Dirofilariaformia pulmoni sp. n. (Nematoda: Onchocercidae) from the eastern gray squirrel (Sciurus carolinensis Gmelin).

Dirofilariaeformia pulmoni sp. n. from the eastern gray squirrel (Sciurus carolinensis Gmelin) is differentiated from other species of the genus by its smaller body size, shorter spicules, arrangement of caudal papillae, and morphology of microfilariae. Adult filarids were found in the pulmonary artery and its branches, and the microfilariae occurred in the blood. A large antemortem thrombus that occluded approximately two-thirds of the lumen of the artery was associated with infection in one squirrel.