Seroprevalence of in Wild European and American Mink ( and ) from Spain.

Toxoplasmosis, caused by the intracellular parasite , affects a wide range of warm-blooded animals, including humans. Domestic and wild felines serve as definitive hosts, excreting oocysts that contaminate the environment. Intermediate hosts, such as the endangered European mink () and the non-native American mink (), can become infected primarily through the ingestion of tissue cysts present in prey, while the ingestion of oocysts from contaminated soil or water plays a secondary role. This study analyzed the seroprevalence of in 179 mink specimens (137 American mink and 42 European mink) collected in northern Spain from 2014 to 2020. Using an optimized indirect immunofluorescence assay, antibodies against were detected in 47 samples (37 American mink and 10 European mink). Seroprevalence was higher in the Ebro basin than in the Cantabrian region, although the difference was not statistically significant. No significant associations were observed between seropositivity and species, sex, or habitat. These findings suggest environmental contamination by oocysts in northern Spain and underscore the potential value of invasive American mink as sentinel species for monitoring public health risks associated with this parasite. The study also highlights the importance of wildlife surveillance in assessing environmental contamination and understanding transmission dynamics of infectious diseases in ecosystems.