Worms & Germs Blog

Canine influenza update: US and Canada, March 13

Posted in Dogs

United States (data courtesy of IDEXX Laboratories)

  • Canine flu continues to cause problems in the US, particularly the west coast.
  • Northern California (471 cases) and Nevada (207 cases) are the hotbeds. As ever, since these data are from diagnostic laboratory submissions, they probably represent the minority of cases (since most dogs with respiratory tract disease don’t typically get tested).
  • Range expansion continues in the affected US areas, as the virus spreads gradually into adjacent areas.
  • Expansion into some major urban centres such as San Francisco and Sacramento raises concern because of the dog density in those areas.

As for Ontario, I’ll give a more detailed update soon.

  • I did another road trip today for sampling and we’re still approaching this from a “search and contain” standpoint.
  • We have flu confirmation in three regions; however, no new affected regions have popped up recently (although we remain on the lookout).
  • The few new positives we’ve seen in the Muskoka region over the past few days have been expected cases (i.e. dogs that were known to have been exposed and which were being tested as part of our investigations). I can live with that, as long as we can continue to identify and isolate the infected and exposed cases. If we start seeing new unexpected cases turning up I’ll be more concerned.
  • The Northumberland cluster is the main concern now as it is less contained.
  • I’m getting a lot of questions about how long I’ll continue testing. My general response is “until it’s gone or it’s clear it’s not containable” (money’s another limitation, but that’s another story). Neither of those situations has clearly occurred yet, and I’d hate to look back in a year and think that we didn’t try. I’m not sure what our odds of success are, but we’re still trying to eradicate the virus from Canada.

More updates to follow.

Ontario canine flu update: March 10

Posted in Dogs

Active canine influenza cases are still known to be present in two regions in Ontario.


  • A small number of dogs from the initial cluster of cases in the Orillia/Bracebridge/Gravenhurst region are still shedding the virus, as expected given this virus can be shed by some dogs for a few weeks. The dogs that made up the earlier cases should be done shedding soon, hopefully decreasing the pool of infected (and infectious) dogs.
  • Surveillance is still underway to detect new clusters.
  • At this point, we have not seen rapid expansion since the problem was first identified and containment measures were implemented. We would like to continue to test dogs in this area that develop signs consistent with influenza (e.g. cough, runny eyes, runny nose). This is particularly true for dogs with known contact with confirmed influenza cases, but testing of any dogs with flu-like disease is desirable to detect new clusters and make sure we know the extent of the problem.

Northumberland County

  • Multiple cases are present in this area, all currently linked to one source.
  • How H3N2 influenza got to this region is still being explored, and while I have some ideas, we do not yet know for sure. It may be indirectly linked to the Muskoka cluster, but this has not yet been confirmed.
  • As in Muskoka, testing of contacts of dogs with influenza, as well as other dogs in the area with flu-like disease is underway.  Owners of local dogs that develop these signs should contact their vet to discuss testing, as we want to determine the extent of the problem and try to contain it.


  • No positives were identified in our round of testing Friday. No known active cases are present in the region at the moment.
  • It is strongly suspected that canine influenza was the cause of disease in a couple of clusters of dogs; however, sampling was late enough that we might have missed active shedding. While that complicates our investigation of the spread, it’s good news in that we don’t have known infectious dogs in the area.
  • Hopefully the small clusters of disease that were likely flu have been contained and this area is now flu-free. However, as with the other regions, we want to continue to do some testing in case there are still cases in the area.

Other areas of Ontario

  • We are testing a smaller number of dogs from other areas, with no known link to the affected regions. This is low yield because we don’t expect influenza to be present (but I didn’t expect it to be present in the Muskoka group either). This testing will be continued in the short term to try to make sure we do not have other clusters (associated or not).

Ontario canine influenza update

Posted in Dogs, Vaccination

Canine influenza continues to cause problems in Ontario. The central Ontario (Bracebridge, Gravenhurst, Orillia) clusters continue to be monitored, with new positives that were expected based on known contact with infected dogs. Whether these clusters have been contained (or are containable) remains to be seen. Testing and contact tracing continues.

As mentioned previously, there was concern about potential exposure in the Grimsby area, because of movement of imported rescue dogs linked to the central Ontario outbreak. These concerns have been realized as canine influenza has been diagnosed in that area. Tracing and testing are underway to determine the scope of the problem and to assist with containment.

