As a journal Associate Editor and reviewer, I see lots of manuscripts about “new” viruses. I tend not to get too excited about most of them, because “new” is usually actually just “new to us” (or newly identified), because as technology improves, we are  able to identify lots of viruses that we’ve been living with for years. Viruses are part of our ecosystem, and most are harmless to us (and animals).

It’s common to find “new” viruses in sick people/animals, but they’re usually just background “noise,” because they can often be found just as frequently in healthy individuals. Differentiating something that’s “newly found but long present and harmless” from something that’s “been around and was an unknown cause of disease” from something that’s “truly a new emerging disease threat” is key (and sometimes easier said than done).

That brings me to a virus I wrote about in May: a “new” coronavirus that was found in 8 people in Malaysia who had pneumonia in 2017-2018. The virus was an alphacoronavirus that most closely resembled a canine coronavirus (notably SARS-CoV-2 and the common canine respiratory coronavirus are betacoronaviruses). The virus was named CCoV-HuPn-2018 (canine coronavirus-human pneumonia-isolated in 2018).  Whether these infections were a rare or one-off event wasn’t clear at the time.

However, a new study has reported finding this virus in a person in Florida who had returned from Haiti in 2017 (Lednicky et al. 2021). The person had pretty mild disease, but it was investigated and this same virus was found.

The fact that the person had only mild disease is important for context – very rarely do people with mild disease get tested, and even more rarely would a hunt for a new virus be performed in people with mild disease that had negative tests for the “usual suspects.” But they did test this person, and they once again found that the virus looks like it came from dogs (at some point), and it was found half a world away the same year.

This second report generates a lot of questions:

  • Was this another rare event, or does it represent a common, mild pathogen that’s circulating internationally?
  • Why were the cases in 2017 for both reports? Is this a virus that spread that year and burned out, or has there been limited study of it since then and it’s still with us (and we’re just not testing for it)?
  • What’s the role of dogs? There’s no information about the epidemiology of disease yet. Is it transmitted dog-to-human or did the dog-origin virus move into people and is now spread human-to-human?
  • Can this specific virus be found in dogs, or is this truly a human variant now?
  • Can the virus be spread back to dogs? If so, can it spread between dogs, can it cause disease in dogs, and can it be spread back to people?

These are all reasonable questions that could use more study. While this virus doesn’t seem like a big deal, it’s worth understanding more about the coronaviruses with which we live.  “Relax, but pay attention” is my typical response to new reports like these, and I think that’s fair here. The authors’ conclusion also fits with that:

Our data highlight the potential among coronaviruses for rapid evolution combined with frequent recombination events, leading to periodic emergence of strains capable of crossing species barriers into human populations. In many instances such strains would appear to be of low virulence for humans, as reflected in our work with PDCoV and now CCoV-Haiti; however, the potential for such strains to carry or acquire genes capable of causing severe disease in humans remains of clear concern.

There’s not as much to update about SARS-CoV-2 in dogs as there was in cats. We have more numbers than we did before, but the overall issues in dogs and our understanding of them haven’t really changed.

Spoiler alert: dogs and owners can both relax, as the risks are very limited.

Are dogs susceptible to the SARS-CoV-2 virus?

Yes, but… not very… maybe.  It depends on what you mean by “susceptible.”

Nice and clear, eh?

There’s a difference between getting infected and getting sick. Yes, dogs can clearly be infected. However, they don’t seem to be as susceptible as cats, and it’s debatable whether they get sick from the infection… I’m still a bit on the fence about that (more below).

How often do dogs get infected?

This is where we’ve gotten the most information recently.  Studies that have looked at dogs living with COVID-19-infected people have generally identified impressive rates of human-to-dog transmission. In these studies, researchers either look for evidence of the virus itself in the dogs (usually using a PCR test) or they look for antibodies against the virus in dogs’ blood. The problem with PCR testing is that there’s a very narrow window of virus shedding in this species, so it’s easy to miss the window (in which case the test comes back negative even though the dog was infected) based on sampling logistics and timing. With good antibody tests, we can get a good idea of whether dogs were infected in the past (although there are potential issues there too) because the antibodies hang around for a lot longer.

