosis for the dog. Waiting a month would be ideal. It’s not a guarantee that the dog won’t still be shedding something, but we’re trying to balance protection and practicality. At a minimum, I’d want to wait two weeks before the dog comes back.

2. Sick dog is identified after being dropped off and the owner leaves

This creates challenges since “get the dog out ASAP” may not be an option. Owners should be contacted to pick up the dog as soon as possible. While waiting, the dog should be kept in an area away from other dogs. Ideally, every facility should have an area to isolate high risk dogs. It doesn’t need to be an isolation unit like in a veterinary clinic, but there needs to be a plan for housing dogs with respiratory disease, diarrhea or other things that get flagged as a concern after drop off. This could be a separate room, or even a well-ventilated storage room or closet, that can hold a crate. The idea is to get as much physical separation between the sick dog and other dogs as possible.

When we can’t physically isolate the dog, we try to contain it as much as possible and use procedures to reduce cross-contamination risks:

  • Keep the dog as far away from others as possible.
  • Position the dog such that there’s limited airflow toward other dogs (e.g. if there’s a window or fan blowing, make sure the high risk dog isn’t upwind).
  • If there are banks of cages, keep the sick dog on the bottom.
  • Put a blanket or something similar over the cage front to reduce aerosol spread.
  • Avoid handling the dog as much as possible. If you have to handle it, either put on single use (disposable or direct to laundry) outerwear like a gown and use gloves. Wash your hands after removing gloves when you’re done.
  • When the dog leaves, disinfect any items in the cage (e.g. bowls), launder any blankets/towels and disinfect the cage.

It’s all pretty basic, but basic is effective if done right.

I’ll write more about where we stand with the ongoing CIRDC situation, but it is a good reminder that we should be upping our routine infection control game.

Dr. Mike Lappin and I are teaming up with Dr. Carrie Jurney (President of Not One More Vet) and Dr. Steve Weinrauch (Chief Veterinary/Product Officer of Trupanion, founder of MightyVet) for a webinar about canine infectious respiratory disease complex (CIRDC) issues in the US (plus some Canadian content). There may be a lot of “we don’t know yet” comments, but we’ll have some insights, some reasonable guesses and, yes, a bit of new data about the situation.

Disclaimer: This webinar is coordinated by Trupanion, a pet insurance company, but it’s a non-commercial talk, and we’re not being paid to do it. We’re just hoping to get some good information out to a broader audience by making use of Trupanion’s interest and reach.

Here are the details about the webinar and how to join:

Trupanion is inviting pet parents and veterinary professionals to join a free, live webinar – “Separating Fact, Fiction, and Uncertainty: Canine Respiratory Illness Q&A” to be held Thursday, November 30, 2023, at 4:30 PM PT / 7:30 PM ET.

This timely event will include: 

  • REAL-TIME UPDATES: Stay informed with the latest updates on canine respiratory illness, leveraging Trupanion’s database of over 3 million Trupanion-protected pets.
  • PREVENTION STRATEGIES:  Learn effective strategies and practical measures you can take to safeguard your pup’s health.
  • SIGNS TO WATCH FOR: Learn how to recognize early signs, empowering you to take proactive steps to address potential concerns.
  • LIVE ANSWERS TO PARTICIPANT QUESTIONS: Participants can engage directly with the panel of experts to ask questions about canine respiratory health.



  • Panelist | Dr. Scott Weese: Dr. Scott Weese is a veterinary internist, a Diplomate of the American College of Veterinary Internal Medicine, and a Fellow of the Canadian Academy of Health Sciences. He is a Professor at the Ontario Veterinary College, University of Guelph, Director of the University of Guelph Centre for Public Health and Zoonoses, Chief of Infection Control at the Ontario Veterinary College Health Sciences Centre, and is a member of numerous national and international committees dealing with infectious diseases and antimicrobial resistance, including the Quadripartite (WHO, WOAH, FAO, UNEP) Global Leaders Group on AMR. 
  • Panelist | Dr. Michael Lappin: Dr. Michael Lappin is a veterinary internist, a Diplomate of the American College of Veterinary Internal Medicine, holds a PhD in Parasitology, is Director of the Center for Companion Animal Studies at Colorado State University School of Veterinary Medicine and Chair of the World Small Animal Veterinary Association One Health Committee. He is also currently a Professor at the College of Veterinary Medicine and Biomedical Sciences at Colorado State University. 
  • Special Guest | Dr. Carrie Jurney: Dr. Carrie Jurney is a veterinary neurologist and practice owner at Remedy Veterinary Specialists in San Francisco. She is a passionate advocate for mental health and wellbeing, and serves as the president of Not One More Vet 501(c)(3), the world’s largest wellness-focused charity for veterinary professionals. 
  • Host | Dr. Steve Weinrauch: Dr. Steve Weinrauch, BVMS, MRCVS is the Chief Veterinary/Product Officer of Trupanion and founder of MightyVet 501(c)(3). Before joining Trupanion, Steve built and ran three veterinary practices in the Seattle area. He has published his research in numerous peer reviewed journals, and he is licensed to practice in both the U.S.A. and the European Union.

