Abstract
<jats:p>A recent parasiticide-industry-funded modelling study by Giannelli et al. (Parasites & Vectors 18:498, 2025 https://link.springer.com/article/10.1186/s13071-025-07137-8) estimates current preventive parasiticide usage in UK dogs and cats, and concludes that this generates substantial economic savings in veterinary costs for households through averted infections/infestations. It further predicts that increased parasiticide use - namely, full compliance with ESCCAP (European Scientific Council Companion Animal Parasites) guidelines - would yield proportionately greater savings. However, several of the model’s key inputs and assumptions are incorrect or inadequately justified. In several instances, higher parasite-prevalence estimates are used as model inputs whilst lower estimates derived from larger or more representative datasets are not included; none of the clinical-disease prevalence used in the model correspond to the quantities reported in the studies cited to support them, and the economic analysis lacks transparency and excludes the costs of preventive parasiticides themselves, which far exceed the claimed savings. These issues materially affect the study’s conclusions and risk misleading clinicians, policymakers, and pet owners. We note that the clinical-disease prevalence values used in the model, which do not correspond to the quantities reported in their cited sources, constitute major errors that compromise the reliability of the findings, meeting the Committee on Publication Ethics (COPE) criteria for retraction.</jats:p>