Worms & Germs Blog

Pets as sentinels (and maybe saving lives)

Posted in Dogs

phone keypad“One Health” gets talked about a lot these days, but is acted on much less often. Getting physicians and vets to talk is tough. Getting physicians to query animal contact is variably successful. Some get it and do it well, others don’t.

When I speak to human medical or public health groups about zoonotic diseases, I often talk about a particular paper on Rocky Mountain Spotted Fever (RMSF) in a person. This tick borne disease is pretty nasty, and can be fatal if not diagnosed and treated promptly.

The case described in the paper is of a woman who went to an ER with some vague clinical signs. She received an equally vague diagnosis and was sent home. She went to her own doctor a couple of days later with worse signs, and was hospitalized. She eventually was seen by an infectious disease physician who suspected she had RMSF. Treatment was started but, by then, she was seriously ill and died.

Where’s the animal side?

Her two dogs had died shortly before she got sick, and they had signs consistent with RMSF too. It isn’t spread from dogs to people, but dogs and people get infected the same way, from tick bites.

What I pose to the audience is whether the question “do you have pets?” would have saved her life. If she had said yes and mentioned that her dogs had recently died, would that have sped up consideration of RMSF? Maybe, and if so, maybe she’d still be alive.

A recent case of plague in Colorado has some similarities, in terms of the relevance of animal disease for aiding rapid identification of human disease. Information has been pretty sparse, but a person in Chaffee County Colorado was recently diagnosed with plague, treated with antibiotics and survived. The animal side is that the person’s dog became ill with signs consistent with plague a few days before the person got sick. I have no idea if they linked the two events and the dog’s illness actually triggered any thought of plague. However, it’s another example of the relevance of animal health to human health, the need for good communication between the veterinary and human medical worlds, and the need for physicians to query pet contact (and really, pet health).

If someone in an area where plague is present comes in with vague disease and says their dog got sick a few days earlier, knowing what that dog has (or might have) might be very important to the person getting proper testing and/or prompt treatment. Unfortunately, it’s a rare event for a physician to call a vet in a situation like that and, somewhat surprisingly, rare for a person to mention a pet’s illness to his or her doctor, even if the pet and person have the same signs.

Greek debt crisis and dog importation

Posted in Dogs

Shelter dogThe Greek debt crisis is obviously getting a lot of attention, and now people are trying to link it to increased importation of stray pets.

That’s a stretch. Greek dogs have been coming into the country in large numbers for years.

Over the past week, I’ve had countless emails about issues with dogs and cats being imported from Cuba, Aruba, Azerbaijan, Dubai and a few others that I can’t remember off the top of my head. Most of these have been dogs but some include cats (which is even more mid-boggling than dogs. About 50% of cats that reach animal shelters in Canada are euthanized. How can anyone think we need to import more?)

Anyway, back to Greece.

Today’s Globe & Mail has a front-page story about shelters shipping abandoned and stray Greek animals to Canada. At first glance, you see the “nice” aspect of it: a homeless animal with no future future finds a new home in Canada. But, if you think about it more, there are a lot of downsides. Most people unfortunately don’t think that far.

Dianne Aldan, 69, provides a link between KAZ and Canadians wanting to adopt. She has been helping Greek dogs find a home since 2001 through a charity out of Toronto called Tails from Greece Rescue. She has airlifted more than 350 pups. “It never ends, and especially now … with the financial situation, a lot of dogs have been abandoned,” she says. Her charity charges a $375 adoption fee, and KAZ takes care of vaccinating and sterilizing the dogs. Once they find a home, they are airlifted from Greece to Amsterdam, where they spend the night before heading to Canada.

Apart from the fact that we have lots of dogs needing homes in Canada, and that we’ve been importing nasty diseases such as leishmaniasis with Greek dogs, there’s the legal aspect to consider. If these are not personal pets being imported by their owners, this type of importation is illegal. Illegal importation of dogs (often of dodgy health status) is rampant in Canada because of lax enforcement.