Currently, the epidemiology of these outbreaks is quite straightforward (and very interesting) as we have clear transmission pathways linking all of the known cases. However, testing of dogs with respiratory disease in other areas is ongoing to determine whether this is still restricted to the known areas or whether it has spread further. That will be important information over the next week, as if this virus is present in more regions and not as closely linked to the index cases, it would support the concern that it is establishing itself in the Ontario dog population.

The same general messages apply:

  • If your dog is sick (depressed, cough, runny eyes, runny nose, decreased appetite), keep it at home and away from other dogs.
  • If you see a sick dog, keep your dog away from it.
  • If your dog develops signs suggestive of canine influenza, contact your vet, but don’t just show up on the clinic doorstep. Many affected dogs don’t need veterinary care and for those that do, the visit should be arranged such that the dog doesn’t encounter other dogs.
  • Vaccination is recommended in the areas where canine influenza is present, as well as adjacent areas, to help reduce the spread. An H3N2 canine influenza vaccine is available in Canada and efforts are underway to try to ensure that an adequate vaccine supply is present. Vaccination requires two doses, 2-4 weeks apart. Vaccination is particularly important in certain groups, as I’ve discussed in a previous post (below).

Canine influenza in Canada: New cluster

New multistate salmonella outbreak

Posted in Other animals, Salmonella

I’m giving my brain a short break from canine flu, so here’s an interesting report about a multistate US outbreak of salmonellosis linked to… no, not turtles… no, not baby poultry… but guinea pigs.

While guinea pigs have been associated with a few different zoonotic diseases, they’re a pretty benign pet species overall. Yet, our common refrain is that low risk doesn’t mean no risk, and strange things happen all the time with infectious diseases.

This CDC report describes a relatively small outbreak of Salmonella Enteritidis infections between July 2015 and December 2017 linked to guinea pigs. Here are the highlights:

  • Nine infections were identified. As always this is presumably an underestimateof total cases because most affected people probably didn’t go to a doctor and get tested.
  • One person was hospitalized. No one died.
  • Four of seven people who were interviewed reported guinea pig contact. In one case, the same strain was found in a person and their guinea pig. This strain was closely related by whole genome sequencing to the isolates from the other people, suggesting this was truly a guinea pig-associated outbreak.

There was no evidence (or suggestion) of the source of infection of the guinea pigs themselves. Large scale breeding and warehouse-type distribution of small pets is a potential way to spread infectious diseases over wide distances, so that could have been involved here. Regardless, it’s yet another good general reminder that basic precautions, particularly good hand hygiene, should be used when handling any pet.

Salmonella in raw pet food: Kitten death and recall

Posted in Cats, Dogs, Salmonella

I haven’t written much lately about recalls of raw pet food because of Salmonella contamination. In large part that’s because it’s essentially an expected event. There are very good reasons why we cook food – one is to kill things that can make us sick. We assume that raw meat intended for our consumption is contaminated with bacteria like Campylobacter and Salmonella (because it often is). Therefore, we similarly expect raw meat for pet consumption to be frequently contaminated. Various research studies have confirmed that.

Highlighting the issues and risks yet again is a recent recall involving Blue Ridge Beef of Eatontown, Georgia. They are recalling “kitten grind” (an unfortunate name, in my opinion, but that’s a different story) after consumer complaints of deaths of two kittens. One death was confirmed to have been the result of Salmonella. Salmonella and Listeria were identified in the food (although it’s not clear to me whether it was the same strain and the same lot). Regardless, it’s not too surprising. Salmonella contamination of raw meat is common, and while disease in animals is fortunately rare, it can happen, sometimes with fatal consequences.

This should be a reminder that handling and feeding raw meat is a risk for exposure to pathogens such as Salmonella. My main recommendation is “don’t feed raw” plain and simple. That’s particularly true in households where there are high-risk people (e.g. young kids, elderly individuals, pregnant women, immunocompromised individuals) or high-risk animals (same types as for people). If someone’s determined to feed raw, it’s important to reduce the risk as much as possible. More information about that can be found in our raw meat infosheet on the Worms & Germs Resources – Pets page.

Canine flu update: Ontario, Canada

Posted in Dogs

The third cluster of canine flu in Ontario is a problem. While the first two, in the Windsor-Essex area, were relatively small and have been contained, the recent, ongoing central Ontario cluster is larger and more widespread.

There are over 20 confirmed cases to date. However, it is very likely that the actual number is in excess of 100 at this point. Some infections have been serious.

