Caudal mesenteric artery

The caudal mesenteric artery is a major unpaired branch of the abdominal aorta, typically arising on the dorsal midline at the level of the sixth or seventh lumbar vertebra, caudal to the origin of the renal arteries and cranial to the aortic bifurcation. In the dog, it courses caudoventrally within the mesocolon toward the descending colon and rectum.

The caudal mesenteric artery gives rise to two principal branches: the left colic artery, which supplies the descending colon, and the cranial rectal artery, which supplies the cranial portion of the rectum. The left colic artery runs cranially along the mesenteric border of the descending colon, while the cranial rectal artery continues caudally toward the rectum. These branches form anastomoses with the terminal branches of the cranial mesenteric artery, providing collateral circulation to the large intestine.