There are certain words that guarantee my interest, and a short list of these (in no particular order) would include: Dogs, Canada, Infectious, Food, and the names of my two human children (probably accessing the internet right now). As such, I was thrilled to see a review article featuring the first three, Dogs as sentinels for Human Infectious Disease and Application to Canadian Populations: https://www.mdpi.com/2306-7381/5/4/83
The publication takes on the valiant task of summarizing research utilizing man’s (or in my case, woman’s) best friend, Canis familiaris (aka the dog) as a sentinel for human infectious disease, i.e. dogs being sick with or that have had exposure to disease-causing pathogens acting as a flashing warning sign for risk to the 2 legged animal (i.e. you, me and…girls-it’s time to stop with the screen time!). As is no real surprise, the idea of using dogs as infectious disease sentinels isn’t very common and per the article is even more radical for us Canadians (only 3% of the included studies, or if you prefer 4/142).
Animals have long been used as human risk sentinels, and as someone who spent much of my childhood in Flin Flon, Manitoba (https://en.wikipedia.org/wiki/Flin_Flon) the author’s use of ‘canary in the coal mine’ was a great way to consider (and re-consider) myriad ways animals have worked to warn us of threats to human health- be these environmental or infectious disease related.
In many ways dogs are the ideal sentinel for human health risk and I’ve written about this before on the Pets and Ticks website, while paraphrasing (parroting) Public Health Ontario’s Systematic Review on Companion Animals and Tick-borne disease (https://www.petsandticks.com/companion-animal-and-tick-borne-dis), which identified considerably more studies (n =44). For the very few of us who do research with dogs acting as sentinels, the human-animal bond and wealth of shared environment, e.g. dogs sleeping in the same room,+/- on the bed, and sharing a life full of things both of us (i.e. dogs and people) need (i.e. snuggles and all items unconditional), makes dogs the ideal (and admittedly just plain fun) research warning bell.
Most of the research (76%) identified by the review was on the use of dogs to estimate seroprevalence (blood antibodies in most cases) to certain pathogens that can cause infections, such as those spread by Ixodes scapularis (black-legged) ticks, most commonly Borrelia burgdorferi (the agent of Lyme disease), but also potentially emerging anaplasmosis, babesiosis and Powassen encephalitis. In ‘Our true north, Canada’, the researchers pointed out that using dogs to look for: 1) viruses like California serogroup viruses, Chikungunya and West Nile, 2) bacteria and rickettsia such as, Rickettsia and Ehrlichia spp., and 3) parasites, like the worm Dirofilaria immitis (canine heartworm), should be strongly considered due to disease emergence caused by our homeland’s increasing hospitality to ticks, mosquitoes and other disease vectors.
Finally, the study concluded with what most of us who do this type of research already know…in order to achieve study ‘do-ability’ a number of critical factors are non-negotiable. I’ve summarized these (and added a few) to create a ‘Top 10 Needs for K9 Sentinel Surveillance Studies” list:
1. Be very clear on what you are looking for, i.e. what disease, type of disease emergence, and/or range of disease spread
2. Do the study in an identified risk (or emerging risk) region
3. Ensure you have study participants (sentinel units) such as veterinary clinics and pet-owners who will participate, i.e. no sentinels = no study
4. If you’re looking for something new (emerging), start with naïve (negative for the bug) dogs and follow them over time and space (see #2)
5. Hope (really hard) that you can repeat your sampling. That means relying on your people (participants and sentinel units) and trusting that they will enable continued study participation (study engagement) and repeat that for as long as the study lasts. This is a big ask.
6. Allow the researcher (s) time, so as to actually ‘do’ the study.
7. Allow the researcher (s) funding, so as to actually ‘do’ the study.
8. Be pet-ethical. Never forget that these dogs have a very important job in many cases- to be a beloved companion. So, don’t do any testing beyond what they are already receiving as routine care from their dedicated veterinary clinic, such as an annual blood draw. Think of them like your own pets i.e. they are not ‘study subjects’.
9. Save your samples- so that if something changes (or a new test or disease emerges) you can go back and look for it (whatever ‘it’ may be)
10. Work with your community of dedicated pet-owners and sentinel clinics- they know the dog best- and can provide a wealth of information reaching far beyond a blood test. This can help you sort out health concerns, risk factors (for the dogs and their people) and put things like travel beyond or between regions into correct data interpretation contexts.
Working with our canine protectors is not a new concept, but it can be a novel for some researchers and particularly funding agencies. The review also does a nice job (IMHO) of emphasizing that enhanced communication and collaboration between doctors of all species (veterinary and human), is looking more and more likely to be the way to identify, increase knowledge and stay safe from intruding infectious disease, particularly in Canada.
It’s heartening to see that research such as the Canadian K9 Lifetime Study or Pet Tick Tracker are regarded as illuminating (at least by researchers from the land of bagpipes, whiskey & Gaelic), and I’ve no doubt that dogs will continue to shine a Lyme-light on ground-breaking studies, that similarly helps their humans.