Figure 2

Photomicrograph of hematoxylin & eosin-stained sections of lung. (a) Intimal thickening, villous proliferation and leukocyte infiltration of the pulmonary artery (arrow) associated with Dirofilaria immitis infection in a non-treated control cat (10× magnification). (b) Medial thickening of pulmonary artery branches (arrowheads) associated with Dirofilaria immitis infection in a non-treated control cat (20× magnification). (c, d) In cats treated with 10% imidacloprid-1% moxidectin prior to repeated inoculation with D. immitis, pulmonary lesions did not develop (10× and 20× magnification, respectively).