Abstract
The azygos veins were anatomically investigated in 100 Japanese black and 50 Holstein cattle, and were divided into 4 types. The left azygos vein dominant type was observed in 71 Japanese black and 42 Holstein cattle. The left azygos vein draining into the anterior vena cava was observed in a Japanese black cattle. The left azygos vein receiving the left costocervical vein was observed in six Japanese black and three Holstein cattle. The anomalous posterior vena cava with azygos continuation was found in four Japanese black and a Holstein cattle.
