An abstract in the upcoming European Conference on Clinical Microbiology and Infectious Diseases (ECCMID) has gotten a fair bit of press and led to a lot of questions because of some sensational headlines. I’ll hopefully be able to check out all the details at ECCMID (I’ll be there for the Global Leaders Group on AMR meeting), but let’s take a quick look at what we know so far…

First, we know there’s regular exchanging of bacteria between people and pets. That’s no surprise. We have close and prolonged contact with our pets, and many bacterial are adept at surviving in a variety of animal species in addition to humans. I’ve done various studies over the years looking at this with specific bugs like methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile.

There are some specific issues with certain bacteria, but there are also some common themes about how many of these bacteria behave:

  • Bacteria are periodically passed between people and pets, in both directions.
  • Bacteria may be more human-associated (e.g. Staphylococcus aureus) or dog-associated (e.g. Staphylococcus pseudintermedius), so when they move to another species, it’s often just a transient visit, such that they soon disappear again on their own.
  • If we look at multiple people and pets in the households, it’s typically more common to find human-associated bugs (like MRSA or C. difficile) in other humans, not pets.
  • When we drill down to see if the same strains of a bacterial species are present in both people and pets in a household, we often don’t find too much overlap.
  • Transmission of many concerning bacteria, particularly multidrug-resistant (MDR) bacteria that are most commonly associated with people, is probably mainly human-to-pet.

None of that is meant to dismiss the issue of transmission of MDR bacteria between people and pets. These strains that emerge and spread in people can spread to pets, and it’s possible for pets to spread them back under the right conditions. However, just finding the same bacterium in people and pets doesn’t mean the pet is an imminent risk. Much of the time, pets are innocent bystanders or victims, with humans being the source and posing a greater risk to other people that the pets. .

The ECCMID study, coordinated by Dr. Carolin Hackmann from Charite University Hospital Berlin, is a nice study of human-animal sharing of MDR bacteria. Here’s a summary of what we know so far about their work:

  • Researchers collected swabs from 2891 human hospital patients, 30% of whom harboured a resistant bacterium of some sort (no surprise).
  • Patients were then asked to submit fecal samples from their pets. Over 300 samples were collected from dogs and cats, of which 15% of dogs and 5% of cats harboured at least one resistant bacterium (no surprise there either, especially if they used a broad definition of a resistant bacterium).
  • In only four instances was the same bacterial species found in the human patient and their pet(s).
  • In only ONE instance (out of 2891 humans and over 300 pets) did a pet and person actually harbour the same bacterial strain, based on genomic testing. This was a MDR E. coli in a person and a dog.
  • In this one instance, nothing is reported in the press reports about directionality of spread. Presumably, there was no way to figure out who infected whom (or whether both person and dog were infected by someone/something else).

Was that dog a risk to other dogs or people? Potentially, just like many other dogs. The owner was probably a greater risk to others, but we can’t dismiss the potential for the dog to be a source of re-infection of the owner either (i.e. were the owner to get rid of the bacterium but then get re-exposed from contact with the dog).

It’s an interesting study and we need more work like this.

But, is this concerning?

Not really. It’s another piece of evidence that we live in a polymicrobial world as part of a vast ecosystem. Sometimes we share bacteria (and other microbes) with other members of that shared ecosystem. Usually, it’s benign; sometimes, it’s disastrous (i.e. SARS-CoV-2); and there are lots of gradations in between.

This doesn’t change my thinking or my behaviours, but adds one more piece of evidence to the notion that we have to look beyond people to control certain human diseases – something that is overlooked surprisingly often. At the same time, we need to maintain perspective and not over-react when we find certain microbes in pets that have close contact with people. There’s always going to be some infectious disease risk with any animal contact, but we can mitigate that risk significantly. When it comes to sharing MDR bacteria in households, the best things we can do are optimize health (both human and animal), improve antibiotic stewardship (to reduce the likelihood one of these bacteria will be present in any individual, human or animal), and use common sense basic infection control practices, like hand hygiene.