Brooke Berrington and Alex Sanderson say it’s worth the wait. The Toronto couple had been looking to adopt a dog, and spied Demi on Petfinder.com, a website that connects animal charities with potential adopters. A video of Demi at the Greek shelter showed her to be “quite calm, very cuddly, the kinds of things we were looking for,” Mr. Sanderson said.

I wonder why they didn’t just look down the road at the local shelter? There are lots of good dogs there, just not with the same wow factor as “look at my rescue dog from Greece!”

Also, assessing the choice of a pet that you’re going to hopefully live with for many years by video (probably with limited temperament testing done at the shelter) isn’t something I’d want to do.

“If you want to have a dog, please adopt one in Canada. Our shelter system is already overburdened,” Barbara Cartwright, chief executive officer of the Canadian Federation of Humane Societies, said. She also warns that lax regulations could lead to animal diseases being brought into the country.

A voice of reason.

Craigslist rabid puppy update

Posted in Dogs, Rabies

The other day, I wrote about an effort to track down adopters of puppies from a litter in the Clay County, Texas, area after one of the puppies was confirmed to be rabid. At last report, 8 of the 9 remaining puppies have been located.

Two of these puppies were adopted by one family, with two kids and 4 children that the mother babysits (so, lots of exposed people). One of the puppies died (which would be consistent with rabies), and rabies testing is underway. The other was euthanized for testing.

The article states that all of the exposed puppies need to be euthanized. That’s not necessarily true, since the options for an apparently healthy but exposed and unvaccinated animal typically are a 6 month strict quarantine or euthanasia (although some jurisdictions may have more rigid rules). If multiple cases of rabies are ultimately identified in the litter, it would be easier to make a case for euthanasia of all the puppies based on the likelihood they all have this fatal disease. Another consideration with young puppies is lack of socialization during the quarantine period. A six month quarantine is a long time for a young puppy, and can have long-term behavioural consequences as it is practically impossible to fully socialize the dog during this critical developmental period. There’s no good solution, so euthanasia is often the choice, as was the case here.

Craigslist + Rabid puppy = Bad news

Posted in Dogs, Rabies

Puppies playingThere are lots of reasons not to get a puppy from Craigslist. While getting a rabid one isn’t likely, it can happen and result in a lot of trouble.

Case and point: A litter of 9 puppies from Henrietta, Texas was recently advertized on Craigslist, and at least one of the adopted puppies had rabies. The puppy in question went to a home in Wichita Falls and ended up biting the adopter. It’s not clear if the puppy was euthanized because of the bite or because it developed signs of rabies, but either way it was tested (fortunately), and that’s when it was discovered it had rabies.

That’s the “good” part of the story, because rabies was identified so the people exposed could be properly treated.

The rest of the story isn’t as good.  Now it’s critical to find the adopters of the other puppies, which is easier said than done when the animals were adopted via a Craigslist ad. There is often no information about the adopters, and no way to follow up.  Public Health is urging adopters to call them immediately, but it’s hard to say how successful that will be.

Reducing antibiotic use in the real world… Easier said than done

Posted in Other diseases

Antibiotic XI did a consultation today about a dog that illustrates some of the practical challenges to reducing antibiotic use. It was an older dog with a test result that could be consistent with an infectious disease, but one that is also common in healthy animals. The signs of illness that the dog had would have been pretty atypical for the infectious disease in question, but the signs and some other testing were also highly suggestive of a (bad and untreatable) non-infectious cause. The owners weren’t willing to pursue any more diagnostic testing.

So, this is a case where an infectious disease is unlikely but it can’t be completely excluded, and where there’s no chance of getting more info. At what point does antibiotic use go from a reasonable outside chance of being effective to inappropriate?

It’s pretty grey.

