不良研究所

May 7, 2026

The quiet rise of drug-resistant parasites

Moving from routine deworming to precision medicine: How U不良研究所 Veterinary Medicine and industry scientists are partnering to use genomics to outsmart parasites
A group of people stand in a row
John Gilleard, fourth from left, and his team at Gilleard Labs. Courtesy John Gilleard

The infection of pets and livestock by a large range of parasites 鈥 from the single-celled Giardia to intestinal roundworms 鈥 has cost farmers and pet owners billions of dollars. 

Similar to the rise of antibiotic-resistant bacteria, parasites are evolving to survive treatments that were once highly effective. Drug-resistant parasites have been a problem for livestock producers for a number of years, but has more recently emerged as an issue for our pets.

Responding to this, new research from the University of 不良研究所 (UCVM) is challenging the long-standing 鈥渢reat early and treat often鈥 approach and could reshape how veterinarians manage parasite infections in the future by focusing more on diagnostics and less on medication.

A (NSERC) Alliance Grant, in partnership with Antech Diagnostics, will bring $1.6 million of research funding to help shift parasite control away from routine drug use towards more evidence-based, diagnostic-driven care. 

, PhD, with UCVM and his group are teaming up with Antech, a USA-based global veterinary diagnostics company and Canadian subsidiary Biovet.  

鈥淭his partnership is a fantastic opportunity to transition discoveries made in the lab into real-world diagnostic tests, by pairing cutting-edge research with practical development, validation and deployment,鈥 says Gilleard.

The growing problem with drug-resistant parasites

A photo of a dog next to a map filled with red dots indicating the locations of parasites in Canada.

Canine hookworm cases with drug resistance mutations across North America.

Courtesy Christian Leutenegger, Michelle Evason and Syed Rahil Tarique

Drug-resistant parasites are a growing concern, says Gilleard.

鈥淭he more we use anti-parasitic drugs, the more we select for resistant parasites reducing the effectiveness of the treatments that we rely on,鈥 he says. 

There are also growing concerns about environmental impacts.

鈥淭hese compounds don鈥檛 just disappear,鈥 Gilleard explains. 鈥淭hey can move through watersheds and ecosystems, where they may have unintended consequences impacting the biodiversity of organisms from insects to fish.鈥

Using genomics to shift toward diagnostics guided treatments

In response, researchers and clinicians are beginning to rethink the 鈥渢reat first鈥 model. Instead, the idea is to use diagnostics to guide treatment decisions and so reduce overall drug use. 

At the heart of the research program is the use of advanced genomic tools to better understand parasites and their response to drug treatments.

The team is working to identify genetic markers associated with drug resistance by analyzing parasite DNA. Using next-generation sequencing, researchers can compare susceptible and resistant strains to pinpoint mutations that signal whether a treatment is likely to work.

鈥淚f we can identify those genetic differences, we can develop diagnostic tests that tell us whether a parasite is resistant and then choose the most effective drug,鈥 says , PhD, a postdoctoral research associate at UCVM. 鈥淕enetic markers are also powerful surveillance tools to help catch drug resistance at a much earlier stage.鈥

A photo of two cows with a microscope image of a parasite

Beef cattle and their Roundworm Parasites.

John Gilleard

From discovery to real-world impact

鈥淎ntech is committed to making molecular diagnostics accessible, affordable and practical for routine use, in order to provide veterinarians with the information they need to choose the best treatment and control options, says Dr. Christian Leutenegger, PhD, DVM, vice-president of research and development, Reference Laboratory Assay Development, at Antech. 

Leutenegger led the development of KeyScreen GI Parasite PCR, a molecular diagnostic test panel that detects DNA for 20 different parasites in canine and feline fecal samples. The test has been used millions of times since its launch in 2022 and already includes some canine hookworm drug-resistance markers as a direct result of previous research and collaborations with Gilleard鈥檚 group. Work is underway to make the same technology available to cattle production in the near future.

鈥淏y expanding our collaborations with the University of 不良研究所 team, we aim to integrate further genomic discoveries into these fast and affordable diagnostic platforms, both to detect parasites and determine their resistance to specific drugs,鈥 says Leutenegger. 鈥

Toward a more-sustainable future

Beyond improving clinical outcomes, the research has broader One Health implications impacting animal health, public health and environmental sustainability. 

鈥淩esponsible drug use is an important part of veterinary clinical care, and we need to get ahead of drug resistance and not just react to it,鈥 says Dr. Michelle Evason, DVM, global firector, Veterinary Clinical Education, with Antech. 鈥淭he shift from routine treatment to evidence-based control is not just beneficial, but necessary.鈥


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