Bilateral pyelonephritis and hydroureter associated with metastatic adenocarcinoma in a dog.

Metastatic adenocarcinoma, involving the trigone of the urinary bladder, resulted in bilateral pyelonephritis and hydroureter in an aged dog. Salient physical examination and clinicopathologic findings included bacterial urinary tract infection, renal pain response to abdominal palpation, and the observation of WBC casts in urine sediment. A good response to antimicrobial drug administration was observed initially; however, the dog later was euthanatized because of progressive renal disease. Necropsy revealed extensive peritoneal carcinomatosis with metastatic lesions causing occlusion of both ureters. Ostensibly, metastatic carcinoma involving the trigone resulted in urine stasis and enhanced the development of renal infection and hydroureter.