So, pay attention but don’t panic (and take headlines with a grain of salt).

Being asked to coordinate a paper for the Journal of Law, Medicine & Ethics wasn’t on my academic bingo card for the year, but like a lot of things in recent years, I’ve come to expect the unexpected. The paper in question is part of a special edition entitled Addressing Antimicrobial Resistance through the Proposed Pandemic Instrument. It has a great series of papers addressing a range of pandemic issues, the threat of antimicrobial resistance (AMR), how a pandemic instrument (meaning an international instrument like a treaty) can address pandemic prevention, and why AMR needs to be part of that.

Why are we talking about AMR and pandemics?

Antimicrobial resistance has been called the “silent pandemic,” since it currently causes substantial but often largely unrecognized harm around the world, and the scope of the problem is only getting worse. While peoples’ first thoughts about pandemic risks almost invariably jump to new viruses (which are absolutely important too), the ongoing pandemic of AMR is killing huge numbers of people, affecting countless lives and livelihoods, compromising advances in healthcare, impacting animal health and welfare, and having a tremendous economic impact. It doesn’t get much press, but it’s one of the biggest global health threats we are currently facing. If we don’t act aggressively, it’s going to get much worse.

The special edition of the Journal of Law, Medicine & Ethics has lots of great information about why AMR needs to be in the pandemic instrument, governance issues related to that, what a pandemic instrument might achieve, and what barriers might be present. If you’re interested in this area, I’d recommend checking out those articles.

Here I’ll comment on the article that we wrote for the series, entitled “Governance Processes and Challenges for Reservation of Antimicrobials Exclusively for Human Use and Restriction of Antimicrobial Use in Animals“. We were asked to write about how restriction of antimicrobial use (AMU) in animals and designation of certain antimicrobials exclusively for human use could be built into an instrument. However, we took a bit of a different tack, partly because governance isn’t my area, but more because there are a lot of nuances to the issue that need to be considered by people with expertise in governance.

Ultimately it sounds simple: just use fewer antimicrobials.

But that’s just part of the story, and there are many related issues. If we don’t dive into those, we can end up with ineffective or impractical efforts that may not be optimal, or worse may not help at all, or even worse yet may cause unintended negative consequences. We’ve seen all those outcomes in the past.

Why? The short answer is, it’s complicated.


Too often, the approach to AMU in animals is focused more on sound bites than science and practical measures that will actually achieve anything positive. That’s partly because of the complexity of the larger problem, partly because of big data gaps, and partly because of a lack of understanding of key issues within the problem.

I don’t want to take the lazy way out and just say “read the paper if you want more details” but I recommend you do if you want to understand the area more. It’s far too complex to summarize neatly in a blog post, but here are a few key points to consider as a start:

  • “Antimicrobial use” encompasses a wide range of uses, including treatment, metaphylaxis, prevention and, in some countries still, growth promotion. The issues differ between those, but even within each category, there can be lots of variation leading to different issues. For example, it’s common to hear “Antimicrobials shouldn’t be used for prophylaxis in animals.” However, prophylaxis is very broad, including things such as medication of thousands of healthy animals at once based on historical use more than data, or a single dose of antibiotics in an animal undergoing a high-risk surgical procedure (where infection is a reasonable concern and would result in a longer therapeutic course). We want to reduce prophylaxis as much as possible but there are some situations where it’s needed for animal health and welfare reasons. There are also situations where use is unnecessary, done based on fear or habit versus evidence, or used in lieu of good management practices. We definitely want to curtail use in those cases.
  • Ideally, we’d have all antimicrobial use in animals driven directly by a veterinarian. That works in areas where there is good access to veterinary care, but it doesn’t work everywhere, at least not at this point. We need to improve veterinary access and animal health systems in parallel with efforts to reduce AMU and bring all AMU under the auspices of a trained veterinarian (or allied health professional). “Stop over the counter access to antimicrobials” makes sense in many places, but in some, it would significantly compromise animal health and welfare. It’s even a challenge in some parts of Canada that are under serviced in terms of access to veterinarians.