Another interesting example can be found in a great commentary in JAMA Internal Medicine (Kavanaugh, 2014). To make an interesting story short:

  • The writer is a physician who was attending a conference (ironically, about antibiotic resistance).
  • The day after, he woke up with a sore throat and fever, and was concerned about strep throat. At the same time, he didn’t want to take an antibiotic unnecessarily.
  • He went to a “doc-in-the-box” clinic and a group A strep test was negative.
  • However, the physician recommended antibiotics, despite the negative test. The patient-physician said he didn’t want antibiotics but the attending physician persisted. He then prescribed azithromycin, which is an unusual choice for strep throat.
  • The patient-physician says he knew he shouldn’t take an unnecessary antibiotic (especially an antibiotic that would be the wrong choice in the unlikely event this was strep throat). Yet, he also felt like he was in a dependent position as the patient, and gave in.
  • After leaving (and no longer being under the physician’s sway) he decided not to fill the prescription, something that was good in this case but not something that is recommended in general.
  • The sore throat resolved on its own in a few days, as expected.

He concluded: “Looking back, my own willingness to go along with “doctor’s orders,” or at least not argue with him when he wrote a prescription, gave me a glimmer of insight into how hard it is for patients to express concerns when in the presence of a figure of authority on whom they are dependent. In my home state of Kentucky, we have the highest rate of prescribing antibiotics to outpatients in the nation. Had I filled the prescription and taken the medicine, I may have contributed to the serious and growing problem of antibiotic resistance. All the conferences in the world will not put a dent in antibiotic overuse unless the medical profession owns the problem and changes its own habits. “

Interesting insight.

Equine herpes alert…Ottawa

Posted in Horses

Horse getting upThe Ontario Ministry of Agriculture Food and Rural Affairs has issued a Biosecurity Alert (2015-07-09 EHM advisory) in response to an equine herpesvirus myeloencephalopathy  (EHM) case. This neurological disease, caused by equine herpesvirus type 1 (EHV-1) gets a lot of attention now, when 10 years ago it would have largely been dismissed (or at least not caused a lot of concern). Back then, we regularly saw sporadic cases and we just managed them where they were. However, in the intervening years, large outbreaks have been widely reported, so we’re a lot more careful now. Whether that’s because the disease is changing or we’re doing a better job of identifying and reporting outbreaks isn’t clear (it’s probably a bit of both). Regardless, while most cases of EHM are just single, sporadic incidents, we tend to be fairly aggressive to try to prevent a bigger problem from developing.

EHV-1 is a hard virus to  completely control. It lives dormant in a large percentage of healthy horses (herpes is forever, as they say), and rarely causes disease in most. So, testing for carriers amongst the general population or trying to eradicate it aren’t realistic options. Rather, we focus on good routine infection control practices and good infection response.

In this case, there will presumably be close monitoring of any in-contact horses, potentially with short term isolation or movement restrictions. As with most infectious diseases, it’s best to be aggressive early in the course of a situation while you’re getting a handle on the problem, then relax those restrictions later on when deemed appropriate. That’s better than the opposite “I hope it will get better” approach of doing little at the start, and trying to play the odds that an outbreak won’t develop.  That is when disaster will usually strike…

Hopefully this is the last we here of this situation, but the next week will be informative.

Raw food recall…with a twist

Posted in Cats, Dogs

Dog foodI don’t usually write about recalls of raw pet foods because… well, finding Salmonella, E. coli or Listeria in raw meat is far from surprising (although certainly concerning). However, the recent recall of Stella & Chewy’s products because of Listeria contamination is noteworthy.


Because their food is treated with high pressure pasteurization (HPP). This process uses high pressure to destroy bacteria. I typically consider HPP-treated food to be similar to commercial cooked products in terms of the risk of bacterial contamination and public health concerns. Yet, I add in the disclaimer that actual evidence of effectiveness on pet food seems to be limited. It makes sense that it would work; however, a variety of factors impact the effectiveness of HPP, so companies should have data that show their specific process works.