Please note: the webinar recording will be available for on-demand viewing at https://k9illness.trupanion.com/

There’s been a lot of discussion about canine infectious respiratory disease complex (CIRDC) going around in dogs in the US recently. In the last week, I’ve already covered this from a few different angles, including what might really be going on with all the reports of sick dogs, reports of the potential involvement of a potential novel canine respiratory pathogen and when and when not to treat dogs with respiratory disease with antimicrobials. I’ll try to get another post done soon about the data we have (and don’t have). This post will address the most common questions dog owners are asking.

What should dog owners do?

Relax. It seems like there’s more respiratory disease in dogs in some areas, but that’s something we often see. Serious disease is being reported in a small subset of infected dogs, but that’s also something we regularly see. So, being aware is good, being anxious is bad, freaking out is definitely unnecessary.

The vast majority of dogs that get CIRDC recover uneventfully. That’s as true now as it was a year or 10 years ago. However, severe disease can occur so we don’t want to be too dismissive.

My dog is sick. What should I do now?

The default answer is “talk to your veterinarian if you’re concerned.”

However, the answer is not “if your dog coughs, it must be taken to a veterinarian ASAP.” A dog should be taken to a veterinarian if it’s really sick, deteriorating quickly, not getting better over the course of several days (but remember dogs may still cough after they’re feeling better), if there might be complications, or if it’s unclear what’s going on.  If the dog just has mild upper respiratory infection, it rarely needs to be seen by a veterinarian. If it has pneumonia, it definitely needs to see a veterinarian.

Think about it in terms of how we react when we get sick or our kids get sick. If you had a cough and felt a bit run down, you probably wouldn’t go to a doctor unless you had underlying risk factors for severe disease. The same applies to dogs – if they’re pretty bright and alert, are eating and breathing normally, but just have a cough and runny nose or eyes, it’s very unlikely they need to be examined (in part because it’s very unlikely that they need any specific treatment or testing, and because a visit to the veterinary clinic might just cause more stress for the dog and risk exposing other animals.) If you felt like you could barely drag yourself out of bed or you were having a hard time breathing, you’d go to the doctor. That’s also the same for dogs.

While I want to avoid being too prescriptive about who should or shouldn’t see a veterinarian (since there are lots of exceptions and grey areas), if the following signs are present, a prompt visit to the veterinary clinic is indicated:

  • Weakness, severe depression (meaning the dog is really quiet, not engaged and just lies around, doesn’t get up when you’d expect it too (like for food))
  • Loss of appetite
  • Difficultly breathing (breathing faster and harder even when not exercising)
  • Rapid worsening of illness
  • Cough that is causing significant problems such as vomiting or making it hard for the dog to breathe

It’s especially important to see the veterinarian if these signs occur in a high-risk dog, including:

  • Elderly
  • Very young
  • Pregnant
  • Immunocompromised (by disease or treatment)
  • Underlying heart or respiratory tract disease
  • Brachycephalic (i.e. squishy-faced) breeds

What will happen when I take my dog to the veterinary clinic?

That’s depends on a lot of things, so it’s hard to say what you should expect.

