First report of (French heartworm) in red foxes ( on Prince Edward Island.

OBJECTIVE

To identify first-stage nematode larvae (L1) recovered from a red fox scat sample and adult female worms recovered from 2 red fox lungs at necropsy, using published molecular methods to confirm a morphological diagnosis of (French heartworm).

ANIMAL

Red fox .

PROCEDURE

Nematode larvae recovered from a Baermann examination survey of wild canid scats ( = 101) conducted from January 2017 to August 2020, were identified by size and morphology and subjected to PCR and DNA sequencing of the small subunit (SSU) rRNA gene, the large subunit (LSU) rRNA gene, or the second internal transcribed spacer (ITS2). In addition, these techniques were applied to adult female worms recovered from the heart/lungs of 2 red foxes (obtained from PEI trappers and stored frozen at -20°C since December of 2018 and 2020).

RESULTS

Size and morphology of L1 recovered by Baermann examination from a wild canid scat sample (presumed to be red fox) collected near Montague, PEI and adult female worms recovered at necropsy from 2 red fox carcasses were identified as . Molecular analysis confirmed the larvae and adult worms were .

CONCLUSION

These findings indicated that has become endemic in the red fox population on PEI.

CLINICAL RELEVANCE

infection is potentially fatal in dogs. Veterinarians and regional diagnostic laboratories in the Maritime provinces should consider the possibility of infection in dogs with clinical signs of cardiopulmonary and/or central nervous system disease or bleeding disorders.