Case Report

Submitted by Olivia Obringer, Michigan State University

My personal pet, Merlin, an 8mo old MN DSH presented to MSU VMC for inability to urinate. He was adopted by myself 29 days prior and had no history of urinary issues. His bladder was firm and painful upon palpation. An IV catheter was placed, and Merlin was sedated and unblocked. This procedure was uneventful, and urinary catheter positioning was successful. A urinalysis was submitted and was positive for crystals and negative for bacteria and casts. An abdominal radiograph of the bladder revealed 2-3 mildly radiolucent stones in the bladder. Ultrasound of the bladder confirmed the stones (see image below).

A cystotomy was performed and the stones were removed and submitted to the Minnesota Urolith Center. Merlin recovered well from surgery and began a diet of Hill’s c/d. 

A few weeks later, the results of the stone submission confirmed Merlin had ammonium urate stones. Because of this result, bile acids were run, and the results were as followed:

Bile Acids Fasting (Enzyme cycling): 8.6H [Range: 0.5-7.9] umol/L

Bile Acid 2 Hour (Enzyme cycling): 88.5 H [Range: 1.9-11.3] umol/L

Two weeks later, Merlin was sedated for a CT with angiogram and bloodwork. His bloodwork results revealed:

Urea Nitrogen: 7 L [19-36] mg/dL
Total Bili 0.1 [0.1-0.3] mg/dL
Direct Bili 0.0 [0.0-0.1] mg/dL
Indirect Bili 0.1 [0.1-0.3] mg/dL
ALP 104 H [13-48] U/L
ALT 71 [25-76] U/L
AST 22 [14-36] U/L

His CT report revealed a “single extrahepatic splenophrenic portosystemic shunt”.

Merlin never had any neurological signs (ataxia, seizures, dysphoria) and only ever had a history of chronic diarrhea. Due to the blood’s diversion of the liver, Merlin accumulated ammonium in his body which promoted the stone formation in his bladder.

Merlin had a good prognosis with surgery, and that option was pursued. An ameroid constrictor was placed around the shunt, and he did well during surgery and post-operatively. He was discharged the day after. Unfortunately, Merlin developed post-attenuation neurological signs (PANS) a few hours after returning home. He was disoriented, ataxic, and experiencing central blindness. Despite proactive treatment, Merlin continued to decline and developed cluster seizures. He was humanely euthanized.

I will miss him dearly.