Detection of Aelurostrongylus spp. Infection in the Neozoan American Mink (Neogale vison) in Southern Chile

Background: The American mink (Neogale vison) is an invasive mustelid in Chile that serves as a natural reservoir host for several pathogens. Cardiorespiratory nematodes of the superfamily Metastrongyloidea, including Aelurostrongylus spp., have been reported in carnivores worldwide but remain poorly documented in South American wildlife and invasive species. This study reports the first detection of Aelurostrongylus spp. infection in American minks in Southern Chile. Methods: Between 2022 and 2024, 27 American mink carcasses were collected from the Los Ríos and Los Lagos regions, Southern Chile. Complete necropsies were performed, and cardiorespiratory organs were examined for presence of parasites. Nematode larvae identified in bronchoalveolar lavage were characterized both morphologically and molecularly through PCR amplification, confirming their classification within the superfamily Metastrongyloidea. Results: Metastrongyloid nematodes were detected in 33.3% (9/27) of examined mink. Histopathological examination of lung tissue in some specimens identified adult parasite specimens. Morphological examination revealed Aelurostrongylus spp. first-stage larvae (L1) with characteristic morphology and morphometry. Molecular analysis confirmed the presence of Aelurostrongylus spp., with sequences showing 99% identity to Aelurostrongylus abstrusus. Most of the infected individuals were adults collected from freshwater environments. Conclusions: This study provides the first evidence of patent Aelurostrongylus spp. infection in neozoan American minks in South America, highlighting the role of this invasive species as a potential reservoir for cardiorespiratory parasites and emphasizing the need for continued surveillance of parasitic infections originating from invasive carnivores.