There are many similar components that sound simple at first, but get much more complex when you delve into them. Failure to understand that complexity dooms approaches to address the issue of AMR.

At the same time, there are lots of potential interventions, some of which are amenable to an international instrument like a treaty. We can’t solve this problem with a treaty, since there’s no single thing that can eliminate the scourge of AMR. However, the way we will solve the problem is through myriad interventions by myriad groups, each providing a small piece of the greater prevention puzzle. An international instrument can be a key part of that by driving some changes and by emphasizing that this is an issue that needs to be addressed across the globe.

If you’ve managed to make it this far through this post, maybe that’s a good indicator you’d be interested in reading the article or the full special edition. Enjoy.

I doubt you’ll be shocked to hear that the normal host of Staphylococcus felis is cats. It’s a bacterium that can often be found in healthy cats and periodically causes disease in cats (e.g. urinary tract infections). Overall, though, it’s a pretty innocuous bug. Human health risks related to S. felis haven’t been well investigated, but it’s been reasonable to assume there’s a potential (but low) risk of infection in people.

Some supportive evidence of this is provided in a recent case report about suspected transmission of S. felis from a cat to its owner in the form of a wound infection (Sips et al, J Med Microbiol 2023).

The case involves a 58-year-old woman who had back surgery. Two weeks after surgery, she delevloped a mild surgical site infection, with some drainage from the incision and mild redness. She was otherwise fine. They did a routine culture of the wound that identified Staphylococcus felis that was susceptible to all of the antibiotics tested. She received some wound care and was sent home with antibiotics.

While Staphylococcus spp. are leading causes of surgical site and wound infections, S. felis isn’t one we’d expect to find here. It’s a coagulase-negative species, part of a large group of staph that typically only cause infections in higher-risk situations. Coagulase-negative staph can also be found as contaminants in cultures when samples pick up bacteria that just happen to be present on the skin, but aren’t actually part of the problem. So, it’s not definitive that S. felis was the cause of the wound infection in this case, but it’s pretty likely.

When they got the culture results, medical staff queried animal exposure and it turned out that the patient had three cats.

Too often, case reports in medical journals stop here. They say “the infection happened in a person… this bacterium is usually found in animals… the person lives with an animal… they must have gotten it from the animal. Eureka, my job is done, let’s write a paper.” In many cases the link is probably real, but no always, so we need to investigate such things properly.

Fortunately, this case report highlights a great investigation of the situation.

After the owner was diagnosed, they tested her three (healthy) cats. Not surprisingly, all three cats had positive oral swabs for S. felis, and there were mixed results from axillary (armpit) and perineum (bum region) samples as well.

But they didn’t stop there. They looked at the genetic sequences of the bacteria and found that the three cats harboured different strains of S. felis. One cat had the same strain as the owner, so that animal was presumably the source of the wound infection. The others were innocent bystanders, even though they harboured the same bacterial species.

What does this change?

Not much, but it’s a good reminder that infections from various bacteria that are present on/in healthy animals can happen, and that proper investigation is required to truly understand any transmission links.

Staphylococcus felis infections haven’t been reported before in people, but I’d guess they have occurred. Until recently, most identification of bacteria in diagnostic labs was done with biochemical tests. Often, testing would stop at “coagulase-negative Staphylococcus spp” on the assumption that the bug was probably not overly relevant and/or it didn’t really matter which one of those different coag-negative staph it was for treatment purposes. In recent years, more advanced testing has become standard, so we now get more specific identification of bacteria that otherwise might have been missed or generically reported. As a result, my guess is that previous incidents of such infections were just not identified. Regardless, it’s still fair to assume this is a rare event.