  • The first thing the staff should do is assess whether it looks like your dog has infectious respiratory disease, and how stable your dog is (in terms of its lung function). Most dogs with CIRDC don’t need anything but time and TLC; so, if your veterinarian says your dog looks stable and no treatment is needed at this point, take that as a good sign. Don’t ask for unnecessary treatments like antimicrobials “just in case.”
  • If your dog’s cough is disruptive, then a cough suppressant may be warranted (but that depends on a few things).
  • If your dog has signs of pneumonia, radiographs of the chest and bloodwork will likely be needed. If pneumonia is confirmed, antimicrobials are indicated.
  • If your dog is really sick, hospitalization with intensive care, antimicrobials and oxygen therapy may be required. That’s uncommon but it happens, and when there’s more respiratory disease activity in an area at a given time, there will be more cases of severe disease too just based on numbers (e.g. 1% severe disease rate in 1000 infected dogs is more really sick dogs than 1% in 100 infected dogs).

The severity of your dog’s illness, the type of illness, what the clinic can offer and (unfortunately) sometimes budget limitations will influence what’s ultimately done.

Additionally, sick dogs should be kept away from other dogs to help reduce the risk of disease transmission. That includes no going to day care, parks or any other places where non-household dogs would be encountered. For how long? That’s hard to say without a diagnosis but I’d aim for at least 2 weeks.

My dog is healthy. What should I do?

Let’s try to keep your dog healthy by limiting its contact with other dogs, especially large numbers of different dogs with unknown health status. Contact with small, stable groups (e.g. an established walking group, a small day care with the same dogs that don’t see a lot of other dogs) is lower risk. Logically, dogs should be kept away from any obviously sick dogs.

What about vaccines for my dog?

Vaccines are available for some of the causes of CIRDC. For any dogs that have frequent contact with other dogs, vaccination against Bordetella bronchiseptica and canine parainfluenza virus is important. Mucosal vaccination (intranasal is preferred, oral is second best) should be done whenever possible. Critically, it is important to use a vaccine that covers both Bordetella and parainfluenza. I suspect that loss of parainfluenza protection because of increased use of Bordetella-only oral vaccines might be driving some of the issues we’re seeing.

Canine influenza (flu) vaccination can be considered too, but it can be hard to get (there are currently some production and backorder issues) and canine flu is a pretty sporadic disease.

My dog is healthy but higher risk for disease or complications (see high risk list above). What should I do?

Take the same precautions described above for non-high risk dogs, but with more rigour. I’d also be quicker to recommend respiratory disease vaccines for these dogs, irrespective of how much contact they have with other dogs.

My own two dogs probably fall into those two risk categories. Both have fairly cloistered lifestyles from an exposure standpoint. Their dog contacts are largely restricted to a small number of well known and similarly low risk dogs.

The young pest, Ozzie, is a one-year-old, healthy Labrador, and is therefore at low risk of exposure and low risk for serious disease. He got an intranasal Bordetella/parainfluenza vaccine this summer so he could go to day care when we were away at a cottage (to give us some Ozzie-free afternoons to relax). The old guy, Merlin, is an 11-year-old Labrador who’s on chemo for chronic lymphoid leukemia. His exposure risk is low but he’s probably at some degree of greater risk for serious disease if he gets infected. There doesn’t seem to be anything remarkable going on locally compared to normal, so it’s status quo for them, but I’d be quicker to vaccinate Merlin if I decided vaccination might be warranted, especially if influenza hit the area.

As with any emerging issue, the current situation in the US is fluid, and we’re trying to sort out more about what’s happening. At the moment, for your average dog owner, it’s still just a matter of some common sense precautions and good dog care.

As concerns about an outbreak of canine infectious respiratory disease in the US continue, we’re still at a point where media hype massively outweighs any true data. Not much new has been reported recently. If anything, I’d say we’re hearing more about things being stable in different areas, that investigations haven’t turned up anything beyond the usual suspects, and the typical messaging to use common sense but relax.

One thing that is getting some press is a suggestion that a rather bizarre little bacterium might be involved in some of the current canine illnesses. “Might” is the key word though. At the risk of having to eat my words later, I’d guess this bug is probably not going to pan out to be a driver of widespread disease – it’s possible, but there’s a long way to go before we can say that with any confidence. In the meantime, let’s recap what we know:


In the spring of 2023, the New Hampshire Veterinary Diagnostic Lab reported they were investigating a potentially novel organism as a cause of respiratory disease in dogs. I remember reading about it in a taxi on my way to the airport in DC; I thought it was interesting, but in my experience, the vast majority of “new pathogens” end up being commensal organisms (i.e. also present in lots of healthy dogs) or otherwise not panning out to being relevant. But, I never totally discount the possibility, and was glad to see it investigated. The initial (and I think only) report involved a pretty small number of dogs. They found snippets of DNA that were similar to IOLA KY405 in 21/31 samples. Their latest update is here.

