Detection of Spirometra sp. (Cestoda: Diphyllobothriidae) eggs and morphological characterization of adult specimens from free-living wild carnivores in Paraguay.

Pseudophilid cestodes the genus Spirometra can infect a wide range of intermediate hosts in larval stages, while adult stages parasitize domestic animals, wildlife, and humans. In South America, descriptions of adults in wildlife are scarce. This study reports the presence of Spirometra sp. eggs in three species of wild carnivores from Paraguay (Chrysocyon brachyurus, Leopardus geoffroyi and Procyon cancrivorus), and microscopic characterization of a recovered adult specimen from L. geoffroyi. Fecal samples were examined using conventional methods, revealing eggs compatible with Spirometra sp., in all three hosts. The adult cestode was processed by basic fuchsin staining for morphological analysis of the complete preparation. General characteristics confirmed the identification at a genus level. These findings represent the first microscopic description of adult Spirometra from wild carnivores in Paraguay and provide baseline anatomical data for future taxonomic and epidemiological studies, highlighting the relevance of wildlife reservoirs within the One Health framework.