There’s no mention of what happened to the cats. Hopefully, nothing. I wouldn’t treat the cats in a case like this because we have no evidence it helps. It’s hard to eliminate a bacterium from its normal ecological niche, and treatment might cause more problems, such as selecting for resistant bacteria that could pose a bigger risk to the owner. Staphylococcus felis is just one of many bacteria present in these cats that can potentially cause disease, and even if was eliminated, the risk posed by the cats wouldn’t drop by much. In these types of situations, I focus on basic hygiene and infection control, and owner awareness about risks.

The antibiotic development pipeline is drying up. More companies are abandoning the area because antibiotics are expensive to develop and license, but they are low profit drugs that we try to use as little as possible.


This is a big issue for human medicine, and was the focus of a lot of discussion at this week’s Global Leaders Group on Antimicrobial Resistance meeting.

It’s a complex issue. I won’t get into the details here, but there are initiatives to support getting X number of new human antimicrobial products to market by year Y. That leads to the question of how many antimicrobial products we should be aiming to develop for animals, and whether we should aim for completely new “animal only” drugs.

At first glance, having antimicrobials that are only used in animals would be ideal, so that they are distinct from those used in humans, and therefore any resistance that developed in bacteria from use in animals would not impact resistance to the unrelated antimicrobials used in people.

Unfortunately, as with most things about antimicrobial resistance (AMR), it’s not that straightforward. It’s not “drugs” we need to think about, it’s “drug classes.” A new drug that’s just a slightly different version of (and works the same way as) drugs we currently use in people isn’t what we want. We need new drug classes that are different in how they work and how bacteria become resistant to them. That’s a much tougher order.

If I had to characterize a “great animal-only antimicrobial class,” I’d say it should be:

  • Effective against a range of bacteria that cause disease (in animals)
  • Able to be given orally (vs injectable)
  • Low cost
  • Safe (in the target species, or ideally in multiple species)
  • Not persist in the body for long after treatment (to shorten withdrawal times for meat and milk)
  • Not excreted into the environment in urine or feces

And the big one: if resistance develops to our animal-only drug, it doesn’t also confer resistance to human drugs.

That would be great.

However, what else did I just describe? A perfect ‘human-only’ drug.

I’d rather use that drug in people than launch it for use in animals.

So, unless we have a new drug class that fulfills those properties and is toxic in people but not animals OR only works on a pathogen that’s of relevance in animals, we’re not likely to get a completely new useful animal-only drug class that would not impact resistance in people.

That doesn’t mean we shouldn’t keep it in mind and explore new drug classes that have been rejected for use in humans (which is already a prime source of many animal drugs). However, it means our main focus should be saving the drugs we have so we don’t need to worry about finding new drug classes. That’s why we need to focus on better animal health systems to reduce the need for antimicrobials, better education and support systems to optimize antimicrobial use, and more study about what situations contribute to more or less resistance risk. That’s antibiotic stewardship.


As the current (and unprecedented) H5N1 avian flu outbreak continues, there’s the ongoing threat of transmission to other species. The extent of spread to mammals is hard to say since it’s hard to know how many wild mammals have been infected. However, we know that an impressive range of species has been infected. Spread to mammals is a concern because the more widely this virus spreads, the greater the chance for recombination with other flu viruses to create a “new” strain that could cause serious problems in humans or other species.

A recent news report and the corresponding WOAH report are light on details but describe H5N1 infection in a domestic cat in France from late 2022.

The cat lived on a duck farm and was euthanized after developing severe neurological disease. That’s a clinical presentation that’s not been uncommon in mammals that have been infected with H5N1 influenza during this outbreak. That doesn’t mean this virus usually causes neurological disease. It might be a matter of animals with neurological disease simply being more likely to be noticed and/or tested. H5N1 avian influenza infection was confirmed, and the virus recovered from the cat had “genetic characteristics of adaptation to mammals.”

