A New Genetic Test for Drug-Resistance Biomarkers in Dogs With Leishmaniosis
Canine leishmaniosis drug resistance is a growing concern in affected regions — and a new genetic test is helping researchers and clinicians better characterize it. Published in BMC Veterinary Research, a 2026 study validated a direct qPCR assay called LeishGenR™ that detects resistance-associated genetic biomarkers directly from clinical samples taken from infected dogs. In plain terms: this test can identify specific genetic markers linked to drug resistance, allowing a genetic drug-resistance profile to be assigned to the parasite found in a dog’s sample.
It’s important to understand what this means — and what it doesn’t. A resistance-associated genetic biomarker indicates that the parasite carries genes associated with resistance. It does not prove that a specific medication will or will not work for that individual dog. The connection between a genetic profile and actual clinical treatment outcome has not yet been established and will require future research.
What Is Leishmaniosis — and Why Is Drug Resistance Such a Problem?
Leishmaniosis (sometimes spelled leishmaniasis) is a disease caused by a tiny parasite called Leishmania. In dogs, it’s spread by the bite of infected sandflies — small insects that look similar to gnats. Once the parasite enters a dog’s body, it can cause serious damage to the skin, internal organs, and immune system.
The disease is treated with specific medications, but here’s the catch: the parasite can develop resistance to those drugs over time. Resistance means the parasite has changed in a way that lets it survive even when the medication is given. It’s similar to how some bacteria become resistant to antibiotics — the drug no longer works the way it should.
When a dog is treated with a medication the parasite is resistant to, the treatment fails — and the dog may get sicker while the owner and vet assume something else is wrong. That wasted time can be harmful.
Why This Research Was Needed
Until now, vets in areas with high rates of leishmaniosis had limited options for detecting drug resistance quickly. Traditional lab methods exist, but they can be slow or require samples that are harder to collect. The result is that many treatment decisions are made without knowing whether the parasite in that specific dog has already developed resistance.
Researchers wanted to find out whether a faster, more direct genetic test — a qPCR assay — could detect resistance markers straight from the clinical samples vets already collect during diagnosis. Think of qPCR (quantitative polymerase chain reaction) as a highly sensitive copy machine for DNA: it amplifies tiny traces of genetic material so researchers can detect very specific signals, including signs of drug resistance, from even small samples.
How the Study Was Conducted
The researchers tested the LeishGenR™ direct qPCR assay on:
- 104 clinical samples collected from 95 dogs diagnosed with leishmaniosis
- Samples were the kind routinely collected during vet visits — no extra invasive procedures required
- The test looked for specific genetic markers (tiny changes in the parasite’s DNA) that are known to signal drug resistance
This is called a “direct” assay because it works on the raw clinical sample without needing to first grow the parasite in a lab — a step that can take a long time. Skipping that step makes the test faster and more practical for real-world veterinary use.
What the Study Found
The Test Accurately Assigned Genetic Drug-Resistance Profiles
The LeishGenR™ assay performed well across all 104 samples. Researchers reported 100% specificity and greater than 87.5% sensitivity for genetic drug-resistance profile assignment — two key measures of a test’s quality.
- Specificity (100%) means the assay produced no false positives for genetic profile assignment — when it indicated no resistance-associated profile, none was detected.
- Sensitivity (>87.5%) means the assay successfully detected resistance-associated genetic profiles in the great majority of samples where they were present.
These figures describe performance for genetic profile classification, not for predicting whether a specific treatment will succeed or fail clinically. A positive result means resistance-associated genetic markers were found in the sample. It does not establish that a medication is clinically ineffective for that dog, nor does it predict individual treatment failure.
Resistance-Associated Genetic Markers Were Detected Directly
The test successfully identified resistance-associated genetic markers in real clinical samples — not just in controlled lab conditions. That’s an important distinction. A test that only works in a perfectly controlled laboratory setting may not hold up in the messier, real-world conditions of a veterinary clinic. The fact that LeishGenR™ worked on actual clinical samples is a promising sign for practical use.
It is also worth noting that detecting these genetic markers is not the same as demonstrating phenotypic drug resistance — that is, actually observing in each dog that the parasite survives drug treatment. The study evaluated genetic profile assignment; whether those profiles reliably predict clinical treatment failure remains to be confirmed in future outcome studies.
What This Means for Dog Owners
What Resistance-Associated Biomarkers Can Tell Us
If your dog lives in or has traveled through a leishmaniosis-endemic area, this research matters to you. Drug resistance is one of the reasons some dogs don’t respond well to initial treatment. A test that can detect resistance-associated genetic biomarkers gives vets and researchers additional information about the parasite’s genetic profile.
However, it’s important to set accurate expectations: knowing a parasite carries resistance-associated genes is not the same as knowing that a specific drug will fail to treat your dog. The study validated the test for genetic profile assignment — not for predicting or improving treatment outcomes in individual dogs. Larger studies confirming a link between genetic profiles and actual clinical treatment response are still needed before this test can guide medication choices.
This Is Still Emerging Technology
It’s important to set realistic expectations: LeishGenR™ may not yet be widely available at all veterinary clinics. This study validates the technology — it confirms the test works — but widespread adoption in veterinary practice takes time. Availability will also vary by region, particularly since leishmaniosis is more of a concern in certain geographic areas.
When to Consult Your Veterinarian
Talk to your vet if:
- Your dog has been diagnosed with leishmaniosis and isn’t improving on treatment
- You live in or recently traveled to a region where leishmaniosis is common (parts of southern Europe, South America, the Middle East, or Africa)
- Your dog has symptoms like skin lesions, weight loss, swollen lymph nodes, or eye problems that haven’t been explained
Ask your vet whether drug-resistance testing is available or appropriate for your dog’s situation. Not every dog with leishmaniosis will need resistance testing, but for dogs who aren’t responding to treatment, it could be a valuable next step.
Study Limitations to Keep in Mind
The researchers themselves noted that the findings need to be confirmed in larger populations and in a wider range of clinical settings. This study used 104 samples from 95 dogs — a meaningful dataset, but not a massive one. Larger follow-up studies will be important to confirm how consistently the test performs across different dog breeds, disease stages, and geographic regions.
Additionally, the study focused on detecting the presence of resistance markers, not on tracking treatment outcomes. Future research will need to show how using this test in practice actually changes treatment decisions — and whether those changes lead to better results for dogs.
The Bottom Line
A new qPCR-based test called LeishGenR™ has shown it can detect resistance-associated genetic biomarkers in clinical samples from dogs with leishmaniosis — directly, without the need for lengthy lab culture. In a study of 104 samples from 95 dogs, the test demonstrated 100% specificity and greater than 87.5% sensitivity for genetic drug-resistance profile assignment.
A resistance-associated genetic biomarker is not proof that a medication will or will not work for an individual dog. This test assigns genetic profiles; it has not yet been shown to predict clinical treatment failure or to improve treatment outcomes. Linking genetic profiles to real-world results in treated dogs will require future outcome research.
For dog owners in areas where leishmaniosis is a real threat, this research marks a meaningful step toward better characterizing drug resistance at the genetic level. In the meantime, always rely on your veterinarian’s guidance for diagnosis and treatment planning.
This article summarizes peer-reviewed research for educational purposes. Always consult with your veterinarian for personalized advice about your pet’s health and behavior.