Early in the pandemic, the virus was identified by PCR in dogs from infected households, setting the scene for further studies. The best initial effort was from Hong Kong, where they identified the SARS-CoV-2 virus in nasal, oral and rectal swabs from 2/15 dogs that were quarantined because their owner was infected. Neither dog had signs of infection, both developed antibodies to the virus, and gene sequencing showed that the viruses in the dogs were the same as the viruses in their respective owners. Subsequent work has found similarly, fairly low rates of PCR-positivity among dogs with household exposure to infected people (e.g. Hamer 2021).

Serological studies looking for antibodies against SARS-CoV-2 in dogs have shown that transmission is actually much more common than this, with rates of up to 46% in dogs from infected households (e.g. Stevanovic 2021Hamer 2021). The results from our (hopefully soon to be submitted) Canadian study were similar, with about 43% of dogs with household exposure testing positive for antibodies to the virus.

Some studies have tested blood from undefined populations of dogs, for example by testing leftover samples of blood submitted by veterinarians to diagnostic labs. These studies tell us very little, because there’s no accompanying info about the dogs, particularly whether dogs were exposed to anyone with COVID-19. Not surprisingly, low rates of antibody detection (0.2-3.4%) have been found in these stuies (e.g. Ito et al. 2021,  Patterson 2020, Smith 2021). Whether these positives represent infected dogs from households with infected people vs false positive results isn’t clear.

Do dogs get sick when they are infected?

That’s still unclear. In small experimental studies, dogs could be infected but didn’t show any signs of disease (e.g. Shi et al. 2020, Bosco-Lauth et al. 2020). Field studies are harder to evaluate because there’s nothing specific about the clinical signs we’d expect to see from SARS-CoV-2 infection in a dog (e.g. lethargy, coughing, sneezing, decreased appetite and other flu-like signs). These non-specific signs can be caused by lots of diseases in dogs, so if we find a dog that has evidence of previous SARS-CoV-2infection (i.e. antibodies) and it was reported to have been sick, it’s hard to say whether it was sick because of SARS-CoV-2 or whether it was sick because of something else and had an incidental SARS-CoV-2 infection. Larger and better designed studies are needed to figure that out.

In our preliminary work, we found an association between antibodies in dogs and the owner reporting that the dog was acting sick around the same time the owner was infected. That is to say, this finding was significantly more common in dogs that had antibodies than in those that didn’t, suggesting infection with SARS-CoV-2 could have caused (or contributed)  to illness in (at least some of) the dogs. However, the signs that were reported were very mild and often vague (e.g. “the dog was a little quieter”), so while it might suggest that dogs can get sick, it would seem any illness is generally really mild.

Serious disease from SARS-CoV-2 has been identified in cats, and there has been some chatter about a very small number of dogs getting really sick or dying. However, when you consider the massive number of people that have been infected and the apparent high rate of transmission to dogs, if there was a true serious disease issue, I think we’d see more evidence of it by now. Also, we’re going to find incidental infection in some dogs with serious diseases or that die for other reasons, just because of the large number of infected dogs.

My take-home message on this at this point – with the variants that are currently circulating – is that SARS-CoV-2 poses very little health risk to dogs. More work on that is underway, though.

Can dogs infect other animals or people with SARS-CoV-2?

Probably not. Dogs are probably much lower risk than cats, and the even the risk from cats is still unclear. The fact that the virus has been isolated from dogs (e.g. Hamer 2021) is a concern, because if there was live virus in the dog’s nose, you have to assume there was some risk of exposure to individuals in-contact with that dog. Whether there was enough virus being shed to actually infect someone is completely unknown, and it’s probably exceptionally rare for a dog to be shedding enough virus to pose a risk. Experimentally, dog-to-dog transmission has not been seen. That’s not a guarantee that it can’t happen, since these experimental studies were conducted in an artificial environment with very small numbers of animals, but it provides more support of limited risk.

Overall, I’d say the risk of SARS-CoV-2 infection from dogs is very low. I don’t think we can say it’s zero (we can’t guarantee much with this virus), but I think it’s very unlikely that a dog would pose a realistic risk to a person or another animal.