What on earth is IOLA KY405?

It’s hard to say. As far as I know, it’s only previously been reported in two papers from the same lab in Japan, where it was found in samples from humans with respiratory disease. It’s reported to be a bacterium with a very small and bizarre genome.

  • The first study (Fukuda et al. 2014) reported finding gene sequences from IOLA KY405 in a lung fluid sample from one person, then followed up by finding those DNA bits in samples from 6/386 samples from other patients with respiratory disease. Some unique aspects of this bacterium are a very small genome, similar to Mycoplasma  (just over 300K base pairs; for reference, staphylococci have about 2.8 million base pairs), and a very high AT content (about 80%).
  • In the second study (Fukuda et al. 2021), they presented the whole genome sequence of the organism. They also used PCR to look for it in samples from more people with respiratory disease, and got positive results in 2.7% of about 500 samples. Eight of the 11 positive patients had significant underlying disease, and five were being treated with corticosteroids or immunosuppressants. So, these individuals had lots of other excuses to have respiratory disease or to be infected with something that’s minimally pathogenic.

Someone with more background in genomics would need to assess the papers to know how confident we can be in the results. If they are real, then the researchers have found a small bacterium that’s similar to Mycoplasma, which maybe isn’t surprising since some Mycoplasma are able to infect lungs (but more often are present as normal respiratory tract inhabitants.)

What we’re still lacking is 1) actually growing the bug to confirm its existence, and most importantly, 2) context. Finding DNA from this bug in a small percentage of people with respiratory disease is interesting, but could it be just as common in healthy individuals and just part of our normal microbiota? I don’t think we can say either way at this point.

When something’s only reported by one group over a long period of time, it raises the question of why. Is one group just way ahead of the curve, or is this something that other people have tried to find but have been unable to replicate the results (or have looked at and dismissed as not being worth investigating)? Publication bias is a big problem in cases like this. If other groups have put in a good effort to investigate this and found nothing, odds are high we wouldn’t find out because there’s a tendency to not publish “negative” results, even though those data are really important. So, we have no idea if there are only two papers because only one group is looking for it, or whether lots of other people have tried and failed to find anything similar.

Genome-based pathogen discovery is an established and effective method. It looks at all the genetic bits we can find in a sample, then tries to assemble them into something interpretable, and then we try to figure out what it actually all means. It’s challenging because we have a vast population of viruses and bacteria that are normal inhabitants in our bodies and those of animals. Most are harmless. Many are beneficial. Some can cause disease. Sorting out into which category a new organism fits takes a lot of work, and is rarely straightforward.

We’ve been lead down the wrong path many times before by reports of a “new” organism found in sick animals (e.g. the panic about canine circovirus). People freak out, start testing more sick animals, find it, and freak out more. However, when the science catches up with the hype, we often realize that we can find the bug in the same percentage of healthy animals, and it’s just a normal inhabitant that we’ve recently discovered, versus something new that is causing disease. With modern molecular techniques, our ability to find something often surpasses our ability to understand it.

While it sounds like I’m downplaying the relevance of this finding, that’s not my intention. I suspect IOLA KY405 is a real organism, I just need a lot more convincing that it’s relevant to disease (in people or animals). In an ideal world, the New Hampshire lab and others would be investigating this robustly, including field studies in dogs, to deterimine what the real story is. Lack of funding for companion animal infectious disease research usually slows these to a crawl. The report from the New Hampshire lab adds good context:

  • It is important to note that this is a preliminary finding, and under normal circumstances of a study we would not release these findings. The technology and methods used by the HCGS include cutting edge metagenomic sequencing, and multiple bioinformatic pipelines that are uncommonly utilized in veterinary medicine. Additionally this is an uncommonly studied group of bacteria. There are multiple experiments that need to be run in order to clarify correlation vs. causation, and this gives reason for pause in releasing the findings. However, the syndrome is ongoing and there may be an opportunity to benefit animal health as we continue to validate these initial findings. There is a chance that this preliminary data is disproven with further study, but at this point it does appear that the bacteria we have identified is a potential causative agent.”

