Ultrasonographic evaluation of renal parenchymal diseases in dogs: 32 cases (1981-1986).

The medical records of 32 dogs with microscopically proven renal parenchymal disease were evaluated to characterize the associated ultrasonographic patterns and to assess the contribution of ultrasonography to the diagnosis and management in each case. Ultrasonography provided additional information on internal renal architecture in 18 dogs with radiographic evidence of structural abnormality. Ultrasonography determined the renal origin of 2 abdominal masses, defined the extent and distribution of neoplastic disease in 6 dogs, and identified kidneys not seen on survey radiographs or excretory urograms in 5 dogs because of decreased abdominal contrast or poor function. The ultrasonographic patterns were most specific for focal and multifocal or diffuse neoplasia. Ultrasonographic findings were least specific for diffuse parenchymal disease without architectural disruption such as glomerulo/interstitial nephritis, renal tubular necrosis, and nephrocalcinosis. In these cases, biopsy was recommended. Six interpretive errors were made. Four of these errors were related to the overestimation of renal pelvic and diverticular size because of confusion with medullary papilla. Two errors occurred in the diagnosis of renal lymphosarcoma, one of which was interpreted to be pyelonephritis. The other was an interpretive dilemma because of absence of hypoechoic multifocal nodules. Renal tubular necrosis was confirmed in this case.