Survey of the morphology of the dog kidney.

Dogs are frequent subjects in experimental studies of renal physiology and pathology in spite of the paucity of information on their normal renal morphology. In this study, gross morphology, light microscopy, and scanning and transmission electron microscopy were used to describe dog renal anatomy. The dog has a multilobed kidney with the medulla fused into an elongate crest and a renal pelvis of elaborate shape. The outer zone of the medulla lacks a definitive outer stripe. The proximal tubule consists of four distinct anatomical segments. Dark cells are abundant in the collecting duct of the inner medulla. The majority of the nephron segments demonstrate remarkable similarities to those of the human kidney and less to those of the kidney of the laboratory rat.