The pulmonary veins were studied on fifteen lungs of donkeys of different ages. The pulmonary veins were injected with colored mass of kemo-apoxy No. 151/20A, as well as 30% suspension of red lead oxide in kemo-apoxy No. 150 for cast formation and radiographic investigation respectively. The present study had revealed that, The pulmonary veins were released from three sinuses of the left atrium; right, left and caudal. The right sinus gave off; the v. pulmonalis lobi cranialis dextri as well as the first and second ventral segmental rami of the right caudal lobe. The left sinus detached the v. pulmonalis lobi cranialis sinistri, while the caudal sinus gave rise to both Vv. pulmonales lobi caudales, v. pulmonalis lobi accessorius as well as the first and second ventral segmental branches of the left caudal lobi. The lobar veins were valueless, while the origin of the majority of the segmental veins was guarded by a cresenteric flap. Nine to ten pulmonary veins collected the blood from both lungs.
The obtained results had also revealed that the left lung comprised 12-13 venous segments, while the right one constituted 15-16 ones . Bronchovascular segmentation can be observed only in the accessory lobe and the caudal segment of both caudal lobes, while the remaining of the lung was bronchoarterially segmented and the venous segmental rami were intersegmentally placed.