Those disclaimers are key, but unfortunately are usually left out of the media reports.

This is an important but very preliminary finding that needs to be studied. However, we also have to realize that most findings like this don’t turn out to be anything big (or anything at all). We can’t dismiss the potential and it’s great to see the work being done, but we need to make sure that we don’t jump from a preliminary finding of some unusual DNA sequences to “here’s the answer!” which is what human nature wants us to do.

As concerns about canine infectious respiratory disease in the US have taken up most of my time lately, let’s merge that issue with what I had hoped to be the focus of the week: World Antimicrobial Resistance (AMR) Awareness Week.


Despite lots of media attention and associated fear, we’re still not sure what’s going on with all these coughing dogs, or even if there’s really a story at all. This could be something new, but more likely, it’s the usual suspects doing their usual thing (possibly at higher rates in some areas, as fairly commonly occurs periodically).

In the unlikely event this is something new, it’s likely viral. It’s much less likely to be something bacteria.

Either way, we have to think about how that might impact treatment. The short answer is: it probably doesn’t affect our treatment approach.

Viral respiratory illness can’t be treated with antimicrobials. Some affected dogs will develop secondary bacterial pneumonia, and antimicrobials are indicated in those cases. But it doesn’t matter what virus triggered it.

Primary bacterial respiratory infections in dogs are less common. The bacterium Bordetella bronchiseptica is typically the number 2 or number 3 overall cause of canine infectious respiratory disease complex (CIRDC), after canine parainfluenza virus and maybe canine respiratory coronavirus. Streptococcus zooepidemicus is a rare cause of CIRDC and usually causes sporadic but really nasty (often rapidly fatal) disease, most often in shelters or other high stress settings. Secondary infections (i.e. things that move in after a virus has already caused some damage) can be caused by a variety of different bacteria.

When considering antimicrobial therapy, we need to think about the disease we’re targeting. Cough isn’t a disease. It’s a sign of disease. Cough can be triggered by infection, be it bacterial or viral, and often persists even after the infection is over. Too often, we get into a mindset of “the dog is coughing really badly” or “the cough isn’t going away” and we unnecessarily reach for antimicrobials, hoping they will somehow help, when in reality we just need to give the dog more time to fully recover, or we can use other approaches to decrease inflammation and suppress the cough if that’s the part that’s still a problem.

Our 2017 Antimicrobial use Guidelines for Treatment of Respiratory Tract Disease in Dogs and Cats from the International Society for Companion Animal Infectious Disease are a good start for thinking about how to manage these sick dogs. We’re starting a revision, and I think we’ll see a few changes to the guideline, but most of the original content still applies. Some newer approaches to care of these cases are already incorporated into the antimicrobial use guidelines available to veterinarians through the Firstline app (see image below).

Here are some of the basic recommendations:

Basic upper respiratory tract infection: cough, runny eyes and nose, maybe a fever and a bit quiet, but dog is usually pretty bright overall.

  • No antibiotics.
  • This is likely viral, and if it’s bacterial, it’s mild and should resolve on its own. Tincture of time and supportive care are recommended.

More serious upper respiratory tract infection that is probably bacterial: more advanced signs of disease, mucopurulent (yellow, goopy) nasal and ocular discharge, but lungs are clear.

  • Consider antibiotics but most cases probably don’t need them.
  • As these cases are more severe it’s easier to justify antibiotics, but I can often go either way and have a fairly high threshold to say “start antibiotics” (at least right away). However, it’s not unreasonable in many cases.
  • Doxycycline is the drug of choice for treatment. It’s lower tier, effective, safe and works against the main bacterial pathogens of concern.
  • If there’s no response to initial treatment, we need to back up and think about whether that’s because it’s a bacterial infection is not responding, or whether what we’re seeing is more likely viral or non-infectious. That’s often hard to sort out, but we need to consider it carefully rather than just jumping to another drug every time we don’t get the response we expect on the first try.

Mild/moderate pneumonia: Varying upper respiratory signs, but with signs of lung involvement, such as audible crackles and wheezes, and radiographic evidence of pneumonia. These dogs are sicker but are stable. They are breathing reasonably normally, are quiet but alert and do are not crashing.

