Dirofilaria repens is a filarial nematode that affects dogs and other carnivores such as cats, wolves, coyotes, foxes, and sea lions, as well as muskrats.

Italy bears the highest burden of European dirofilariasis cases in humans [citation needed]: (66%), followed by France (22%), Greece (8%), and Spain (4%).

In the first stage, mated adult female worms produce thousands of microfilariae (larvae) into the circulation daily, which are ingested by mosquitoes in a blood meal.

In addition, rare cases of organ manifestation have been reported, affecting the lung, male genitals, female breast, or the eye.

In terms of surgical care, excision of lesions and affected areas is the treatment of choice for patients with human dirofilariasis.

Some authors have recommended a period of observing chest coin lesions for several months if dirofilariasis is suspected and no other features in the history or examination suggesting malignancy or other infection are present.