Cases have been confirmed in Bracebridge, Gravenhurst and Orillia, Ontario. All known cases have a link (direct or secondary) to a rescue that recently imported dogs from China. While confirmation is not yet available, this is the presumed source because of the epidemiological link and the fact that importation of Asian dogs is still the most likely source of H3N2 canine influenza in Canada at this time.

Grimsby area vets/dog owners take note: It appears that a group of dogs from the implicated shipment from China also went to Grimsby. Veterinarians and dog owners in that area should be aware of the potential risk of influenza.

Click here to read the veterinary disease advisory released by the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) on Friday.  Or you can read it on the Ontario Animal Health Network webiste.

More updates will follow.

Canine influenza in Canada: New cluster

Posted in Dogs

While we had hoped that control of the two recent clusters of H3N2 canine influenza in Windsor-Essex, Ontario, meant that the province was again free of that virus, another cluster of infections has been identified, this time in Orillia, Ontario. Investigation is ongoing so the number of infected dogs is currently unclear, but as always, introduction of this virus into a population of dogs with no pre-existing immunity from previous influenza exposure or vaccination raises concern that the virus could spread quickly if it gets a foothold in the community.

At this time, the source of infection is not known, although a potential link to a rescue that has imported dogs from Asia is being investigated. There is no known link with the earlier Windsor-Essex County clusters. Contact tracing and testing is underway.

Dog owners in the Orillia area should be aware, but not paranoid.

Here are some key messages (for dogs anywhere, but particularly those in areas where canine flu has been confirmed):

  • If your dog is sick, keep it away from other dogs.
  • If you are out with your dog and see a sick dog, keep your dog away from it.
  • If you have contact with a sick dog, wash your hands (and ideally change clothes) before you touch your dog.
  • Most dogs with influenza get over it on their own. As long as they are bright, alert, eating and don’t have yellowish nasal discharge, we typically do not provide any specific treatments beyond cough suppressants, if coughing is excessive.
  • If your dog has signs that could be consistent with influenza (e.g. cough, nasal discharge, fever, runny nose or eyes) and you are taking it to your veterinarian, make sure you call the veterinary clinic first so that they can use measures to prevent exposure of other dogs at the clinic (e.g. admitting your dog directly to an exam room or isolation area).
  • If your dog is sick and has been at a kennel, doggy daycare, puppy class, or any other event, contact the owner/operator to let them know.
  • If your dog is diagnosed with influenza or has signs consistent with influenza, it should be kept away from other dogs for 4 weeks (even if it no longer looks sick sooner than this).

What to do about vaccination is a common question. Now that we have evidence of three separate canine flu clusters in Ontario, it’s quite possible that this virus is spreading in different areas of the province. Vaccination is not a guarantee but it can reduce the likelihood and severity of disease. At this point, I think vaccination of high risk dogs in Orillia is justifiable, and that could be extended to anywhere in Ontario since it seems like the virus may be more widespread than we had thought.

Dogs that I prioritize for vaccination are:

Dogs at increased risk of exposure to the virus

  • Dogs that attend kennels, classes, day cares, shows/competitions and other areas where many dogs mix.

Dogs that are at increased risk of severe disease if they get infected

  • Elderly dogs.
  • Dogs with underlying heart or respiratory disease.
  • Bulldogs and other brachycephalic breeds.
  • Breeding kennel dogs.

It’s a fluid situation and more information will be released as it becomes available.

More information about canine influenza in Canada and the US, as well as some of our informational materials, can be found is in the Worms & Germs Archive – Influenza.  Also click here for an H3N2 Canine Influenza Information Sheet for veterinarians.

US canine flu update

Posted in Dogs

The table below has the latest H3N2 canine influenza numbers from IDEXX Laboratories. Some of the highlights include:

  • Numbers continue to increase. Northern California and Nevada are the hotbeds, with northern CA cases increasing to 343 and Nevada 151. As always, these are just the tested cases, and they presumably represent a small minority of affected dogs.
  • Expansion of flu continues in northern California, with spread to the north, east and south.
  • The concern about spread to and within Los Angeles has decreased for the moment, as the previously reported LA case turned out to have been a dog from northern CA. However, if it keeps spreading, southern CA is certainly in the line of fire.

What about the Ontario situation? So far, things seem to be under control. No further cases have been identified outside the two initial clusters. While the risk remains, it’s possible that canine flu is no longer in the country (knock on lots of wood).


