By Dr. Jennifer Lavender, DVM
• Hydronephrosis is caused by increased intrarenal pressure due to ureteral defect (ie. ectopic, stenotic, hypoplastic, torsed, etc.)
• Uretronephrectomy is a viable solution when contralateral renal function is adequate.
A four week old kitten presented for abdominal distension. The owner had noticed the enlarging abdomen over the last week. None of this kitten’s littermates exhibited clinical signs. Aside from the enlarged abdomen, the owner reported a relatively normal history. The kitten displayed a good appetite, normal water intake, and an adequate activity level. The owner reported normal urine output.
Upon physical examination, the female kitten was quiet, alert, and responsive. Temperature was 101°F; respiratory rate was 24 breaths/min; and heart rate was 180bpm. Thoracic auscultation was unremarkable. Abdominal palpation revealed a very large, firm, discrete mass on the left side, extending the entire length of the abdomen.
Initial diagnostics included the radiograph at right. The film showed a large, homogeneous mass effect on the left side of the abdomen. It was, unfortunately, difficult to determine the source of the mass due to poor serosal detail. Poor detail was attributed to the patient’s juvenile status, but free fluid in the abdomen was not ruled out.
A sample of fluid was collected using a 22-gauge needle. At the time of collection, it was indeterminable whether the fluid was free in the abdomen or from a fluid-filled structure. The straw-colored, translucent fluid was acellular and had a specific gravity of 1.005.
Additional diagnostics were offered to the owner, including bloodwork, urinalysis, and additional imaging (ie. contrast study and/or ultrasonography). The owner declined further testing. Therefore, an exploratory laparotomy was recommended to identify, and potentially correct, the abnormality.
Visualization of the abdominal cavity revealed an extremely enlarged, fluid-filled sac in place of the left kidney. The ureter appeared to be normally positioned and no obvious cause of obstruction could be detected. The contralateral kidney appeared normal in size, shape, position, and texture. No free fluid was noted in the abdomen.
A uretronephrectomy was performed on the left side.
The kitten’s urinary output was monitored closely post-operatively. She voided normally 4 hours after surgery and has continued to do so since.
At 1 year post-op, this kitten (which was renamed “One-Kidney Sidney”) was asymptomatic and healthy.