That said, why chance it? If a dog is infected or at risk of being infected (e.g. living in a household with an infected person), it should be kept away from other people and dogs. Dogs interact nose-to-nose and nose-to-bum a lot, and have a lot of contact with their faces, so keeping exposed dogs under control and away from others is a reasonable precaution. We’ve also seen transmission of other respiratory viruses between neighbouring dogs through fence-line contact, so this should be avoided as well, just in case.

Could dogs be an important reservoir of the SARS-CoV-2 virus once it’s controlled in people?

No, dogs are not susceptible enough to the virus to serve as a reservoir. To be a reservoir, the virus would have to be able to keep spreading dog-to-dog. That’s not going to happen because of the low susceptibility and short shedding time in this species. You’d need a very large number of dogs in regular close contact to even begin to have a risk, and then only IF dogs were able to effectively transmit the virus.

What about variants of concern (VOCs) in dogs?

Variants of SARS-CoV-2 such as alpha have been reported in dogs (e.g. Barroso-Arevalo 2021 and Hamer 2021). That’s expected as different variants become dominant in people, because people are the source of infection in dogs. Unless a human variant has more or less affinity for dogs than the original strains (possible, but not very likely), we expect the strains infecting dogs to be a reflection of the strains infecting in humans. I assume that large numbers of dogs have been infected with the delta variant as it now dominates in people as well.

Could new variants of concern emerge in dogs?

Almost certainly not. Variants develop by chance during viral replication. The more transmission, the more replication, the greater the risk of a variant emerging through random mutation. Since dogs are not going to be involved in sustained transmission of the virus, there’s pretty much no chance we’d see a new variant emerge in dogs and spread back to people. Yes, it just takes one replication error and transmission event for a variant to emerge, but the odds of it happening from a human-to-dog transmission AND the dog then infecting a person are pretty much zero.

Could dogs be a bridge to infecting wildlife with SARS-CoV-2?

Probably not, or at least much less likely than cats. Their low susceptibility, short period of infection, limited (if any) infectivity to others, and limited direct contact with susceptible wildlife mean the odds of dogs being infected by their owners and then infecting wildlife are very low.

So, we shouldn’t worry about SARS-CoV-2 in dogs?

Worry, no.  But we still need to pay attention to it.

What should be done with dogs?

Do the same as for cats:

  • If you are infected, try to stay away from animals… all animals, human and otherwise.
  • If your dog has been exposed to a person with COVID-19, keep it inside and away from others.

The risks to and from dogs are exceptionally low, but precautions are common sense and easy… a few short term mild hassles for some peace of mind.

Ultimately, dogs are part of the family – so if your family is isolating, the dog should be included in that too.

I’ve had a couple of reports today about an apparent H1N1 influenza outbreak in dogs in the US. Note that I said influenza in dogs, not canine influenza – there’s a reason for that, explained below…

The situation revolves around a respiratory disease outbreak in a dog kennel in California, and PCR testing of some of the sick animals identified H1N1 influenza. Clinically, it sounds like a moderate to severe outbreak, with a reasonable number of infected dogs.

We generally see two types of influenza in dogs:

  • “Canine flu” is caused by dog-adapted strains of influenza A, and they are maintained through spread in the dog population.  The two main canine flu strains that we know about are H3N8 (which seems to have disappeared) and H3N2 (still sporadically present in the US and endemic in some parts of Asia).
  • Spillover infections in dogs with flu viruses that are primarily adapted to other species are also detected occasionally.  Most often this involves stains of influenza A that are adapted to humans, when a dog gets infected from its owner. We usually assume that these are “dead-end” infections, in that the dog doesn’t pass the virus on any further, because it’s not a canine flu virus so the infected dog likely doesn’t produce enough virus to infect others.

Back to the H1N1 in California.  We periodically see human (previous pandemic) H1N1 virus in dogs, which they catch from their owners. However, there can be different strains of the virus even within a single flu “type” like H1N1. If we look at H3N2, we have human H3N2, canine H3N2, swine H3N2, and so on. While they are all H3N2, they are adapted to a specific animal species and don’t infect others as readily. The important question in this case is, what type of H1N1 influenza is involved?  Finding a single case of human H1N1 flu in a dog wouldn’t surprise or concern me. But detecting a whole outbreak is a different story.  More information is needed, since this could range from an interesting story to a serious canine disease threat.