Zinc, pigs and the meaning of antimicrobial stewardship

Posted in MRSA/MRSP, Other animals

Bacteria are smarter than we give them credit for.
Or maybe we’re not a bright as we think we are.

Antimicrobial stewardship is sometimes (wrongly) assumed to simply be the practice of “using fewer antimicrobials,” but it’s more complex than that, because the issue is complex. At face value, overall reduction in antimicrobial use is a logical target, and it’s true that it is a big part of stewardship. However, what is an “antibiotic?” “Raised without antibiotics” and “Antibiotic-free” are flashy marketing terms, but what do they mean in terms of antimicrobial resistance? That’s less clear. In pig production, control of post weaning E. coli diarrhea is a big problem. Prophylactic antibiotics are effective for this, but their use is not ideal. The main thing that’s done to replace antibiotics and still maintain control of the disease is to add a lot of zinc to the piglets’ diets at that age.

  • The reason: zinc still kills bacteria, even though it’s not a conventional antibiotic.
  • The problem: bacteria don’t care whether we call it an antibiotic or not, just that it’s trying to kill them. So, they try to resist it.
  • The bigger problem: the way bacteria resist the action of zinc can be linked to the way they resist conventional antibiotics.

We (and others) have previously shown that addition of high levels of zinc to the diet of piglets selects as well for MRSA (methicillin-resistant Staphylococcus aureus) as tetracycline, the most commonly used antibiotic for prevention of post-weaning diarrhea. If zinc selects for MRSA but not other resistant bugs, while tetracycline selects for a broader range of resistance, zinc use might still be a concern, but it would be a better option than tetracycline. However, that’s not actually the case, and a recent paper in PLOS ONE (Ciesinski et al 2018) provides more information on the impact of zinc on other important drug-resistant bacteria.

In the study, researchers fed groups of pigs either low levels (i.e. basic dietary requirement) or high levels (antibacterial level) of zinc, and they investigated what happens with intestinal E. coli. They found significantly higher levels of multidrug-resistant E. coli in association with feeding high levels of zinc: 5.8-14% in the control group compared to 29-30% in the high-level zinc group. This appeared to be because the resistant strains persisted better than susceptible strains, as numbers of E. coli didn’t increase, just the proportion of resistant strains.

Does this mean we shouldn’t be feeding high levels of zinc to piglets?

  • I don’t know. Prevention of disease is important for a lot of reasons, including piglet welfare, reduced need to use therapeutic antibiotics (which are often more important drug classes than those used for prevention) and the need for economic production of safe food.
  • Whether antibiotics or zinc are better (or less worse) in terms of promoting resistance in bacteria in piglets and the corresponding risk to human health is still unclear.
  • Another unanswered question is the impact of high levels of zinc in manure, since that ultimately makes its way into the environment/ecosystem (just like some antibiotic residues).

However, the study provides more evidence that “common sense isn’t evidence” when it comes to antimicrobial resistance. We can’t assume things will have positive or negative effects because “it makes sense.” We need sound research to figure out the best ways to optimize and improve antimicrobial use, minimizing resistance while maximizing the care of people and animals.
That’s antimicrobial stewardship.

Yet another reason not to feed raw chicken

Posted in Dogs, Other diseases

As if another reason was needed, a recent study from Australia (Martinez-Anton et al. 2018 J Vet Internal Med) found a strong association between dogs that consume raw chicken meat and a serious neurological condition known as acute polyradiculoneuritis (APN).  APN is comparable to Guillain-Barré syndrome (GBS) in humans.  The main objective of the study was to look at the association between APN and Campylobacter spp. infection, but knowing that this bacterium is commonly found in raw chicken, they also looked at consumption of raw chicken as a risk factor.  Owners of dogs with APN were 71 times more likely to report feeding raw chicken to their dogs compared to controls.  Of the 27 dogs in the study with APN, 96% (all but 1) were fed raw chicken, compared to 26% of control dogs.

And of course, anytime we’re talking about feeding a raw diet to a dog, we also need to consider the risk to the people who handle the food as well.  According to the CDC, about 1 in every 1,000 reported Campylobacter illnesses in people leads to GBS, and as many as 40% of GBS cases in the United States are thought to be triggered by Campylobacter infection.

Just one more reason to avoid feeding raw chicken to pets, and some extra motivation to pay close attention to safe food handling practices at home.