RADIOGRAPHIC AND ANGIOGRAPHIC EVALUATIONS OF FERRETS EXPERIMENTALLY INFECTED WITH DIROFILARIA-IMMITIS

Five ferrets of each sex were each inoculated with 15 third-stage infe ctive larvae of Dirofilaria immitis to study radiographic and angiogra phic changes in the cardiopulmonary system following heartworm infecti on; 5 additional ferrets of each sex served as noninfected controls. P rior to inoculation and every 8 weeks thereafter until 40 weeks, the i nfected and noninfected ferrets were radiographed; angiographic examin ations were done prior to necropsy. At necropsy, the worms in the hear t, lungs, and associated vessels were counted, and lung histosections were prepared and examined for changes. Radiographic changes were seen in the right side of the heart and associated vessels of infected fer rets as compared with the noninfected ferrets, but changes were less p rominent than those seen in heartworm-infected dogs and cats. The chan ges were primarily an increase in the size of the right side of the he art, especially the right atrium. Radiographically, no changes could b e visualized in the pulmonary vascular system. Worms in the enlarged c ranial vena cava, azygous vein, and left caudal lobar pulmonary artery of infected animals were delineated by angiography. Histologically, n o changes were seen in the pulmonary vascular tissues.