The good news is that cats (as far as we know) don’t have their own flu virus in circulation (unlike dogs, horses, and pigs). That makes it unlikely that a cat would be infected with avian flu and another flu strain simultaneously, which would increase the potential for viral recombination. However, it’s still a concern since cats can (rarely) be infected with flu strains from other species, including human flu viruses.

Overall, the relevance here is mainly to the cat. The odds of this signalling a new problem are low, but it highlights the concerns we have about how far this virus continues to spread. It’s playing with fire.

The other consideration is the potential for cats to act as a bridge from wildlife to humans. Cats that get infected through exposure to wild birds can bring the virus into closer contact with people. It’s another good reason to keep cats indoors whenever possible, particularly if avian flu is circulating.

As a journal associate editor and reviewer, I’ve seen lots of papers about SARS-CoV-2 in animals. Some have been great, ground breaking papers. Many have been small, weak studies rushed out to be “first,” with inadequate depth and lacking critical assessment. Some have been a complete disaster. The latter two groups are a concern beyond just being bad science. Shortcuts can lead to bad conclusions when things aren’t studied properly.

A recent study (Hoppe et al, Infection 2023) highlights the need for proper study to avoid bad conclusions. It describes SARS-CoV-2 infection in a household where both people and a dog were identified as infected.

A human (the father) was the first identified case, and the rest of the family subsequently got COVID-19 as well. The source of the father’s infection was unclear, but he noted that his dog had been sick (i.e. coughing, lethargic) starting 11 days before the onset of his own illness. The dog had been taken to a veterinarian and tested negative for some routine respiratory pathogens, but false negatives are very common with these tests based on timing of sampling and our inability to test for all causes of respiratory disease.

After the owner was diagnosed with COVID-19, the dog was tested for SARS-CoV-2. Samples were taken 18 days after the onset of the dog’s respiratory disease, and all 3 samples from the dog were positive for SARS-CoV-2 at that time.

Timeframe figure of SARS-CoV-2 infection in a dog and 4 family members, with the dog’s infection preceding human infections.

It was suggested that the time frame was consistent with dog-to-human SARS-CoV-2 transmission. I’d say that’s a bit of a stretch based on what we know about infection of dogs, but it’s not impossible. Dogs seem to be commonly infected from their owners, but seem to be pretty resistant to clinical infection and don’t seem to be great hosts for the virus. Virus shedding in dogs tends to be low and of short duration. With a fairly short incubation period in people, the dog would have had to have been infectious for well over a week to be responsible for the father’s infection, and that’s unlikely. The dog also would have had to have been PCR-positive for 18 days after the onset of disease, which I’d consider really unlikely.

However, “unlikely” doesn’t mean “impossible,” so more study was needed. Presumably, at this point, they thought the dog was the source of the family’s infection and were waiting for sequencing results to confirm that.

(Un)surprisingly, the sequencing results didn’t implicate the dog.

There were enough differences in the viral sequences between the dog and owner that the viruses were classified as two different lineages (B.1.1.29 and B.1.1.163, respectively). They concluded the infections were independent, since the series of mutations that would have to happen between the dog and person were “so unlikely, that secondary zoonotic transmission can virtually be excluded.”

It’s pretty clear that the dog was infected. The dog was PCR-positive and antibodies to SARS-CoV-2 were later detected in the dog’s blood.

It’s also pretty clear that the dog wasn’t the source of human infection. The dog’s infection was actually unrelated.

Then how did the dog get infected?

That’s an interesting and unresolved question, since the pet had little outside contact given restrictions that were in place at the time.

  • Maybe he picked it up from unreported contact outside the household.
  • Maybe a person in the household had an undiagnosed (potentially asymptomatic infection) with the strain that infected the dog.
  • Maybe the dog picked up the virus while visiting the veterinary clinic.

It’s impossible to say. That highlights a challenge. Confirming interspecies transmission of a virus that’s widespread in humans is very difficult, and often a really unique set of circumstances need to be present (as was for the cat-human transmission of SARS-CoV-2 that occurred in a Thai veterinarian).