The big question here isn’t “why were bacteria in the food?” It’s a raw animal-based diet, bacteria are common contaminants.  The real question is “why were live bacteria in the food?” Figuring out how Listeria made it through the HPP processing is critically important. Hopefully there’s a real investigation into this.

There are a few possible explanations that I can come up with, and they vary greatly in the level of concern they would cause.

Post-treatment contamination: Careful review of the manufacturing process and testing (culture) of various environmental surfaces would typically be part of in investigation of this issue. If this was the problem, things such as physical or procedural changes and more QC testing might be indicated.

Ineffective HPP: There could be two different scenarios:

  • One is a breakdown in the process, with equipment problems, human error or some similar issue preventing an effective method from working. This is a problem but would presumably be fixable.
  • The other (more concerning) scenario is that the procedure they use is not actually adequately effective for the pet food they’re manufacturing.

Figuring out the cause of the problem is important to reduce the risk and help people make informed decisions about buying raw products.

A near fatal dog lick?

Posted in Cats, Dogs, Other diseases

Spaniel tongueI like to write about interesting papers that appear in the medical literature. A problem with that is that it’s often weird cases that get published.  So, it’s important to keep things in perspective.

Regardless, reports of rare things still provide some insight, as long as people don’t over-react (which, unfortunately, is often the case).

A great example of this is a recent case report entitled “An unusual case of meningitis” in the Canadian Journal of Infectious Diseases and Medical Microbiology (Pond et al, 2015).

Here’s the short version:

  • A 56-year-old man with chronic ear discharge and a perforated eardrum was admitted to hospital for ear surgery.
  • Post-operatively, he developed neurological disease and was diagnosed with meningitis. Ultimately, the cause was identified as the bacterium Pasteurella multocida. This bacterium is most commonly associated with the mouth of cats and dogs (particularly cats) and periodically causes infections in people (especially cat bite infections).
  • Finding this bacterium led to investigation of pet contact (ideally, this should be queried routinely, not just in response to a potential pet-associated infection) and it was discovered that the man took care of several cats and a dog.
  • There was no history of a bite (a common source of Pasteurella infection), but the pets were occasionally allowed to lick his face. That’s presumably the route of infection here, although there was no further investigation.
  • The good news is the man recovered.

I get asked about risks associated with licking all the time. My typical response is that I don’t like my dog licking me – it’s not a germaphobic thing, I just don’t particularly like it. The risk to most people is quite low. I do recommend that licking of people at increased risk of infection be avoided. That would include infants, elderly individuals, people with compromised immune systems and people with open sores. I especially recommend avoiding licking around the face, for a few reasons.

The person in this case report would have fallen under the higher-risk group, by virtue of his chronic ear problems and perforated eardrum. Licking around the ear would pose an increased risk of the bacterium accessing the brain through the ear and perforated eardrum. Certainly, it’s a rare problem, but it emphasizes the need for people at increased risk of infection to take additional precautions.

A big challenge is identifying higher-risk individuals and getting them information about what to do and not do. Better communication between veterinarians and physicians, routine questioning of pet contact in human patients, and better access to basic educational materials (like the info sheets we have on the Worms & Germs Resources – Pets page) are important aspects of this.

Cats, Toxoplasma and mental health (with a side of over-exuberant reporting)

Posted in Cats, Toxoplasmosis

Cat paw over faceThere’s been a lot of discussion about toxoplasmosis and mental health over the past few weeks in response to a paper in Schizophrenia Research (Torrey et al 2015). Some internet sources are having a great time writing “crazy cat lady” and similar headlines.

But is there any substance to it?

Yes, and no.

The science in the paper that’s being cited is pretty limited. From my reading of it (and I doubt most people that have written about the paper actually read it), the paper wasn’t meant to be a definitive answer. It was meant to raise awareness.

It certainly did that.

