A new study published in Parasites & Vectors has attempted to put numbers on a familiar question in small animal practice: what does routine parasite prevention actually prevent?
Using a modelling approach rather than clinical trial data, the authors estimated how many parasite infections and infestations are currently avoided each year in UK dogs and cats through existing prevention practices. The parasites included were roundworms (Toxocara spp.), lungworm (Angiostrongylus vasorum), fleas, and ticks.
The model compared two scenarios. The first reflected current parasite treatment coverage in the UK, based on published data and expert opinion. The second assumed optimal coverage, meaning pets receive parasite prevention in line with recommended guidelines.
The headline finding is that current parasite control practices may already be preventing around 5.5 million infections or infestations each year. If treatment uptake and adherence were improved to optimal levels, the model suggests this could increase to around 9.3 million. The authors also estimated that current prevention saves UK pet-owning households roughly £53 million per year in veterinary costs, potentially rising to over £95 million with better compliance.
Importantly, this study does not measure real-world outcomes directly. It relies on assumptions about how well treatments work, how often pets are treated, and how infection levels change over time. It does not fully account for issues such as missed doses, incorrect administration, reinfection, or parasite resistance. The authors are clear that this is a modelling exercise, not proof of cause and effect.
What does this mean for practice?
For veterinary teams, the study provides a useful way to explain the value of parasite prevention to clients who question its need or cost. It highlights that prevention is likely stopping a large amount of disease, even if that benefit is often invisible.
It also reinforces that compliance matters. Much of the gap between current and optimal benefit comes down to pets not being treated regularly or correctly. Clear advice, practical parasite plans, and good reminder systems remain key.
Finally, the authors acknowledge growing concerns about environmental impact and support risk-based, targeted parasite control rather than blanket approaches.