This is a good example of the need to investigate interspecies transmission but the need to do it right. 

Dog image from: http://www.quickmeme.com/meme/3oyz00

Figure from Hoppe et al, Infection 2023.

The ongoing H5N1 avian influenza outbreak is an unprecedented event in its size, scope and duration (but it’s not getting much press anymore these days). As infections continue to occur is birds in large numbers over a vast geographic range, we worry about spillover events into other species.

There have now been many reports of H5N1 influenza infection in a variety of wild mammals, including foxes, skunks, raccoons and most recently bears. Sporadic transmission into wild mammals that live fairly solitary lives and probably aren’t (currently) great hosts for the virus raises concern, but the broader risks are probably limited because of the low odds that rare infections would result in a relevant change in the virus or recombination with another flu virus. However, more infections create more risk, and infections of species with more animal-to-animal contact, and animal-to-human contact amplify that risk.

That’s why the recent report of H5N1 avian flu on a mink farm in Spain raises some alarm bells. Infection of a farm with tens of thousands of mink is a whole lot different than infection of the odd free-roaming fox or raccoon.

Mink in cages. Source: https://www.bbc.com/news/business-37679652

The good news is that even though the report just came out, the outbreak occurred in October, and there’s no evidence I’ve seen that this resulted in a broader issue. The bad news is that it shows what can potentially happen (and surveillance is far from good enough to say that this hasn’t caused an issue).

The report is about an outbreak on a farm in Spain that housed over 50 000 mink. Concerns were raised when the mink mortality rate increased in October, suggesting something was going on. It seemed like a pretty classic infectious disease problem, as it started in one barn and was characterized by “multiple ‘hot  spots’ within the affected barns consisting of 2–4 pens where all the animals died within a period of 1–2 days.” Mortality rates then increased in neighbouring barns, then eventually across the whole farm. Infection with SARS-CoV-2 was initially the main concern, as has been seen on mink farms in many countries now, but tests for that were negative. Eventually they confirmed H5N1 flu as the cause of illness in the mink, and sequencing of the virus showed it was the same clade ( that’s been circulating in birds in Europe.

The decision was made to cull the mink, and over the course of about a month, all of the mink were euthanized and their remains disposed.

Farm workers were tested at one point, and all 11 were negative. That was good news, but single point-in-time testing of people exposed to an infected mink farm over the course of weeks doesn’t rule out transmission. (Though it’s worth noting employees were already required to use enhanced precautions, like wearing masks, because of the concerns over SARS-CoV-2 transmission to (and from) the mink, which may have also helped limit transmission of flu.) One of the workers later developed flu-like signs but tested negative for flu virus. Because of the disease transmission concerns, a “semi-quarantine” of the people was performed to limit contact with other people for 10 days after their last contact with the farm.

The source of the outbreak isn’t known. It’s possible that it was introduced by poultry products fed to the mink, but there’s no evidence that any supply farms were infected. It’s much more likely that wild birds were the source, and infected wild birds had already been found in the area at the time of the outbreak. This highlights concerns about mink farms as a wildlife/domestic animal/human interface. It’s hard to keep wildlife away from a mink farm, which creates risk for transmission both from and to wildlife. If wild birds can infect mink, it’s equally likely that wild birds (and other wildlife) could be infected from mink, through contact with the mink farm environment. A virus that spreads to the mink can then spread to human farm workers, domestic animals on the farm, or other “visiting” wildlife. That’s not a comforting scenario.

The report concludes by stating that the mink sector is still important economically and “it is necessary to strengthen the culture of biosafety and biosecurity in this farming system and promote the implementation of ad hoc surveillance programs for influenza A viruses and other zoonotic pathogens at a global level”. I agree with the second part of this statement, but as for the first part, we need to think and risk versus reward. Are the benefits of mink farming worth the risks that come with raising large numbers of animals that are susceptible to various human viruses, in close proximity and with ongoing contact with people and wildlife? The broader societal benefits of mink farming are (to me) negligible, and the risks may be low, but they are not zero and not adequately understood.

