Known Case Conference

After a few weeks’ break from KCC while the senior residents were off studying for boards, we are back with more great cases. This group of cases had a urinary tract theme.

Case 1

A mature cat with azotemia underwent an excretory urogram at the referring veterinarian. During the procedure, the cat started vomiting. There were two radiographs of the abdomen. The right kidney was enlarged and opacified with contrast medium. The left kidney was faintly visible and very small. The urine was also contrast enhanced. The ureters appeared normal. The liver was enlarged and had increased opacity relative to the other abdominal organs. Differential diagnoses included compensatory hypertrophy of the right kidney due to atrophy of the left, and contrast induced renal failure, ureteral obstruction, or hypotension. CIRF was considered to be most likely because of the onset of vomiting during the procedure. Hypotension may have been a predisposing or concurrent factor.

Why was the liver enhanced? Biliary excretion of contrast is the alternate route to urinary excretion. The persistent renal enhancement after several hours indicated renal failure, so the liver took over extracting the iodine from the blood.

Case 2

13 year old female Pekinese straining to urinate. On survey radiographs, there was a soft tissue mass in the caudal abdomen displacing the colon dorsally. This may have been the urinary bladder, or part of the reproductive tract. A vaginourethrogram was performed, and showed a dilated, contrast filled vagina with a large intramural filling defect dorsally, and a small bladder ventrally. The mass was located in the pelvic inlet and partially in the caudal abdomen. Differential diagnoses included a neoplasia or hematoma affecting the vaginal wall. Diagnosis: Leiomyoma of the vagina. This case was difficult to interpret because the dilated vagina resembled the shape of the bladder. However, it was located dorsally to the second structure (the bladder) and both the vagina and the ureter could be followed to the vestibule without crossing over each other.

Case 3

3 year old female spayed Rottweiler dribbling urine. Survey radiographs showed no abnormalities. An excretory urogram was requested to rule out an ectopic ureter as the cause for incontinence. The study showed normal kidneys and ureters. The bladder was gourd shaped, with a symmetric narrowing as it passed into the pelvis. The trigone was located in the mid portion of the pelvic canal. Both ureters entered the trigone normally. Diagnosis: pelvic bladder. These are typically slightly misshapen due to their location, and are caudally positioned.