1991 Volume 44 Issue 11 Pages 1115-1120
A parasitic location of living adult Dirofilaria immitis and heart rate, diameter fo pulmonary arteries, right cardiac output, stroke volume and right cardiac velocity in 18 infected and 6 normal control dogs were estimated by 2-dimensional echocardiography (2-DE) and pulse doppler method (PD). The 2-DE indicated that living adult D. immitis commonly habited the main pulmonary arteries of the infected dogs used in this study. This was reconfirmed by 2-DE in 2 experimentally infected dogs that were surgically implanted with each 30 fresh living worms of adult D. immitis through jugular vein. The observation by 2-DE revealed that all the worms implanted consistently invaded the pulmonary arteries, particularly the inner part. Data of PD analyzed indicated that a decrease in blood flow induced a movement of the worms from the inner part of the pulmonary arteries toward the pulmonary artery valve. This was reconfirmed in two overanesthetized dogs, showing that the worms inversely moved from the inner part of the pulmonary arteries into the right ventricle beyond the pulmonary artery valve when the heart was suspended.