Surveillance for Aelurostrongylus abstrusus in feral cats on Prince Edward Island reveals low prevalence

Aelurostrongylus abstrusus is a metastrongyloid nematode of domestic and wild felids with a cosmopolitan distribution. In Canada, confirmed cases have been reported from several provinces, but no published data exist for Prince Edward Island (PEI). This study aimed to determine the occurrence of A. abstrusus in feral cats from PEI. Between January and December 2024, fecal samples were collected opportunistically from feral cats presented for trap-neuter-return (TNR) surgery at the Atlantic Veterinary College. The Baermann technique was used to detect first-stage larvae, which were identified morphologically. Molecular confirmation was performed by PCR amplification and DNA sequencing of the internal transcribed spacer 2 region. Of 378 cats submitted for surgery, 229 (60.6 %) yielded fecal samples suitable for testing. One adult male cat (0.4 %) was positive for A. abstrusus. The larvae exhibited characteristic morphology, and DNA sequencing confirmed 100 % identity with A. abstrusus reference sequences. This represents the first confirmed detection of A. abstrusus in cats from PEI and confirms that A. abstrusus can persist locally, given the presence of suitable gastropod intermediate hosts and known distribution of other gastropod-borne metastrongyloids in the region. To further clarify the epidemiology and potential impact of feline lungworm infection in PEI, additional surveillance, the use of more sensitive diagnostic methods such as serology, and investigation of intermediate hosts are warranted.