Image from https://www.bbc.com/news/business-37679652

Canada has a long-standing requirement for rabies vaccination of most categories of dogs and cats being imported from countries not considered free of non-bat rabies.  While this requirement helps protect dogs and cats from rabies infection should they be exposed to endemic wildlife rabies that is present in Canada, it does little to prevent rabies in animals that were exposed to the virus prior to vaccination and importation.  Two cases (July 2021 and January 2022) of rabies in dogs recently imported into Ontario, along with ongoing pressure from public health agencies for more regulatory control of canine importation, lead to the Canadian Food Inspection Agency (CFIA) prohibiting the importation of all commercial dogs from countries considered high-risk for canine rabies, effective September 28, 2022 (World Rabies Day).

Many members of the public and organizations involved in canine importation do not understand the rabies disease process, risk periods for virus shedding, and how and when rabies vaccination is or is not effective at preventing infection.  Providing an explanation of these nuances in a format that can be relatively easily understood by members of the public is key to garnering support for and compliance with current and future canine import requirements regarding rabies, which helps support both animal health and public health efforts to reduce the risks from this deadly disease.  The companion animal Ontario Animal Health Network (OAHN) therefore undertook a project to produce the short whiteboard video below on this topic (which I think is pretty awesome, but I’m a bit biased!). Check it out on the OAHN website or directly on YouTube for links to additional rabies resources for pet owners and veterinarians.

I’ve written (ranted?) about this before – namely the misuse of antimicrobials intended for treatment of aquarium fish in other species. Usually such posts are followed by a deluge of nasty emails along with a bunch of curious requests for links to fish antibiotic sellers (8% kickback available!).

Another sponsorship request came in this morning, prompting this rant. I guess it was a poorly programmed bot, or someone who didn’t carefully read even the title, let alone the content of my previous posts.

Picture of a bottle of 'fish ciprofloxacin'

In some ways, this issues is small potatoes in the grand scheme of the “silent pandemic” of antimicrobial resistance (AMR), something that impacts millions of people and costs billions of dollars every year, but it flies largely under the radar. However, even small potatoes need to be addressed when we’re dealing with a problem like AMR. Everyone has a role to play.

Why is diversion of fish antibiotics an issue?

Anytime an antibiotic is used, in any species (including humans) there are risks: adverse effects, treatment failure, emergence of resistance, etc. So, when antibiotics are used, we need to make sure we maximize the benefits and minimize the risks/costs. The more antibiotics are used without medical (human/veterinary) advice and control, the more risks and the fewer benefits there are.

What are “fish antibiotics?”

They’re the same antibiotics we use in people and other animals, but with “fish” slapped on the label. They’re marketed that way to try to keep them under the regulatory radar (even though it’s still illegal in some countries where they are sold this way). If you look at websites that sell fish antibiotics, you’ll often find the same drugs and same formations (even the same tablet sizes and shapes) as are used in other species. Websites are smart enough now not to explicitly say you can use them on yourself or in other species, but that’s pretty well known so they don’t have to, and product reviews show other people what’s being done.

Do many people actually use fish antibiotics on themselves?

It’s hard to say. One study of internet reviews reported that 2.4% of reviews suggested they were purchased for use in people (see screenshot below). That’s presumably an underestimate, since most people who buy fish antibiotics to use on themselves or their kids likely don’t write that in a review. A larger percentage probably bought them for use in their dogs or cats.

Is the ability to buy and divert fish antibiotics actually causing harm?

Who knows? However, there are a number of potential issues.

Adverse effects: Antibiotics are not innocuous. There’s always some risk of adverse effects. Some situations and some drugs pose higher risk, which is just part of the reason to always get medical advice before taking antibiotics.

Product safety: Who knows what’s actually in these products? A 500 mg ciprofloxacin tablet for fish might contain 500 mg of ciprofloxacin. However, I suspect it often doesn’t. It could contain more or less (both potentially being an issue) or contain contaminants. I’m not going to have much confidence in quality control for a product that’s being produced for dodgy or illegal sale.