Here are the big questions:

Is the diagnosis confirmed/solid?

  • Is this really on outbreak of H1N1 or is it a different flu strain?
  • Is it an H1N1 outbreak, or was there an outbreak of something different and some incidental H1N1 infection was detected in the process of testing? (Unlikely since it seems like at least a few dogs were diagnosed with H1N1.)

Is this “human” H1N1 in dogs?

  • Is this outbreak due to spillover infection from humans, or is it from a different source? Presumably someone’s sequencing the virus, which will help answer that question. If it’s actually H1N1, hopefully it’s just an oddball scenario with a cluster of human H1N1 flu infections that will die out, versus an indication that we have a new canine H1N1 flu strain, or a human strain that is now more adept at infecting dogs.

Is this virus a “canine” flu virus?

  • It’s too early to say. Hopefully not. We don’t want a new flu strain in dogs for lots of reasons.  A new strain could spread easily through the dog population because no dogs would have any immunity to it. That can cause a significant amount of disease.  There would also be potential zoonotic concerns with a new strain. H3N2 and H3N8 canine flu viruses haven’t been significant zoonotic risks. They’ve stayed in dogs and haven’t spread to people, as far as we can tell. However, flu viruses like to adapt and change, and we just don’t want any more influenza viruses floating around, in terms of their potential for direct infection of people or the potential for recombination with other human flu viruses which could make more new flu strains (to which we might not have any immunity).

At this point, I’m interested and curious but not worried. Hopefully this situation is being investigated thoroughly (I assume it is).

A recent paper in the Journal of Clinical Pharmacy and Therapeutics entitled “A doggy tale: Risk of zoonotic infection with Bordetella bronchiseptica for cystic fibrosis (CF) patients from live licensed bacterial veterinary vaccines for dogs and cats” (Moore et al. 2021) discusses (as the title suggests) human health risks from commonly-used B. bronchiseptica vaccines for pets.

Bordetella bronchiseptica is just one of a few different bugs that causes “kennel cough” in dogs (more accurately called canine infectious respiratory disease complex (CIDRC)). A variety of vaccines against B. bronchiseptica are available, including both oral and intranasal formulations that contain “modified live” bacteria, and injectable formulations that contain killed bacteria. Modified live vaccines (MLVs) contain attenuated (weakened) forms of the bacterium or virus in question that are not supposed to be able to cause disease, but induce a more natural immune response. So MLVs aren’t completely innocuous, and therefore generally aren’t used in immunocompromised individuals, because of the chance that even a modified/weakened bug could cause disease in such a person.

Bordetella bronchiseptica causes disease in a number of different animal species, but seems to be a rare cause of disease in people (unlike it’s cousin, Bordetella pertussis which causes whooping cough). However, infection with B. brochiseptica can occur in people, and those with diseases like cystic fibrosis (CF) are presumably at higher risk.

The authors of the paper state that patients with CF “should avoid exposure to live veterinary bacterial vaccines and seek animal vaccination utilising non- live vaccines.

  • I agree with point #1. High-risk individuals should avoid direct exposure to live vaccines, which can occur during vaccination of the animal, as the vaccine is squirted into the dog’s mouth or nose (and sometimes splattered elsewhere). Ideally, high-risk owners should not be in the room when such a vaccine is given. That’s a very practical, very easy and probably the most effective preventive measure.
  • I’d argue against point #2. Injectable killed vaccines for B. brochiseptica are inferior to MLVs, and that has relevance to the exposure and health of a high-risk owner too.

Here is my thought process when is comes to this situation:

  • No vaccination or less effective vaccination increases the risk of disease in the pet.
  • Bordetella bronchiseptica can cause disease in high-risk people, so we don’t want the pet to be infected.
  • Disease probably also increases the risk of exposure of people to this bacterium and others (from coughing/sneezing pets).
  • Disease also increases the risk that the pet may need to be treated with antibiotics, leading to an increased risk of antibiotic resistance in other bacteria carried by the pet, and some of those bugs can also be transmitted to people.

Millions of doses of these MLVs have been given to dogs with little to no clear evidence of risk to people. The main reference to which the authors point is a report about a mild infection in a boy who was squirted directly in the eye with a vaccine. That’s a lot different in terms of exposure than having contact with a recently vaccinated dog.

