Q&A with Drs. Michelle Evason (BSc DVM DACVIM MRCVS) and Graham Bilbrough (MA VetMB CertVA MRCBS) • Antech, part of Mars Science & Diagnostics Climate change is reshaping the landscape of vector-borne pathogens, and their disease outcomes, for both dogs and humans. Rising temperatures, and increasingly mild winters, are expanding both the abundance and regional ranges of ticks, mosquitoes, and other biting insects that serve as potential disease-carrying vectors. Timely diagnostic testing allows incorporation of One Health—i.e. dogs as sentinels of vector-borne disease (VBD) risk for humans—into our clinical day-to-day and elevates the veterinary response to current, and emerging, regional VBD threats for dogs and their people. To help veterinary professionals better understand the relationship between climate change, VBD pathogen proliferation, and the diagnostic solutions available for detection, Drs. Michelle and Graham answer your pressing clinical questions. Q: How are climate change and VBD related? ME: As the climate in the U.S. and Canada continues to change, and habitats shift, tick, mosquito and other biting insect populations are expanding into new regions- and their numbers are increasing. And as the climate warms, and there are more ‘on average’ days above freezing during the winter months, this gives these vectors (like ticks) more time to be ‘out and about’ infecting hosts like dogs and people. Unfortunately, this brings veterinary and human health care teams new clinical challenges due to the emergence of VBD into areas of the U.S. and Canada that haven’t traditionally seen these, had to screen for them, and/or diagnose them in their patients. This presents a learning curve, and it can be difficult (for everyone!) to stay up to speed- plus educate clients on risk. GB: Climate change is a major driver of shifting VBD pathogen patterns, but it is not the only factor at play. Increased travel of pets, and the transport of dogs from endemic areas into new ones, are introducing unexpected diagnoses due to carrying vectors and their disease risks into our veterinary clinics—and in some cases inadvertently introducing them into novel regions of the U.S. and Canada. Urbanization and habitat destruction are also altering interactions between wildlife, domestic animals, and vectors, and this further emphasizes the One Health aspect of VBD pathogens. Additionally, changes in vector behavior, insecticide resistance, and gaps in year-round parasite prevention for pets, are further contributing to the rise and spread of these vectors and the disease risks they carry. Q: I keep hearing about the ‘big four’ in VBD. What are these pathogens-and how do we screen for them? GB: Four does seem to be the ‘magic number’ in VBD screening, and many common tests have ‘four’ in their name. Naturally, when we hear ‘four’, we think about testing four ‘bugs’—Heartworm (Dirofilaria immitis antigen), and antibodies to Lyme (Borrelia burgdorferi), Ehrlichia, and Anaplasma. However, considering all the changes in vectors (like ticks), the diagnostic landscape must also evolve alongside emerging VBD threats. That’s why Antech’s Accuplex was expanded to detect a broader range of Ehrlichia species. Likewise, Antech’s new in-hospital test, trūRapid FOUR, offers an increased VBD pathogen platform for those preferring an in-clinic option for their workflow. If we rely on outdated testing assumptions for VBD, we risk missing today’s emerging pathogens. Q: How do you decide what test to use? For example, when to choose Accuplex vs. trūRapid FOUR? GB: Both tests are excellent choices for tick-borne pathogen screening and heartworm antigen testing—it ultimately comes down to what works best for your hospital and patients. Accuplex and trūRapid FOUR both offer broad detection and have evolved to meet veterinary needs in a changing VBD landscape—adapted for today, ready for tomorrow. Accuplex is ideal if you’re already submitting a wellness panel to our reference lab since it can be conveniently run it on the serum you’re already sending. trūRapid FOUR is a great option when you need immediate results, such as when determining whether to dispense heartworm prevention the same day. Both tests provide excellent reliability, so the choice depends on your workflow and clinical need. For some hospitals it may work best for their workflow, during specific situations, to use trūRapid FOUR. For others it may be best to use Accuplex. We’re strong believers in providing diagnostic options, and support, across the spectrum. Q: trūRapid FOUR isn’t the first in-hospital VBD test. What makes it different? GB: It’s always great to give veterinarians more choices, especially when those choices offer excellent reliability. Plus, we are always listening to veterinary teams and many shared that they wanted this as an option. Looking at Companion Animal Parasite Council (CAPC) maps,1 it’s clear that many, many dogs in the U.S. aren’t getting yearly VBD screening—some only get heartworm testing, while others receive no testing at all. trūRapid FOUR is an opportunity to expand care and reach the millions of dogs who are currently left untested. It is also an opportunity to alert their human caregivers, and the broader community, to potential disease risk for Lyme, Ehrlichia, and Anaplasma. How to Access Antech’s Clinical Decision-Making Algorithms: View in Technical Details and Downloads section: https://www.antechdiagnostics.com/antech-product/trurapid-four-test/ Q: It feels like I’m getting more positive results in dogs than I used to. Are there resources to help with clinical management- and pet-owner communication? GB: Absolutely- we know that’s happening, i.e. more positive dogs in your practice. This is associated with the increase in these vectors, their pathogens- and due to the innovations and updates made to the test platforms. ME: To support vet teams, Antech offers some great clinical algorithms (linked at the end of this article) for heartworm, Lyme, Ehrlichia and Anaplasma to help vet teams with result interpretation, clinical management and communication. We’re aware that it can be a challenge to have conversations around VBD test results with dog-owners, plus address human risk. Not to mention that all of us need to be increasingly mindful of antimicrobial use/stewardship as part of our clinical day-today. So, we’ve tried to provide support, and guidance, for questions like, ‘Do I treat that seropositive, clinically normal, dog- or not?’. Q: What is the relationship between VBD and One Health? ME: VBD pathogens are a perfect example of why a One Health approach is essential in today’s veterinary landscape- and in one’s clinic. These diseases don’t just affect dogs—they exist at the intersection of animal health, human health, and environmental (climate, wildlife) change- in addition to having antimicrobial use and stewardship implications. Shared Risk Between Dogs and Humans We know that Ehrlichia, Anaplasma, and Borrelia burgdorferi (Lyme), can cause illness in dogs and humans. Infected tick vectors can bite, attach and transmit these pathogens to dogs, and humans, who share the same environment. By monitoring trends in canine exposure to VBD pathogens (like Lyme or Ehrlichia spp.), veterinarians performing the advised CAPC screening enable dogs to serve as VBD risk sentinels for their humans- their families, and broader community. Q: Why is it so important for all dogs to be screened for VBD? GB: The truth is that most dogs in the U.S. and Canada aren’t getting screened for VBD pathogens. We want to change that, and recognize that there is a significant opportunity to expand access to care, which protects not just our pets but us humans, too. ME: From a One Health point of view, we as veterinary professionals must understand and share the knowledge with our pet-owners that, due to climate change, and other factors, like travel and dog importation, past conditions surrounding VBD pathogen risk may no longer be applicable. Just as we must adapt to the warming climate on a human level, we must also adapt how we practice veterinary medicine, and utilize diagnostic testing to screen for, and manage, today’s VBD pathogens. Want to learn more about Antech and VBD? Please visit https://www.antechdiagnostics.com/ Dr. Graham Bilbrough (MA, VetMB, CertVA, MRCVS) is Director of Clinical Expertise and Medical Marketing at Antech. Dr. Michelle Evason (BSc, DVM, DACVIM, MRCVS) serves as Global Director, Veterinary Clinical Education for Antech. References https://capcvet.org/maps/#/
