Imaging Diagnosis—urinary Bladder Duplication in a Cat

Abstract

A female kitten presented for chronic, intermittent, antibiotic-responsive urinary incontinence and chronic kidney disease. Abdominal ultrasound identified bilateral pelvic/ureteral dilation and three closely apposed thin-walled fluid-filled structures in the caudal abdomen, extending toward the pelvic inlet. Excretory urography and negative contrast cystography identified contrast medium accumulation from the dilated ureters into two tubular soft tissue masses of the caudal abdomen, with subsequent gradual filling of a more cranially located urinary bladder. A retrograde vaginocystourethrogram identified a normal uterus, normal vagina, and a single urethra continuous with the cranially located urinary bladder. Antemortem diagnosis was suspicious for bilateral ectopic ureteroceles. Postmortem diagnosis, 35 months following initial presentation, determined the fluid-filled masses to have abundant smooth muscle in the wall, including a muscularis mucosa connected by a common ostium, consistent with urinary bladder duplication. Urinary bladder duplication should be included as a differential diagnosis in cats with these clinical and imaging characteristics. In this case, differentiation of ectopic ureterocele from urinary bladder duplication required histological confirmation.

Retrospective analysis of diagnoses and outcomes of 45 cats with micturition disorders presenting as urinary incontinence

“…Congenital abnormalities accounted for only 18% of our series of incontinent cats and included 4 cats with congenital spinal canal malformations (eg, Manx syndrome or spinal dysraphism), 1 cat with bilateral ureteral ectopia, 2 cats with presumed congenital USMI, and 1 cat with urethral hypoplasia . These and other congenital causes of UI in cats have been reported previously . It is difficult to draw conclusions on the proportional morbidity of congenital disorders in our series of cats because of relatively small numbers of affected cats and the fact that previous studies rarely reported congenital spinal cord diseases.…”

“…In our series of cats, UI was associated with a variety of congenital and acquired disorders that affected both phases of micturition with similar frequency. The proportional morbidity of causes, sex, age distribution, and outcomes of UI in our series of cats differed substantially from previous reports of UI in cats and dogs . Our observations indicated that spinal cord disorders were a common cause of UI in cats and were associated with less favorable outcomes compared to bladder and urethral disorders.…”

“…Urinary incontinence in cats has been associated with over 43 congenital or acquired disorders affecting the spinal cord, urinary bladder, urethra, or reproductive tract . However, descriptions of disorders associated with UI in cats often have been limited to anecdotal case reports or selected case series.…”

Surgical treatment and outcome of complete unilateral urinary tract duplication in a dog

“…Although there are no previous reports of complete duplication of the urinary tract in veterinary medicine, there are reported cases of duplication of various parts of the tract including the kidney, ureter, bladder, and urethra. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Duplex kidney is a commonly encountered abnormality of renal development in human medicine, with an incidence of approximately 1%. 17 A complete duplex kidney is defined as two separate pelvicalyceal systems that have arisen from two ureteral buds from the mesonephric duct.…”

“…18 Bladder duplication has been described in isolation in one cat and one dog. [7][8] In one case report, bladder duplication was also reported associated with multiple anomalies including diphallia, cryptorchidism, renal hypoplasia, and bifurcation of the descending colon. 9 Urethral duplication without associated diphallia has been described three times in veterinary medicine.…”