Inadequate/ineffective treatment: Some reviews I’ve seen talk about use for things where there’s not much hope of the antibiotic working. People using it themselves have to know the right drug, the right dose and the right duration. I doubt that’s common.

Resistance: Anytime an antibiotic is used, there’s pressure to select for antibiotic resistant bacteria. At the individual level, it’s a small risk, but the more it’s done, the more that risk becomes relevant at a population level.

It’s easy to say “just stop it,” but we need to consider why this happens in the first place.

A general principle of antibiotic stewardship and good medicine is that antibiotics should be available only by prescription (human or animal). That helps makes sure they are used when needed, not used when not needed and used properly (right drug, dose, duration and any other necessary treatments).

Some people are looking for a cheaper option, even though they can afford to see a doctor or take their pet to a veterinarian, and purchase the proper product. However, what’s the true cost savings if the antibiotic they buy online isn’t necessary, is the wrong drug, is harmful or isn’t used properly?

Some people truly can’t afford the proper product. Access to treatment needs to be a right, not a privilege.

Lack of access to healthcare is a big issue. At the core of antibiotic stewardship is a need to improve human and animal health systems in general. Whether it’s because they can’t afford healthcare, don’t have access to a doctor or veterinarian in their area, have tenuous employment where they can’t get time to go see a doctor or veterinarian, some people truly have significant barriers to getting antibiotics through the proper pathways. We need to improve those pathways so people can get antibiotics when needed (for themselves and their pets) and get proper preventative healthcare to avoid needing antibiotics in the first place.

Education is another issue. If someone can buy something that is labelled the same and looks the same as a product licensed for people or other pets, it’s easy to see why they’d think it’s fine. We need more general education about antibiotics, antibiotic use and antibiotic resistance so people are more aware of the risks associated with misuse of these products.

So, what can be done about diversion of fish antibiotics?

When there are companies based in countries where it’s illegal to market products like this, it’s simply an enforcement issue. Selling over the counter fish antibiotics is illegal in the US (and in Canada) and many of the companies selling these products list US addresses. So, it’s a matter of someone deciding to crack down on these kinds of sales. That doesn’t address the broader issue of black market drugs being imported into North America, but it’s at least a start.

Even some “main stream” companies are involved in these scenarios, probably inadvertently, but it’s something they need to scrutenize. For example, I looked at Walmart’s PetRx website and there are reviews that indicate diversion of pet medications. I’m not sure how rigourous some of the US online veterinary pharmacies are with their verification of prescriptions and “vetting” of purchases, but some effort to minimize diversion would be good. At a minimum, removing reviews that show others are misusing these products (which might encourage others to do the same) is a no-brainer.

Undoubtedly, small improvements in antibiotic use in human healthcare, veterinary medicine and food production would have much more of an impact than completely eliminating diversion of fish antibiotics. However, the scourge of AMR is a complex, multifactorial problem. There will never be a simple, single solution. We need a toolbox of many different interventions that on their own only contribute a little, but put together and over time will have a larger impact. Low hanging fruit like this needs to be part of that.

It’s been a busy fall for canine flu.   We’ve started tracking canine influenza cases to have a better idea of its spread and to help with risk assessment and vaccination decisions (although canine flu vaccine shortages have also been an issue).

We’ve created an interactive map of our preliminary canine flu surveillance to date.  A screen shot of the current map is shown below.

More data are hopefully coming, so the map should be more detailed in the near future. Veterinarians can use this link to quickly submit additional case information (just number of cases and location).

Our definition of a confirmed canine influenza case for the map is:

  • Laboratory-confirmed diagnosis of canine influenza OR
  • Acute respiratory disease in a dog that has had direct contact with a laboratory-confirmed case of canine influenza

More frequent map updates will likely be provided on Twitter: weese_scott