The content relates to the protozoal parasite Toxoplasma gondii. Cats are the definitive host, meaning the adult stage of the parasite lives in the intestinal tract of cats. If infected, cats can pass eggs in their feces. After a few days outside the cat’s body, these eggs are able to infect people, if ingested. A reasonable percentage of healthy people have been exposed to Toxoplasma, potentially directly from cat poop, but more likely from general environmental exposures (e.g. gardens, sandboxes) or unwashed vegetables. Rarely does disease occur, and the main concerns are for severely immunocompromised individuals (who can get Toxoplasma encephalitis (i.e. inflammation of the brain)) and for pregnant women who have not been exposed to the parasite previously (in which the parasite can cause severe infection or death of the fetus).

There have been lingering concerns about the role of toxo in other diseases, schizophrenia being one of them. There have been two studies that suggested a link, but the evidence was relatively weak:  basically they simply found that the incidence of cat ownership while young seemed to be more common in schizophrenia patients compared to a control group.

The Torrey study set out to look at that again, using existing data. They looked at data from a 1982 survey of families of schizophrenic patients, collected from people that attended the National Alliance for the Mentally Ill (NAMI) convention. They compared those numbers to a 1991 survey of the general public reported by the American Veterinary Medical Association. Cat ownership was 51% in the schizophrenia population and 43% in the AVMA survey. So, it’s suggestive.

However, these are two completely different studies of different groups in different decades using different methods. A control group has to be very well matched to a “case” group to make a valid comparison, something that may not be true here (there’s no way to know).  Various confounding factors could be present. For example, the paper mentions that at the time of the 1982 survey, people with schizophrenia tended to be disproportionately middle and upper class. That would probably be biased even further by including only people that attended a convention (and had the money, time and motivation to go). Could that type of person also be more likely to own a cat?  Could that have affected the results? Certainly, it must be possible.

A key point that’s being missed by most reports is the final paragraph of the paper.

It is important to ascertain whether or not cat ownership in child-hood is a risk factor for later schizophrenia since it is a risk factor which could be minimized. We therefore urge our colleagues in other countries to collect data on cat and other pet ownership, and a major goal of this paper is to encourage such research.

It’s important to ascertain….

More work needs to be done….

Not, ‘”cats cause mental illness.”

It’s good to pay attention to the potential link and properly explore it. At the same time, toxo avoidance measures are very easy for cat owners. They include:

  • Cleaning the litterbox daily
  • Avoiding contact with cat feces, especially old feces
  • Handwashing after contact with the litterbox or feces
  • Keeping your cat inside so it doesn’t get infected by eating infected rodents
  • Keeping sandboxes covered to they don’t become neighbourhood cat litterboxes.

More information about toxoplasmosis can be found in on the Worms & Germs Resources – Pets page.

Giardia in dogs

Posted in Dogs

Beagle PupThe parasite Giardia often raises concern for both dog and human health. In reality, while it’s a potential problem, it’s probably over-rated (or at least there’s a bit too much paranoia at times). A reasonabe percentage of healthy dogs (probably ~7% in Ontario) are shedding the parasite at any given time, but very few will go on to develop disease. It can cause diarrhea, but only in a small minority of exposed animals, and usually it’s not a big deal. Giardia also a zoonotic pathogen, but as we’ve learned more about this parasite in recent years, it’s becoming clear that pets pose a limited risk to people. Most studies have identified Giardia found in dogs to be dog-specific strains that do not infect people.

Here are some interesting tidbits about Giardia from a few recent papers.

Does that mean we should just ignore Giardia? No. It can definitely cause disease in dogs, and sometimes it’s hard to treat. It can also cause disease in people (I spent a couple days in hospital with Giardia many years ago… never did figure out how I got it). It’s important to remain balanced, though. Pets are a minimal to inconsequential source and people shouldn’t freak out if their dog is diagnosed with Giardia. At the same time, it’s a “don’t eat poop” disease, so basic prevention practices are easy.