Elaeophora is a genus of parasitic nematodes which live attached to the interior surfaces of major arteries, veins and/or heart chambers in various large mammal hosts.

Despite the fact that they produce aneurysms in the arteries and heart of their hosts which measure up to 2 cm in diameter, overt clinical symptoms of infestation are seldom reported, with the notable exception of E. schneideri infestation in sheep, elk, and moose.

Microfilariae (not eggs) are shed by the adult female from her attachment site inside the lumen of the carotid artery of the definitive host.

The microfilariae are carried through the blood stream and become lodged in the small capillaries of the skin in the head and facial areas.

The infective larvae enter a new definitive (mammal) host through the bite wound when the fly feeds again.