The issue of residual modified live bacteria from the vaccine being present in the dog’s nose or mouth for a while after vaccination is usually raised. That’s fair, to some extent, but it ignores the big picture. Yes, there is a very minimally risk that the modified live bug might be present in the dog’s nose/mouth, but there are lots of other (and more dangerous) bacteria in the nose/mouth of every dog. The risk is basically no different from a dog that was recently vaccinated and one that has not been vaccinated, because it’s the more common bacteria found in both dogs that I’m most worried about.

The statement that vaccination “requir[es] a period of CF patient exclusion from the shedding dog,” is not supported by anything I’ve ever seen and doesn’t make sense to me given the above thought process.

Like most things, we need to consider the cost-benefit in each situation.

What’s the human health risk of using MLVs for B. brochiseptica in dogs?

  • Exceptionally low.

What’s the benefit of using MLVs for B. brochiseptica in dogs?

  • Improved animal health, and I could argue reduced human health risks from decreased exposure to sick animals (because we have to think beyond just the risk from the vaccine).

There’s also a statement in the paper that “CF pharmacists, hospital pharmacists and community pharmacists are important custodians of vaccine-related advice to people with CF, who are frequently consulted for such advice. “

  • Very true. However, I’d add the need for a One Health approach. Veterinary input is needed for a proper risk assessment, and to put the issues into context for the individual pet/pet owner. It would be nice to see papers like this written in collaboration with veterinary experts, and for pharmacists and veterinarians to engage more with each other in situations like this. Connections between pharmacists (and many other human healthcare professionals) and veterinarians tend to be pretty poor.

As I mentioned recently, we’re tracking anecdotal reports of increased respiratory disease activity in dogs in Ontario.  If you have observations or cases to contribute/report, please take a few minutes to fill out our short survey here:

https://uoguelph.eu.qualtrics.com/jfe/form/SV_eP6E6AzIiJfnDlY

Infectious respiratory disease is endemic in dogs everywhere, so there’s always some disease activity going on. Sometimes we see what are likely true outbreaks, caused by either by our usual suspects or by something we haven’t yet identified. Sometimes the “outbreaks” are actually just more attention being paid to the normal level of disease.

Usually infectious respiratory disease is self-limiting in dogs – they cough, have a runny nose and eyes and feel run down for a few days, and then they get over it on their own. It’s really just like people with the common cold. However, sometimes more severe disease can occur, and I’ve had what I’d consider a lot more reports of serious disease lately, so we’re trying to sort out what’s happening.

So far, there’s not much to report. Some of our preliminary case maps are below; the size of the dots corresponds to the number of cases reported from that area. At this point, most reported cases are in Toronto, but there are also more dogs and more people there, so we have to be cautious not to over-interpret that.

Most reported cases have also been in dogs not vaccinated against “kennel cough.”  Those vaccines only cover some of the potential agents of canine infectious respiratory disease complex (CIRDC), namely Bordetella bronchiseptica, +/- canine parainfluenza virus, so it’s hard to interpret that result with the limited information we have so far too.

Limited diagnostic testing has been performed, which isn’t surprising. Testing doesn’t usually influence care of the individual dog so most owners don’t want to pay for it, and we don’t actually recommend it as a standard tool (although it would potentially help us in situations like this).

More updates will follow if I get more reports.  Please fill out the survey if you have additional cases to contribute.

Key points for any concerned pet owners:

  • If your dog is sick, keep it at home.
  • Don’t let your dog interact with sick dogs. In particular, try to stay away from dogs that are coughing, or have runny eyes and a runny nose. (I know, that’s not easy in some situations.)
  • Consider “kennel cough” vaccination if your dog regularly encounters other dogs (talk to your veterinarian).
  • Preventing exposure at places like parks where your dog may encounter many other dogs of unknown health status is tough. If you’re concerned or your dog is at higher risk for complications (e.g. old, pre-existing respiratory or heart disease, brachycephalic breed like a bulldog), be more restrictive about your dog’s contact with other dogs, and talk to your veterinarian about the value of a “kennel cough” vaccine.

I get calls about concerns regarding increased respiratory disease in dogs all the time.

