A new narrative review published in Frontiers consolidates what veterinary medicine actually knows about ivermectin: the macrocyclic lactone remains a cornerstone antiparasitic across companion, food and production animal practice, but resistance evolution and contested antiviral claims now sit at the center of the drug's profile.

The review, which synthesizes published literature rather than reporting new trial data, organizes its analysis around four axes: antiparasitic efficacy, the evolution of resistance, the evidence base for antiviral use, and One Health implications that link animal dosing to environmental and public-health outcomes.

What does the review say about antiparasitic efficacy?

Ivermectin's standing in veterinary medicine rests on decades of use against nematodes and ectoparasites in cattle, sheep, horses, dogs and cats. The authors frame the drug as a sustained success story in parasite control, one that reshaped how practitioners manage endo- and ectoparasite burdens at the herd and individual animal level.

At the exam table, that history still matters. Ivermectin and related macrocyclic lactones remain among the most widely deployed antiparasitic classes worldwide, and the review's synthesis underscores how central they are to routine protocols in both small-animal clinics and livestock production systems.

How serious is resistance evolution?

The review's resistance section is the operational core for practitioners. Sustained, often indiscriminate use of ivermectin has selected for resistant parasite populations, and the authors trace how resistance has emerged across veterinary host species and production settings.

The practice-level implication is direct: refugia-based strategies, targeted selective treatment and rotation decisions can no longer be treated as optional refinements. Where producers have relied on repeated whole-herd ivermectin dosing, the review's framing suggests practitioners should expect diminished efficacy and plan parasitology-guided protocols rather than calendar-based ones.

What is the state of the antiviral evidence?

Ivermectin attracted intense attention during the COVID-19 pandemic as a proposed antiviral, and the review addresses that episode head-on. The authors evaluate the antiviral evidence and place it in veterinary context, distinguishing between in vitro observations that sparked interest and the clinical evidence that followed.

For veterinarians, the relevance is twofold. First, the antiviral controversy shaped public perception of a drug practitioners use daily, and client questions about ivermectin now extend beyond parasites. Second, the review's treatment of the evidence serves as a reminder that extrapolation from cell-culture findings to clinical use — animal or human — demands controlled trial data.

The review notes no regulatory body has approved ivermectin as an antiviral, and its veterinary approvals remain antiparasitic. Practitioners fielding off-label questions can anchor their answers in that regulatory status.

What are the One Health implications?

The review's final section connects veterinary ivermectin use to broader ecological and public-health concerns. Ivermectin and its metabolites reach the environment through feces and manure of treated animals, where the drug retains activity against dung-dependent invertebrates. That persistence links food-animal dosing decisions to non-target biodiversity on pasture.

The authors also frame the human–animal dimension: mass drug administration in livestock and companion animals, resistance selection, and public interest in repurposing veterinary drugs all converge on the need for coordinated stewardship across human and veterinary medicine — the core One Health argument of the paper.

What changes for clinicians?

For companion-animal practice, the review reinforces evidence-based use of ivermectin within approved label indications, with attention to known safety considerations in sensitive breeds.

For food-animal and production practice, the resistance findings carry the most weight. Producers and herd veterinarians should treat ivermectin as a finite resource whose efficacy depends on how it is deployed — a conclusion the review grounds in documented resistance evolution rather than projection.

For public health, the One Health framing positions veterinary prescribing decisions as part of a larger system involving environmental residues, resistance transmission and cross-species drug policy.

As a narrative review, the paper prescribes no new protocol. Its value lies in consolidating the evidence that will inform the next generation of antiparasitic stewardship guidelines, and the authors point toward integrated resistance management and environmentally conscious dosing as the directions veterinary ivermectin use must now take.