Pterygodermatites species are riticulariid nematodes that are found in the gastrointestinal tract of a variety of mammalian vertebrates worldwide. The genus is traditionally subdivided into five subgenera, and species determination is difficult. With the recent identification of Pterygodermatites whartoni in Cuban treefrogs (Osteopilus septentrionalis) in Florida and its expansion into new geographic areas, there is a growing need to raise awareness of this poorly characterized parasitic genus. From November 2024 to March 2025, organs (heart, lungs, gastrointestinal tract) collected from 15 wild rats (species) were submitted to the University of Florida Diagnostic Parasitology Lab for Angiostrongylus cantonensis surveillance. Organs were dissected and endoparasites were collected and preserved in 70% ethanol for morphologic and molecular identification. In addition to A. cantonensis, additional nematodes were recovered from the small intestines, cecum, and stomach of 5 rats. The morphology of the buccal capsule, arrangement of the cloacal papillae, and presence of cuticular projections (spines and combs) were consistent with Pterygodermatites spp. Following DNA extraction from a representative nematode, portions of the mitochondrial cytochrome oxidase subunit I gene and the small subunit (18S) ribosomal RNA gene were amplified and sequenced. Sequencing results had 100% homology for P. whartoni previously obtained from Cuban treefrogs in Florida. This case report solidifies the establishment of the life cycle of this parasite in the United States. Additional research is needed to elucidate the risks posed by this invasive parasite and others, on the health of our native wildlife, domestic species, and ecosystems.
Dr. Walden discussed the rat lungworm issue in a 2022 podcast.