  • Sometimes, they’re the result of local disease outbreaks.
  • Sometimes, they’re just a result of increased awareness of the normal “baseline” disease rate, since “kennel cough” is always occurring at some level.
  • Sometimes, the circumstances just seem different, and we need to get more information.

The last of these is where I stand at the moment. I’ve been getting more reports of canine infectious respiratory disease, including a concerning number of reports of severely affected dogs (with some fatalities). My impression is that something unusual is happening. Most often, the cause is actually one of our “usual suspects,” – the bacteria and viruses that normally cause canine infectious respiratory disease complex (CIRDC). It’s often very difficult to sort these things out because limited testing is done, there are limitations on the testing that is done, and there’s no formal tracking system for these infections.

However, we want to figure out what’s going on if we can, because sometimes we do see new (or new-to-us) pathogens (like when canine influenza hit Ontario in 2018), or we can identify hot spots for disease transmission (we’ve implicated specific dog parks in the past).

So, once again, we’re trying to track respiratory disease cases in dogs in Ontario (and beyond Ontario, if people want to report them). We have a quick online survey to collect more information and hopefully figure out if something unusual is happening and what it might be.  The survey can be accessed here: https://uoguelph.eu.qualtrics.com/jfe/form/SV_eP6E6AzIiJfnDlY

I’ve recently received a few reports of serious (including fatal) respiratory disease in dogs in regions east of Toronto, Ontario. We often see localized variations in the incidence of “kennel cough” (aka canine infectious respiratory disease complex (CIRDC)), including sporadic outbreaks, but in this case there is particular concern about the number of severe infections and deaths. No cause has been identified yet, so I’m trying to collect some more information to facilitate the investigation and get a better idea of what’s happening.

If you are a veterinarian or or owner of a dog with recent respiratory disease in Ontario, you can help by filling out this quick survey: https://uoguelph.eu.qualtrics.com/jfe/form/SV_832gfSKndCStP7g

I’ll post more information about these reports soon.

We continue to track cases of canine infectious respiratory disease in various parts of Canada, for what it’s worth. The data are obviously a bit dodgy because it’s primarily from self-reporting, but I think we’re getting some interesting information. Cases seem to be slowing down, but we continue to get reports from the two main areas in Canada (and a trickle from the  US). Part of the clustering we’re seeing is probably due to local increased awareness and reporting, but I don’t doubt that a couple of reasonable-sized outbreaks have been ongoing.

Click here for the latest version of our canine infectious respiratory disease complex (CIRDC) map (December 31), now with the ability to display cases reported by month.  A snapshot of the map is also shown below.

Here are some additional details from the data we’ve collected via the reporting survey:

65% of affected dogs had been vaccinated against “kennel cough” in the past year.

  • That’s not too surprising. Kennel cough vaccines protect against one, two or three of the many potential causes of CIRDC, but not all of the causes, by any means. Furthermore, no vaccine is 100% effective. These data don’t tell us anything about how well those vaccines work (they actually work quite well).

Of that 65% of affected dogs that were vaccinated in the past year:

  • 40% were vaccinated orally: The oral vaccine only covers Bordetella bronchiseptica, which consistently comes in as the #2 cause of CIRDC in Canada. It’s a good vaccine for that bacterium but has less coverage than intranasal vaccines.
  • 29% got an intranasal vaccine: Intranasal vaccines in Canada cover Bordetella bronchiseptica and canine parainfluenza virus, giving protection against the top 2 causes or CIRDC. Some also include protection against canine adenovirus type 2.
  • 35% received an injectable vaccine: Injectable vaccines are less protective when it comes to CIRDC. Oral and intranasal vaccines provide better protection where the infection occurs – in the upper respiratory tract.
  • 26% were unsure of the vaccine type: So whether these dogs were truly vaccinated against kennel cough is unclear.

Over half of affected dogs had visited a dog park shortly before they got sick.

  • That’s not surprising at all, since CIRDC is spread dog-to-dog, and parks are a place where dogs congregate.  Groomers came in as the #2 most common previous contact, followed by doggie day care.
  • Since we just looked at sick dogs, we can’t say anything about risk factors (e.g. we don’t know if visiting a dog park was more common among sick dogs since we couldn’t compare them to healthy dogs).
  • There were a couple specific parks that were frequently named, so it’s likely there were some true hot spots of transmission at those parks.