  • Antibiotics are definitely indicated.
  • Doxycycline is still the drug of choice. Along with the points listed above, it achieves good drug levels in the lung and is a great first line choice for pneumonia. If it’s a rare, milder or earlier Strep zooepidemicus pneumonia (mainly we’d suspect this because it’s part of an outbreak), amoxicillin would be fine instead, but usually we want a broader spectrum drug than that and one that gets better levels in the lung.
  • Some people are suggesting that enrofloxacin seems to work better in some of the more recently reported cases. That could be a true reflection of better activity against certain bugs, or issues with resistance to other drugs, but could also just be a function of using enrofloxacin as a second line option later in disease (where its use corresponds to natural resolution of disease, versus a true effect of the drug). It’s a good observation and I don’t dismiss anecdotes like that, I want to explore it more to try to tease out the reasons versus making a full switch to regularly using a higher tier drug like that. It could be that enrofloxacin is a better drug (overall or in specific areas), but given the potential issues with use of this higher tier drug, we’re best to be cautious and try to make sure we really have a firm indication that it’s necessary. If we put every dog with pneumonia on a fluoroquinolone like enrofloxacin, we won’t be able to use the drug for long because resistance will quickly become an even bigger problem.
  • Azithromycin is another option for treatment of pneumonia, as it also achieves great levels in the lung.
  • The more convinced I am of a true treatment failure, and the more severe the disease, the more I’d escalate, but sometimes we can be mislead by our observations. If it’s clear that doxycycline isn’t working in one area but another drug is, it’s logical to use that other drug, but we want to make sure we’re limiting changes in approaches and use of higher tier drugs as much as we can, because the more we use them, the quicker we lose them.

Severe/septic pneumonia

  • One of my big considerations when deciding whether to use more broad spectrum treatment in any patient is “What’s likely to happen if my drug choice is wrong?” If the answer is “the animal will probably die,” I can justify using a higher tier drug or combination to help ensure it’s effective on the first try. For the cases above, I wouldn’t typically jump to a broader spectrum combination, but with severe septic pneumonia we are dealing with a subset of dogs that are really sick with significant lung disease. They are not oxygenating well. They have low blood pressure or other signs of severe systemic inflammation. They’re at risk of crashing hard and fast, and I need to get the infection under control pronto. So, I can justify a broad spectrum antimicrobial – nothing crazy (e.g. not meropenem), but a broad spectrum drug/combination that’s higher tier and something I generally avoid, but am comfortable using in a situation like this.
  • Intravenous clindamycin & enrofloxacin, ampicillin & enrofloxacin, or an intravenous 3rd generation cephalosporin (e.g. ceftiofur, cefotaxime) would be reasonable choices in these cases.

How long do we treat a dog with pneumonia?

We have very little duration of treatment data for most infections we deal with in veterinary medicine, especially companion animals. We tend to be quite risk averse and therefore default to really long antimicrobial treatment courses.  Based on the short durations of antimicrobial use in people with similar conditions (where there’s lots of evidence that shorter is better), and even in cattle (where there’s lots of evidence and desire for shorter courses because it’s a hassle treating them), we need to be aim for shorter courses of antimicrobials in pets too.

  • Five days is what I’m recommending now. We don’t have data for that, but we also don’t have data for using any longer duration of treatment, and since we have good comparative data from other species, increasing anecdotal evidence and a duty to consider a “least harm” approach, I’m happy with five days. We can always go longer if needed, based on patient response and complicating factors, but short durations are often effective, come with fewer adverse event risks, and are cheaper and easier for owners (who, realistically, often don’t complete long treatment courses when their pet is doing well anyway).

We have to remember that antibiotics are there to help resolve bacterial infection, but eliminating the infection doesn’t immediately fix everything. Signs like cough and radiographic changes can linger, and more antibiotics don’t help those things resolve any faster.

So, while we’re not sure what’s going on with all the coughing dogs in the US right now, we can be reasonably confident we know how to treat them. Our usual approaches will still work. We need to be conservative with antimicrobials, but also ready to use appropriate drugs (including broad spectrum, higher tier drugs) when indicated. The right drug at the right dose for the right patient still applies.

Next in the World AMR Awareness Week (WAAW) series is a recycled post about our cat Rumple from this past summer. It’s not just because I’m lazy. It’s largely because it’s a great topic and an issue for which there’s a lot of unnecessary antibiotic use (especially in cats).

