Morphological and molecular identification of cardiopulmonary nematodes in the European wildcat (Felis silvestris) and nine other carnivores in Spain

Cardiopulmonary nematodes (CPN) are among the most pathogenic helminths, with wild carnivores serving as hosts for a variety of species. Knowledge of their presence in the Iberian Peninsula is limited, and for certain hosts, such as the European wildcat (Felis silvestris), no data are currently available. Lung and heart samples from 112 road-killed individuals belonging to 10 different species, primarily wildcats (n = 33), collected in Navarra (northern Spain) were collected. Morphological identification of nematodes was done and confirmed, when possible, by sequencing fragments of the cytochrome c oxidase subunit I (cox1) and the internal transcribed spacer 2 (ITS2) genes. Fifteen wildcats (45%) were found to be parasitized, with the following species identified: Troglostrongylus brevior (30%), Angiostrongylus chabaudi (15%), and Oslerus rostratus (3%). Other CPN-positive hosts included the Eurasian badger (Meles meles) (3/15), with Angiostrongylus daskalovi and Crenosoma melesi; the pine marten (Martes martes) (3/13) and the stone marten (Martes foina) (5/11), both parasitized by Eucoleus aerophilus and Crenosoma petrowi; and the European polecat (Mustela putorius) (4/8), with Crenosoma melesi. This study reports the first identification of A. chabaudi in the Iberian Peninsula and confirms previous, though rare, records of other CPN species. Additionally, several novel genetic sequences are provided for poorly characterized taxa. Conducting parasitological surveys in free-roaming domestic cats in areas where wildcats are present, to assess the potential for cross-species transmission of these parasites, is highly recommended.