Diagnostic testing was performed on 17% of sick dogs, but nothing remarkable was apparent in terms of diagnosis.

  • That’s actually a pretty high percentage for testing in cases like this. Testing isn’t commonly recommended for routine cases of CIRDC since the cost is hard to justify where there’s little impact of test results on individual patient care.
  • Testing is more useful when there’s an outbreak (to figure out what the culprit is and see if there are any control measures that might be applied), with imported dogs (worried about bringing in influenza strains), kennels (outbreak potential) and breeders (outbreak potential, risk of more severe disease in young and pregnant dogs).
  • Limited test results were provided on the survey but nothing remarkable was present.

Most of these outbreaks of CIRDC die out over time and we never find the cause.

  • Canine parainfluenza is always high on my list since it’s common (common things occur commonly) and can be missed with routine testing because the virus isn’t shed for long. By the time the dog is taken to a veterinarian and sampled, PCR tests looking for the virus may be negative (and other approaches like antibody-based testing aren’t usually done).
  • A “new” or (more likely) established but unknown cause of illness is certainly possible. There are undoubtedly many canine respiratory viruses out there that we don’t know about.
  • Introduction of canine influenza from imported dogs is always a concern. It’s a “foreign” disease, but canine influenza was introduced to Ontario a few years ago, and was ultimately eradicated (as far as we can tell).  Here, since there haven’t been any positive test results, it’s unlikely to be the cause. That virus is shed for a while in infected dogs, and I’d expect to see a positive result with a reasonable number of tests. Introduction of influenza into areas where few to no dogs have immunity to the virus would almost certainly result in more widespread disease. So, I think flu is pretty unlikely here, but the potential for flu is a reason to test. We’ve shown it can be controlled when it’s caught early, but if it’s not, it can cause a lot of damage.

Disease tracking like this won’t provide clear answers, but helps identify and refine things we need to look at, so I think there’s a role for it  as an easy, low-cost surveillance tool.

We’re continuing to track informal reports of canine infectious respiratory disease in a number of areas.  Click here for the latest version of our canine infectious respiratory disease complex (CIRDC) map (December 17).

We’re still getting lots of reports of sick dogs in Edmonton and Calgary, both via cases reported through our survey for the map and through emails that I get from various people.

The cause of illness in these dogs is currently still unclear. There have been a few positive tests for canine parainfluenza virus (our most common cause of canine infectious respiratory disease) and Mycoplasma (something I’m not convinced is truly a primary cause of disease in dogs), but nothing consistent. Limited testing and testing late in disease affect our ability to figure out what’s really going on.

Nonetheless we are seeing some clustering around specific parks and some cases linked to groomers, which is not uncommon in situations like this.

A few days ago, I wrote about our efforts to track infectious respiratory disease in dogs, based on informal reports of potentially increased disease activity in a couple of areas (particularly Calgary AB and Guelph ON).  Click here for the latest version of our canine infectious respiratory disease complex (CIRDC) map.

As expected, once we started asking, we started getting more reports of sick dogs in several areas. There are also some interesting potential links. For example, numerous cases from Edmonton have a link to Lauderdale dog park. It’s unclear whether that means there’s a true cluster associated with the park versus it simply being a very busy park frequented by a lot of dogs (sounds like it is) versus people being more likely to report exposure to that park. But it’s something to consider, and that’s a large reason why we do this kind of data collection. We’re not trying to get really accurate and specific information, we’re simply trying to spot trends and find things on which we can potentially act. The more data we have, the more we can hopefully figure out.

So veterinarians and dog owners, please keep reporting cases of dogs with suspected infectious respiratory disease through our survey, even if the signs are relatively mild. It’s quick and anonymous.

A few disclaimers:

  • The survey results and map are always going to be biased, since we depend on people to report cases. A cluster of cases can be a cluster of increased disease or a cluster of increased reporting.
  • For privacy reasons, we plot cases at the FSA level (forward sortation area, aka first 3 digits of the postal code). Where the dot ends up on the map isn’t reflective of the exact location of the reports. (As I said in a Tweet about dots on the map, please don’t yell at me if your house ends up under a dot. It’s not supposed to be that accurate.)