Rumple’s an indoor-outdoor cat that we adopted years ago through Guelph Humane Society’s working cat program. He was deemed unsuitable for a household, so we got him as a barn cat, but he migrated from the barn to the deck to the garage to being a part time indoor cat afterall (as I write this, he’s stretched out sleeping on my bed). He’s a big suck who spends a lot of time inside, but wouldn’t tolerate being inside 24/7. That creates some risks.

As I was working at my desk, Rumple wandered over the keyboard (typical cat editing that I don’t always realize) and I noticed a little scab on his ear and one on his neck. I figured he’d tangled with something outside (we occasionally see other cats around here, as well as the usual wildlife). No big deal.

However, a few days later, I felt a soft fluctuant swelling on his neck, just past his head. It wasn’t overly painful, there was no inflammation around the site and he seemed perfectly normal otherwise, all of which is consistent with a localized abscess.

Antimicrobials? Nope.

Antimicrobials don’t work well for an abscess. The drugs don’t penetrate the abscess well, and the environment inside the abscess can hinder them from working.

More importantly, we have a much more effective treatment: incision and drainage, as illustrated below.

Clipping around a cat bite abscess in preparation for incision and drainage.
Draining cat bite abscess.

Since he was systemically healthy and there was no evidence of a tissue infection beyond the abscess, incision and drainage was all he needed. There was a soft spot under a scab that I opened up with a hemostat and we got big gush of pus. (Abscesses can be really rewarding to treat when they drain like that!) I flushed it out quickly (he’d had enough of me at that point), and that was it. It stopped draining quickly so he didn’t need any more wound care. A few days later, the site had a bit of a scab but is otherwise normal (see last picture below).

If I’d given Rumple antimicrobials when I drained the abscess, one might have thought “wow, look how well the antibiotics worked – it cleared up right away,” but this shows that they weren’t needed. However, as clinicians, we often feel a need to “do something,” even though that “something” may not be required. We also tend to be quick to ascribe good responses to what we did, vs what was going to happen anyway.

What percentage of cats in Rumple’s situation would have been treated unnecessarily with an antimicrobial?

  • Probably a very high percentage.

Why is that? There are lots of potential reasons:

  • Risk aversion
  • Habit
  • Lack of education on abscess management
  • Lack of confidence treating without antimicrobials.
  • Veterinarians thinking the client expects it.
  • Owners asking for antimicrobials.
  • More fear of someone complaining that the veterinarian didn’t use antimicrobials if things don’t go well, than concern about adverse effects of antimicrobials (in the individual or the population).
  • It’s easier and quicker to give an antibiotic than to explain to an owner why it’s not being given.

Sometimes, animals do need antimicrobials if they have an abscess, such as when they have concurrent active tissue infection or systemic disease. (Rumple had a soft tissue infection a few years ago, likely also from a bite, but that time he needed antimicrobials.) In most cases, though, cat bite abscesses are discrete abscesses that just need incision and drainage.

Not using antimicrobials is easier on the cat (no need for pilling or injections), easier on the owner (no need to pill the cat, cheaper), and means there are no risks of adverse drug reactions or promoting antimicrobial resistance.

Another question that will come up about this case: Did I culture Rumple’s abscess?

No. There are a few reasons I chose not to do a bacterial culture, but the biggest one is that it doesn’t really matter what bug is present – I’m going to treat it the same regardless with incision and drainage. A culture is more useful if I am going to use a systemic antimicrobial, but since I wasn’t going to, it wouldn’t add any value (apart from satisfying my curiosity). Culture is a really valuable tool that’s underused overall, but it’s also overused in some situations, providing information that’s not needed or that can even be misleading. For your typical abscess that’s easily managed with incision and drainage, it’s pretty low yield.

After the initial post, a reader commented “why weren’t you wearing gloves”? Fair question. In the clinic, I would have. At home, it wouldn’t have been a bad idea either but to be honest, it was a quick procedure and I really didn’t think about it given the atypical circumstances. Gloves would have been to protect me and I washed my hands well. He was low risk for having a significant zoonotic risk or multidrug resistant bug. It still would have been a reasonable idea and in a clinic with a patient, I definitely would have. I think we tend to be a little lax doing things to our own pets at times.