Date of this Version
French Heartworm is the common name for a parasitic disease affecting foxes, dogs, and other members of the dog family. Caused by the nematode (worm) Angiostrongylus vasorum, this disease was first thought to exist in France in the mid 1800's. It is now considered to exist generally in Europe but has not been reported in North America other than on the Island of Newfoundland, with the exception of infected animals imported from Europe but diagnosed in North America. The first case recorded in Newfoundland was in Aquaforte (Avalon Peninsula) in 1973.
When and how it might have come over from Europe is unknown; however, red foxes could easily have been imported to the Island of Newfoundland for hunting purposes numerous times over the last hundreds of years giving many opportunities to mix with local wild foxes. As well, the disease could have come in through infected dogs, snails, or slugs. Why this would not also have happened at other sites on the eastern coast of North America as well is unknown.